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href="command-line-options.html#version">&#x2011;version</a><a href="command-line-options.html#view">&#x2011;view</a><a href="command-line-options.html#vignette">&#x2011;vignette</a><a href="command-line-options.html#virtual-pixel">&#x2011;virtual&#x2011;pixel</a><a href="command-line-options.html#visual">&#x2011;visual</a><a href="command-line-options.html#watermark">&#x2011;watermark</a><a href="command-line-options.html#wave">&#x2011;wave</a><a href="command-line-options.html#wavelet-denoise">&#x2011;wavelet&#x2011;denoise</a><a href="command-line-options.html#weight">&#x2011;weight</a><a href="command-line-options.html#white-point">&#x2011;white&#x2011;point</a><a href="command-line-options.html#white-threshold">&#x2011;white&#x2011;threshold</a><a href="command-line-options.html#window">&#x2011;window</a><a href="command-line-options.html#window-group">&#x2011;window&#x2011;group</a><a href="command-line-options.html#write">&#x2011;write</a><a href="command-line-options.html#write-mask">&#x2011;write&#x2011;mask</a> </p>
Cristy882d9f42015-10-29 16:48:39 -040057<p class="lead magick-description">Below is list of command-line options recognized by the ImageMagick <a href="command-line-tools.html">command-line tools</a>. If you want a description of a particular option, click on the option name in the navigation bar above and you will go right to it. Unless otherwise noted, each option is recognized by the commands: <a href="convert.html">convert</a> and <a href="mogrify.html">mogrify</a>.</p>
58
59<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -040060 <h3><a id="adaptive-blur"></a>-adaptive-blur <var>radius</var>[x<var>sigma</var>]</h3>
Cristy882d9f42015-10-29 16:48:39 -040061</div>
62
63<p class="magick-description">Adaptively blur pixels, with decreasing effect near edges.</p>
64
65<p>A Gaussian operator of the given radius and standard deviation (<var>sigma</var>) is used. If <var>sigma</var> is not given it
66defaults to 1.</p>
67
68<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -040069 <h3><a id="adaptive-resize"></a>-adaptive-resize <var>geometry</var></h3>
Cristy882d9f42015-10-29 16:48:39 -040070</div>
71
72<p class="magick-description">Resize the image using data-dependent triangulation.</p>
73
74<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. The <a href="command-line-options.html#adaptive-resize">-adaptive-resize</a>
Cristy594d2772015-11-15 10:47:42 -050075option defaults to data-dependent triangulation. Use the <a
76href="command-line-options.html#filter">-filter</a> to choose a different resampling algorithm.
77Offsets, if present in the geometry string, are ignored, and the <a
78href="command-line-options.html#gravity">-gravity</a> option has no effect.</p>
Cristy882d9f42015-10-29 16:48:39 -040079
80<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -040081 <h3><a id="adaptive-sharpen"></a>-adaptive-sharpen <var>radius</var>[x<var>sigma</var>]</h3>
Cristy882d9f42015-10-29 16:48:39 -040082</div>
83
84<p class="magick-description">Adaptively sharpen pixels, with increasing effect near edges.</p>
85
86<p>A Gaussian operator of the given radius and standard deviation
87(<var>sigma</var>) is used. If <var>sigma</var> is not given it
88defaults to 1.</p>
89
90<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -040091 <h3><a id="adjoin"></a>-adjoin</h3>
Cristy882d9f42015-10-29 16:48:39 -040092</div>
93
94<p class="magick-description">Join images into a single multi-image file.</p>
95
96<p>This option is enabled by default. An attempt is made to save all images of
97an image sequence into the given output file. However, some formats, such as
98JPEG and PNG, do not support more than one image per file, and in that case
99ImageMagick is forced to write each image as a separate file. As such, if
100more than one image needs to be written, the filename given is modified by
101adding a <a href="command-line-options.html#scene">-scene</a> number before the suffix, in order to
102make distinct names for each image. </p>
103
104<p>Use <a href="command-line-options.html#adjoin">+adjoin</a> to force each image to be written to
105separate files, whether or not the file format allows multiple images per file
106(for example, GIF, MIFF, and TIFF). </p>
107
108<p>Including a C-style integer format string in the output filename will
109automagically enable <a href="command-line-options.html#adjoin">+adjoin</a> and are used to specify
110where the <a href="command-line-options.html#scene">-scene</a> number is placed in the filenames. These
111strings, such as '<code>%d</code>' or '<code>%03d</code>', are familiar to those
112who have used the standard <code>printf()</code>' C-library function. As an
113example, the command</p>
114
Cristy49380402017-06-29 11:24:55 -0400115<pre><code>
Cristy882d9f42015-10-29 16:48:39 -0400116convert logo: rose: -morph 15 my%02dmorph.jpg
Cristy49380402017-06-29 11:24:55 -0400117</code></pre>
Cristy882d9f42015-10-29 16:48:39 -0400118
119<p>will create a sequence of 17 images (the two given plus 15 more created by
120<a href="command-line-options.html#morph">-morph</a>), named: my00morph.jpg, my01morph.jpg,
121my02morph.jpg, ..., my16morph.jpg. </p>
122
123<p>In summary, ImageMagick tries to write all images to one file, but will
124save to multiple files, if any of the following conditions exist...</p>
125<ol>
126<li>the output image's file format does not allow multi-image files,</li>
127<li>the <a href="command-line-options.html#adjoin">+adjoin</a> option is given, or</li>
128<li>a printf() integer format string (eg: "%d") is present in the output
129 filename.</li>
130</ol>
131
132
133<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400134 <h3><a id="affine"></a>-affine
Cristy882d9f42015-10-29 16:48:39 -0400135 <var>s<sub>x</sub></var>,<var>r<sub>x</sub></var>,<var>r<sub>y</sub></var>,<var>s<sub>y</sub></var>[,<var>t<sub>x</sub></var>,<var>t<sub>y</sub></var>]</h3>
136</div>
137
138<p class="magick-description">Set the drawing transformation matrix for combined rotating and scaling.</p>
139
Cristy594d2772015-11-15 10:47:42 -0500140<p>This option sets a transformation matrix, for use by subsequent <a
141href="command-line-options.html#draw">-draw</a> or <a href="command-line-options.html#transform">-transform</a> options. </p>
Cristy882d9f42015-10-29 16:48:39 -0400142
143<p>The matrix entries are entered as comma-separated numeric values either in
144quotes or without spaces. </p>
145
146<p>Internally, the transformation matrix has 3x3 elements, but three of them
147are omitted from the input because they are constant. The new (transformed)
148coordinates (<var>x'</var>, <var>y'</var>) of a pixel at
149position (<var>x</var>, <var>y</var>) in the original
150image are calculated using the following matrix equation.</p>
151
Cristy594d2772015-11-15 10:47:42 -0500152<p class="text-center"><img class="img-thumbnail" alt="affine transformation" src="../images/affine.png"/> </p>
Cristy882d9f42015-10-29 16:48:39 -0400153
154<p> The size of the resulting image is that of the smallest rectangle that
155contains the transformed source image. The parameters
156<var>t<sub>x</sub></var> and <var>t<sub>y</sub></var>
157subsequently shift the image pixels so that those that are moved out of the
158image area are cut off.</p>
159
160<p>The transformation matrix complies with the left-handed pixel coordinate
161system: positive <var>x</var> and <var>y</var> directions
162are rightward and downward, resp.; positive rotation is clockwise.</p>
163
164<p> If the translation coefficients <var>t<sub>x</sub></var> and
165<var>t<sub>y</sub></var> are omitted they default to 0,0. Therefore,
166four parameters suffice for rotation and scaling without translation.</p>
167
168<p>Scaling by the factors <var>s<sub>x</sub></var> and
169<var>s<sub>y</sub></var> in the <var>x</var> and <var>y</var> directions,
170respectively, is accomplished with the following.</p>
171
Cristy594d2772015-11-15 10:47:42 -0500172<p>See <a href="command-line-options.html#transform">-transform</a>, and the <a
173href="command-line-options.html#distort">-distort</a> method '<code>Affineprojection</code> for more
Cristy882d9f42015-10-29 16:48:39 -0400174information </p>
175
176
Cristy49380402017-06-29 11:24:55 -0400177<pre><code>
Cristy882d9f42015-10-29 16:48:39 -0400178-affine <var>s<sub>x</sub></var>,0,0,<var>s<sub>y</sub></var>
Cristy49380402017-06-29 11:24:55 -0400179</code></pre>
Cristy882d9f42015-10-29 16:48:39 -0400180
181<p>Translation by a displacement (<var>t<sub>x</sub></var>, <var>t<sub>y</sub></var>) is accomplished like so:</p>
182
Cristy49380402017-06-29 11:24:55 -0400183<pre><code>
Cristy882d9f42015-10-29 16:48:39 -0400184-affine 1,0,0,1,<var>t<sub>x</sub></var>,<var>t<sub>y</sub></var>
Cristy49380402017-06-29 11:24:55 -0400185</code></pre>
Cristy882d9f42015-10-29 16:48:39 -0400186
187<p>Rotate clockwise about the origin (the upper left-hand corner) by an angle
188<var>a</var> by letting <var>c</var> = cos(<var>a</var>), <var>s</var>
189= sin(<var>a</var>), and using the following.</p>
190
Cristy49380402017-06-29 11:24:55 -0400191<pre><code>
Cristy882d9f42015-10-29 16:48:39 -0400192-affine <var>c</var>,<var>s</var>,-<var>s</var>,<var>c</var>
Cristy49380402017-06-29 11:24:55 -0400193</code></pre>
Cristy882d9f42015-10-29 16:48:39 -0400194
Cristy594d2772015-11-15 10:47:42 -0500195<p>The cumulative effect of a sequence of <a href="command-line-options.html#affine" >-affine</a>
196transformations can be accomplished by instead by a single <a href="command-line-options.html#affine"
197>-affine</a> operation using the matrix equal to the product of the matrices
Cristy882d9f42015-10-29 16:48:39 -0400198of the individual transformations.</p>
199
200<p>An attempt is made to detect near-singular transformation matrices. If the
201matrix determinant has a sufficiently small absolute value it is rejected.</p>
202
203<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400204 <h3><a id="alpha"></a>-alpha <var>type</var></h3>
Cristy882d9f42015-10-29 16:48:39 -0400205</div>
206
207<p class="magick-description">Gives control of the alpha/matte channel of an image.</p>
208
209<p>Used to set a flag on an image indicating whether or not to use existing alpha
210channel data, to create an alpha channel, or to perform other operations on the alpha channel. Choose the argument <var>type</var> from the list below.</p>
211
Cristy49380402017-06-29 11:24:55 -0400212<dl class="row">
213 <dt class="col-md-4">Activate</dt>
214 <dd class="col-md-8">
Cristy882d9f42015-10-29 16:48:39 -0400215 Enable the image's transparency channel. Note normally Set
216 should be used instead of this, unless you specifically need to
217 preserve existing (but specifically turned Off) transparency
218 channel. </dd>
219
Cristy49380402017-06-29 11:24:55 -0400220 <dt class="col-md-4">Associate</dt>
221 <dd class="col-md-8">
Cristy882d9f42015-10-29 16:48:39 -0400222 associate the alpha channel with the image.</dd>
223
Cristy49380402017-06-29 11:24:55 -0400224 <dt class="col-md-4">Deactivate</dt>
225 <dd class="col-md-8">
Cristy882d9f42015-10-29 16:48:39 -0400226 Disables the image's transparency channel. Does not delete or change the
227 existing data, just turns off the use of that data.</dd>
228
Cristy49380402017-06-29 11:24:55 -0400229 <dt class="col-md-4">Disassociate</dt>
230 <dd class="col-md-8">
Cristy882d9f42015-10-29 16:48:39 -0400231 disassociate the alpha channel from the image.</dd>
232
Cristy49380402017-06-29 11:24:55 -0400233 <dt class="col-md-4">Set</dt>
234 <dd class="col-md-8">
Cristy882d9f42015-10-29 16:48:39 -0400235 Activates the alpha/matte channel. If it was previously turned off
236 then it also resets the channel to opaque. If the image already had
237 the alpha channel turned on, it will have no effect.</dd>
238
Cristy49380402017-06-29 11:24:55 -0400239 <dt class="col-md-4">Opaque</dt>
240 <dd class="col-md-8">
Cristy882d9f42015-10-29 16:48:39 -0400241 Enables the alpha/matte channel and forces it to be fully opaque.
242 </dd>
243
Cristy49380402017-06-29 11:24:55 -0400244 <dt class="col-md-4">Transparent</dt>
245 <dd class="col-md-8">
Cristy882d9f42015-10-29 16:48:39 -0400246 Activates the alpha/matte channel and forces it to be fully
247 transparent. This effectively creates a fully transparent image the
248 same size as the original and with all its original RGB data still
249 intact, but fully transparent. </dd>
250
Cristy49380402017-06-29 11:24:55 -0400251 <dt class="col-md-4">Extract</dt>
252 <dd class="col-md-8">
Cristy882d9f42015-10-29 16:48:39 -0400253 Copies the alpha channel values into all the color channels and turns
254 'Off' the the image's transparency, so as to generate
Cristy769d8892016-01-19 18:11:14 -0500255 a grayscale mask of the image's shape. The alpha channel data is left
Cristy882d9f42015-10-29 16:48:39 -0400256 intact just deactivated. This is the inverse of 'Copy'.
257 </dd>
258
Cristy49380402017-06-29 11:24:55 -0400259 <dt class="col-md-4">Copy</dt>
260 <dd class="col-md-8">
Cristy882d9f42015-10-29 16:48:39 -0400261 Turns 'On' the alpha/matte channel, then copies the
Cristy769d8892016-01-19 18:11:14 -0500262 grayscale intensity of the image, into the alpha channel, converting
263 a grayscale mask into a transparent shaped mask ready to be colored
Cristy882d9f42015-10-29 16:48:39 -0400264 appropriately. The color channels are not modified. </dd>
265
Cristy49380402017-06-29 11:24:55 -0400266 <dt class="col-md-4">Shape</dt>
267 <dd class="col-md-8">
Cristy882d9f42015-10-29 16:48:39 -0400268 As per 'Copy' but also colors the resulting shape mask with
269 the current background color. That is the RGB color channels is
270 replaced, with appropriate alpha shape.
271 </dd>
272
Cristy49380402017-06-29 11:24:55 -0400273 <dt class="col-md-4">Remove</dt>
274 <dd class="col-md-8">
Cristy882d9f42015-10-29 16:48:39 -0400275 Composite the image over the background color.
276 </dd>
277
Cristy49380402017-06-29 11:24:55 -0400278 <dt class="col-md-4">Background</dt>
279 <dd class="col-md-8">
Cristy882d9f42015-10-29 16:48:39 -0400280 Set any fully-transparent pixel to the background color, while leaving
281 it fully-transparent. This can make some image file formats, such as
282 PNG, smaller as the RGB values of transparent pixels are more uniform,
283 and thus can compress better.
284 </dd>
285</dl>
286
287<p>Note that while the obsolete <code>+matte</code> operation was the
Cristy594d2772015-11-15 10:47:42 -0500288same as "<code><a href="command-line-options.html#alpha" >-alpha</a> Off</code>", the <code>
289>-matte</code> operation was the same as "<code><a href="command-line-options.html#alpha" >-alpha</a>
290Set</code>" and not "<code><a href="command-line-options.html#alpha" >-alpha</a> On</code>". </p>
Cristy882d9f42015-10-29 16:48:39 -0400291
Cristyf650f4f2016-04-01 10:53:07 -0400292<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400293 <h3><a id="annotate"></a>
Cristy594d2772015-11-15 10:47:42 -0500294 -annotate <var>degrees</var> <var>text</var><br />
295 -annotate <var>Xdegrees</var>x<var>Ydegrees</var> <var>text</var><br /> -annotate <var>Xdegrees</var>x<var>Ydegrees</var> {+-}<var>t<sub>x</sub></var>{+-}<var>t<sub>y</sub></var> <var>text</var><br /> -annotate {+-}<var>t<sub>x</sub></var>{+-}<var>t<sub>y</sub></var> <var>text</var></h3>
Cristy882d9f42015-10-29 16:48:39 -0400296</div>
297
298<p class="magick-description">Annotate an image with text</p>
299
300<p>This is a convenience for annotating an image with text. For more precise
301control over text annotations, use <a href="command-line-options.html#draw">-draw</a>.</p>
302
303
304<p>The values <var>Xdegrees</var> and <var>Ydegrees</var>
Cristy594d2772015-11-15 10:47:42 -0500305control the shears applied to the text, while <var>t<sub>x</sub></var> and <var>t<sub>y</sub></var> are offsets that give the location of the text relative any <a href="command-line-options.html#gravity" >-gravity</a> setting and defaults to the upper left corner of the image.</p>
Cristy882d9f42015-10-29 16:48:39 -0400306
307<p>Using <a href="command-line-options.html#annotate">-annotate</a> <var>degrees</var>
308or <a href="command-line-options.html#annotate">-annotate</a> <var>degrees</var>x<var>degrees</var> produces an unsheared rotation of the text. The
309direction of the rotation is positive, which means a clockwise rotation if <var>degrees</var> is positive. (This conforms to the usual mathematical
310convention once it is realized that the positive <var>y</var>–direction is
311conventionally considered to be <var>downward</var> for images.)</p>
312
313<p>The new (transformed) coordinates (<var>x'</var>, <var>y'</var>) of a pixel at position (<var>x</var>, <var>y</var>) in the image are calculated using the following matrix
314equation.</p>
315
Cristy594d2772015-11-15 10:47:42 -0500316<p class="text-center"><img class="img-thumbnail" alt="annotate transformation" src="../images/annotate.png"/></p>
Cristy882d9f42015-10-29 16:48:39 -0400317
318<p>If <var>t<sub>x</sub></var> and <var>t<sub>y</sub></var> are omitted, they default to 0. This makes the
319bottom-left of the text becomes the upper-left corner of the image, which is
Cristy594d2772015-11-15 10:47:42 -0500320probably undesirable. Adding a <a href="command-line-options.html#gravity" >-gravity</a> option in this
Cristy882d9f42015-10-29 16:48:39 -0400321case leads to nice results.</p>
322
323<p>Text is any UTF-8 encoded character sequence. If <var>text</var>
324is of the form '@mytext.txt', the text is read from the file
325<code>mytext.txt</code>. Text in a file is taken literally; no embedded
326formatting characters are recognized.</p>
327
328<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400329 <h3><a id="antialias"></a>-antialias</h3>
Cristy882d9f42015-10-29 16:48:39 -0400330</div>
331
332<p class="magick-description">Enable/Disable of the rendering of anti-aliasing pixels when drawing fonts and lines.</p>
333
334<p>By default, objects (e.g. text, lines, polygons, etc.) are antialiased when
335drawn. Use <a href="command-line-options.html#antialias">+antialias</a> to disable the addition of
336antialiasing edge pixels. This will then reduce the number of colors added to
337an image to just the colors being directly drawn. That is, no mixed colors
338are added when drawing such objects. </p>
339
340<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400341 <h3><a id="append"></a>-append</h3>
Cristy882d9f42015-10-29 16:48:39 -0400342</div>
343
344<p class="magick-description">Join current images vertically or horizontally.</p>
345
346<p>This option creates a single longer image, by joining all the current
347images in sequence top-to-bottom. Use <a href="command-line-options.html#append">+append</a> to
348stack images left-to-right. </p>
349
350<p>If they are not of the same width, narrower images are padded with the
351current <a href="command-line-options.html#background">-background</a> color setting, and their
Cristy594d2772015-11-15 10:47:42 -0500352position relative to each other can be controlled by the current <a
353href="command-line-options.html#gravity">-gravity</a> setting. </p>
Cristy882d9f42015-10-29 16:48:39 -0400354
355
356<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400357 <h3><a id="attenuate"></a>-attenuate <var>value</var></h3>
Cristy882d9f42015-10-29 16:48:39 -0400358</div>
359
360<p class="magick-description">Lessen (or intensify) when adding noise to an image.</p>
361
362<p>If unset the value is equivalent to 1.0, or a maximum noise addition</p>
363
364<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400365 <h3><a id="authenticate"></a>-authenticate <var>password</var></h3>
Cristy882d9f42015-10-29 16:48:39 -0400366</div>
367
368<p class="magick-description">Decrypt a PDF with a password.</p>
369
370<p>Use this option to supply a <var>password</var> for decrypting
371a PDF that has been encrypted using Microsoft Crypto API (MSC API). The
372encrypting using the MSC API is not supported.</p>
373
374<p>For a different encryption method, see <a href="command-line-options.html#encipher">-encipher</a>
375and <a href="command-line-options.html#decipher">-decipher</a>. </p>
376
377
378<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400379 <h3><a id="auto-gamma"></a>-auto-gamma</h3>
Cristy882d9f42015-10-29 16:48:39 -0400380</div>
381
382<p class="magick-description">Automagically adjust gamma level of image.</p>
383
Cristy594d2772015-11-15 10:47:42 -0500384<p>This calculates the mean values of an image, then applies a calculated <a
385href="command-line-options.html#gamma" >-gamma</a> adjustment so that is the mean color exists in the
Cristy882d9f42015-10-29 16:48:39 -0400386image it will get a have a value of 50%. </p>
387
388<p>This means that any solid 'gray' image becomes 50% gray. </p>
389
390<p>This works well for real-life images with little or no extreme dark and
391light areas, but tend to fail for images with large amounts of bright sky or
392dark shadows. It also does not work well for diagrams or cartoon like images.
393</p>
394
Cristy594d2772015-11-15 10:47:42 -0500395<p>It uses the <a href="command-line-options.html#channel" >-channel</a> setting, (including the
Cristy882d9f42015-10-29 16:48:39 -0400396'<var>sync</var>' flag for channel synchronization), to determine which color
Cristy594d2772015-11-15 10:47:42 -0500397values is used and modified. As the default <a href="command-line-options.html#channel"
398>-channel</a> setting is '<var>RGB,sync</var>', channels are modified
Cristy882d9f42015-10-29 16:48:39 -0400399together by the same gamma value, preserving colors. </p>
400
401
402
403<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400404 <h3><a id="auto-level"></a>-auto-level</h3>
Cristy882d9f42015-10-29 16:48:39 -0400405</div>
406
407<p class="magick-description">Automagically adjust color levels of image.</p>
408
409<p>This is a 'perfect' image normalization operator. It finds the exact
Cristy594d2772015-11-15 10:47:42 -0500410minimum and maximum color values in the image and then applies a <a
411href="command-line-options.html#level" >-level</a> operator to stretch the values to the full range of
Cristy882d9f42015-10-29 16:48:39 -0400412values. </p>
413
414<p>The operator is not typically used for real-life images, image scans, or
415JPEG format images, as a single 'out-rider' pixel can set a bad min/max values
Cristy594d2772015-11-15 10:47:42 -0500416for the <a href="command-line-options.html#level" >-level</a> operation. On the other hand it is the
Cristy882d9f42015-10-29 16:48:39 -0400417right operator to use for color stretching gradient images being used to
418generate Color lookup tables, distortion maps, or other 'mathematically'
419defined images. </p>
420
Cristy594d2772015-11-15 10:47:42 -0500421<p>The operator is very similar to the <a href="command-line-options.html#normalize">-normalize</a>, <a
422href="command-line-options.html#contrast-stretch" >-contrast-stretch</a>, and <a href="command-line-options.html#linear-stretch"
423>-linear-stretch</a> operators, but without 'histogram binning' or 'clipping'
424problems that these operators may have. That is <a href="command-line-options.html#auto-level"
425>-auto-level</a> is the perfect or ideal version these operators. </p>
Cristy882d9f42015-10-29 16:48:39 -0400426
Cristy594d2772015-11-15 10:47:42 -0500427<p>It uses the <a href="command-line-options.html#channel" >-channel</a> setting, (including the
Cristy882d9f42015-10-29 16:48:39 -0400428special '<var>sync</var>' flag for channel synchronization), to determine
Cristy594d2772015-11-15 10:47:42 -0500429which color values are used and modified. As the default <a
430href="command-line-options.html#channel" >+channel</a> setting is '<var>RGB,sync</var>', the
Cristy882d9f42015-10-29 16:48:39 -0400431'<var>sync</var>' ensures that the color channels will are modified
432together by the same gamma value, preserving colors, and ignoring
433transparency. </p>
434
435
436<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400437 <h3><a id="auto-orient"></a>-auto-orient</h3>
Cristy882d9f42015-10-29 16:48:39 -0400438</div>
439
440<p class="magick-description">adjusts an image so that its orientation is suitable for viewing (i.e. top-left orientation).</p>
441
442<p>This operator reads and resets the EXIF image profile setting 'Orientation'
443and then performs the appropriate 90 degree rotation on the image to orient
444the image, for correct viewing. </p>
445
446<p>This EXIF profile setting is usually set using a gravity sensor in digital
447camera, however photos taken directly downward or upward may not have an
448appropriate value. Also images that have been orientation 'corrected' without
449reseting this setting, may be 'corrected' again resulting in a incorrect
Cristy594d2772015-11-15 10:47:42 -0500450result. If the EXIF profile was previously stripped, the <a
451href="command-line-options.html#auto-orient" >-auto-orient</a> operator will do nothing. </p>
Cristy882d9f42015-10-29 16:48:39 -0400452
453
454<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400455 <h3><a id="average"></a>-average</h3>
Cristy882d9f42015-10-29 16:48:39 -0400456</div>
457
458<p class="magick-description">Average a set of images.</p>
459
460<p>An error results if the images are not identically sized.</p>
461
462
463<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400464 <h3><a id="backdrop"></a>-backdrop</h3>
Cristy882d9f42015-10-29 16:48:39 -0400465</div>
466
467<p class="magick-description">Display the image centered on a backdrop.</p>
468
469<p>This backdrop covers the entire workstation screen and is useful for hiding
470other X window activity while viewing the image. The color of the backdrop is
471specified as the background color. The color is specified using the format
472described under the <a href="command-line-options.html#fill">-fill</a> option.</p>
473
474<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400475 <h3><a id="background"></a>-background <var>color</var></h3>
Cristy882d9f42015-10-29 16:48:39 -0400476</div>
477
478<p class="magick-description">Set the background color.</p>
479
Cristy594d2772015-11-15 10:47:42 -0500480<p>The color is specified using the format described under the <a
481href="command-line-options.html#fill">-fill</a> option. The default background color (if none is
Cristy882d9f42015-10-29 16:48:39 -0400482specified or found in the image) is white.</p>
483
484<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400485 <h3><a id="bench"></a>-bench <var>iterations</var></h3>
Cristy882d9f42015-10-29 16:48:39 -0400486</div>
487
488<p class="magick-description">Measure performance.</p>
489
490<p>Repeat the entire command for the given number of <var>iterations</var> and report the user-time and elapsed time. For instance,
491consider the following command and its output. Modify the benchmark with the
492-duration to run the benchmark for a fixed number of seconds and -concurrent
493to run the benchmark in parallel (requires the OpenMP feature).</p>
494
Cristy49380402017-06-29 11:24:55 -0400495<pre><code>
Cristye09ed312016-03-06 08:07:39 -0500496-> convert logo: -resize 200% -bench 5 logo.png
497Performance[1]: 5i 1.344ips 1.000e 3.710u 0:03.720
498Performance[2]: 5i 1.634ips 0.549e 3.890u 0:03.060
499Performance[3]: 5i 2.174ips 0.618e 3.190u 0:02.300
500Performance[4]: 5i 1.678ips 0.555e 3.810u 0:02.980
Cristy882d9f42015-10-29 16:48:39 -0400501Performance[4]: 5i 0.875657ips 6.880u 0:05.710
Cristy49380402017-06-29 11:24:55 -0400502</code></pre>
Cristy882d9f42015-10-29 16:48:39 -0400503
Cristye09ed312016-03-06 08:07:39 -0500504<p>In this example, 5 iterations were completed at 2.174 iterations per
505second, using 3 threads and 3.190 seconds of the user allotted time, for
506a total elapsed time of 2.300 seconds.</p>
Cristy882d9f42015-10-29 16:48:39 -0400507
508<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400509 <h3><a id="bias"></a>-bias <var>value</var>{<var>%</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -0400510</div>
511
512<p class="magick-description">Add bias when convolving an image.</p>
513
Cristy594d2772015-11-15 10:47:42 -0500514<p>This option shifts the output of <a href="command-line-options.html#convolve">&#x2011;convolve</a> so that
Cristy882d9f42015-10-29 16:48:39 -0400515positive and negative results are relative to the specified bias value. </p>
516
517<p>This is important for non-HDRI compilations of ImageMagick when dealing
518with convolutions that contain negative as well as positive values. This is
519especially the case with convolutions involving high pass filters or edge
520detection. Without an output bias, the negative values are clipped at
521zero.</p>
522
Cristy594d2772015-11-15 10:47:42 -0500523<p>When using an ImageMagick with the HDRI compile-time setting, <a href="command-line-options.html#bias">&#x2011;bias</a> is not needed, as ImageMagick is able to store/handle any
Cristy882d9f42015-10-29 16:48:39 -0400524negative results without clipping to the color value range
525(0..QuantumRange).</p>
526
Cristy594d2772015-11-15 10:47:42 -0500527<p>See the discussion on HDRI implementations of ImageMagick on the page <a
528href="high-dynamic-range.html" >High Dynamic-Range Images</a>. For more
529about HDRI go the ImageMagick <a
Cristy364a72f2016-11-04 22:38:41 -0400530href="https://www.imagemagick.org/Usage/basics/#hdri" >Usage</a> pages or this
Cristy594d2772015-11-15 10:47:42 -0500531<a
532href="http://en.wikipedia.org/wiki/High_dynamic_range_imaging">Wikipedia</a>
Cristy882d9f42015-10-29 16:48:39 -0400533entry. </p>
534
535<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400536 <h3><a id="black-point-compensation"></a>-black-point-compensation</h3>
Cristy882d9f42015-10-29 16:48:39 -0400537</div>
538
539<p class="magick-description">Use black point compensation.</p>
540
541<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400542 <h3><a id="black-threshold"></a>-black-threshold <var>value</var>{<var>%</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -0400543</div>
544
545<p class="magick-description">Force to black all pixels below the threshold while leaving all pixels at or above the threshold unchanged.</p>
546
547<p> The threshold value can be given as a percentage or as an absolute integer
548value within [0, <var>QuantumRange</var>] corresponding to the
Cristy594d2772015-11-15 10:47:42 -0500549desired <a href="command-line-options.html#channel">&#x2011;channel</a> value. See <a href="command-line-options.html#threshold">&#x2011;threshold</a>for more details on thresholds and resulting values. </p>
Cristy882d9f42015-10-29 16:48:39 -0400550
551
552<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400553 <h3><a id="blend"></a>-blend <var>geometry</var></h3>
Cristy882d9f42015-10-29 16:48:39 -0400554</div>
555
556<p class="magick-description">blend an image into another by the given absolute value or percent.</p>
557
558<p>Blend will average the images together ('plus') according to the
559percentages given and each pixels transparency. If only a single percentage
560value is given it sets the weight of the composite or 'source' image, while
561the background image is weighted by the exact opposite amount. That is a
562<code>-blend 30%</code> merges 30% of the 'source' image with 70% of the
563'destination' image. Thus it is equivalent to <code>-blend 30x70%</code>.</p>
564
565
566<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400567 <h3><a id="blue-primary"></a>-blue-primary <var>x</var>,<var>y</var></h3>
Cristy882d9f42015-10-29 16:48:39 -0400568</div>
569
570<p class="magick-description">Set the blue chromaticity primary point.</p>
571
572<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400573 <h3><a id="blue-shift"></a>-blue-shift <var>factor</var></h3>
Cristy882d9f42015-10-29 16:48:39 -0400574</div>
575
576<p class="magick-description">simulate a scene at nighttime in the moonlight. Start with a factor of 1.5</p>
577
578<div style="margin: auto;">
579
580<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400581 <h3><a id="blur"></a>-blur <var>radius</var><br />-blur <var>radius</var>x<var>sigma</var></h3>
Cristy882d9f42015-10-29 16:48:39 -0400582</div>
583
584<p class="magick-description">Reduce image noise and reduce detail levels.</p>
585
586<p>Convolve the image with a Gaussian or normal distribution using the given
Cristy594d2772015-11-15 10:47:42 -0500587<var >Sigma</var> value. The formula is:</p>
Cristy882d9f42015-10-29 16:48:39 -0400588
Cristy594d2772015-11-15 10:47:42 -0500589<p class="text-center"><img class="img-thumbnail" alt="gaussian distribution" width="243px" height="42px" src="../images/gaussian-blur.png"/></p>
Cristy882d9f42015-10-29 16:48:39 -0400590
Cristy594d2772015-11-15 10:47:42 -0500591<p>The <var >Sigma</var> value is the important argument, and
Cristy882d9f42015-10-29 16:48:39 -0400592determines the actual amount of blurring that will take place. </p>
593
Cristy594d2772015-11-15 10:47:42 -0500594<p>The <var >Radius</var> is only used to determine the size of the
Cristy882d9f42015-10-29 16:48:39 -0400595array which will hold the calculated Gaussian distribution. It should be an
596integer. If not given, or set to zero, IM will calculate the largest possible
597radius that will provide meaningful results for the Gaussian distribution.
598</p>
599
Cristy594d2772015-11-15 10:47:42 -0500600<p>The larger the <var >Radius</var> the slower the
601operation is. However too small a <var >Radius</var>, and sever
602aliasing effects may result. As a guideline, <var >Radius</var>
603should be at least twice the <var >Sigma</var> value, though three
Cristy882d9f42015-10-29 16:48:39 -0400604times will produce a more accurate result. </p>
605
606<p>This option differs from <a href="command-line-options.html#gaussian-blur">-gaussian-blur</a> simply
607by taking advantage of the separability properties of the distribution. Here
608we apply a single-dimensional Gaussian matrix in the horizontal direction,
609then repeat the process in the vertical direction.</p>
610
611<p>The <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting will determine how
612pixels which are outside the image proper are blurred into the final result.
613</p>
614
615
616<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400617 <h3><a id="border"></a>-border <var>geometry</var></h3>
Cristy882d9f42015-10-29 16:48:39 -0400618</div>
619
620<p class="magick-description">Surround the image with a border of color. </p>
621
622<p>Set the width and height using the <var>size</var> portion of the
623<var>geometry</var> argument. See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. Offsets are
624ignored. </p>
625
626<p>As of IM 6.7.8-8, the <var>geometry</var> arguments behave as follows:</p>
627
Cristy49380402017-06-29 11:24:55 -0400628<dl class="row">
629<dt class="col-md-4"><var>value</var></dt>
630<dd class="col-md-8">value is added to both left/right and top/bottom</dd>
631<dt class="col-md-4"><var>value-x</var><kbd>x</kbd></dt>
632<dd class="col-md-8">value-x is added only to left/right and top/bottom are unchanged</dd>
633<dt class="col-md-4"><kbd>x</kbd><var>value-y</var></dt>
634<dd class="col-md-8">value-y is added only to top/bottom and left/right are unchanged</dd>
635<dt class="col-md-4"><var>value-x</var><kbd>x</kbd><var>value-y</var></dt>
636<dd class="col-md-8">value-x is added to left/right and value-y added to top/bottom</dd>
637<dt class="col-md-4"><var>value-x</var><kbd>x</kbd>0</dt>
638<dd class="col-md-8">value-x is added only to left/right and top/bottom are unchanged</dd>
639<dt class="col-md-4">0<kbd>x</kbd><var>value-y</var></dt>
640<dd class="col-md-8">value-y is added only to top/bottom and left/right are unchanged</dd>
641<dt class="col-md-4"><var>value</var>%</dt>
642<dd class="col-md-8">value % of width is added to left/right and value % of height is added to top/bottom</dd>
643<dt class="col-md-4"><var>value-x</var><kbd>x</kbd>%</dt>
644<dd class="col-md-8">value-x % of width is added to left/right and to top/bottom</dd>
645<dt class="col-md-4">x<var>value-y</var>%</dt>
646<dd class="col-md-8">value-y % of height is added to top/bottom and to left/right</dd>
647<dt class="col-md-4"><var>value-x</var>%<kbd>x</kbd><var>value-y</var>%</dt>
648<dd class="col-md-8">value-x % of width is added to left/right and value-y % of height is added to top/bottom</dd>
649<dt class="col-md-4"><var>value-x</var>%<kbd>x</kbd>0%</dt>
650<dd class="col-md-8">value-x % of width is added to left/right and top/bottom are unchanged</dd>
651<dt class="col-md-4">0%<kbd>x</kbd><var>value-y</var>%</dt>
652<dd class="col-md-8">value-y % of height is added to top/bottom and left/right are unchanged</dd>
Cristy882d9f42015-10-29 16:48:39 -0400653</dl>
654
Cristy594d2772015-11-15 10:47:42 -0500655<p>Set the border color by preceding with the <a
656href="command-line-options.html#bordercolor">-bordercolor</a> setting.</p>
Cristy882d9f42015-10-29 16:48:39 -0400657
Cristy594d2772015-11-15 10:47:42 -0500658<p>The <a href="command-line-options.html#border">-border</a> operation is affected by the current <a
659href="command-line-options.html#compose">-compose</a> setting and assumes that this is using the default
Cristy882d9f42015-10-29 16:48:39 -0400660'<code>Over</code>' composition method. It generates an image of the appropriate
661size colors by the current <a href="command-line-options.html#bordercolor">-bordercolor</a> before
662overlaying the original image in the center of this net image. This means that
663with the default compose method of '<code>Over</code>' any transparent parts may
664be replaced by the current <a href="command-line-options.html#bordercolor">-bordercolor</a> setting.</p>
665<p>See also the <a href="command-line-options.html#frame">-frame</a> option, which has more
666functionality.</p>
667
668<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400669 <h3><a id="bordercolor"></a>-bordercolor <var>color</var></h3>
Cristy882d9f42015-10-29 16:48:39 -0400670</div>
671
672<p class="magick-description">Set the border color.</p>
673
674<p>The color is specified using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p>
675
676<p>The default border color is <code>#DFDFDF</code>, <span style="background-color: #dfdfdf;">this shade of gray</span>.</p>
677
678<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400679 <h3><a id="borderwidth"></a>-borderwidth <var>geometry</var> </h3>
Cristy882d9f42015-10-29 16:48:39 -0400680</div>
681
682<p class="magick-description">Set the border width.</p>
683
684<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400685 <h3><a id="brightness-contrast"></a>-brightness-contrast <var>brightness</var><br />-brightness-contrast <var>brightness</var>{x<var>contrast</var>}{<var>%</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -0400686</div>
687
688<p class="magick-description">Adjust the brightness and/or contrast of the image.</p>
689
690<p>Brightness and Contrast values apply changes to the input image. They are
691not absolute settings. A brightness or contrast value of zero means no change.
692The range of values is -100 to +100 on each. Positive values increase the
693brightness or contrast and negative values decrease the brightness or contrast.
694To control only contrast, set the brightness=0. To control only brightness,
695set contrast=0 or just leave it off.</p>
696
697<p>You may also use <a href="command-line-options.html#fill">-channel</a> to control which channels to
698apply the brightness and/or contrast change. The default is to apply the same
699transformation to all channels.</p>
700
701<p>Brightness and Contrast arguments are converted to offset and slope of a
702linear transform and applied
703using <a href="command-line-options.html#fill">-function polynomial "slope,offset"</a>.</p>
704
705<p>The slope varies from 0 at contrast=-100 to almost vertical at
706contrast=+100. For brightness=0 and contrast=-100, the result are totally
707midgray. For brightness=0 and contrast=+100, the result will approach but
708not quite reach a threshold at midgray; that is the linear transformation
709is a very steep vertical line at mid gray.</p>
710
711<p>Negative slopes, i.e. negating the image, are not possible with this
712function. All achievable slopes are zero or positive.</p>
713
714<p>The offset varies from -0.5 at brightness=-100 to 0 at brightness=0 to +0.5
715at brightness=+100. Thus, when contrast=0 and brightness=100, the result is
716totally white. Similarly, when contrast=0 and brightness=-100, the result is
717totally black.</p>
718
719<p>As the range of values for the arguments are -100 to +100, adding the '%'
720symbol is no different than leaving it off.</p>
721
722<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400723 <h3><a id="cache"></a>-cache <var>threshold</var></h3>
Cristy882d9f42015-10-29 16:48:39 -0400724</div>
725
Cristy594d2772015-11-15 10:47:42 -0500726<p class="magick-description">(This option has been replaced by the <a href='command-line-options.html#limit'>-limit</a> option).</p>
Cristy882d9f42015-10-29 16:48:39 -0400727
728<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400729 <h3><a id="canny"></a>-canny <var>radius</var><br/>-canny <var>radius</var>x<var>sigma</var>{<var>+lower-percent</var>}{<var>+upper-percent</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -0400730</div>
731
732<p class="magick-description">Canny edge detector uses a multi-stage algorithm to detect a wide range of edges in the image.</p>
733
734<p>The thresholds range from 0 to 100% (e.g. -canny 0x1+10%+30%) with {<var>+lower-percent</var>} &lt; {<var>+upper-percent</var>}. If {<var>+upper-percent</var>} is increased but {<var>+lower-percent</var>} remains the same, lesser edge components will be detected, but their lengths will be the same. If {<var>+lower-percent</var>} is increased but {<var>+upper-percent</var>} is the same, the same number of edge components will be detected but their lengths will be shorter. The default thresholds are shown. The <var>radius</var>x<var>sigma</var> controls a gaussian blur applied to the input image to reduce noise and smooth the edges.</p>
735
736<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400737 <h3><a id="caption"></a>-caption <var>string</var></h3>
Cristy882d9f42015-10-29 16:48:39 -0400738</div>
739
740<p class="magick-description">Assign a caption to an image.</p>
741
742<p>This option sets the caption meta-data of an image read in after this
743option has been given. To modify a caption of images already in memory use
744"<code><a href="command-line-options.html#set">-set</a> caption</code>". </p>
745
Cristy594d2772015-11-15 10:47:42 -0500746<p>The caption can contain special format characters listed in the <a
747href="escape.html">Format and
Cristy882d9f42015-10-29 16:48:39 -0400748Print Image Properties</a>. These attributes are expanded when the caption
749is finally assigned to the individual images. </p>
750
751<p>If the first character of <var>string</var> is <var>@</var>, the image caption is read from a file titled by the
752remaining characters in the string. Comments read in from a file are literal;
753no embedded formatting characters are recognized.</p>
754
755<p>Caption meta-data is not visible on the image itself. To do that use the
756<a href="command-line-options.html#annotate">-annotate</a> or <a href="command-line-options.html#draw">-draw</a> options
757instead.</p>
758
759<p>For example,</p>
760
Cristy49380402017-06-29 11:24:55 -0400761<pre><code>
Cristy882d9f42015-10-29 16:48:39 -0400762-caption "%m:%f %wx%h" bird.miff
Cristy49380402017-06-29 11:24:55 -0400763</code></pre>
Cristy882d9f42015-10-29 16:48:39 -0400764
765<p>produces an image caption of <code>MIFF:bird.miff 512x480</code> (assuming
766that the image <code>bird.miff</code> has a width of 512 and a height of
767480.</p>
768
769
770<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400771 <h3><a id="cdl"></a>-cdl <var>filename</var></h3>
Cristy882d9f42015-10-29 16:48:39 -0400772</div>
773
774<p class="magick-description">color correct with a color decision list.</p>
775
776<p>Here is an example color correction collection:</p>
777
Cristy49380402017-06-29 11:24:55 -0400778<pre><code>
Cristy882d9f42015-10-29 16:48:39 -0400779&lt;?xml version="1.0" encoding="UTF-8"?&gt;
780&lt;ColorCorrectionCollection xmlns="urn:ASC:CDL:v1.2"&gt;
781 &lt;ColorCorrection id="cc06668"&gt;
782 &lt;SOPNode&gt;
783 &lt;Slope&gt; 0.9 1.2 0.5 &lt;/Slope&gt;
784 &lt;Offset&gt; 0.4 -0.5 0.6 &lt;/Offset&gt;
785 &lt;Power&gt; 1.0 0.8 1.5 &lt;/Power&gt;
786 &lt;/SOPNode&gt;
787 &lt;SATNode&gt;
788 &lt;Saturation&gt; 0.85 &lt;/Saturation&gt;
789 &lt;/SATNode&gt;
790 &lt;/ColorCorrection&gt;
791&lt;/ColorCorrectionCollection&gt;
Cristy49380402017-06-29 11:24:55 -0400792</code></pre>
Cristy882d9f42015-10-29 16:48:39 -0400793
794<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400795 <h3><a id="channel"></a>-channel <var>type</var></h3>
Cristy882d9f42015-10-29 16:48:39 -0400796</div>
797
798<p class="magick-description">Specify those image color channels to which subsequent operators are limited.</p>
799
800<p>Choose from: <code>Red</code>, <code>Green</code>, <code>Blue</code>,
801<code>Alpha</code>, <code>Gray</code>, <code>Cyan</code>, <code>Magenta</code>,
802<code>Yellow</code>, <code>Black</code>, <code>Opacity</code>,
803<code>Index</code>, <code>RGB</code>, <code>RGBA</code>, <code>CMYK</code>, or
804<code>CMYKA</code>.</p>
805
806<p>The channels above can also be specified as a comma-separated list or can be
807abbreviated as a concatenation of the letters '<code>R</code>', '<code>G</code>',
808'<code>B</code>', '<code>A</code>', '<code>O</code>', '<code>C</code>',
809'<code>M</code>', '<code>Y</code>', '<code>K</code>'.
810
811For example, to only select the <code>Red</code> and <code>Blue</code> channels
812you can either use </p>
Cristy49380402017-06-29 11:24:55 -0400813<pre><code>
Cristy882d9f42015-10-29 16:48:39 -0400814-channel Red,Blue
Cristy49380402017-06-29 11:24:55 -0400815</code></pre>
Cristy882d9f42015-10-29 16:48:39 -0400816<p>or you can use the short hand form</p>
Cristy49380402017-06-29 11:24:55 -0400817<pre><code>
Cristy882d9f42015-10-29 16:48:39 -0400818-channel RB
Cristy49380402017-06-29 11:24:55 -0400819</code></pre>
Cristy882d9f42015-10-29 16:48:39 -0400820
821<p>All the channels that are present in an image can be specified using the
822special channel type <code>All</code>. Not all operators are 'channel capable',
823but generally any operators that are generally 'grey-scale' image operators,
824will understand this setting. See individual operator documentation. </p>
825
Cristy594d2772015-11-15 10:47:42 -0500826<br/>
Cristy882d9f42015-10-29 16:48:39 -0400827
828<p>On top of the normal channel selection an extra flag can be specified,
829'<code>Sync</code>'. This is turned on by default and if set means that
830operators that understand this flag should perform: cross-channel
831synchronization of the channels. If not specified, then most grey-scale
832operators will apply their image processing operations to each individual
833channel (as specified by the rest of the <a href="command-line-options.html#channel">-channel</a>
834setting) completely independently from each other. </p>
835
836<p>For example for operators such as <a href="command-line-options.html#auto-level">-auto-level</a> and
837<a href="command-line-options.html#auto-gamma">-auto-gamma</a> the color channels are modified
838together in exactly the same way so that colors will remain in-sync. Without
839it being set, then each channel is modified separately and
840independently, which may produce color distortion. </p>
841
842<p>The <a href="command-line-options.html#morphology">-morphology</a> '<code>Convolve</code>' method
843and the <a href="command-line-options.html#compose">-compose</a> mathematical methods, also understands
844the '<code>Sync</code>' flag to modify the behavior of pixel colors according
845to the alpha channel (if present). That is to say it will modify the image
846processing with the understanding that fully-transparent colors should not
847contribute to the final result. </p>
848
849<p>Basically, by default, operators work with color channels in synchronous, and
850treats transparency as special, unless the <a href="command-line-options.html#channel">-channel</a>
851setting is modified so as to remove the effect of the '<code>Sync</code>' flag.
852How each operator does this depends on that operators current implementation.
853Not all operators understands this flag at this time, but that is changing.
854</p>
855
856<p>To print a complete list of channel types, use <a href="command-line-options.html#list">-list
857channel</a>.</p>
858
859<p>By default, ImageMagick sets <a href="command-line-options.html#channel">-channel</a> to the value
860'<code>RGBK,sync</code>', which specifies that operators act on all color
861channels except the transparency channel, and that all the color channels are
862to be modified in exactly the same way, with an understanding of transparency
Cristy594d2772015-11-15 10:47:42 -0500863(depending on the operation being applied). The 'plus' form <a
864href="command-line-options.html#channel" >+channel</a> will reset the value back to this default. </p>
Cristy882d9f42015-10-29 16:48:39 -0400865
Cristy594d2772015-11-15 10:47:42 -0500866<p>Options that are affected by the <a href="command-line-options.html#channel" >-channel</a> setting
Cristy882d9f42015-10-29 16:48:39 -0400867include the following.
868
869<a href="command-line-options.html#auto-gamma">-auto-gamma</a>,
870<a href="command-line-options.html#auto-level">-auto-level</a>,
871<a href="command-line-options.html#black-threshold">-black-threshold</a>,
872<a href="command-line-options.html#blur">-blur</a>,
873<a href="command-line-options.html#clamp">-clamp</a>,
874<a href="command-line-options.html#clut">-clut</a>,
875<a href="command-line-options.html#combine">-combine</a>,
876<a href="command-line-options.html#composite">-composite</a> (Mathematical compose methods only),
877<a href="command-line-options.html#convolve">-convolve</a>,
878<a href="command-line-options.html#contrast-stretch">-contrast-stretch</a>,
879<a href="command-line-options.html#evaluate">-evaluate</a>,
880<a href="command-line-options.html#function">-function</a>,
881<a href="command-line-options.html#fx">-fx</a>,
882<a href="command-line-options.html#gaussian-blur">-gaussian-blur</a>,
883<a href="command-line-options.html#hald-clut">-hald-clut</a>,
884<a href="command-line-options.html#motion-blur">-motion-blur</a>,
885<a href="command-line-options.html#morphology">-morphology</a>,
886<a href="command-line-options.html#negate">-negate</a>,
887<a href="command-line-options.html#normalize">-normalize</a>,
888<a href="command-line-options.html#ordered-dither">-ordered-dither</a>,
889<a href="command-line-options.html#radial-blur">-radial-blur</a>,
890<a href="command-line-options.html#random-threshold">-random-threshold</a>,
891<a href="command-line-options.html#separate">-separate</a>,
892<a href="command-line-options.html#threshold">-threshold</a>, and
893<a href="command-line-options.html#white-threshold">-white-threshold</a>.
894</p>
895
Cristy594d2772015-11-15 10:47:42 -0500896<p>Warning, some operators behave differently when the <a href="command-line-options.html#channel"
897>+channel</a> default setting is in effect, verses ANY user defined <a
898href="command-line-options.html#channel" >-channel</a> setting (including the equivalent of the
Cristy882d9f42015-10-29 16:48:39 -0400899default). These operators have yet to be made to understand the newer 'Sync'
900flag. </p>
901
Cristy769d8892016-01-19 18:11:14 -0500902<p>For example <a href="command-line-options.html#threshold">-threshold</a> will by default grayscale
Cristy594d2772015-11-15 10:47:42 -0500903the image before thresholding, if no <a href="command-line-options.html#channel" >-channel</a> setting
Cristy882d9f42015-10-29 16:48:39 -0400904has been defined. This is not 'Sync flag controlled, yet. </p>
905
Cristy594d2772015-11-15 10:47:42 -0500906<p>Also some operators such as <a href="command-line-options.html#blur">-blur</a>, <a
907href="command-line-options.html#gaussian-blur">-gaussian-blur</a>, will modify their handling of the
908color channels if the '<code>alpha</code>' channel is also enabled by <a
909href="command-line-options.html#channel" >-channel</a>. Generally this done to ensure that
Cristy882d9f42015-10-29 16:48:39 -0400910fully-transparent colors are treated as being fully-transparent, and thus any
911underlying 'hidden' color has no effect on the final results. Typically
912resulting in 'halo' effects. The newer <a href="command-line-options.html#morphology">-morphology</a>
913convolution equivalents however does have a understanding of the 'Sync' flag
914and will thus handle transparency correctly by default. </p>
915
916<p>As a alpha channel is optional within images, some operators will read the
917color channels of an image as a greyscale alpha mask, when the image has no
Cristy594d2772015-11-15 10:47:42 -0500918alpha channel present, and the <a href="command-line-options.html#channel" >-channel</a> setting tells
919the operator to apply the operation using alpha channels. The <a
920href="command-line-options.html#clut">-clut</a> operator is a good example of this. </p>
Cristy882d9f42015-10-29 16:48:39 -0400921
Cristyd474b372017-02-14 12:19:13 -0500922<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400923 <h3><a id="channel-fx"></a>-channel-fx <var>expression</var></h3>
Cristyd474b372017-02-14 12:19:13 -0500924</div>
Cristy882d9f42015-10-29 16:48:39 -0400925
Cristyd474b372017-02-14 12:19:13 -0500926<p class="magick-description">exchange, extract, or copy one or more image channels.</p>
927
928<p>The expression consists of one or more channels, either mnemonic or numeric (e.g. red or 0, green or 1, etc.), separated by certain operation symbols as follows:</p>
929
Cristy49380402017-06-29 11:24:55 -0400930<pre><code>
Cristyd474b372017-02-14 12:19:13 -0500931&lt;=&gt; exchange two channels (e.g. red&lt;=&gt;blue)
932=&gt; copy one channel to another channel (e.g. red=&gt;green)
933= assign a constant value to a channel (e.g. red=50%)
934, write new image with channels in the specified order (e.g. red, green)
935; add a new output image for the next set of channel operations (e.g. red; green; blue)
936| move to the next input image for the source of channel data (e.g. | gray=>alpha)
Cristy49380402017-06-29 11:24:55 -0400937</code></pre>
Cristyd474b372017-02-14 12:19:13 -0500938
939<p>For example, to create 3 grayscale images from the red, green, and blue channels of an image, use:</p>
940
Cristy49380402017-06-29 11:24:55 -0400941<pre><code>
Cristyd474b372017-02-14 12:19:13 -0500942-channel-fx "red; green; blue"
Cristy49380402017-06-29 11:24:55 -0400943</code></pre>
Cristyd474b372017-02-14 12:19:13 -0500944
945<p>A channel without an operation symbol implies separate (i.e, semicolon).</p>
946
947<p>Here we take an sRGB image and a grayscale image and inject the grayscale image into the alpha channel:</p>
Cristy49380402017-06-29 11:24:55 -0400948<pre><code>
Cristyd474b372017-02-14 12:19:13 -0500949convert wizard.png mask.pgm -channel-fx '| gray=>alpha' wizard-alpha.png
Cristy49380402017-06-29 11:24:55 -0400950</code></pre>
Cristyd474b372017-02-14 12:19:13 -0500951<p>Use a similar command to define a read mask:</p>
Cristy49380402017-06-29 11:24:55 -0400952<pre><code>
Cristyd474b372017-02-14 12:19:13 -0500953convert wizard.png mask.pgm -channel-fx '| gray=>read-mask' wizard-mask.png
Cristy49380402017-06-29 11:24:55 -0400954</code></pre>
Cristyd474b372017-02-14 12:19:13 -0500955
956<p>Add <code>-debug pixel</code> prior to the <code>-channel-fx</code> option to track the channel morphology.</p>
Cristy882d9f42015-10-29 16:48:39 -0400957
958<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400959 <h3><a id="charcoal"></a>-charcoal <var>factor</var></h3>
Cristy882d9f42015-10-29 16:48:39 -0400960</div>
961
962<p class="magick-description">Simulate a charcoal drawing.</p>
963
Cristyd474b372017-02-14 12:19:13 -0500964
Cristy882d9f42015-10-29 16:48:39 -0400965<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400966 <h3><a id="chop"></a>-chop <var>geometry</var></h3>
Cristy882d9f42015-10-29 16:48:39 -0400967</div>
968
969<p class="magick-description">Remove pixels from the interior of an image.</p>
970
971<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. The <var>width</var>
972and <var>height</var> given in the of the <var>size</var>
973portion of the <var>geometry</var> argument give the number of
974columns and rows to remove. The <var>offset</var> portion of
975the <var>geometry</var> argument is influenced by
976a <a href="command-line-options.html#gravity">-gravity</a> setting, if present.</p>
977
978<p>The <a href="command-line-options.html#chop">-chop</a> option removes entire rows and columns,
979and moves the remaining corner blocks leftward and upward to close the gaps.</p>
980
981<p>While it can remove internal rows and columns of pixels, it is more
982typically used with as <a href="command-line-options.html#gravity">-gravity</a> setting and zero
Cristy594d2772015-11-15 10:47:42 -0500983offsets so as to remove a single edge from an image. Compare this to <a
984href="command-line-options.html#shave" >-shave</a> which removes equal numbers of pixels from opposite
Cristy882d9f42015-10-29 16:48:39 -0400985sides of the image. </p>
986
Cristy594d2772015-11-15 10:47:42 -0500987<p>Using <a href="command-line-options.html#chop">-chop</a> effectively undoes the results of a <a
988href="command-line-options.html#splice">-splice</a> that was given the same <var>geometry</var> and <a href="command-line-options.html#gravity">-gravity</a> settings. </p>
Cristy882d9f42015-10-29 16:48:39 -0400989
990<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400991 <h3><a id="clamp"></a>-clamp</h3>
Cristy882d9f42015-10-29 16:48:39 -0400992</div>
993
994<p class="magick-description">set each pixel whose value is below zero to zero and any the pixel whose value is above the quantum range to the quantum range (e.g. 65535) otherwise the pixel value remains unchanged.</p>
995
996<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -0400997 <h3><a id="clip"></a>-clip</h3>
Cristy882d9f42015-10-29 16:48:39 -0400998</div>
999
1000<p class="magick-description">Apply the clipping path if one is present.</p>
1001
1002<p>If a clipping path is present, it is applied to subsequent operations.</p>
1003
1004<p>For example, in the command</p>
1005
Cristy49380402017-06-29 11:24:55 -04001006<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04001007convert cockatoo.tif -clip -negate negated.tif
Cristy49380402017-06-29 11:24:55 -04001008</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04001009
1010<p>only the pixels within the clipping path are negated.</p>
1011
1012<p>The <a href="command-line-options.html#clip">-clip</a> feature requires SVG support. If the SVG
1013delegate library is not present, the option is ignored.</p>
1014
1015<p>Use <a href="command-line-options.html#clip">+clip</a> to disable clipping for subsequent operations.</p>
1016
1017<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001018 <h3><a id="clip-mask"></a>-clip-mask</h3>
Cristy882d9f42015-10-29 16:48:39 -04001019</div>
1020
1021<p class="magick-description">Clip the image as defined by this mask.</p>
1022
1023<p>Use the alpha channel of the current image as a mask. Any areas that is
1024white is not modified by any of the 'image processing operators' that follow,
1025until the mask is removed. Pixels in the black areas of the clip mask are
1026modified per the requirements of the operator. </p>
1027
1028<p>In some ways this is similar to (though not the same) as defining
Cristy594d2772015-11-15 10:47:42 -05001029a rectangular <a href="command-line-options.html#region" >-region</a>, or using the negative of the
1030mask (third) image in a three image <a href="command-line-options.html#composite" >-composite</a>,
Cristy882d9f42015-10-29 16:48:39 -04001031operation. </p>
1032
1033<p>Use <a href="command-line-options.html#clip-mask">+clip-mask</a> to disable clipping for subsequent operations.</p>
1034
1035<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001036 <h3><a id="clip-path"></a>-clip-path <var>id</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04001037</div>
1038
1039<p class="magick-description">Clip along a named path from the 8BIM profile.</p>
1040
1041<p>This is identical to <a href="command-line-options.html#clip">-clip</a> except choose a specific clip path in the event the image has more than one path available. </p>
1042
1043<p>Use <a href="command-line-options.html#clip-path">+clip-path</a> to disable clipping for subsequent operations.</p>
1044
1045<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001046 <h3><a id="clone"></a>-clone <var>index(s)</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04001047</div>
1048
1049<p class="magick-description">make a clone of an image (or images).</p>
1050
1051<p>Inside parenthesis (where the operator is normally used) it will make a
1052clone of the images from the last 'pushed' image sequence, and adds them to
1053the end of the current image sequence. Outside parenthesis
1054(not recommended) it clones the images from the current image sequence. </p>
1055
1056<p>Specify the image by its index in the sequence. The first image is index
10570. Negative indexes are relative to the end of the sequence; for
1058example, <code>−1</code>
1059represents the last image of the sequence. Specify a range of images with a
1060dash (e.g. <code>0−4</code>). Separate multiple indexes with commas but no
1061spaces (e.g. <code>0,2,5</code>). A value of '<code>0−−1</code> will
1062effectively clone all the images. </p>
1063
1064<p>The <a href="command-line-options.html#clone">+clone</a> will simply make a copy of the last image
1065in the image sequence, and is thus equivalent to using a argument of
1066'<code>−1</code>'. </p>
1067
1068<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001069 <h3><a id="clut"></a>-clut</h3>
Cristy882d9f42015-10-29 16:48:39 -04001070</div>
1071
1072<p class="magick-description">Replace the channel values in the first image using each corresponding channel in the second image as a <b>c</b>olor <b>l</b>ook<b>u</b>p <b>t</b>able.</p>
1073
1074<p>The second (LUT) image is ordinarily a gradient image containing the
1075histogram mapping of how each channel should be modified. Typically it is a
1076either a single row or column image of replacement color values. If larger
1077than a single row or column, values are taken from a diagonal line from
1078top-left to bottom-right corners.</p>
1079
Cristy594d2772015-11-15 10:47:42 -05001080<p>The lookup is further controlled by the <a
1081href="command-line-options.html#interpolate">-interpolate</a> setting, which is especially handy for an
Cristy882d9f42015-10-29 16:48:39 -04001082LUT which is not the full length needed by the ImageMagick installed Quality
1083(Q) level. Good settings for this are the '<code>bilinear</code>' and
1084'<code>bicubic</code>' interpolation settings, which give smooth color
1085gradients, and the '<code>integer</code>' setting for a direct, unsmoothed
1086lookup of color values. </p>
1087
1088<p>This operator is especially suited to replacing a grayscale image with a
1089specific color gradient from the CLUT image. </p>
1090
1091<p>Only the channel values defined by the <a href="command-line-options.html#channel">-channel</a>
Cristy594d2772015-11-15 10:47:42 -05001092setting will have their values replaced. In particular, since the default <a
1093href="command-line-options.html#channel">-channel</a> setting is <code>RGB</code>, this means that
1094transparency (alpha/matte channel) is not affected, unless the <a
1095href="command-line-options.html#channel">-channel</a> setting is modified. When the alpha channel is
1096set, it is treated by the <a href="command-line-options.html#clut" >-clut</a> operator in the same way
Cristy882d9f42015-10-29 16:48:39 -04001097as the other channels, implying that alpha/matte values are replaced using the
1098alpha/matte values of the original image. </p>
1099
1100<p>If either the image being modified, or the lookup image, contains no
Cristy594d2772015-11-15 10:47:42 -05001101transparency (i.e. <a href="command-line-options.html#alpha" >-alpha</a> is turned 'off') but the <a
1102href="command-line-options.html#channel">-channel</a> setting includes alpha replacement, then it is
Cristy769d8892016-01-19 18:11:14 -05001103assumed that image represents a grayscale gradient which is used for the
1104replacement alpha values. That is you can use a grayscale CLUT image to
1105adjust a existing images alpha channel, or you can color a grayscale image
Cristy882d9f42015-10-29 16:48:39 -04001106using colors form CLUT containing the desired colors, including transparency.
1107</p>
1108
Cristy594d2772015-11-15 10:47:42 -05001109<p>See also <a href="command-line-options.html#hald-clut" >-hald-clut</a> which replaces colors
Cristy882d9f42015-10-29 16:48:39 -04001110according to the lookup of the full color RGB value from a 2D representation
1111of a 3D color cube. </p>
1112
1113
1114<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001115 <h3><a id="coalesce"></a>-coalesce</h3>
Cristy882d9f42015-10-29 16:48:39 -04001116</div>
1117
1118<p class="magick-description">Fully define the look of each frame of an GIF animation sequence, to form a 'film strip' animation.</p>
1119
1120<p>Overlay each image in an image sequence according to
1121its <a href="command-line-options.html#dispose">-dispose</a> meta-data, to reproduce the look of
1122an animation at each point in the animation sequence. All images should be
1123the same size, and are assigned appropriate GIF disposal settings for the
1124animation to continue working as expected as a GIF animation. Such frames
1125are more easily viewed and processed than the highly optimized GIF overlay
1126images. </p>
1127
1128<p>The animation can be re-optimized after processing using
1129the <a href="command-line-options.html#layers">-layers</a> method '<code>optimize</code>', although
1130there is no guarantee that the restored GIF animation optimization is
1131better than the original. </p>
1132
1133
1134<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001135 <h3><a id="colorize"></a>-colorize <var>value</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04001136</div>
1137
Cristy594d2772015-11-15 10:47:42 -05001138<p class="magick-description">Colorize the image by an amount specified by <var>value</var> using the color specified by the most recent <a href="command-line-options.html#fill" >-fill</a> setting.</p>
Cristy882d9f42015-10-29 16:48:39 -04001139
1140<p>Specify the amount of colorization as a percentage. Separate colorization
1141values can be applied to the red, green, and blue channels of the image with
1142a comma-delimited list of colorization
1143values (e.g., <code>-colorize 0,0,50</code>).</p>
1144
1145<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001146 <h3><a id="colormap"></a>-colormap <var>type</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04001147</div>
1148
1149<p class="magick-description">Define the colormap type.</p>
1150
1151<p>The <var>type</var> can be <code>shared</code> or <code>private</code>.</p>
1152
1153<p>This option only applies when the default X server visual
1154is <code>PseudoColor</code> or <code>GrayScale</code>. Refer
1155to <a href="command-line-options.html#visual">-visual</a> for more details. By default,
1156a shared colormap is allocated. The image shares colors with
1157other X clients. Some image colors could be approximated,
1158therefore your image may look very different than intended.
1159If <code>private</code> is chosen, the image colors appear exactly
1160as they are defined. However, other clients may go <var>technicolor</var>
1161when the image colormap is installed.</p>
1162
1163<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001164 <h3><a id="colors"></a>-colors <var>value</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04001165</div>
1166
1167<p class="magick-description">Set the preferred number of colors in the image.</p>
1168
1169<p>The actual number of colors in the image may be less than your request,
1170but never more. Note that this a color reduction option. Images with fewer
1171unique colors than specified by <var>value</var> will have any
1172duplicate or unused colors removed. The ordering of an existing color
1173palette may be altered. When converting an image from color to grayscale,
1174it is more efficient to convert the image to the gray colorspace before
1175reducing the number of colors. Refer to
Cristy6549abb2016-11-10 08:25:55 -05001176the <a href="http://www.imagemagick.org/www/quantize.html">
Cristy882d9f42015-10-29 16:48:39 -04001177color reduction algorithm</a> for more details.</p>
1178
1179<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001180 <h3><a id="color-matrix"></a>-color-matrix <var>matrix</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04001181</div>
1182
1183<p class="magick-description">apply color correction to the image.</p>
1184
1185<p>This option permits saturation changes, hue rotation, luminance to alpha,
1186and various other effects. Although variable-sized transformation matrices
1187can be used, typically one uses a 5x5 matrix for an RGBA image and a 6x6
1188for CMYKA (or RGBA with offsets). The matrix is similar to those used by
1189Adobe Flash except offsets are in column 6 rather than 5 (in support of
1190CMYKA images) and offsets are normalized (divide Flash offset by 255).</p>
1191
1192<p>As an example, to add contrast to an image with offsets, try this command:</p>
1193
Cristy49380402017-06-29 11:24:55 -04001194<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04001195convert kittens.jpg -color-matrix \
1196 " 1.5 0.0 0.0 0.0, 0.0, -0.157 \
1197 0.0 1.5 0.0 0.0, 0.0, -0.157 \
1198 0.0 0.0 1.5 0.0, 0.0, -0.157 \
1199 0.0 0.0 0.0 1.0, 0.0, 0.0 \
1200 0.0 0.0 0.0 0.0, 1.0, 0.0 \
1201 0.0 0.0 0.0 0.0, 0.0, 1.0" kittens.png
Cristy49380402017-06-29 11:24:55 -04001202</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04001203<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001204 <h3><a id="colorspace"></a>-colorspace <var>value</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04001205</div>
1206
1207<p class="magick-description">Set the image colorspace.</p>
1208
1209<p>Choices are:</p>
1210
Cristy49380402017-06-29 11:24:55 -04001211<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04001212CMY CMYK Gray HCL
1213HCLp HSB HSI HSL
1214HSV HWB Lab LCHab
1215LCHuv LMS Log Luv
1216OHTA Rec601YCbCr Rec709YCbCr RGB
1217scRGB sRGB Transparent xyY
1218XYZ YCbCr YCC YDbDr
Cristyd474b372017-02-14 12:19:13 -05001219YIQ YPbPr YUV Undefined
Cristy49380402017-06-29 11:24:55 -04001220</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04001221
1222<p>To print a complete list of colorspaces, use <a href="command-line-options.html#list">-list colorspace</a>.</p>
1223
1224<p>For a more accurate color conversion to or from the linear RGB, CMYK, or grayscale colorspaces, use the <a href="command-line-options.html#profile">-profile</a> option. Note, ImageMagick assumes the sRGB colorspace if the image format does not indicate otherwise. For colorspace conversion, the gamma function is first removed to produce linear RGB.</p>
1225
Cristy49380402017-06-29 11:24:55 -04001226<table class="table table-sm table-striped">
Cristy882d9f42015-10-29 16:48:39 -04001227 <caption>Conversion of RGB to Other Color Spaces</caption>
1228 <tr><th valign="middle">CMY</th></tr>
1229 <tr><td valign="middle">C=<var>QuantumRange</var>−R</td></tr>
1230 <tr><td valign="middle">M=<var>QuantumRange</var>−G</td></tr>
1231 <tr><td valign="middle">Y=<var>QuantumRange</var>−B</td></tr>
1232 <tr><th valign="middle">CMYK — starts with CMY from above</th></tr>
1233 <tr><td valign="middle">K=min(C,Y,M)</td></tr>
1234 <tr><td valign="middle">C=<var>QuantumRange</var>*(C−K)/(<var>QuantumRange</var>−K)</td></tr>
1235 <tr><td valign="middle">M=<var>QuantumRange</var>*(M−K)/(<var>QuantumRange</var>−K)</td></tr>
1236 <tr><td valign="middle">Y=<var>QuantumRange</var>*(Y−K)/(<var>QuantumRange</var>−K)</td></tr>
1237
1238 <tr><th valign="middle">Gray</th></tr>
1239 <tr><td valign="middle">Gray = 0.298839*R+0.586811*G+0.114350*B</td></tr>
1240
1241 <tr><th valign="middle">HSB — Hue, Saturation, Brightness; like a cone peak downward</th></tr>
1242 <tr><td valign="middle">H=angle around perimeter (0 to 360 deg); H=0 is red; increasing angles toward green</td></tr>
1243 <tr><td valign="middle">S=distance from axis outward</td></tr>
1244 <tr><td valign="middle">B=distance along axis from bottom upward; B=max(R,G,B); <var>intensity-like</var></td></tr>
1245
1246 <tr><th valign="middle">HSL — Hue, Saturation, Lightness; like a double cone end-to-end with peaks at very top and bottom</th></tr>
1247 <tr><td valign="middle">H=angle around perimeter (0 to 360 deg); H=0 is red; increasing angles toward green</td></tr>
1248 <tr><td valign="middle">S=distance from axis outward</td></tr>
1249 <tr><td valign="middle">L=distance along axis from bottom upward; L=0.5*max(R,G,B) + 0.5*min(R,G,B); <var>intensity-like</var></td></tr>
1250
1251 <tr><th valign="middle">HWB — Hue, Whiteness, Blackness</th></tr>
1252 <tr><td valign="middle">Hue (complicated equation)</td></tr>
1253 <tr><td valign="middle">Whiteness (complicated equation)</td></tr>
1254 <tr><td valign="middle">Blackness (complicated equation)</td></tr>
1255
1256 <tr><th valign="middle">LAB</th></tr>
1257 <tr><td valign="middle">L (complicated equation relating X,Y,Z)</td></tr>
1258 <tr><td valign="middle">A (complicated equation relating X,Y,Z)</td></tr>
1259 <tr><td valign="middle">B (complicated equation relating X,Y,Z)</td></tr>
1260
1261 <tr><th valign="middle">LOG</th></tr>
1262 <tr><td valign="middle">I1 (complicated equation involving logarithm of R)</td></tr>
1263 <tr><td valign="middle">I2 (complicated equation involving logarithm of G)</td></tr>
1264 <tr><td valign="middle">I3 (complicated equation involving logarithm of B)</td></tr>
1265
1266 <tr><th valign="middle">OHTA — approximates principal components transformation</th></tr>
1267 <tr><td valign="middle">I1=0.33333*R+0.33334*G+0.33333*B; <var>intensity-like</var></td></tr>
1268 <tr><td valign="middle">I2=(0.50000*R+0.00000*G−0.50000*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1269 <tr><td valign="middle">I3=(−0.25000*R+0.50000*G−0.25000*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1270
1271 <tr><th valign="middle">Rec601Luma</th></tr>
1272 <tr><td valign="middle">Gray = 0.298839*R+0.586811*G+0.114350*B</td></tr>
1273
1274 <tr><th valign="middle">Rec601YCbCr</th></tr>
1275 <tr><td valign="middle">Y=0.2988390*R+0.5868110*G+0.1143500*B; <var>intensity-like</var></td></tr>
1276 <tr><td valign="middle">Cb=(−0.168736*R-0.331264*G+0.500000*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1277 <tr><td valign="middle">Cr=(0.500000*R−0.418688*G−0.081312*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1278
1279 <tr><th valign="middle">Rec709Luma</th></tr>
1280 <tr><td valign="middle">Gray=0.212656*R+0.715158*G+0.072186*B</td></tr>
1281
1282 <tr><th valign="middle">Rec709YCbCr</th></tr>
1283 <tr><td valign="middle">Y=0.212656*R+0.715158*G+0.072186*B; <var>intensity-like</var></td></tr>
1284 <tr><td valign="middle">Cb=(−0.114572*R−0.385428*G+0.500000*B)+(<var>QuantumRange</var>+1)/2</td></tr>
1285 <tr><td valign="middle">Cr=(0.500000*R−0.454153*G−0.045847*B)+(<var>QuantumRange</var>+1)/2</td></tr>
1286
1287 <tr><th valign="middle">sRGB</th></tr>
1288 <tr><td valign="middle">if R ≤ .0.0031308 then Rs=R/12.92 else Rs=1.055 R ^ (1.0 / 2.4) ? 0.055</td></tr>
1289 <tr><td valign="middle">if G ≤ .0.0031308 then Gs=B/12.92 else Gs=1.055 R ^ (1.0 / 2.4) ? 0.055</td></tr>
1290 <tr><td valign="middle">if B ≤ .0.0031308 then Bs=B/12.92 else Bs=1.055 R ^ (1.0 / 2.4) ? 0.055</td></tr>
1291
1292 <tr><th valign="middle">XYZ</th></tr>
1293 <tr><td valign="middle">X=0.4124564*R+0.3575761*G+0.1804375*B</td></tr>
1294 <tr><td valign="middle">Y=0.2126729*R+0.7151522*G+0.0721750*B</td></tr>
1295 <tr><td valign="middle">Z=0.0193339*R+0.1191920*G+0.9503041*B</td></tr>
1296
1297 <tr><th valign="middle">YCC</th></tr>
1298 <tr><td valign="middle">Y=(0.298839*R+0.586811*G+0.114350*B) (with complicated scaling); <var>intensity-like</var></td></tr>
1299 <tr><td valign="middle">C1=(−0.298839*R−0.586811*G+0.88600*B) (with complicated scaling)</td></tr>
1300 <tr><td valign="middle">C2=(0.70100*R−0.586811*G−0.114350*B) (with complicated scaling)</td></tr>
1301
1302 <tr><th valign="middle">YCbCr</th></tr>
1303 <tr><td valign="middle">Y=0.2988390*R+0.5868110*G+0.1143500*B; <var>intensity-like</var></td></tr>
1304 <tr><td valign="middle">Cb=(−0.168736*R−0.331264*G+0.500000*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1305 <tr><td valign="middle">Cr=(0.500000*R−0.418688*G−0.081312*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1306
1307 <tr><th valign="middle">YIQ</th></tr>
1308 <tr><td valign="middle">Y=0.298839*R+0.586811*G+0.114350*B; <var>intensity-like</var></td></tr>
1309 <tr><td valign="middle">I=(0.59600*R−0.27400*G−0.32200*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1310 <tr><td valign="middle">Q=(0.21100*R−0.52300*G+0.31200*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1311
1312 <tr><th valign="middle">YPbPr</th></tr>
1313 <tr><td valign="middle">Y=0.2988390*R+0.5868110*G+0.1143500*B; <var>intensity-like</var></td></tr>
1314 <tr><td valign="middle">Pb=(−0.168736*R−0.331264*G+0.500000*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1315 <tr><td valign="middle">Pr=(0.500000*R−0.418688*G−0.081312*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1316
1317 <tr><th valign="middle">YUV</th></tr>
1318 <tr><td valign="middle">Y=0.298839*R+0.586811*G+0.114350*B; <var>intensity-like</var></td></tr>
1319 <tr><td valign="middle">U=(−0.14740*R−0.28950*G+0.43690*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1320 <tr><td valign="middle">V=(0.61500*R−0.51500*G−0.10000*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1321</table>
1322
1323<p>Note the scRGB colorspace requires HDRI support otherwise it behaves just like linear RGB.</p>
1324
Cristyd474b372017-02-14 12:19:13 -05001325<p>Use the <code>Undefined</code> colorspace to identify multi-spectral images.</p>
1326
Cristy882d9f42015-10-29 16:48:39 -04001327<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001328 <h3><a id="combine"></a>-combine</h3>
1329 <h3>+combine <var>colorspace</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04001330</div>
1331
1332<p class="magick-description">Combine one or more images into a single image.</p>
1333
1334<p>The channels (previously set by <a href="command-line-options.html#channel">-channel</a>) of the
1335combined image are taken from the grayscale values of each image in the
1336sequence, in order. For the default -channel setting of <code>RGB</code>, this
1337means the first image is assigned to the <code>Red</code> channel, the second
1338to the <code>Green</code> channel, the third to the <code>Blue</code>.</p>
1339
Cristy594d2772015-11-15 10:47:42 -05001340<p>This option can be thought of as the inverse to <a
1341href="command-line-options.html#separate">-separate</a>, so long as the channel settings are the same.
Cristy882d9f42015-10-29 16:48:39 -04001342Thus, in the following example, the final image should be a copy of the
1343original. </p>
1344
Cristy49380402017-06-29 11:24:55 -04001345<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04001346convert original.png -channel RGB -separate sepimage.png
1347convert sepimage-0.png sepimage-1.png sepimage-2.png -channel RGB \
1348 -combine imagecopy.png
Cristy49380402017-06-29 11:24:55 -04001349</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04001350
1351<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001352 <h3><a id="comment"></a>-comment <var>string</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04001353</div>
1354
1355<p class="magick-description">Embed a comment in an image.</p>
1356
1357<p>This option sets the comment meta-data of an image read in after this
1358option has been given. To modify a comment of images already in memory use
1359"<code><a href="command-line-options.html#set">-set</a> comment</code>". </p>
1360
Cristy594d2772015-11-15 10:47:42 -05001361<p>The comment can contain special format characters listed in the <a
1362href="escape.html">Format and
Cristy882d9f42015-10-29 16:48:39 -04001363Print Image Properties</a>. These attributes are expanded when the comment
1364is finally assigned to the individual images. </p>
1365
1366<p>If the first character of <var>string</var> is <var>@</var>, the image comment is read from a file titled by the
1367remaining characters in the string. Comments read in from a file are literal;
1368no embedded formatting characters are recognized.</p>
1369
1370<p>Comment meta-data are not visible on the image itself. To do that use the
1371<a href="command-line-options.html#annotate">-annotate</a> or <a href="command-line-options.html#draw">-draw</a> options
1372instead.</p>
1373
1374<p>For example,</p>
1375
Cristy49380402017-06-29 11:24:55 -04001376<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04001377-comment "%m:%f %wx%h" bird.miff
Cristy49380402017-06-29 11:24:55 -04001378</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04001379
1380<p>produces an image comment of <code>MIFF:bird.miff 512x480</code> (assuming
1381that the image <code>bird.miff</code> has a width of 512 and a height of
1382480.</p>
1383
1384<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001385 <h3><a id="compare"></a>-compare</h3>
Cristy882d9f42015-10-29 16:48:39 -04001386</div>
1387
1388<p class="magick-description">mathematically and visually annotate the difference between an image and its reconstruction</p>
1389
1390<p>This is a convert version of "<code>compare</code>" for two same sized images. The syntax is as follows, but other metrics are allowed.</p>
1391
Cristy49380402017-06-29 11:24:55 -04001392<pre><code>
Cristy594d2772015-11-15 10:47:42 -05001393convert image.png reference.png -metric RMSE -compare \ <br/> difference.png
Cristy49380402017-06-29 11:24:55 -04001394</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04001395
1396<p>To get the metric value use the string format "%[distortion]".</p>
1397
Cristy49380402017-06-29 11:24:55 -04001398<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04001399convert image.png reference.png -metric RMSE -compare -format \
1400 "%[distortion]" info:
Cristy49380402017-06-29 11:24:55 -04001401</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04001402
1403<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001404 <h3><a id="complex"></a>-complex <var>operator</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04001405</div>
1406
1407<p class="magick-description">perform complex mathematics on an image sequence</p>
1408
1409Choose from these operators:
1410
Cristy49380402017-06-29 11:24:55 -04001411<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04001412add
1413conjugate
1414divide
1415magnitude-phase
1416multiply
1417real-imaginary
1418subtract
Cristy49380402017-06-29 11:24:55 -04001419</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04001420
1421<p>Optionally specify the <code>divide</code> operator SNR with <code><a href="command-line-options.html#define">-define</a> complex:snr=float</code>.</p>
1422
1423<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001424 <h3><a id="compose"></a>-compose <var>operator</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04001425</div>
1426
1427<p class="magick-description">Set the type of image composition.</p>
1428
Cristy6549abb2016-11-10 08:25:55 -05001429<p>See <a href="http://www.imagemagick.org/www/compose.html">Alpha Compositing</a> for
Cristy882d9f42015-10-29 16:48:39 -04001430a detailed discussion of alpha compositing.</p>
1431
1432<p>This setting effects image processing operators that merge two (or more)
1433images together in some way. This includes the operators,
1434<a href="command-line-options.html#composite">-compare</a>,
1435<a href="command-line-options.html#composite">-composite</a>,
1436<a href="command-line-options.html#layers">-layers</a> composite,
1437<a href="command-line-options.html#flatten">-flatten</a>,
1438<a href="command-line-options.html#mosaic">-mosaic</a>,
1439<a href="command-line-options.html#layers">-layers</a> merge,
1440<a href="command-line-options.html#border">-border</a>,
1441<a href="command-line-options.html#frame">-frame</a>,
1442and <a href="command-line-options.html#extent">-extent</a>. </p>
1443
1444<p>It is also one of the primary options for the "<code>composite</code>"
1445command. </p>
1446
1447
1448<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001449 <h3><a id="composite"></a>-composite</h3>
Cristy882d9f42015-10-29 16:48:39 -04001450</div>
1451
1452<p class="magick-description">Perform alpha composition on two images and an optional mask</p>
1453
1454<p>Take the first image 'destination' and overlay the second 'source' image
1455according to the current <a href="command-line-options.html#compose">-compose</a> setting. The location
Cristy594d2772015-11-15 10:47:42 -05001456of the 'source' or 'overlay' image is controlled according to <a
Cristye93be682015-11-26 09:07:51 -05001457href="command-line-options.html#gravity" >-gravity</a>, and <a href="command-line-options.html#geometry" >-geometry</a>
Cristy882d9f42015-10-29 16:48:39 -04001458settings. </p>
1459
Cristy769d8892016-01-19 18:11:14 -05001460<p>If a third image is given this is treated as a grayscale blending 'mask' image
Cristy882d9f42015-10-29 16:48:39 -04001461relative to the first 'destination' image. This mask is blended with the
1462source image. However for the '<code>displace</code>' compose method, the
1463mask is used to provide a separate Y-displacement image instead. </p>
1464
1465<p>If a <a href="command-line-options.html#compose">-compose</a> method requires extra numerical
Cristy594d2772015-11-15 10:47:42 -05001466arguments or flags these can be provided by setting the <a
1467href="command-line-options.html#set">-set</a> '<code>option:compose:args</code>'
Cristy882d9f42015-10-29 16:48:39 -04001468appropriately for the compose method. </p>
1469
1470<p>Some <a href="command-line-options.html#compose">-compose</a> methods can modify the 'destination'
Cristy594d2772015-11-15 10:47:42 -05001471image outside the overlay area. You can disable this by setting the special <a
1472href="command-line-options.html#set">-set</a> '<code>option:compose:outside-overlay</code>'
Cristy882d9f42015-10-29 16:48:39 -04001473to '<code>false</code>'. </p>
1474
1475<p>The SVG compositing specification requires that color and opacity values range between zero and QuantumRange inclusive. You can permit values outside this range with this option: <a href="command-line-options.html#set">-set</a> '<code>option:compose:clamp=false</code></p>
1476
1477
1478<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001479 <h3><a id="compress"></a>-compress <var>type</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04001480</div>
1481
1482<p class="magick-description">Use pixel compression specified by <var>type</var> when writing the image.</p>
1483
Cristy594d2772015-11-15 10:47:42 -05001484<p>Choices are: <code>None</code>, <code>BZip</code>, <code
1485>Fax</code>, <code>Group4</code>, <code
1486>JPEG</code>, <code>JPEG2000</code>, <code
1487>Lossless</code>, <code>LZW</code>, <code
1488>RLE</code> or <code>Zip</code>.</p>
Cristy882d9f42015-10-29 16:48:39 -04001489
1490<p>To print a complete list of compression types, use <a href="command-line-options.html#list">-list
1491compress</a>.</p>
1492
1493<p>Specify <a href="command-line-options.html#compress">+compress</a> to store the binary image in an
1494uncompressed format. The default is the compression type of the specified
1495image file.</p>
1496
1497<p>If <code>LZW</code> compression is specified but LZW compression has not been
1498enabled, the image data is written in an uncompressed LZW format that can be
1499read by LZW decoders. This may result in larger-than-expected GIF files.</p>
1500
1501<p><code>Lossless</code> refers to lossless JPEG, which is only available if the
1502JPEG library has been patched to support it. Use of lossless JPEG is generally
1503not recommended.</p>
1504
1505<p>
1506When writing an ICO file, you may request that the images be encoded in
1507PNG format, by specifying <code>Zip</code> compression.</p>
1508
1509<p>
1510When writing a JNG file, specify <code>Zip</code> compression to request that
1511the alpha channel be encoded in PNG "IDAT" format, or <code>JPEG</code>
1512to request that it be encoded in JPG "JDAA" format.</p>
1513
1514<p>Use the <a href="command-line-options.html#quality">-quality</a> option to set the compression level
1515to be used by JPEG, PNG, MIFF, and MPEG encoders.
1516Use the <a href="command-line-options.html#sampling-factor">-sampling-factor</a> option to set the
1517sampling factor to be used by JPEG, MPEG, and YUV encoders for down-sampling
1518the chroma channels.</p>
1519
1520<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001521 <h3><a id="connected-components"></a>-connected-components <var>connectivity</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04001522</div>
1523
Cristyce4a3552015-12-14 13:53:35 -05001524<p class="magick-description"><a href="connected-components.html">connected-components</a> labeling detects connected regions in an image, choose from 4 or 8 way connectivity.</p>
Cristy882d9f42015-10-29 16:48:39 -04001525
Cristy594d2772015-11-15 10:47:42 -05001526<p>Use <code><a href="command-line-options.html#define" >-define</a> connected-components:verbose=true</code> to output statistics associated with each unique label.</p>
Cristy882d9f42015-10-29 16:48:39 -04001527
1528<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001529 <h3><a id="contrast"></a>-contrast</h3>
Cristy882d9f42015-10-29 16:48:39 -04001530</div>
1531
1532<p class="magick-description">Enhance or reduce the image contrast.</p>
1533
1534<p>This option enhances the intensity differences between the lighter and
1535darker elements of the image. Use <a href="command-line-options.html#contrast">-contrast</a> to enhance
1536the image or <a href="command-line-options.html#contrast">+contrast</a> to reduce the image
1537contrast.</p>
1538
1539<p>For a more pronounced effect you can repeat the option:</p>
1540
Cristy49380402017-06-29 11:24:55 -04001541<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04001542convert rose: -contrast -contrast rose_c2.png
Cristy49380402017-06-29 11:24:55 -04001543</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04001544
1545<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001546 <h3><a id="contrast-stretch"></a>-contrast-stretch <var>black-point</var><br />-contrast-stretch <var>black-point</var>{x<var>white-point</var>}{<var>%</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -04001547</div>
1548
1549<p class="magick-description">Increase the contrast in an image by <var>stretching</var> the range of intensity values.</p>
1550
1551<p>While performing the stretch, black-out at most <var>black-point</var> pixels and white-out at most <var>white-point</var> pixels. Or, if percent is used, black-out at most
Cristy594d2772015-11-15 10:47:42 -05001552<var >black-point %</var> pixels and white-out at most <var>white-point %</var> pixels.</p>
Cristy882d9f42015-10-29 16:48:39 -04001553
Cristy594d2772015-11-15 10:47:42 -05001554<p>Prior to ImageMagick 6.4.7-0, <a href="command-line-options.html#contrast-stretch"
1555>-contrast-stretch</a> will black-out at most <var>black-point</var> pixels and white-out at most <var >total pixels
Cristy882d9f42015-10-29 16:48:39 -04001556minus white-point</var> pixels. Or, if percent is used, black-out at most <var>black-point %</var> pixels and white-out at most <var>100% minus white-point %</var> pixels.</p>
1557
1558<p>Note that <code>-contrast-stretch 0</code> will modify the image such that
1559the image's min and max values are stretched to 0 and <var>QuantumRange</var>, respectively, without any loss of data due to burn-out or
Cristy594d2772015-11-15 10:47:42 -05001560clipping at either end. This is not the same as <a href="command-line-options.html#normalize"
1561>-normalize</a>, which is equivalent to <code>-contrast-stretch 0.15x0.05%</code> (or
Cristy882d9f42015-10-29 16:48:39 -04001562prior to ImageMagick 6.4.7-0, <code>-contrast-stretch 2%x99%</code>).</p>
1563
1564<p>Internally operator works by creating a histogram bin, and then uses that
1565bin to modify the image. As such some colors may be merged together when they
1566originally fell into the same 'bin'. </p>
1567
Cristy769d8892016-01-19 18:11:14 -05001568<p>All the channels are normalized in concert by the same amount so as to
Cristy594d2772015-11-15 10:47:42 -05001569preserve color integrity, when the default <a href="command-line-options.html#channel" >+channel</a>
1570setting is in use. Specifying any other <a href="command-line-options.html#channel" >-channel</a>
Cristy882d9f42015-10-29 16:48:39 -04001571setting will normalize the RGB channels independently.</p>
1572
Cristy594d2772015-11-15 10:47:42 -05001573<p>See also <a href="command-line-options.html#auto-level" >-auto-level</a> for a 'perfect'
Cristy882d9f42015-10-29 16:48:39 -04001574normalization of mathematical images. </p>
1575
1576<p>This operator is under review for re-development. </p>
1577
1578
1579<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001580 <h3><a id="convolve"></a>-convolve <var>kernel</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04001581</div>
1582
1583<p class="magick-description">Convolve an image with a user-supplied convolution kernel.</p>
1584
1585<p>The <var>kernel</var> is a matrix specified as
1586a comma-separated list of integers (with no spaces), ordered left-to right,
1587starting with the top row. Presently, only odd-dimensioned kernels are
1588supported, and therefore the number of entries in the specified <var>kernel</var> must be 3<sup>2</sup>=9, 5<sup>2</sup>=25,
15897<sup>2</sup>=49, etc. </p>
1590
Cristy594d2772015-11-15 10:47:42 -05001591<p>Note that the <a href="command-line-options.html#convolve">&#x2011;convolve</a> operator supports the <a href="command-line-options.html#bias">&#x2011;bias</a> setting. This option shifts the convolution so that
Cristy882d9f42015-10-29 16:48:39 -04001592positive and negative results are relative to a user-specified bias value.
1593This is important for non-HDRI compilations of ImageMagick when dealing with
1594convolutions that contain negative as well as positive values. This is
1595especially the case with convolutions involving high pass filters or edge
1596detection. Without an output bias, the negative values is clipped at zero.
1597</p>
1598
Cristy594d2772015-11-15 10:47:42 -05001599<p>When using an ImageMagick with the HDRI compile-time setting, <a href="command-line-options.html#bias">&#x2011;bias</a> is not needed, as ImageMagick is able to store/handle any
Cristy882d9f42015-10-29 16:48:39 -04001600negative results without clipping to the color value range (0..QuantumRange).
Cristy594d2772015-11-15 10:47:42 -05001601See the discussion on HDRI implementations of ImageMagick on the page <a
1602href="high-dynamic-range.html">High
1603Dynamic-Range Images</a>. For more about HDRI go the ImageMagick <a
Cristy364a72f2016-11-04 22:38:41 -04001604href="https://www.imagemagick.org/Usage/basics/#hdri">Usage</a> pages or this
Cristy882d9f42015-10-29 16:48:39 -04001605<a href="http://en.wikipedia.org/wiki/High_dynamic_range_imaging">Wikipedia</a>
1606entry. </p>
1607
1608
1609<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001610 <h3><a id="copy"></a>-copy <var>geometry</var> <var>offset</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04001611</div>
1612
1613<p class="magick-description">copy pixels from one area of an image to another.</p>
1614
1615<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001616 <h3><a id="crop"></a>-crop <var>geometry</var>{<var>@</var>}{<var>!</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -04001617</div>
1618
1619<p class="magick-description">Cut out one or more rectangular regions of the image.</p>
1620
1621<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
1622
1623<p>The <var>width</var> and <var>height</var> of the <var>geometry</var> argument give the size of the image that remains
1624after cropping, and <var>x</var> and <var>y</var> in the
1625<var>offset</var> (if present) gives the location of the top left
1626corner of the cropped image with respect to the original image. To specify the
1627amount to be removed, use <a href="command-line-options.html#shave">-shave</a> instead.</p>
1628
1629<p>If the <var>x</var> and <var>y</var> offsets are
1630present, a single image is generated, consisting of the pixels from the
1631cropping region. The offsets specify the location of the upper left corner of
1632the cropping region measured downward and rightward with respect to the upper
1633left corner of the image. If the <a href="command-line-options.html#gravity">-gravity</a> option is
1634present with <code>NorthEast</code>, <code>East</code>, or <code>SouthEast</code>
1635gravity, it gives the distance leftward from the right edge of the image to
Cristy594d2772015-11-15 10:47:42 -05001636the right edge of the cropping region. Similarly, if the <a
1637href="command-line-options.html#gravity">-gravity</a> option is present with <code>SouthWest</code>,
Cristy882d9f42015-10-29 16:48:39 -04001638<code>South</code>, or <code>SouthEast</code> gravity, the distance is measured
1639upward between the bottom edges.</p>
1640
1641<p>If the <var>x</var> and <var>y</var> offsets are
1642omitted, a set of tiles of the specified geometry, covering the entire input
1643image, is generated. The rightmost tiles and the bottom tiles are smaller if
1644the specified geometry extends beyond the dimensions of the input image.</p>
1645
1646<p>You can add the <var>@</var> to the geometry argument to equally divide the image into the number of tiles generated.</p>
1647
1648<p>By adding a exclamation character flag to the geometry argument, the
1649cropped images virtual canvas page size and offset is set as if the
1650geometry argument was a viewport or window. This means the canvas page size
1651is set to exactly the same size you specified, the image offset set
1652relative top left corner of the region cropped. </p>
1653
1654<p>If the cropped image 'missed' the actual image on its virtual canvas, a
1655special single pixel transparent 'missed' image is returned, and a 'crop
1656missed' warning given. </p>
1657
Cristy594d2772015-11-15 10:47:42 -05001658<p>It might be necessary to <a href="command-line-options.html#repage" >+repage</a> the image prior to
Cristy882d9f42015-10-29 16:48:39 -04001659cropping the image to ensure the crop coordinate frame is relocated to the
1660upper-left corner of the visible image.
1661
Cristy594d2772015-11-15 10:47:42 -05001662Similarly you may want to use <a href="command-line-options.html#repage" >+repage</a> after cropping to
Cristy882d9f42015-10-29 16:48:39 -04001663remove the page offset that will be left behind. This is especially true when
1664you are going to write to an image format such as PNG that supports an image
1665offset.</p>
1666
1667<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001668 <h3><a id="cycle"></a>-cycle <var>amount</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04001669</div>
1670
1671<p class="magick-description">displace image colormap by amount.</p>
1672
1673<p><var>Amount</var> defines the number of positions each
1674colormap entry is shifted.</p>
1675
1676
1677<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001678 <h3><a id="debug"></a>-debug <var>events</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04001679</div>
1680
1681<p class="magick-description">enable debug printout.</p>
1682
1683<p>The <code>events</code> parameter specifies which events are to be logged. It
1684can be either <code>None</code>, <code>All</code>, <code>Trace</code>, or
1685a comma-separated list consisting of one or more of the following domains:
1686<code>Accelerate</code>, <code>Annotate</code>, <code>Blob</code>, <code>Cache</code>,
1687<code>Coder</code>, <code>Configure</code>, <code>Deprecate</code>,
1688<code>Exception</code>, <code>Locale</code>, <code>Render</code>,
1689<code>Resource</code>, <code>Security</code>, <code>TemporaryFile</code>,
1690<code>Transform</code>, <code>X11</code>, or <code>User</code>. </p>
1691
1692
1693<p>For example, to log cache and blob events, use.</p>
1694
Cristy49380402017-06-29 11:24:55 -04001695<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04001696convert -debug "Cache,Blob" rose: rose.png
Cristy49380402017-06-29 11:24:55 -04001697</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04001698
1699<p>The <code>User</code> domain is normally empty, but developers can log user
1700events in their private copy of ImageMagick.</p>
1701
1702<p>To print the complete list of debug methods, use <a href="command-line-options.html#list">-list
1703debug</a>.</p>
1704
1705<p>Use the <a href="command-line-options.html#log">-log</a> option to specify the format for debugging
1706output.</p>
1707
1708<p>Use <a href="command-line-options.html#debug">+debug</a> to turn off all logging.</p>
1709
Cristy594d2772015-11-15 10:47:42 -05001710<p>Debugging may also be set using the <code>MAGICK_DEBUG</code> <a href="resources.html#environment"
1711>environment variable</a>. The allowed values for the <code>MAGICK_DEBUG</code>
Cristy882d9f42015-10-29 16:48:39 -04001712environment variable are the same as for the <a href="command-line-options.html#debug">-debug</a>
1713option.</p>
1714
1715
1716<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001717 <h3><a id="decipher"></a>-decipher <var>filename</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04001718</div>
1719
1720<p class="magick-description">Decipher and restore pixels that were previously transformed by <a href="command-line-options.html#encipher">-encipher</a>.</p>
1721
1722<p>Get the passphrase from the file specified by <var>filename</var>.</p>
1723
Cristy594d2772015-11-15 10:47:42 -05001724<p>For more information, see the webpage, <a
Cristy6549abb2016-11-10 08:25:55 -05001725href="https://www.imagemagick.org/script/cipher.html">ImageMagick: Encipher or
Cristy882d9f42015-10-29 16:48:39 -04001726Decipher an Image</a>.</p>
1727
1728
1729<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001730 <h3><a id="deconstruct"></a>-deconstruct</h3>
Cristy882d9f42015-10-29 16:48:39 -04001731</div>
1732
1733<p class="magick-description">find areas that has changed between images </p>
1734
Cristy594d2772015-11-15 10:47:42 -05001735<p>Given a sequence of images all the same size, such as produced by <a
1736href="command-line-options.html#coalesce">-coalesce</a>, replace the second and later images, with
Cristy882d9f42015-10-29 16:48:39 -04001737a smaller image of just the area that changed relative to the previous image.
1738</p>
1739
1740<p>The resulting sequence of images can be used to optimize an animation
1741sequence, though will not work correctly for GIF animations when parts of the
1742animation can go from opaque to transparent. </p>
1743
1744<p>This option is actually equivalent to the <a href="command-line-options.html#layers">-layers</a>
1745method '<code>compare-any</code>'. </p>
1746
1747
1748<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04001749 <h3><a id="define"></a>-define <var>key</var>{<var>=value</var>}<var>...</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04001750</div>
1751
1752<p class="magick-description">add specific global settings generally used to control coders and image processing operations.</p>
1753
1754<p>This option creates one or more definitions for coders and decoders to use
1755while reading and writing image data. Definitions are generally used to
1756control image file format coder modules, and image processing operations,
Cristy594d2772015-11-15 10:47:42 -05001757beyond what is provided by normal means. Defined settings are listed in <a
1758href="command-line-options.html#verbose" >-verbose</a> information ("<code>info:</code>" output format)
Cristy882d9f42015-10-29 16:48:39 -04001759as "Artifacts". </p>
1760
1761<p>If <var>value</var> is missing for a definition, an empty-valued
1762definition of a flag is created with that name. This used to control on/off
1763options. Use <a href="command-line-options.html#define">+define key</a> to remove definitions
1764previously created. Use <a href="command-line-options.html#define">+define "*"</a> to remove all
1765existing definitions.</p>
1766
Cristy594d2772015-11-15 10:47:42 -05001767<p>The same 'artifact' settings can also be defined using the <a
1768href="command-line-options.html#set" >-set "option:<var>key</var>" "<var>value</var>"</a> option, which also allows the use of <a href="escape.html" >Format and Print Image
Cristy882d9f42015-10-29 16:48:39 -04001769Properties</a> in the defined value. </p>
1770
1771<p>The <var>option</var> and <var>key</var> are case-independent (they are
1772converted to lowercase for use within the decoders) while the <var>value</var>
1773is case-dependent.</p>
1774
1775<p>Such settings are global in scope, and affect all images and operations. </p>
1776
1777<p>The following definitions are just some of the artifacts that are
1778available:</p>
1779
Cristy49380402017-06-29 11:24:55 -04001780<table class="table table-sm table-striped">
Cristy882d9f42015-10-29 16:48:39 -04001781 <tr>
Cristye0779712016-07-30 17:25:22 -04001782 <td>bmp:alpha=<var>true|false</var></td>
1783 <td>include any alpha channel when writing in the BMP image format.</td>
1784 </tr>
1785
1786 <tr>
Cristy882d9f42015-10-29 16:48:39 -04001787 <td>bmp:format=<var>value</var></td>
1788 <td> valid values are <var>bmp2</var>, <var>bmp3</var>,
1789 and <var>bmp4</var>. This option can be useful when the
1790 method of prepending "BMP2:" to the output filename is inconvenient or
1791 is not available, such as when using the <a href="mogrify.html">mogrify</a> utility.</td>
1792 </tr>
1793
1794 <tr>
1795 <td>colorspace:auto-grayscale=<var>on|off</var></td>
Cristyd474b372017-02-14 12:19:13 -05001796 <td>prevent automatic conversion to grayscale inside coders that support
1797 grayscale. This should be accompanied by -type truecolor. PNG and TIF do
1798 not need this define. With PNG, just use PNG24:image. With TIF, just use
1799 -type truecolor. JPG and PSD will need this define.</td>
Cristy882d9f42015-10-29 16:48:39 -04001800 </tr>
1801
1802 <tr>
1803 <td>complex:snr=<var>value</var></td>
1804 <td>Set the divide SNR constant<a href="command-line-options.html#complex">-complex</a></td>
1805 </tr>
1806
1807 <tr>
1808 <td>compose:args=<var>arguments</var></td>
1809 <td>Sets certain compose argument values when using convert ... -compose ...
Cristy1f1f3a02016-06-01 07:25:42 -04001810 -composite. See <a href="compose.html"
Cristy594d2772015-11-15 10:47:42 -05001811 >Image Composition</a></td>
Cristy882d9f42015-10-29 16:48:39 -04001812 </tr>
1813
1814 <tr>
1815 <td>compose:clamp=<var>on|off</var></td>
Cristyd474b372017-02-14 12:19:13 -05001816 <td>set each pixel whose value is below zero to zero and any the pixel
1817 whose value is above the quantum range to the quantum range (e.g. 65535)
1818 otherwise the pixel value remains unchanged. Define supported in
Cristybc232422016-11-22 07:46:18 -05001819 ImageMagick 6.9.1-3 and above.</td>
Cristy882d9f42015-10-29 16:48:39 -04001820 </tr>
1821
1822 <tr>
Cristyde27d762016-01-02 12:56:44 -05001823 <td>connected-components:area-threshold=<var>value</var></td>
1824 <td>Merges any region with area smaller than <var>value</var> into its surrounding region or largest neighbor.</td>
1825 </tr>
1826
1827 <tr>
1828 <td>connected-components:keep=<var>list-of-ids</var></td>
Cristybc232422016-11-22 07:46:18 -05001829 <td>Comma and/or hyphenated list of id values to keep in the output.
1830 Supported in Imagemagick 6.9.3-0.</td>
Cristyde27d762016-01-02 12:56:44 -05001831 </tr>
1832
1833 <tr>
1834 <td>connected-components:mean-color=<var>true</var></td>
Cristybc232422016-11-22 07:46:18 -05001835 <td>Changes the output image from id values to mean color values. Supported
1836 in Imagemagick 6.9.2-8.</td>
Cristyde27d762016-01-02 12:56:44 -05001837 </tr>
1838
1839 <tr>
1840 <td>connected-components:remove=<var>list-of-ids</var></td>
Cristybc232422016-11-22 07:46:18 -05001841 <td>Comma and/or hyphenated list of id values to remove from the output.
1842 Supported in Imagemagick 6.9.2-9.</td>
Cristyde27d762016-01-02 12:56:44 -05001843 </tr>
1844
1845 <tr>
1846 <td>connected-components:verbose=<var>true</var></td>
1847 <td>Lists id, bounding box, centroid, area, mean color for each region.</td>
1848 </tr>
1849
1850 <tr>
Cristy882d9f42015-10-29 16:48:39 -04001851 <td>convolve:scale=<var>{kernel_scale}[!^] [,{origin_addition}] [%]</var></td>
1852 <td>Defines the kernel scaling. The special flag ! automatically scales to
1853 full dynamic range. The ! flag can be used in combination with a factor or
1854 percent. The factor or percent is then applied after the automatic scaling.
1855 An example is 50%!. This produces a result 50% darker than full dynamic
1856 range scaling. The ^ flag assures the kernel is 'zero-summing', for
1857 example when some values are positive and some are negative as in edge
1858 detection kernels. The origin addition adds that value to the center
1859 pixel of the kernel. This produces and effect that is like adding the image
1860 that many times to the result of the filtered image. The typical value
1861 is 1 so that the original image is added to the result of the convolution.
1862 The default is 0.</td>
1863 </tr>
1864
1865 <tr>
1866 <td>convolve:showkernel=<var>1</var></td>
Cristy594d2772015-11-15 10:47:42 -05001867 <td>Outputs (to 'standard error') all the information about a specified <a
1868 href="command-line-options.html#morphology" >-morphology convolve</a> kernel.</td>
Cristy882d9f42015-10-29 16:48:39 -04001869 </tr>
1870
1871 <tr>
1872 <td>dcm:display-range=<var>reset</var></td>
1873 <td>Sets the display range to the minimum and maximum pixel values for the
1874 DCM image format.</td>
1875 </tr>
1876
1877 <tr>
1878 <td>dds:cluster-fit=<var>true|false</var></td>
1879 <td>Enables the dds cluster-fit.</td>
1880 </tr>
1881
1882 <tr>
1883 <td>dds:compression=<var>dxt1|dxt5|none</var></td>
1884 <td>Sets the dds compression.</td>
1885 </tr>
1886
1887 <tr>
1888 <td>dds:mipmaps=<var>value</var></td>
1889 <td>Sets the dds number of mipmaps.</td>
1890 </tr>
1891
1892 <tr>
Cristy3b0b58d2016-11-06 07:40:23 -05001893 <td>dds:weight-by-alpha=<var>true|false</var></td>
Cristy882d9f42015-10-29 16:48:39 -04001894 <td>Enables the dds alpha weighting.</td>
1895 </tr>
1896
1897 <tr>
Cristy3b0b58d2016-11-06 07:40:23 -05001898 <td>deskew:auto-crop=<var>true</var></td>
1899 <td>auto crop the image after deskewing.</td>
1900 </tr>
1901
1902 <tr>
Cristy882d9f42015-10-29 16:48:39 -04001903 <td>delegate:bimodal=<var>true</var></td>
1904 <td>Specifies direct conversion from Postscript to PDF.</td>
1905 </tr>
1906
1907 <tr>
1908 <td>distort:scale=<var>value</var></td>
Cristy594d2772015-11-15 10:47:42 -05001909 <td>Sets the output scaling factor for use with <a href="command-line-options.html#distort"
1910 >-distort</a></td>
Cristy882d9f42015-10-29 16:48:39 -04001911 </tr>
1912
1913 <tr>
1914 <td>distort:viewport=<var>WxH+X+Y</var></td>
1915 <td>Sets the viewport for use with <a href="command-line-options.html#distort">-distort</a></td>
1916 </tr>
1917
1918 <tr>
1919 <td>dot:layout-engine=<var>value</var></td>
1920 <td>Specifies the layout engine for the DOT image format (e.g.
1921 <code>neato</code>).</td>
1922 </tr>
1923
1924 <tr>
Cristyf41bcd12017-03-28 05:59:57 -04001925 <td>exr:color-type=<var>value</var></td>
1926 <td>Specifies the color type for the EXR format: RGB, RGBA, YC, YCA, Y, YA, R, G, B, A).</td>
1927 </tr>
1928
1929 <tr>
Cristy882d9f42015-10-29 16:48:39 -04001930 <td>filter:option=<var>value</var></td>
1931 <td>Set a filter option for use with <a href="command-line-options.html#resize">-resize</a>.
1932 See <a href="command-line-options.html#filter">-filter</a> for details.</td>
1933 </tr>
1934
1935 <tr>
1936 <td>fourier:normalize=<var>inverse</var></td>
1937 <td>Sets the location for the FFT/IFT normalization as use by
1938 <a href="command-line-options.html#fft">+-fft</a> and <a href="command-line-options.html#ift">+-ift</a>. The default is
1939 <var>forward</var>.</td>
1940 </tr>
1941
1942 <tr>
1943 <td>h:format=<var>value</var></td>
1944 <td>Set the image encoding format use when writing a C-style header.
1945 <var>format</var> can be any output format supported by ImageMagick
Cristy579a0cb2016-11-26 12:27:17 -05001946 except for <var>h</var> and <var>magick</var>. If this
Cristy882d9f42015-10-29 16:48:39 -04001947 option is omitted, the default is <var>GIF</var> for PseudoClass
1948 images and <var>PNM</var> for DirectClass images.
Cristy579a0cb2016-11-26 12:27:17 -05001949 </td>
Cristy882d9f42015-10-29 16:48:39 -04001950 </tr>
1951
1952 <tr>
1953 <td>icon:auto-resize</td>
1954 <td>Automatically stores multiple sizes when writing an ico image
1955 (requires a 256x256 input image).</td>
1956 </tr>
1957
1958 <tr>
Cristyf41bcd12017-03-28 05:59:57 -04001959 <td>identify:locate=<var>minimum|maximum</var></td>
1960 <td>Locates the coordinates of one or more image minimum or maximum</td>
1961 </tr>
1962
1963 <tr>
1964 <td>identify:limit=<var>number</var></td>
1965 <td>Locates the coordinates for the number of minima or maxima specified</td>
1966 </tr>
1967
1968 <tr>
Cristy882d9f42015-10-29 16:48:39 -04001969 <td>jp2:layer-number=<var>value</var></td>
1970 <td>Sets the maximum number of quality layers to decode. Same for JPT, JC2,
1971 and J2K</td>
1972 </tr>
1973
1974 <tr>
1975 <td>jp2:number-resolutions=<var>value</var></td>
Cristybc232422016-11-22 07:46:18 -05001976 <td>Sets the number of resolutions to encode.Same for JPT, JC2, and
1977 J2K</td>
Cristy882d9f42015-10-29 16:48:39 -04001978 </tr>
1979
1980 <tr>
1981 <td>jp2:progression-order=<var>value</var></td>
1982 <td>choose from LRCP, RLCP, RPCL, PCRL or CPRL. Same for JPT, JC2, and
1983 J2K</td>
1984 </tr>
1985
1986 <tr>
1987 <td>jp2:quality=<var>value,value...</var></td>
1988 <td>Sets the quality layer PSNR, given in dB. The order is from left to
1989 right in ascending order. The default is a single lossless quality layer.
1990 Same for JPT, JC2, and J2K</td>
1991 </tr>
1992
1993 <tr>
1994 <td>jp2:rate=<var>value</var></td>
Cristybc232422016-11-22 07:46:18 -05001995 <td>Specify the compression factor to use while writing JPEG-2000 files.
1996 The compression factor is the reciprocal of the compression ratio. The
1997 valid range is 0.0 to 1.0, with 1.0 indicating lossless compression. If
1998 defined, this value overrides the -quality setting. A quality setting
1999 of 75 results in a rate value of 0.06641. Same for JPT, JC2, and J2K</td>
Cristy882d9f42015-10-29 16:48:39 -04002000 </tr>
2001
2002 <tr>
2003 <td>jp2:reduce-factor=<var>value</var></td>
2004 <td>Sets the number of highest resolution levels to be discarded.Same for
2005 JPT, JC2, and J2K</td>
2006 </tr>
2007
2008 <tr>
2009 <td>jpeg:block-smoothing=<var>on|off</var></td>
Cristybc232422016-11-22 07:46:18 -05002010 <td> </td>
Cristy882d9f42015-10-29 16:48:39 -04002011 </tr>
2012
2013 <tr>
2014 <td>jpeg:colors=<var>value</var></td>
2015 <td>Set the desired number of colors and let the JPEG encoder do the
2016 quantizing.</td>
2017 </tr>
2018
2019 <tr>
2020 <td>jpeg:dct-method=<var>value</var></td>
2021 <td>Choose from <code>default</code>, <code>fastest</code>,
2022 <code>float</code>, <code>ifast</code>, and <code>islow</code>.</td>
2023 </tr>
2024
2025 <tr>
2026 <td>jpeg:extent=<var>value</var></td>
2027 <td>Restrict the maximum JPEG file size, for example <code>-define
2028 jpeg:extent=400KB</code>. The JPEG encoder will search for the highest
2029 compression quality level that results in an output file that does not
Cristye93be682015-11-26 09:07:51 -05002030 exceed the value. The <code>-quality</code> option also will be respected
2031 starting with version 6.9.2-5. Between 6.9.1-0 and 6.9.2-4, add -quality
2032 100 in order for the jpeg:extent to work properly. Prior to 6.9.1-0, the
2033 -quality setting was ignored.</td>
Cristy882d9f42015-10-29 16:48:39 -04002034 </tr>
2035
2036 <tr>
2037 <td>jpeg:fancy-upsampling=<var>on|off</var></td>
Cristybc232422016-11-22 07:46:18 -05002038 <td> </td>
Cristy882d9f42015-10-29 16:48:39 -04002039 </tr>
2040
2041 <tr>
2042 <td>jpeg:optimize-coding=<var>on|off</var></td>
Cristybc232422016-11-22 07:46:18 -05002043 <td> </td>
Cristy882d9f42015-10-29 16:48:39 -04002044 </tr>
2045
2046 <tr>
2047 <td>jpeg:q-table=<var>table</var></td>
Cristybc232422016-11-22 07:46:18 -05002048 <td> </td>
Cristy882d9f42015-10-29 16:48:39 -04002049 </tr>
2050
2051 <tr>
2052 <td>jpeg:sampling-factor=<var>sampling-factor-string</var></td>
Cristybc232422016-11-22 07:46:18 -05002053 <td> </td>
Cristy882d9f42015-10-29 16:48:39 -04002054 </tr>
2055
2056 <tr>
2057 <td>jpeg:size=<var>geometry</var></td>
2058 <td>Set the size hint of a JPEG image, for
2059 example, <code>-define jpeg:size=128x128</code>.
2060 It is most useful for increasing performance and reducing the memory
2061 requirements when reducing the size of a large JPEG image.</td>
2062 </tr>
2063
2064 <tr>
2065 <td>json:features</td>
2066 <td>includes features in verbose information</td>
2067 </tr>
2068
2069 <tr>
2070 <td>json:limit</td>
Cristybc232422016-11-22 07:46:18 -05002071 <td> </td>
Cristy882d9f42015-10-29 16:48:39 -04002072 </tr>
2073
2074 <tr>
2075 <td>json:locate</td>
Cristybc232422016-11-22 07:46:18 -05002076 <td> </td>
Cristy882d9f42015-10-29 16:48:39 -04002077 </tr>
2078
2079 <tr>
2080 <td>json:moments</td>
2081 <td>includes image moments in verbose information</td>
2082 </tr>
2083
2084 <tr>
2085 <td>magick:format=<var>value</var></td>
2086 <td>Set the image encoding format use when writing a C-style header.
Cristy579a0cb2016-11-26 12:27:17 -05002087 This is the same as "h:format=format" described above.</td>
Cristy882d9f42015-10-29 16:48:39 -04002088 </tr>
2089
2090 <tr>
2091 <td>mng:need-cacheoff</td>
2092 <td>turn playback caching off for streaming MNG.</td>
2093 </tr>
2094
2095 <tr>
2096 <td>morphology:compose=<var>compose-method</var></td>
Cristy594d2772015-11-15 10:47:42 -05002097 <td>Specifies how to merge results generated by multiple<a
2098 href="command-line-options.html#morphology" >-morphology</a> kernel. The default is none. One
Cristy882d9f42015-10-29 16:48:39 -04002099 typical value is 'lighten' as used, for example, with the sobel edge
2100 kernels. </td>
2101 </tr>
2102
2103 <tr>
2104 <td>morphology:showkernel=<var>1</var></td>
Cristy594d2772015-11-15 10:47:42 -05002105 <td>Outputs (to 'standard error') all the information about a generated <a
2106 href="command-line-options.html#morphology" >-morphology</a> kernel.</td>
Cristy882d9f42015-10-29 16:48:39 -04002107 </tr>
2108
2109 <tr>
2110 <td>pcl:fit-to-page=<var>true</var></td>
Cristy579a0cb2016-11-26 12:27:17 -05002111 </tr>
Cristy882d9f42015-10-29 16:48:39 -04002112
Cristy594d2772015-11-15 10:47:42 -05002113 <tr>
Cristy882d9f42015-10-29 16:48:39 -04002114 <td>pdf:fit-page=<var>geometry</var></td>
2115 <td> geometry specifies the scaling dimensions for resizing when the PDF is
2116 being read. The geometry is either WxH{%} or page size. No offsets are
2117 allowed. (introduced in IM 6.8.8-8)</td>
2118 </tr>
2119
2120 <tr>
2121 <td>pdf:fit-to-page=<var>true</var></td>
Cristybc232422016-11-22 07:46:18 -05002122 <td> </td>
Cristy882d9f42015-10-29 16:48:39 -04002123 </tr>
2124
2125 <tr>
2126 <td>pdf:use-cropbox=<var>true</var></td>
Cristybc232422016-11-22 07:46:18 -05002127 <td> </td>
Cristy882d9f42015-10-29 16:48:39 -04002128 </tr>
2129
2130 <tr>
2131 <td>pdf:use-trimbox=<var>true</var></td>
Cristybc232422016-11-22 07:46:18 -05002132 <td> </td>
Cristy882d9f42015-10-29 16:48:39 -04002133 </tr>
2134
2135 <tr>
Cristyf41bcd12017-03-28 05:59:57 -04002136 <td>pdf:stop-on-error=<var>true</var></td>
2137 <td> </td>
2138 </tr>
2139
2140 <tr>
2141 <td>pdf:pdf:page-direction=<var>right-to-left</var></td>
2142 <td> </td>
2143 </tr>
2144
2145 <tr>
Cristy3b0b58d2016-11-06 07:40:23 -05002146 <td>phash:colorspaces=<var>colorspace,colorspace,...</var></td>
Cristybc232422016-11-22 07:46:18 -05002147 <td>the perceptual hash defaults to the sRGB and HCLp colorspaces. When
2148 using this define, you can specify up to six alternative colorspaces. (as
2149 of IM 7.0.3-8)</td>
2150 </tr>
2151
2152 <tr>
2153 <td>phash:normalize=<var>true</var></td>
2154 <td>normalizes the phash metric by dividing by the number of channels
2155 specified by <code>-define phash:colorspaces</code> when using compare
2156 -metric phash. (as of IM 7.0.3-8)</td>
Cristy3b0b58d2016-11-06 07:40:23 -05002157 </tr>
2158
2159 <tr>
Cristy882d9f42015-10-29 16:48:39 -04002160 <td>png:bit-depth=<var>value</var></td>
Cristybc232422016-11-22 07:46:18 -05002161 <td> </td>
Cristy882d9f42015-10-29 16:48:39 -04002162 </tr>
Cristy3b0b58d2016-11-06 07:40:23 -05002163
Cristy882d9f42015-10-29 16:48:39 -04002164 <tr>
2165 <td>png:color-type=<var>value</var></td>
2166 <td>desired bit-depth and color-type for PNG output. You can force the PNG
2167 encoder to use a different bit-depth and color-type than it would have
2168 normally selected, but only if this does not cause any loss of image
2169 quality. Any attempt to reduce image quality is treated as an error and no
2170 PNG file is written. E.g., if you have a 1-bit black-and-white image, you
2171 can use these "defines" to cause it to be written as an 8-bit grayscale,
2172 indexed, or even a 64-bit RGBA. But if you have a 16-million color image,
2173 you cannot force it to be written as a grayscale or indexed PNG. If you
2174 wish to do this, you must use the appropriate <a href="command-line-options.html#depth">-depth</a>,
2175 <a href="command-line-options.html#colors">-colors</a>, or <a href="command-line-options.html#type">-type</a> directives to
2176 reduce the image quality prior to using the PNG encoder. Note that in
2177 indexed PNG files, "bit-depth" refers to the number of bits per index,
2178 which can be 1, 2, 4, or 8. In such files, the color samples always have
2179 8-bit depth.</td>
2180 </tr>
2181
2182 <tr>
2183 <td>png:compression-filter=<var>value</var></td>
2184 <td> valid values are 0 through 9. 0-4 are the corresponding PNG filters,
2185 5 means adaptive filtering except for images with a colormap, 6 means
2186 adaptive filtering for all images, 7 means MNG "loco" compression, 8 means
2187 Z_RLE strategy with adaptive filtering, and 9 means Z_RLE strategy with no
2188 filtering.</td>
2189 </tr>
2190
2191 <tr>
2192 <td>png:compression-level=<var>value</var></td>
2193 <td> valid values are 0 through 9, with 0 providing the least but fastest
2194 compression and 9 usually providing the best and always the slowest.</td>
2195 </tr>
2196
2197 <tr>
2198 <td>png:compression-strategy=<var>value</var></td>
2199 <td> valid values are 0 through 4, meaning default, filtered, huffman_only,
2200 rle, and fixed ZLIB compression strategy. If you are using an old zlib
2201 that does not support Z_RLE (before 1.2.0) or Z_FIXED (before 1.2.2.2),
2202 values 3 and 4, respectively, will use the zlib default strategy
2203 instead.</td>
2204 </tr>
2205
2206 <tr>
2207 <td>png:format=<var>value</var></td>
2208 <td> valid values are <var>png8</var>, <var>png24</var>,
2209 <var>png32</var>, <var>png48</var>,
2210 <var>png64</var>, and <var>png00</var>.
2211 This property can be useful for specifying
2212 the specific PNG format to be used, when the usual method of prepending the
2213 format name to the output filename is inconvenient, such as when writing
2214 a PNG-encoded ICO file or when using <a href="mogrify.html">mogrify</a>.
2215 Value = <var>png8</var> reduces the number of colors to 256,
2216 only one of which may be fully transparent, if necessary. The other
2217 values do not force any reduction of quality; it is an error to request
2218 a format that cannot represent the image data without loss (except that
2219 it is allowed to reduce the bit-depth from 16 to 8 for all formats).
2220 Value = <var>png24</var> and <var>png48</var>
2221 allow transparency, only if a single color is fully transparent and that
2222 color does not also appear in an opaque pixel; such transparency is
2223 written in a PNG <code>tRNS</code> chunk.
2224 Value = <var>png00</var> causes the image to inherit its
2225 color-type and bit-depth from the input image, if the input was also
2226 a PNG.</td>
2227 </tr>
2228
2229 <tr>
2230 <td>png:exclude-chunk=<var>value</var></td>
2231
Cristy594d2772015-11-15 10:47:42 -05002232 <tr>
Cristy882d9f42015-10-29 16:48:39 -04002233 <td>png:include-chunk=<var>value</var></td>
2234 <td>ancillary chunks to be excluded from or included in PNG output.
2235
2236 <p>The <var>value</var> can be the name of a PNG chunk-type such
2237 as <var>bKGD</var>, a comma-separated list of chunk-names
2238 (which can include the word <var>date</var>, the word
2239 <var>all</var>, or the word <var>none</var>).
2240 Although PNG chunk-names are case-dependent, you can use all lowercase
2241 names if you prefer.</p>
2242
2243 <p>The "include-chunk" and "exclude-chunk" lists only affect the behavior
2244 of the PNG encoder and have no effect on the PNG decoder.</p>
2245
2246 <p>As a special case, if the <code>sRGB</code> chunk is excluded and
2247 the <code>gAMA</code> chunk is included, the <code>gAMA</code> chunk will
2248 only be written if gamma is not 1/2.2, since most decoders assume
2249 sRGB and gamma=1/2.2 when no colorspace information is included in
2250 the PNG file. Because the list is processed from left to right, you
2251 can achieve this with a single define:</p>
2252
Cristy49380402017-06-29 11:24:55 -04002253<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04002254-define png:include-chunk=none,gAMA
Cristy49380402017-06-29 11:24:55 -04002255</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04002256
2257 <p>As a special case, if the <code>sRGB</code> chunk is not excluded and
2258 the PNG encoder recognizes that the image contains the sRGB ICC profile,
2259 the PNG encoder will write the <code>sRGB</code> chunk instead of the
2260 entire ICC profile. To force the PNG encoder to write the sRGB
2261 profile as an <code>iCCP</code> chunk in the output PNG instead of the
2262 <code>sRGB</code> chunk, exclude the <code>sRGB</code> chunk.</p>
2263
2264 <p>The critical PNG chunks <code>IHDR</code>, <code>PLTE</code>,
2265 <code>IDAT</code>, and <code>IEND</code> cannot be excluded. Any such
2266 entries appearing in the list will be ignored.</p>
2267
2268 <p>If the ancillary PNG <code>tRNS</code> chunk is excluded and the
2269 image has transparency, the PNG colortype is forced to be 4 or 6
2270 (GRAY_ALPHA or RGBA). If the image is not transparent, then the
2271 <code>tRNS</code> chunk isn't written anyhow, and there is no effect
2272 on the PNG colortype of the output image.</p>
2273
2274 <p>The <a href="command-line-options.html#strip">-strip</a> option does the equivalent of the
2275 following for PNG output:</p>
2276
Cristy49380402017-06-29 11:24:55 -04002277<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04002278-define png:exclude-chunk=EXIF,iCCP,iTXt,sRGB,tEXt,zCCP,zTXt,date
Cristy49380402017-06-29 11:24:55 -04002279</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04002280
2281 <p>The default behavior is to include all known PNG ancillary chunks
2282 plus ImageMagick's private <code>vpAg</code> ("virtual page") chunk,
2283 and to exclude all PNG chunks that are unknown to ImageMagick,
2284 regardless of their PNG "copy-safe" status as described in the
2285 PNG specification.</p>
2286
2287 <p>Any chunk names that are not known to ImageMagick are ignored
2288 if they appear in either the "include-chunk" or "exclude-chunk" list.
2289 The ancillary chunks currently known to ImageMagick are
2290 <code>bKGD</code>, <code>cHRM</code>, <code>gAMA</code>, <code>iCCP</code>,
2291 <code>oFFs</code>, <code>pHYs</code>, <code>sRGB</code>, <code>tEXt</code>,
2292 <code>tRNS</code>, <code>vpAg</code>, and <code>zTXt</code>.</p>
2293
2294 <p>You can also put <code>date</code> in the list to include or exclude
2295 the "Date:create" and "Date:modify" text chunks that ImageMagick normally
2296 inserts in the output PNG.</p></td>
2297 </tr>
2298
2299 <tr>
2300 <td>png:preserve-colormap[=<var>true</var>]</td>
Cristy594d2772015-11-15 10:47:42 -05002301 <td>Use the existing image->colormap. Normally the PNG encoder will
Cristy882d9f42015-10-29 16:48:39 -04002302 try to optimize the palette, eliminating unused entries and putting
2303 the transparent colors first. If this flag is set, that behavior
2304 is suppressed.</td>
2305 </tr>
2306
2307 <tr>
2308 <td>png:preserve-iCCP[=<var>true</var>]</td>
2309 <td>By default, the PNG decoder and encoder examine any ICC profile
2310 that is present, either from an <code>iCCP</code> chunk in the PNG
2311 input or supplied via an option, and if the profile is recognized
2312 to be the sRGB profile, converts it to the <code>sRGB</code> chunk.
2313 You can use <code>-define png:preserve-iCCP</code> to prevent
2314 this from happening; in such cases the <code>iCCP</code> chunk
2315 will be read or written and no <code>sRGB</code> chunk will be
2316 written. There are some ICC profiles that claim to be sRGB but
2317 have various errors that cause them to be rejected by libpng16; such
2318 profiles are recognized anyhow and converted to the <code>sRGB</code>
2319 chunk, but are rejected if the <code>-define png:preserve-iCCP</code>
2320 is present. Note that not all "sRGB" ICC profiles are recognized
2321 yet; we will add them to the list as we encounter them.</td>
2322 </tr>
2323
2324 <tr>
2325 <td>png:swap-bytes[=<var>true</var>]</td>
2326 <td>The PNG specification requires that any multi-byte integers be stored in
2327 network byte order (MSB-LSB endian). This option allows you to
2328 fix any invalid PNG files that have 16-bit samples stored incorrectly
2329 in little-endian order (LSB-MSB). The "-define png:swap-bytes" option
2330 must appear before the input filename on the commandline. The swapping
2331 is done during the libpng decoding operation.</td>
2332 </tr>
2333
2334 <tr>
2335 <td>profile:skip=<var>name1,name2,...</var></td>
2336 <td>Skip the named profile[s] when reading the image. Use skip="*" to
2337 skip all named profiles in the image. Many named profiles exist,
2338 including ICC, EXIF, APP1, IPTC, XMP, and others.</td>
2339 </tr>
2340
2341 <tr>
2342 <td>ps:imagemask</td>
2343 <td>If the ps:imagemask flag is defined, the PS3 and EPS3 coders will
2344 create Postscript files that render bilevel images with the Postscript
2345 imagemask operator instead of the image operator.</td>
2346 </tr>
2347
2348 <tr>
Cristy3b0b58d2016-11-06 07:40:23 -05002349 <td>psd:additional-info=all|selective</td>
Cristybc232422016-11-22 07:46:18 -05002350 <td>This option should only be used when converting from a PSD file to
2351 another PSD file. This should be placed after the image is read. The two
2352 options are 'all' and 'selective'. The 'selective' option will preserve
2353 all additional information that is not related to the geometry of the
2354 image. The 'all' option should only be used when the geometry of the
2355 image has not been changed. This option is helpful when transferring
2356 non-simple layers, such as adjustment layers from the input PSD file to
2357 the output PSD file. If this option is not used, the additional
2358 information will not be preserved. This define is available as of
2359 Imagemagick version 6.9.5-8.
Cristy3b0b58d2016-11-06 07:40:23 -05002360</td>
2361 </tr>
2362
2363 <tr>
Cristy882d9f42015-10-29 16:48:39 -04002364 <td>psd:alpha-unblend=off</td>
2365 <td>Disables new automatic un-blending of transparency with the base image
2366 for the flattened layer 0 before adding the alpha channel to the output
2367 image. This define must be placed before the input psd image. (Available
2368 as of IM 6.9.2.5). The automatic un-blending is new to IM 6.9.2.5 and
2369 prevents the transparency from being applied twice in the output
Cristy3b0b58d2016-11-06 07:40:23 -05002370 image. This option should be set before reading the image.</td>
2371 </tr>
2372
2373 <tr>
2374 <td>psd:preserve-opacity-mask=true</td>
Cristybc232422016-11-22 07:46:18 -05002375 <td>This option should only be used when converting from a PSD file to
2376 another PSD file. It will preserve the opacity mask of a layer and add it
2377 back to the layer when the image is saved. Setting this to 'true' will
2378 enable this feature. This define is available as of Imagemagick version
2379 6.9.5-10.
Cristy3b0b58d2016-11-06 07:40:23 -05002380</td>
Cristy882d9f42015-10-29 16:48:39 -04002381 </tr>
2382
2383 <tr>
Cristy1f1f3a02016-06-01 07:25:42 -04002384 <td>preserve-timestamp=<var>{True, False}</var></td>
2385 <td>Preserve file timestamp (<code>mogrify</code> only).</td>
2386 </tr>
2387
2388 <tr>
Cristy882d9f42015-10-29 16:48:39 -04002389 <td>quantum:format=<var>type</var></td>
2390 <td>Set the type to <code>floating-point</code> to specify a floating-point
2391 format for raw files (e.g. GRAY:) or for MIFF and TIFF images in HDRI mode
2392 to preserve negative values. If <a href="command-line-options.html#depth">-depth</a> 16 is
2393 included, the result is a single precision floating point format.
2394 If <a href="command-line-options.html#depth">-depth</a> 32 is included, the result is
2395 double precision floating point format.</td>
2396 </tr>
2397
2398 <tr>
2399 <td>quantum:polarity=<var>photometric-interpretation</var></td>
Cristybc232422016-11-22 07:46:18 -05002400 <td>Set the photometric-interpretation of an image (typically for TIFF
2401 image file format) to either <code>min-is-black</code> (default) or
Cristy882d9f42015-10-29 16:48:39 -04002402 <code>min-is-white</code>.</td>
2403 </tr>
2404
2405 <tr>
2406 <td>sample:offset=<var>geometry</var></td>
2407 <td>Location of the sampling point within the sub-region being sampled,
Cristy594d2772015-11-15 10:47:42 -05002408 expressed as percentages (see <a href="command-line-options.html#sample" >-sample</a>).</td>
Cristy882d9f42015-10-29 16:48:39 -04002409 </tr>
2410
2411 <tr>
2412 <td>showkernel=<var>1</var></td>
Cristy594d2772015-11-15 10:47:42 -05002413 <td>Outputs (to 'standard error') all the information about a generated <a
2414 href="command-line-options.html#morphology" >-morphology</a> kernel.</td>
Cristy882d9f42015-10-29 16:48:39 -04002415 </tr>
2416
2417 <tr>
2418 <td>stream:buffer-size=<var>value</var></td>
2419 <td>Set the stream buffer size. Select 0 for unbuffered I/O.</td>
2420 </tr>
2421
2422 <tr>
2423 <td>tiff:alpha=<var>associated|unassociated|unspecified</var></td>
Cristybc232422016-11-22 07:46:18 -05002424 <td>Specify the alpha extra samples as associated, unassociated or
2425 unspecified </td>
Cristy882d9f42015-10-29 16:48:39 -04002426 </tr>
2427
2428 <tr>
2429 <td>tiff:endian=<var>msb|lsb</var></td>
Cristybc232422016-11-22 07:46:18 -05002430 <td> </td>
Cristy882d9f42015-10-29 16:48:39 -04002431 </tr>
2432
2433 <tr>
Cristyf41bcd12017-03-28 05:59:57 -04002434 <td>tiff:exif-properties=<var>true</var></td>
2435 <td>Enables reading the EXIF properties.</td>
Cristy882d9f42015-10-29 16:48:39 -04002436 </tr>
2437
2438 <tr>
2439 <td>tiff:fill-order=<var>msb|lsb</var></td>
Cristybc232422016-11-22 07:46:18 -05002440 <td> </td>
Cristy882d9f42015-10-29 16:48:39 -04002441 </tr>
2442
2443 <tr>
2444 <td>tiff:ignore-layers=<var>true</var></td>
2445 <td>Ignores the photoshop layers.</td>
2446 </tr>
2447
2448 <tr>
2449 <td>tiff:ignore-tags=<var>comma-separate-list-of-tag-IDs</var></td>
2450 <td>Allows one or more tag ID values to be ignored.</td>
2451 </tr>
2452
2453 <tr>
2454 <td>tiff:rows-per-strip=<var>value</var></td>
2455 <td>Sets the number of rows per strip</td>
2456 </tr>
2457
2458 <tr>
2459 <td>tiff:tile-geometry=<var>WxH</var></td>
2460 <td>Sets the tile size for pyramid tiffs. Requires the suffix
2461 PTIF: before the outputname</td>
2462 </tr>
Cristye09ed312016-03-06 08:07:39 -05002463
2464 <tr>
2465 <td>type:features=<var>string</var></td>
Cristybc232422016-11-22 07:46:18 -05002466 <td> </td>
Cristye09ed312016-03-06 08:07:39 -05002467 </tr>
2468
2469 <tr>
2470 <td>type:hinting=<var>off</var></td>
Cristybc232422016-11-22 07:46:18 -05002471 <td> </td>
Cristye09ed312016-03-06 08:07:39 -05002472 </tr>
Cristyf41bcd12017-03-28 05:59:57 -04002473
2474 <tr>
2475 <td>txt:compliance=<var>css</var></td>
2476 <td> </td>
2477 </tr>
2478
2479 <tr>
2480 <td>x:screen=<var>true</var></td>
2481 <td>Obtains the image from the root window </td>
2482 </tr>
2483
2484 <tr>
2485 <td>x:silent=<var>true</var></td>
2486 <td>Turns off the beep when importing an image </td>
2487 </tr>
Cristy882d9f42015-10-29 16:48:39 -04002488</table>
2489
2490<p>For example, to create a postscript file that will render only the black
2491pixels of a bilevel image, use:</p>
2492
Cristy49380402017-06-29 11:24:55 -04002493<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04002494convert bilevel.tif -define ps:imagemask eps3:stencil.ps
Cristy49380402017-06-29 11:24:55 -04002495</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04002496
2497<p>Set attributes of the image registry by prefixing the value with
2498<code>registry:</code>. For example, to set a temporary path to put work files,
2499use:</p>
2500
Cristy49380402017-06-29 11:24:55 -04002501<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04002502-define registry:temporary-path=/data/tmp
Cristy49380402017-06-29 11:24:55 -04002503</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04002504
2505<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04002506 <h3><a id="delay"></a>-delay <var>ticks</var> <br />-delay <var>ticks</var>x<var>ticks-per-second</var> {<var>&lt;</var>} {<var>&gt;</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -04002507</div>
2508
2509<p class="magick-description">display the next image after pausing.</p>
2510
2511<p>This option is useful for regulating the animation of image sequences
2512<var>ticks/ticks-per-second</var> seconds must expire before the display of the
2513next image. The default is no delay between each showing of the image
2514sequence. The default ticks-per-second is 100.</p>
2515
2516<p>Use <code>&gt;</code> to change the image delay <var>only</var> if its current
2517value exceeds the given delay. <code>&lt;</code> changes the image delay
2518<var>only</var> if current value is less than the given delay. For example, if
2519you specify <code>30&gt;</code> and the image delay is 20, the image delay does
2520not change. However, if the image delay is 40 or 50, the delay it is changed
2521to 30. Enclose the given delay in quotation marks to prevent the
2522<code>&lt;</code> or <code>&gt;</code> from being interpreted by your shell as
2523a file redirection.</p>
2524
2525
2526<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04002527 <h3><a id="delete"></a>-delete <var>indexes</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04002528</div>
2529
2530<p class="magick-description">delete the images specified by index, from the image sequence.</p>
2531
2532<p>Specify the image by its index in the sequence. The first image is index
25330. Negative indexes are relative to the end of the sequence, for example, -1
2534represents the last image of the sequence. Specify a range of images with
2535a dash (e.g. 0-4). Separate indexes with a comma (e.g. 0,2). Use
Cristy912a9222016-06-17 15:37:28 -04002536<code>+delete</code> to delete the last image in the current image sequence. Use <code>-delete 0--1</code> to delete the entire image sequence.</p>
Cristy882d9f42015-10-29 16:48:39 -04002537
2538
2539<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04002540 <h3><a id="density"></a>-density <var>width</var><br />-density <var>width</var>x<var>height</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04002541</div>
2542
2543<p class="magick-description">Set the horizontal and vertical resolution of an image for rendering to devices.</p>
2544
2545<p>This option specifies the image resolution to store while encoding a raster
2546image or the canvas resolution while rendering (reading) vector formats such
2547as Postscript, PDF, WMF, and SVG into a raster image. Image resolution
2548provides the unit of measure to apply when rendering to an output device or
Cristy594d2772015-11-15 10:47:42 -05002549raster image. The default unit of measure is in dots per inch (DPI). The <a
2550href="command-line-options.html#units">-units</a> option may be used to select dots per centimeter
Cristy882d9f42015-10-29 16:48:39 -04002551instead.</p>
2552
2553<p>The default resolution is 72 dots per inch, which is equivalent to one
2554point per pixel (Macintosh and Postscript standard). Computer screens are
2555normally 72 or 96 dots per inch, while printers typically support 150, 300,
2556600, or 1200 dots per inch. To determine the resolution of your display, use
2557a ruler to measure the width of your screen in inches, and divide by the
2558number of horizontal pixels (1024 on a 1024x768 display).</p>
2559
2560<p>If the file format supports it, this option may be used to update the
2561stored image resolution. Note that Photoshop stores and obtains image
2562resolution from a proprietary embedded profile. If this profile is not
2563stripped from the image, then Photoshop will continue to treat the image using
2564its former resolution, ignoring the image resolution specified in the standard
2565file header.</p>
2566
2567<p>The <a href="command-line-options.html#density">-density</a> option sets an <var>attribute</var> and
2568does not alter the underlying raster image. It may be used to adjust the
2569rendered size for desktop publishing purposes by adjusting the scale applied
2570to the pixels. To resize the image so that it is the same size at a different
2571resolution, use the <a href="command-line-options.html#resample">-resample</a> option.</p>
2572
2573<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04002574 <h3><a id="depth"></a>-depth <var>value</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04002575</div>
2576
2577<p class="magick-description">depth of the image.</p>
2578
2579<p>This the number of bits in a color sample within a pixel. Use this option
2580to specify the depth of raw images whose depth is unknown such as GRAY, RGB,
2581or CMYK, or to change the depth of any image after it has been read.</p>
2582
2583<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04002584 <h3><a id="descend"></a>-descend</h3>
Cristy882d9f42015-10-29 16:48:39 -04002585</div>
2586
2587<p class="magick-description">obtain image by descending window hierarchy.</p>
2588
2589<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04002590 <h3><a id="deskew"></a>-deskew <var>threshold{%}</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04002591</div>
2592
2593<p class="magick-description">straighten an image. A threshold of 40% works for most images.</p>
2594
2595<p>Use <a href="command-line-options.html#set">-set</a> <code>option:deskew:auto-crop
Cristy3b0b58d2016-11-06 07:40:23 -05002596<var>true | false</var></code> to auto crop the image.</p>
Cristy882d9f42015-10-29 16:48:39 -04002597
2598<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04002599 <h3><a id="despeckle"></a>-despeckle</h3>
Cristy882d9f42015-10-29 16:48:39 -04002600</div>
2601
2602<p class="magick-description">reduce the speckles within an image.</p>
2603
2604<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04002605 <h3><a id="direction"></a>-direction <var>type</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04002606</div>
2607
2608<p class="magick-description">render text right-to-left or left-to-right.</p>
2609
2610<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04002611 <h3><a id="displace"></a>-displace <var>horizontal-scale</var>{%}{!}<br />-displace <var>horizontal-scale</var>x<var>vertical-scale</var>{%}{!}</h3>
Cristy882d9f42015-10-29 16:48:39 -04002612</div>
2613
2614<p class="magick-description">shift image pixels as defined by a displacement map.</p>
2615
2616<p>With this option, the 'overlay' image, and optionally the 'mask' image,
2617is used as a displacement map, which is used to displace the lookup of
2618what part of the 'background' image is seen at each point of the overlaid
2619area. Much like the displacement map is a 'lens' that redirects light shining
2620through it so as to present a distorted view the original 'background' image
2621behind it. </p>
2622
2623<p>Any perfect grey areas of the displacement map produce a zero
2624displacement of the image. Black areas produce the given maximum negative
2625displacement of the lookup point, while white produce a maximum positive
2626displacement of the lookup. </p>
2627
2628<p>Note that it is the lookup of the 'background' that is displaced, not a
2629displacement of the image itself. As such an area of the displacement map
2630containing 'white' will have the lookup point 'shifted' by a positive amount,
2631and thus generating a copy of the destination image to the right/downward from
2632the correct position. That is the image will look like it may have been
2633'shifted' in a negative left/upward direction. Understanding this is a very
2634important in understanding how displacement maps work. </p>
2635
2636<p>The given arguments define the maximum amount of displacement in pixels
2637that a particular map can produce. If the displacement scale is large enough
2638it is also possible to lookup parts of the 'background' image that lie well
2639outside the bounds of the displacement map itself. That is you could very
2640easily copy a section of the original image from outside the overlay area
2641into the overlay area. </p>
2642
2643<p>The '%' flag makes the displacement scale relative to the size of the
2644overlay image (100% = half width/height of image). Using '!' switches
2645percentage arguments to refer to the destination image size instead.
2646these flags were added as of IM v6.5.3-5.</p>
2647
2648<p>Normally a single grayscale displacement map is provided, which with the
2649given scaling values will determine a single direction (vector) in which
2650displacements can occur (positively or negatively). However, if you also
2651specify a third image which is normally used as a <var>mask</var>,
2652the <var>composite image</var> is used for horizontal X
2653displacement, while the <var>mask image</var> is used for vertical Y
2654displacement. This allows you to define completely different displacement
2655values for the X and Y directions, and allowing you to lookup any point within
2656the <var>scale</var> bounds. In other words each pixel can lookup
2657any other nearby pixel, producing complex 2 dimensional displacements, rather
2658than a simple 1 dimensional vector displacements. </p>
2659
2660<p>Alternatively rather than supplying two separate images, as of IM v6.4.4-0,
2661you can use the 'red' channel of the overlay image to specify the horizontal
2662or X displacement, and the 'green' channel for the vertical or Y displacement.
2663</p>
2664
2665<p>As of IM v6.5.3-5 any alpha channel in the overlay image is used as a
2666mask the transparency of the destination image. However areas outside the
2667overlaid areas will not be effected. </p>
2668
2669
2670<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04002671 <h3><a id="display"></a>-display <var>host:display[.screen]</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04002672</div>
2673
2674<p class="magick-description">Specifies the X server to contact.</p>
2675
2676<p>This option is used with convert for obtaining image or font from this
2677X server. See <var>X(1)</var>.</p>
2678
2679<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04002680 <h3><a id="dispose"></a>-dispose <var>method</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04002681</div>
2682
2683<p class="magick-description">define the GIF disposal image setting for images that are being created or read in. </p>
2684
2685<p>The layer disposal method defines the way each the displayed image is to be
2686modified after the current 'frame' of an animation has finished being
2687displayed (after its 'delay' period), but before the next frame on an
2688animation is to be overlaid onto the display. </p>
2689
2690<p>Here are the valid methods:</p>
2691
Cristy49380402017-06-29 11:24:55 -04002692<dl class="row">
2693<dt class="col-md-4">Undefined</dt><dd class="col-md-8">0: No disposal specified (equivalent to '<code>none</code>').</dd>
2694<dt class="col-md-4">None</dt><dd class="col-md-8">1: Do not dispose, just overlay next frame image.</dd>
2695<dt class="col-md-4">Background</dt><dd class="col-md-8">2: Clear the frame area with the background color.</dd>
2696<dt class="col-md-4">Previous</dt><dd class="col-md-8">3: Clear to the image prior to this frames overlay.</dd>
Cristy882d9f42015-10-29 16:48:39 -04002697</dl>
2698
2699<p>You can also use the numbers given above, which is what the GIF format
2700uses internally to represent the above settings. </p>
2701
2702<p>To print a complete list of dispose methods, use <a href="command-line-options.html#list">-list dispose</a>.</p>
2703
Cristy594d2772015-11-15 10:47:42 -05002704<p>Use <a href="command-line-options.html#dispose" >+dispose</a>, turn off the setting and prevent
Cristy882d9f42015-10-29 16:48:39 -04002705resetting the layer disposal methods of images being read in. </p>
2706
2707<p>Use <a href="command-line-options.html#set">-set</a> '<code>dispose</code>' method to set the image
2708disposal method for images already in memory.</p>
2709
2710<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04002711 <h3><a id="dissimilarity-threshold"></a>-dissimilarity-threshold <var>value</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04002712</div>
2713
2714<p class="magick-description">maximum RMSE for subimage match (default 0.2).</p>
2715
2716
2717<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04002718 <h3><a id="dissolve"></a>-dissolve <var>src_percent</var>[x<var>dst_percent</var>]</h3>
Cristy882d9f42015-10-29 16:48:39 -04002719</div>
2720
2721<p class="magick-description">dissolve an image into another by the given percent.</p>
2722
2723<p>The opacity of the composite image is multiplied by the given percent, then
2724it is composited 'over' the main image. If <var>src_percent</var>
2725is greater than 100, start dissolving the main image so it becomes
2726transparent at a value of '<code>200</code>'. If both percentages
2727are given, each image are dissolved to the percentages given. </p>
2728
2729<p>Note that dissolve percentages do not add, two opaque images dissolved
2730'50,50', produce a 75% transparency. For a 50% + 50% blending of the two
2731images, you would need to use dissolve values of '50,100'. </p>
2732
2733<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04002734 <h3><a id="distort"></a>-distort <var>method arguments</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04002735</div>
2736
2737<p class="magick-description">distort an image, using the given <var>method</var> and its required <var>arguments</var>.</p>
2738
2739<p>The <var>arguments</var> is a single string containing a list
2740of floating point numbers separated by commas or spaces. The number of
2741and meaning of the floating point values depends on the distortion <var>method</var> being used. </p>
2742
2743<p>Choose from these distortion types:</p>
2744
Cristy49380402017-06-29 11:24:55 -04002745<table class="table table-sm table-striped">
Cristy882d9f42015-10-29 16:48:39 -04002746 <tr>
2747 <th style="width: 8%">Method</th>
2748 <th>Description</th>
2749 </tr>
2750
2751 <tr>
Cristy594d2772015-11-15 10:47:42 -05002752 <td>ScaleRotateTranslate <br/> SRT</td>
Cristy882d9f42015-10-29 16:48:39 -04002753 <td>
2754 Distort image by first scaling and rotating about a given 'center',
2755 before translating that 'center' to the new location, in that order. It
2756 is an alternative method of specifying a 'Affine' type of
2757 distortion, but without shearing effects. It also provides a good way
2758 of rotating and displacing a smaller image for tiling onto a larger
Cristy594d2772015-11-15 10:47:42 -05002759 background (IE 2-dimensional animations). <br/>
Cristy882d9f42015-10-29 16:48:39 -04002760
2761 The number of arguments determine the specific meaning of each
Cristy594d2772015-11-15 10:47:42 -05002762 argument for the scales, rotation, and translation operations. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002763
Cristy49380402017-06-29 11:24:55 -04002764 <dl class="row">
2765 <dt class="col-md-4">2:</dt><dd class="col-md-8"><var>Scale Angle</var></dd>
2766 <dt class="col-md-4">3:</dt><dd class="col-md-8"><var>X,Y Angle</var></dd>
2767 <dt class="col-md-4">4:</dt><dd class="col-md-8"><var>X,Y Scale Angle</var></dd>
2768 <dt class="col-md-4">5:</dt> <dd class="col-md-8"><var>X,Y ScaleX,ScaleY Angle</var></dd>
2769 <dt class="col-md-4">6:</dt> <dd class="col-md-8"><var>X,Y Scale Angle NewX,NewY</var></dd>
2770 <dt class="col-md-4">7:</dt> <dd class="col-md-8"><var>X,Y ScaleX,ScaleY Angle NewX,NewY</var></dd>
Cristy882d9f42015-10-29 16:48:39 -04002771 </dl>
2772
2773 This is actually an alternative way of specifying a 2 dimensional linear
2774 'Affine' or 'AffineProjection' distortion. </td> </tr>
2775
2776 <tr>
2777 <td>Affine</td>
2778 <td>
2779 Distort the image linearly by moving a list of at least 3 or more sets
2780 of control points (as defined below). Ideally 3 sets or 12 floating
2781 point values are given allowing the image to be linearly scaled,
2782 rotated, sheared, and translated, according to those three points. See
2783 also the related 'AffineProjection' and 'SRT'
Cristy594d2772015-11-15 10:47:42 -05002784 distortions. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002785
2786 More than 3 sets given control point pairs (12 numbers) is least
2787 squares fitted to best match a linear affine distortion. If only 2
2788 control point pairs (8 numbers) are given a two point image translation
2789 rotation and scaling is performed, without any possible shearing,
2790 flipping or changes in aspect ratio to the resulting image. If only one
2791 control point pair is provides the image is only translated, (which may
Cristy594d2772015-11-15 10:47:42 -05002792 be a floating point non-integer translation). <br/>
Cristy882d9f42015-10-29 16:48:39 -04002793
2794 This distortion does not include any form of perspective distortion.
2795 </td>
2796
2797 </tr>
2798
2799 <tr>
2800 <td>AffineProjection</td>
2801 <td>
2802 Linearly distort an image using the given Affine Matrix of 6
2803 pre-calculated coefficients forming a set of Affine Equations to map
2804 the source image to the destination image.
2805
2806 <p class="text-center"><var>
2807 s<sub>x</sub>, r<sub>x</sub>,
2808 r<sub>y</sub>, s<sub>y</sub>,
2809 t<sub>x</sub>, t<sub>y</sub>
2810 </var></p>
2811
Cristy594d2772015-11-15 10:47:42 -05002812 See <a href="command-line-options.html#affine" >-affine</a> setting for more detail, and
2813 meanings of these coefficients. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002814
2815 The distortions 'Affine' and 'SRT' provide
2816 alternative methods of defining this distortion, with ImageMagick doing
2817 the calculations needed to generate the required coefficients. You can
Cristy594d2772015-11-15 10:47:42 -05002818 see the internally generated coefficients, by using a <a
2819 href="command-line-options.html#verbose" >-verbose</a> setting with those other variants. </td>
Cristy882d9f42015-10-29 16:48:39 -04002820
2821 </tr>
2822
2823 <tr>
Cristy594d2772015-11-15 10:47:42 -05002824 <td>BilinearForward<br/>
Cristy882d9f42015-10-29 16:48:39 -04002825 BilinearReverse</td>
2826 <td>
2827 Bilinear Distortion, given a minimum of 4 sets of coordinate pairs, or
2828 16 values (see below). Not that lines may not appear straight after
2829 distortion, though the distance between coordinates will remain
Cristy594d2772015-11-15 10:47:42 -05002830 consistent. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002831
2832 The 'BilinearForward' is used to map rectangles to any
2833 quadrilateral, while the 'BilinearReverse' form maps any
2834 quadrilateral to a rectangle, while preserving the straight line edges
Cristy594d2772015-11-15 10:47:42 -05002835 in each case. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002836
2837 Note that 'BilinearForward' can generate invalid pixels
Cristyb7f455a2017-03-03 19:30:34 -05002838 which will be colored using the <a href="command-line-options.html#mattecolor" >-mattecolor</a>
Cristy882d9f42015-10-29 16:48:39 -04002839 color setting. Also if the quadrilateral becomes 'flipped' the image
Cristy594d2772015-11-15 10:47:42 -05002840 may disappear. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002841
2842 There are future plans to produce a true Bilinear distortion that will
2843 attempt to map any quadrilateral to any other quadrilateral, while
2844 preserving edges (and edge distance ratios).
2845
2846 </td>
2847 </tr>
2848
2849 <tr>
2850 <td>Perspective</td>
2851 <td>
2852 Perspective distort the images, using a list of 4 or more sets of
2853 control points (as defined below). More that 4 sets (16 numbers) of
2854 control points provide least squares fitting for more accurate
2855 distortions (for the purposes of image registration and panorama
2856 effects). Less than 4 sets will fall back to a 'Affine'
Cristy594d2772015-11-15 10:47:42 -05002857 linear distortion. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002858
2859 Perspective Distorted images ensures that straight lines remain
2860 straight, but the scale of the distorted image will vary. The horizon
2861 is anti-aliased, and the 'sky' color may be set using the
Cristyb7f455a2017-03-03 19:30:34 -05002862 <a href="command-line-options.html#mattecolor" >-mattecolor</a> setting. </td>
Cristy882d9f42015-10-29 16:48:39 -04002863 </tr>
2864
2865 <tr>
2866 <td>PerspectiveProjection </td>
2867 <td>
2868 Do a 'Perspective' distortion biased on a set of 8
2869 pre-calculated coefficients. You can get these coefficients by looking
Cristy594d2772015-11-15 10:47:42 -05002870 at the <a href="command-line-options.html#verbose" >-verbose</a> output of a
Cristy882d9f42015-10-29 16:48:39 -04002871 'Perspective' distortion, or by calculating them yourself.
2872 If the last two perspective scaling coefficients are zero, the
2873 remaining 6 represents a transposed 'Affine Matrix'. </td>
2874
2875 </tr>
2876
2877 <tr>
2878 <td>Arc</td>
2879 <td>
2880 Arc the image (variation of polar mapping) over the angle given around
2881 a circle.
2882
Cristy49380402017-06-29 11:24:55 -04002883 <dl class="row">
2884 <dt class="col-md-4">arc_angle</dt>
2885 <dd class="col-md-8">The angle over which to arc the image side-to-side</dd>
2886 <dt class="col-md-4">rotate_angle</dt>
2887 <dd class="col-md-8">Angle to rotate resulting image from vertical center</dd>
2888 <dt class="col-md-4">top_radius</dt>
2889 <dd class="col-md-8">Set top edge of source image at this radius</dd>
2890 <dt class="col-md-4">bottom_radius </dt>
2891 <dd class="col-md-8">Set bottom edge to this radius (radial scaling)</dd>
Cristy579a0cb2016-11-26 12:27:17 -05002892 </dl>
Cristy882d9f42015-10-29 16:48:39 -04002893
2894 The resulting image is always resized to best fit the resulting image,
Cristy594d2772015-11-15 10:47:42 -05002895 (as if using <a href="command-line-options.html#distort" >+distort</a>) while attempting to
Cristy882d9f42015-10-29 16:48:39 -04002896 preserve scale and aspect ratio of the original image as much as
2897 possible with the arguments given by the user. All four arguments will
Cristy594d2772015-11-15 10:47:42 -05002898 be needed to change the overall aspect ratio of an 'Arc'ed image. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002899
2900 This a variation of a polar distortion designed to try to preserve the
2901 aspect ratio of the image rather than direct Cartesian to Polar
2902 conversion. </td>
2903 </tr>
2904
2905 <tr>
2906 <td>Polar</td>
2907 <td>
2908 Like 'Arc' but do a complete Cartesian to Polar mapping of
2909 the image. that is the height of the input image is mapped to the
2910 radius limits, while the width is wrapped around between the
Cristy594d2772015-11-15 10:47:42 -05002911 angle limits. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002912
Cristy594d2772015-11-15 10:47:42 -05002913 Arguments: <var>Rmax,Rmin CenterX,CenterY, start,end_angle</var> <br/>
Cristy882d9f42015-10-29 16:48:39 -04002914
2915 All arguments are optional. With <var>Rmin</var> defaulting to zero, the
2916 center to the center of the image, and the angles going from -180 (top)
2917 to +180 (top). If <var>Rmax</var> is given the special value of
2918 '0', the the distance from the center to the nearest edge
2919 is used for the radius of the output image, which will ensure the whole
2920 image is visible (though scaled smaller). However a special value of
2921 '-1' will use the distance from the center to the furthest
2922 corner, This may 'clip' the corners from the input rectangular image,
2923 but will generate the exact reverse of a 'DePolar' with
Cristy594d2772015-11-15 10:47:42 -05002924 the same arguments. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002925
Cristy594d2772015-11-15 10:47:42 -05002926 If the plus form of distort (<a href="command-line-options.html#distort" >+distort</a>) is used
Cristy882d9f42015-10-29 16:48:39 -04002927 output image center will default to 0,0 of the virtual
2928 canvas, and the image size adjusted to ensure the whole input image is
2929 made visible in the output image on the virtual canvas. </td>
2930
2931 </tr>
2932
2933 <tr>
2934 <td>DePolar</td>
2935 <td>
2936 Uses the same arguments and meanings as a 'Polar' distortion
Cristy594d2772015-11-15 10:47:42 -05002937 but generates the reverse Polar to Cartesian distortion. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002938
2939 The special <var>Rmax</var> setting of '0' may however clip
2940 the corners of the input image. However using the special
2941 <var>Rmax</var> setting of '-1' (maximum center to corner
2942 distance) will ensure the whole distorted image is preserved in the
2943 generated result, so that the same argument to 'Polar' will
2944 reverse the distortion re-producing the original.
2945
2946 Note that as this distortion requires the area resampling of a circular
2947 arc, which can not be handled by the builtin EWA resampling function.
2948 As such the normal EWA filters are turned off. It is recommended some
2949 form of 'super-sampling' image processing technique be used to produce
2950 a high quality result. </td>
2951
2952 </tr>
2953
2954 <tr>
2955 <td>Barrel</td>
2956 <td>
Cristy594d2772015-11-15 10:47:42 -05002957 Given the four coefficients (A,B,C,D) as defined by <a
2958 href="http://wiki.panotools.org/Lens_correction_model" >Helmut
Cristy882d9f42015-10-29 16:48:39 -04002959 Dersch</a>, perform a barrel or pin-cushion distortion appropriate to
2960 correct radial lens distortions. That is in photographs, make straight
Cristy594d2772015-11-15 10:47:42 -05002961 lines straight again. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002962
2963 <p class="text-center">Arguments: <var>A B C</var> [ <var>D</var> [
Cristy594d2772015-11-15 10:47:42 -05002964 <var>X</var> , <var>Y</var> ] ] <br/>
Cristy882d9f42015-10-29 16:48:39 -04002965 or <var>A<sub>x</sub> B<sub>x</sub> C<sub>x</sub> D<sub>x</sub>
2966 A<sub>y</sub> B<sub>y</sub> C<sub>y</sub> D<sub>y</sub></var>
2967 [ <var>X</var> , <var>Y</var> ] </p>
2968 So that it forms the function
2969 <p class="text-center">Rsrc = r * ( <var>A</var>*r<sup>3</sup> + <var>B</var>*r<sup>2</sup> +
2970 <var>C</var>*r + <var>D</var> )</p>
2971
2972 Where <var>X</var>,<var>Y</var> is the optional center of the distortion
Cristy594d2772015-11-15 10:47:42 -05002973 (defaulting to the center of the image). <br/>
Cristy882d9f42015-10-29 16:48:39 -04002974 The second form is typically used to distort images, rather than
Cristy594d2772015-11-15 10:47:42 -05002975 correct lens distortions. <br/>
Cristy882d9f42015-10-29 16:48:39 -04002976 </td>
2977
2978 </tr>
2979
2980 <tr>
2981 <td>BarrelInverse</td>
2982 <td>
2983 This is very similar to 'Barrel' with the same set of
2984 arguments, and argument handling. However it uses the inverse
2985 of the radial polynomial,
2986 so that it forms the function
2987 <p class="text-center">Rsrc = r / ( <var>A</var>*r<sup>3</sup> + <var>B</var>*r<sup>2</sup> +
2988 <var>C</var>*r + <var>D</var> )</p>
2989 Note that this is not the reverse of the 'Barrel'
2990 distortion, just a different barrel-like radial distortion method.
2991
2992 </td>
2993 </tr>
2994
2995 <tr>
2996 <td>Shepards</td>
2997 <td>
2998 Distort the given list control points (any number) using an Inverse
Cristy594d2772015-11-15 10:47:42 -05002999 Squared Distance Interpolation Method (<a
3000 href="http://en.wikipedia.org/wiki/Shepard%27s_method" >Shepards
Cristy882d9f42015-10-29 16:48:39 -04003001 Method</a>). The control points in effect do 'localized' displacement
3002 of the image around the given control point (preserving the look and
3003 the rotation of the area near the control points. For best results
3004 extra control points should be added to 'lock' the positions of the
3005 corners, edges and other unchanging parts of the image, to prevent
Cristy594d2772015-11-15 10:47:42 -05003006 their movement. <br/>
Cristy882d9f42015-10-29 16:48:39 -04003007
3008 The distortion has been likened to 'taffy pulling' using nails, or
3009 pins' stuck in a block of 'jelly' which is then moved to the new
Cristy594d2772015-11-15 10:47:42 -05003010 position, distorting the surface of the jelly. <br/>
Cristy882d9f42015-10-29 16:48:39 -04003011
Cristy594d2772015-11-15 10:47:42 -05003012 Internally it is equivalent to generating a displacement map (see <a
3013 href="command-line-options.html#displace" >-displace</a>) for source image color look-up using
3014 the <a href="command-line-options.html#sparse-color" >-sparse-color</a> method of the same name.
Cristy882d9f42015-10-29 16:48:39 -04003015
3016 </td>
3017 </tr>
3018
3019</table>
3020
3021<p>To print a complete list of distortion methods, use <a href="command-line-options.html#list">-list
3022distort</a>.</p>
3023
3024<p>Many of the above distortion methods such as '<code>Affine</code>',
3025'<code>Perspective</code>', and '<code>Shepards</code>' use a list control points
3026defining how these points in the given image should be distorted in the
3027destination image. Each set of four floating point values represent a source
3028image coordinate, followed immediately by the destination image coordinate.
3029This produces a list of values such as...</p>
3030<p class="text-center"><var>
3031 U<sub>1</sub>,V<sub>1</sub> X<sub>1</sub>,Y<sub>1</sub>
3032 U<sub>2</sub>,V<sub>2</sub> X<sub>2</sub>,Y<sub>2</sub>
3033 U<sub>3</sub>,V<sub>3</sub> X<sub>3</sub>,Y<sub>3</sub>
3034 ...
3035 U<sub>n</sub>,V<sub>n</sub> X<sub>n</sub>,Y<sub>n</sub>
3036</var></p>
3037<p>where <var>U,V</var> on the source image is mapped to <var>X,Y</var> on the
3038destination image. </p>
3039
3040<p>For example, to warp an image using '<code>perspective</code>' distortion,
3041needs a list of at least 4 sets of coordinates, or 16 numbers. Here is the
3042perspective distortion of the built-in "rose:" image. Note how spaces were
3043used to group the 4 sets of coordinate pairs, to make it easier to read and
3044understand.</p>
3045
Cristy49380402017-06-29 11:24:55 -04003046<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04003047convert rose: -virtual-pixel black \
3048 -distort Perspective '0,0,0,0 0,45,0,45 69,0,60,10 69,45,60,35' \
3049 rose_3d_rotated.gif"
Cristy49380402017-06-29 11:24:55 -04003050</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04003051
3052<p>If more that the required number of coordinate pairs are given for
3053a distortion, the distortion method is 'least squares' fitted to produce the
3054best result for all the coordinate pairs given. If less than the ideal number
3055of points are given, the distort will generally fall back to a simpler form of
3056distortion that can handles the smaller number of coordinates (usually a linear
3057'<code>Affine</code>' distortion). </p>
3058
3059<p>By using more coordinates you can make use of image registration tool to
3060find matching coordinate pairs in overlapping images, so as to improve the
3061'fit' of the distortion. Of course a bad coordinate pair can also make the
3062'fit' worse. Caution is always advised. </p>
3063
3064<p>Colors are acquired from the source image according to a cylindrical
Cristy594d2772015-11-15 10:47:42 -05003065resampling <a href="command-line-options.html#filter" >-filter</a>, using a special technique known as
Cristy882d9f42015-10-29 16:48:39 -04003066EWA resampling. This produces very high quality results, especially when
3067images become smaller (minified) in the output, which is very common when
3068using '<code>perspective</code>' distortion. For example here we view
3069a infinitely tiled 'plane' all the way to the horizon. </p>
3070
Cristy49380402017-06-29 11:24:55 -04003071<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04003072convert -size 90x90 pattern:checkerboard -normalize -virtual-pixel tile \
3073 -distort perspective '0,0,5,45 89,0,45,46 0,89,0,89 89,89,89,89' \
3074 checks_tiled.jpg
Cristy49380402017-06-29 11:24:55 -04003075</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04003076
3077<p>Note that a infinitely tiled perspective images involving the horizon can
3078be very slow, because of the number of pixels that are compressed to generate
3079each individual pixel close to the 'horizon'. You can turn off EWA
Cristy594d2772015-11-15 10:47:42 -05003080resampling, by specifying the special <a href="command-line-options.html#filter" >-filter</a> setting of
Cristy882d9f42015-10-29 16:48:39 -04003081'<code>point</code>' (recommended if you plan to use super-sampling instead).
3082</p>
3083
3084<p>If an image generates <i>invalid pixels</i>, such as the 'sky' in the last
Cristy594d2772015-11-15 10:47:42 -05003085example, <a href="command-line-options.html#distort" >-distort</a> will use the current <a
Cristyb7f455a2017-03-03 19:30:34 -05003086href="command-line-options.html#mattecolor" >-mattecolor</a> setting for these pixels. If you do not
Cristy882d9f42015-10-29 16:48:39 -04003087what these pixels to be visible, set the color to match the rest of the
3088ground. </p>
3089
3090<p>The output image size will by default be the same as the input image. This
3091means that if the part of the distorted image falls outside the viewed area of
3092the 'distorted space', those parts is clipped and lost. However if you use
Cristy594d2772015-11-15 10:47:42 -05003093the plus form of the operator (<a href="command-line-options.html#distort" >+distort</a>) the operator
Cristy882d9f42015-10-29 16:48:39 -04003094will attempt (if possible) to show the whole of the distorted image, while
3095retaining a correct 'virtual canvas' offset, for image layering. This offset
Cristy594d2772015-11-15 10:47:42 -05003096may need to be removed using <a href="command-line-options.html#repage" >+repage</a>, to remove if it
Cristy882d9f42015-10-29 16:48:39 -04003097is unwanted. </p>
3098
Cristy594d2772015-11-15 10:47:42 -05003099<p>Setting <a href="command-line-options.html#verbose" >-verbose</a> setting, will cause <a
3100href="command-line-options.html#distort" >-distort</a> to attempt to output the internal coefficients,
3101and the <a href="command-line-options.html#fx" >-fx</a> equivalent to the distortion, for expert study,
Cristy882d9f42015-10-29 16:48:39 -04003102and debugging purposes. This many not be available for all distorts. </p>
3103
Cristy594d2772015-11-15 10:47:42 -05003104<p>You can alternatively specify a special "<code><a href="command-line-options.html#define"
3105>-define</a> distort:viewport={geometry_string}</code>" setting which will
Cristy882d9f42015-10-29 16:48:39 -04003106specify the size and the offset of the generated 'viewport' image of the
3107distorted image space.</p>
3108
Cristy594d2772015-11-15 10:47:42 -05003109<p>Setting a "<code><a href="command-line-options.html#define" >-define</a>
Cristy769d8892016-01-19 18:11:14 -05003110distort:scale=<var>scale_factor</var></code>" will scale the output image (viewport or
Cristy882d9f42015-10-29 16:48:39 -04003111otherwise) by that factor without changing the viewed contents of the
3112distorted image. This can be used either for 'super-sampling' the image for
3113a higher quality result, or for panning and zooming around the image (with
3114appropriate viewport changes, or post-distort cropping and resizing). </p>
3115
Cristy594d2772015-11-15 10:47:42 -05003116<p>Setting "<code><a href="command-line-options.html#define" >-define</a> resample:verbose=1</code>"
Cristy882d9f42015-10-29 16:48:39 -04003117will output the cylindrical filter lookup table created by the EWA (Elliptical
3118Weighted Average) resampling algorithm. Note this table uses a squared radius
3119lookup value. This is typically only used for debugging EWA resampling. </p>
3120
3121
3122<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04003123 <h3><a id="distribute-cache"></a>-distribute-cache <var>port</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04003124</div>
3125
3126<p class="magick-description">launch a distributed pixel cache server. </p>
3127
3128<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04003129 <h3><a id="dither"></a>-dither <var>method</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04003130</div>
3131
3132<p class="magick-description">Apply a Riemersma or Floyd-Steinberg error diffusion dither to
3133images when general color reduction is applied via an option, or automagically
3134when saving to specific formats. This enabled by default.</p>
3135
3136<p>Dithering places two or more colors in neighboring pixels so that to the
3137eye a closer approximation of the images original color is reproduced. This
3138reduces the number of colors needed to reproduce the image but at the cost of
3139a lower level pattern of colors. Error diffusion dithers can use any set of
3140colors (generated or user defined) to an image. </p>
3141
3142<p>Dithering is turned on by default, to turn it off use the plus form of the
3143setting, <a href="command-line-options.html#dither">+dither</a>. This will also also render PostScript
3144without text or graphic aliasing. Disabling dithering often (but not always)
3145leads to faster process, a smaller number of colors, but more cartoon like
3146image coloring. Generally resulting in 'color banding' effects in areas with
3147color gradients. </p>
3148
Cristy594d2772015-11-15 10:47:42 -05003149<p>The color reduction operators <a href="command-line-options.html#colors">-colors</a>, <a
3150href="command-line-options.html#monochrome">-monochrome</a>, <a href="command-line-options.html#remap ">-remap</a>, and <a
3151href="command-line-options.html#posterize">-posterize</a>, apply dithering to images using the reduced
Cristy882d9f42015-10-29 16:48:39 -04003152color set they created. These operators are also used as part of automatic
3153color reduction when saving images to formats with limited color support, such
3154as <code>GIF:</code>, <code>XBM:</code>, and others, so dithering may also be used
3155in these cases. </p>
3156
3157<p>Alternatively you can use <a href="command-line-options.html#random-threshold">-random-threshold</a>
Cristy594d2772015-11-15 10:47:42 -05003158to generate purely random dither. Or use <a
3159href="command-line-options.html#ordered-dither">-ordered-dither</a> to apply threshold mapped dither
Cristy882d9f42015-10-29 16:48:39 -04003160patterns, using uniform color maps, rather than specific color maps. </p>
3161
3162
3163<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04003164 <h3><a id="draw"></a>-draw <var>string</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04003165</div>
3166
3167<p class="magick-description">Annotate an image with one or more graphic primitives.</p>
3168
3169<p>Use this option to annotate or decorate an image with one or more graphic
3170primitives. The primitives include shapes, text, transformations, and pixel
3171operations.</p>
3172
3173<p>The shape primitives:</p>
3174
Cristy49380402017-06-29 11:24:55 -04003175<dl class="row">
3176<dt class="col-md-4">point</dt><dd class="col-md-8"> x,y</dd>
3177<dt class="col-md-4">line</dt><dd class="col-md-8"> x0,y0 x1,y1</dd>
3178<dt class="col-md-4">rectangle</dt><dd class="col-md-8"> x0,y0 x1,y1</dd>
3179<dt class="col-md-4">roundRectangle</dt><dd class="col-md-8"> x0,y0 x1,y1 wc,hc</dd>
3180<dt class="col-md-4">arc</dt><dd class="col-md-8"> x0,y0 x1,y1 a0,a1</dd>
3181<dt class="col-md-4">ellipse</dt><dd class="col-md-8"> x0,y0 rx,ry a0,a1</dd>
3182<dt class="col-md-4">circle</dt><dd class="col-md-8"> x0,y0 x1,y1</dd>
3183<dt class="col-md-4">polyline</dt><dd class="col-md-8"> x0,y0 ... xn,yn</dd>
3184<dt class="col-md-4">polygon</dt><dd class="col-md-8"> x0,y0 ... xn,yn</dd>
3185<dt class="col-md-4">bezier</dt><dd class="col-md-8"> x0,y0 ... xn,yn</dd>
3186<dt class="col-md-4">path</dt><dd class="col-md-8">specification </dd>
3187<dt class="col-md-4">image</dt><dd class="col-md-8"> operator x0,y0 w,h filename</dd>
Cristy882d9f42015-10-29 16:48:39 -04003188</dl>
3189
3190<p>The text primitive:</p>
3191
Cristy49380402017-06-29 11:24:55 -04003192<dl class="row">
3193<dt class="col-md-4">text</dt><dd class="col-md-8">x0,y0 string</dd>
Cristy882d9f42015-10-29 16:48:39 -04003194</dl>
3195<p>The text gravity primitive:</p>
3196
Cristy49380402017-06-29 11:24:55 -04003197<dl class="row">
3198<dt class="col-md-4">gravity</dt><dd class="col-md-8">NorthWest, North, NorthEast, West, Center, East, SouthWest, South, or SouthEast</dd>
Cristy882d9f42015-10-29 16:48:39 -04003199</dl>
3200
3201<p>The text gravity primitive only affects the placement of text and does not
Cristy594d2772015-11-15 10:47:42 -05003202interact with the other primitives. It is equivalent to using the <a
3203href="command-line-options.html#gravity">-gravity</a> command-line option, except that it is limited in
Cristy882d9f42015-10-29 16:48:39 -04003204scope to the <a href="command-line-options.html#draw">-draw</a> option in which it appears.</p>
3205
3206<p>The transformation primitives:</p>
3207
Cristy49380402017-06-29 11:24:55 -04003208<dl class="row">
3209<dt class="col-md-4">rotate</dt><dd class="col-md-8">degrees</dd>
3210<dt class="col-md-4">translate</dt><dd class="col-md-8">dx,dy</dd>
3211<dt class="col-md-4">scale</dt><dd class="col-md-8">sx,sy</dd>
3212<dt class="col-md-4">skewX</dt><dd class="col-md-8">degrees</dd>
3213<dt class="col-md-4">skewY</dt><dd class="col-md-8">degrees</dd>
Cristy882d9f42015-10-29 16:48:39 -04003214</dl>
3215
3216<p>The pixel operation primitives:</p>
3217
Cristy49380402017-06-29 11:24:55 -04003218<dl class="row">
3219<dt class="col-md-4">color</dt><dd class="col-md-8">x0,y0 method</dd>
3220<dt class="col-md-4">matte</dt><dd class="col-md-8">x0,y0 method</dd>
Cristy882d9f42015-10-29 16:48:39 -04003221</dl>
3222
Cristy594d2772015-11-15 10:47:42 -05003223<p>The shape primitives are drawn in the color specified by the preceding <a
3224href="command-line-options.html#fill">-fill</a> setting. For unfilled shapes, use <a
3225href="command-line-options.html#fill">-fill none</a>. You can optionally control the stroke (the
3226"outline" of a shape) with the <a href="command-line-options.html#stroke">-stroke</a> and <a
3227href="command-line-options.html#strokewidth">-strokewidth</a> settings.</p>
Cristy882d9f42015-10-29 16:48:39 -04003228
3229<p>A <code>point</code> primitive is specified by a single <var>point</var> in the
3230pixel plane, that is, by an ordered pair of integer coordinates,
3231<var>x</var>,<var>y</var>. (As it involves only a single pixel, a <code>point</code>
Cristy594d2772015-11-15 10:47:42 -05003232primitive is not affected by <a href="command-line-options.html#stroke">-stroke</a> or <a
3233href="command-line-options.html#strokewidth">-strokewidth</a>.)</p>
Cristy882d9f42015-10-29 16:48:39 -04003234
3235<p>A <code>line</code> primitive requires a start point and end point.</p>
3236
3237<p>A <code>rectangle</code> primitive is specified by the pair of points at the
3238upper left and lower right corners.</p>
3239
3240<p>A <code>roundRectangle</code> primitive takes the same corner points as
3241a <code>rectangle</code> followed by the width and height of the rounded corners
3242to be removed.</p>
3243
3244<p>The <code>circle</code> primitive makes a disk (filled) or circle (unfilled).
3245Give the center and any point on the perimeter (boundary).</p>
3246
3247<p>The <code>arc</code> primitive is used to inscribe an elliptical segment in
3248to a given rectangle. An <code>arc</code> requires the two corners used for
3249<code>rectangle</code> (see above) followed by the start and end angles of the
3250arc of the segment segment (e.g. 130,30 200,100 45,90). The start and end
3251points produced are then joined with a line segment and the resulting segment
3252of an ellipse is filled.</p>
3253
3254<p>Use <code>ellipse</code> to draw a partial (or whole) ellipse. Give the
3255center point, the horizontal and vertical "radii" (the <var>semi-axes</var> of
3256the ellipse) and start and end angles in degrees (e.g. 100,100 100,150
32570,360).</p>
3258
3259<p>The <code>polyline</code> and <code>polygon</code> primitives require three or
3260more points to define their perimeters. A <code>polyline</code> is simply
3261a <code>polygon</code> in which the final point is not stroked to the start
Cristy594d2772015-11-15 10:47:42 -05003262point. When unfilled, this is a <var>polygonal line</var>. If the <a
3263href="command-line-options.html#stroke">-stroke</a> setting is <code>none</code> (the default), then
Cristy882d9f42015-10-29 16:48:39 -04003264a <code>polyline</code> is identical to a <code>polygon</code>. </p>
3265
3266<p>A <var>coordinate</var> is a pair of integers separated by a space or
3267optional comma. </p>
3268
3269<p>As an example, to define a circle centered at 100,100 that extends to
3270150,150 use:</p>
3271
Cristy49380402017-06-29 11:24:55 -04003272<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04003273-draw 'circle 100,100 150,150'
Cristy49380402017-06-29 11:24:55 -04003274</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04003275
3276<p>The <code>Bezier</code> primitive creates a spline curve and requires three
3277or points to define its shape. The first and last points are the
3278<var>knots</var> and these points are attained by the curve, while any
3279intermediate coordinates are <var>control points</var>. If two control points
3280are specified, the line between each end knot and its sequentially respective
3281control point determines the tangent direction of the curve at that end. If
3282one control point is specified, the lines from the end knots to the one
3283control point determines the tangent directions of the curve at each end. If
3284more than two control points are specified, then the additional control points
3285act in combination to determine the intermediate shape of the curve. In order
3286to draw complex curves, it is highly recommended either to use the
3287<code>path</code> primitive or to draw multiple four-point bezier segments with
3288the start and end knots of each successive segment repeated. For example:</p>
3289
Cristy49380402017-06-29 11:24:55 -04003290<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04003291-draw 'bezier 20,50 45,100 45,0 70,50'
3292-draw 'bezier 70,50 95,100 95,0 120,50'
Cristy49380402017-06-29 11:24:55 -04003293</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04003294
3295<p>A <code>path</code> represents an outline of an object, defined in terms of
3296moveto (set a new current point), lineto (draw a straight line), curveto (draw
3297a Bezier curve), arc (elliptical or circular arc) and closepath (close the
3298current shape by drawing a line to the last moveto) elements. Compound paths
3299(i.e., a path with subpaths, each consisting of a single moveto followed by
3300one or more line or curve operations) are possible to allow effects such as
Cristy594d2772015-11-15 10:47:42 -05003301<var>donut holes</var> in objects. (See <a
3302href="http://www.w3.org/TR/SVG/paths.html">Paths</a>.)</p>
Cristy882d9f42015-10-29 16:48:39 -04003303
3304<p>Use <code>image</code> to composite an image with another image. Follow the
3305image keyword with the composite operator, image location, image size, and
3306filename:</p>
3307
Cristy49380402017-06-29 11:24:55 -04003308<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04003309-draw 'image SrcOver 100,100 225,225 image.jpg'
Cristy49380402017-06-29 11:24:55 -04003310</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04003311
3312<p>You can use 0,0 for the image size, which means to use the actual
3313dimensions found in the image header. Otherwise, it is scaled to the given
Cristy6549abb2016-11-10 08:25:55 -05003314dimensions. See <a href="http://www.imagemagick.org/www/compose.html">Alpha Compositing</a> for
Cristy882d9f42015-10-29 16:48:39 -04003315a detailed discussion of alpha composition methods that are available. </p>
3316
3317<p>The "special augmented compose operators" such as "dissolve" that require
3318arguments cannot be used at present with the <code>-draw image</code> option.
3319 </p>
3320
3321<p>Use <code>text</code> to annotate an image with text. Follow the text
3322coordinates with a string. If the string has embedded spaces, enclose it in
3323single or double quotes.</p>
3324
3325<p>For example, the following annotates the image with <code>Works like
3326magick!</code> for an image titled <code>bird.miff</code>. </p>
3327
Cristy49380402017-06-29 11:24:55 -04003328<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04003329-draw "text 100,100 'Works like magick!' "
Cristy49380402017-06-29 11:24:55 -04003330</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04003331
3332<p>See the <a href="command-line-options.html#annotate">-annotate</a> option for another convenient way
3333to annotate an image with text.</p>
3334
3335<p>The <code>rotate</code> primitive rotates subsequent shape primitives and
Cristy594d2772015-11-15 10:47:42 -05003336text primitives about the origin of the main image. If the <a
3337href="command-line-options.html#region">-region</a> option precedes the <a href="command-line-options.html#draw">-draw</a>
Cristy882d9f42015-10-29 16:48:39 -04003338option, the origin for transformations is the upper left corner of the
3339region.</p>
3340
3341<p>The <code>translate</code> primitive translates subsequent shape and text
3342primitives.</p>
3343
3344<p>The <code>scale</code> primitive scales them.</p>
3345
3346<p>The <code>skewX</code> and <code>skewY</code> primitives skew them with respect
3347to the origin of the main image or the region.</p>
3348
3349<p>The transformations modify the current affine matrix, which is initialized
3350from the initial affine matrix defined by the <a href="command-line-options.html#affine">-affine</a>
3351option. Transformations are cumulative within the <a href="command-line-options.html#draw">-draw</a>
3352option. The initial affine matrix is not affected; that matrix is only changed
3353by the appearance of another <a href="command-line-options.html#affine">-affine</a> option. If another
3354<a href="command-line-options.html#draw">-draw</a> option appears, the current affine matrix is
3355reinitialized from the initial affine matrix.</p>
3356
3357<p>Use the <code>color</code> primitive to change the color of a pixel to the
3358fill color (see <a href="command-line-options.html#fill">-fill</a>). Follow the pixel coordinate with
3359a method:</p>
3360
Cristy49380402017-06-29 11:24:55 -04003361<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04003362point
3363replace
3364floodfill
3365filltoborder
3366reset
Cristy49380402017-06-29 11:24:55 -04003367</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04003368
3369<p>Consider the target pixel as that specified by your coordinate. The
3370<code>point</code> method recolors the target pixel. The <code>replace</code>
3371method recolors any pixel that matches the color of the target pixel.
3372<code>Floodfill</code> recolors any pixel that matches the color of the target
3373pixel and is a neighbor, whereas <code>filltoborder</code> recolors any neighbor
3374pixel that is not the border color. Finally, <code>reset</code> recolors all
3375pixels.</p>
3376
3377<p>Use <code>matte</code> to the change the pixel matte value to transparent.
3378Follow the pixel coordinate with a method (see the <code>color</code> primitive
3379for a description of methods). The <code>point</code> method changes the matte
3380value of the target pixel. The <code>replace</code> method changes the matte
3381value of any pixel that matches the color of the target pixel.
3382<code>Floodfill</code> changes the matte value of any pixel that matches the
3383color of the target pixel and is a neighbor, whereas <code>filltoborder</code>
Cristy594d2772015-11-15 10:47:42 -05003384changes the matte value of any neighbor pixel that is not the border color (<a
3385href="command-line-options.html#bordercolor">-bordercolor</a>). Finally <code>reset</code> changes the
Cristy882d9f42015-10-29 16:48:39 -04003386matte value of all pixels.</p>
3387
Cristy594d2772015-11-15 10:47:42 -05003388<p>You can set the primitive color, font, and font bounding box color with <a
3389href="command-line-options.html#fill">-fill</a>, <a href="command-line-options.html#font">-font</a>, and <a href="command-line-options.html#box">-box</a>
Cristy882d9f42015-10-29 16:48:39 -04003390respectively. Options are processed in command line order so be sure to use
3391these options <var>before</var> the <a href="command-line-options.html#draw">-draw</a> option.</p>
3392
3393<p>Strings that begin with a number must be quoted (e.g. use '1.png' rather
3394than 1.png).</p>
3395
Cristy594d2772015-11-15 10:47:42 -05003396<p>Drawing primitives conform to the <a href="magick-vector-graphics.html" >Magick
Cristy882d9f42015-10-29 16:48:39 -04003397Vector Graphics</a> format.</p>
3398
3399
3400<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04003401 <h3><a id="duplicate"></a>-duplicate <var>count,indexes</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04003402</div>
3403
3404<p class="magick-description">duplicate an image one or more times.</p>
3405
3406<p>Specify the count and the image to duplicate by its index in the sequence.
3407The first image is index 0. Negative indexes are relative to the end of the
3408sequence, for example, -1 represents the last image of the sequence. Specify
3409a range of images with a dash (e.g. 0-4). Separate indexes with a comma (e.g.
34100,2). Use <code>+duplicate</code> to duplicate the last image in the current
3411image sequence.</p>
3412
3413<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04003414 <h3><a id="edge"></a>-edge <var>radius</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04003415</div>
3416
3417<p class="magick-description">detect edges within an image.</p>
3418
3419<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04003420 <h3><a id="emboss"></a>-emboss <var>radius</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04003421</div>
3422
3423<p class="magick-description">emboss an image.</p>
3424
3425<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04003426 <h3><a id="encipher"></a>-encipher <var>filename</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04003427</div>
3428
3429<p class="magick-description">Encipher pixels for later deciphering by <a href="command-line-options.html#decipher">-decipher</a>.</p>
3430
3431<p>Get the passphrase from the file specified by <var>filename</var>.</p>
3432
Cristy594d2772015-11-15 10:47:42 -05003433<p>For more information, see the webpage, <a
Cristy6549abb2016-11-10 08:25:55 -05003434href="https://www.imagemagick.org/script/cipher.html">ImageMagick: Encipher or
Cristy882d9f42015-10-29 16:48:39 -04003435Decipher an Image</a>.</p>
3436
3437
3438
3439<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04003440 <h3><a id="encoding"></a>-encoding <var>type</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04003441</div>
3442
3443<p class="magick-description">specify the text encoding.</p>
3444
3445<p>Choose from</p>
3446
Cristy49380402017-06-29 11:24:55 -04003447<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04003448AdobeCustom AdobeExpert
3449AdobeStandard AppleRoman
3450BIG5 GB2312
3451Latin 2 None
3452SJIScode Symbol
3453Unicode Wansung
Cristy49380402017-06-29 11:24:55 -04003454</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04003455
3456<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04003457 <h3><a id="endian"></a>-endian <var>type</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04003458</div>
3459
3460<p class="magick-description">Specify endianness (<code>MSB</code> or <code>LSB</code>) of the image.</p>
3461
3462<p>To print a complete list of endian types, use the <a href="command-line-options.html#list">-list endian</a> option.</p>
3463
3464<p>Use <a href="command-line-options.html#endian">+endian</a> to revert to unspecified endianness.</p>
3465
3466
3467<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04003468 <h3><a id="enhance"></a>-enhance</h3>
Cristy882d9f42015-10-29 16:48:39 -04003469</div>
3470
3471<p class="magick-description">Apply a digital filter to enhance a noisy image.</p>
3472
3473
3474<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04003475 <h3><a id="equalize"></a>-equalize</h3>
Cristy882d9f42015-10-29 16:48:39 -04003476</div>
3477
3478<p class="magick-description">perform histogram equalization on the image channel-by-channel.</p>
3479
3480<p>To perform histogram equalization on all channels in concert, transform the
3481image into some other color space, such as HSL, OHTA, YIQ or YUV, then
3482equalize the appropriate intensity-like channel, then convert back to RGB.</p>
3483
3484<p>For example using HSL, we have: ... <code>-colorspace HSL -channel lightness
3485-equalize -colorspace RGB</code> ...</p>
3486
3487<p>For YIQ, YUV and OHTA use the red channel. For example, OHTA is a principal
3488components transformation that puts most of the information in the first
3489channel. Here we have ... <code>-colorspace OHTA -channel red -equalize
3490-colorspace RGB</code> ...</p>
3491
3492<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04003493 <h3><a id="evaluate"></a>-evaluate <var>operator value</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04003494</div>
3495
3496<p class="magick-description">Alter channel pixels by evaluating an arithmetic, relational, or logical expression.</p>
3497
Cristy594d2772015-11-15 10:47:42 -05003498<p>(See the <a href="command-line-options.html#function" >-function</a> operator for some
3499multi-parameter functions. See the <a href="command-line-options.html#fx" >-fx</a> operator if more
Cristy882d9f42015-10-29 16:48:39 -04003500elaborate calculations are needed.)</p>
3501
3502<p>The behaviors of each <var>operator</var> are summarized in the
3503following list. For brevity, the numerical value of a "pixel" referred to
3504below is the value of the corresponding channel of that pixel, while
3505a "normalized pixel" is that number divided by the maximum
3506(installation-dependent) value <var>QuantumRange</var>. (If
3507normalized pixels are used, they are restored, following the other
3508calculations, to the full range by multiplying by <var>QuantumRange</var>.)</p>
3509
Cristy49380402017-06-29 11:24:55 -04003510<table class="table table-sm table-striped">
Cristy594d2772015-11-15 10:47:42 -05003511 <col width="25%" />
3512 <col width="75%" />
Cristy882d9f42015-10-29 16:48:39 -04003513 <thead>
3514 <tr>
3515 <th><var>operator</var></th>
3516 <th>Summary (see further below for details)</th>
3517 </tr>
3518 </thead>
3519 <tbody>
3520
3521 <tr><td>Abs </td> <td>Add <var>value</var> to pixels and return absolute value. </td></tr>
3522 <tr><td>Add </td> <td>Add <var>value</var> to pixels. </td></tr>
3523 <tr><td>AddModulus </td> <td>Add <var>value</var> to pixels modulo <var>QuantumRange</var>.</td></tr>
3524 <tr><td>And </td> <td>Binary AND of pixels with <var>value</var>.</td></tr>
3525 <tr><td>Cos, Cosine </td> <td>Apply cosine to pixels with frequency <var>value</var> with 50% bias added.</td></tr>
3526 <tr><td>Divide </td> <td>Divide pixels by <var>value</var>.</td></tr>
3527 <tr><td>Exp </td> <td>base-e exponential function</td></tr>
3528 <tr><td>Exponential </td> <td>base-e exponential function</td></tr>
3529 <tr><td>LeftShift </td> <td>Shift the pixel values left by <var>value</var> bits (i.e., multiply pixels by 2<sup><var>value</var></sup>).</td></tr>
3530 <tr><td>Log </td> <td>Apply scaled logarithm to normalized pixels.</td></tr>
3531 <tr><td>Max </td> <td>Set pixels to maximum of <var>value</var> and current pixel <var>value</var> (i.e. set any pixels currently less than <var>value</var> to <var>value</var>).</td></tr>
3532 <tr><td>Mean </td> <td>Add the <var>value</var> and divide by 2.</td></tr>
3533 <tr><td>Median </td> <td>Choose the median value from an image sequence.</td></tr>
3534 <tr><td>Min </td> <td>Set pixels to minimum of <var>value</var> and current pixel <var>value</var> (i.e. set any pixels currently greater than <var>value</var> to <var>value</var>).</td></tr>
3535 <tr><td>Multiply </td> <td>Multiply pixels by <var>value</var>.</td></tr>
3536 <tr><td>Or </td> <td>Binary OR of pixels with <var>value</var>.</td></tr>
3537 <tr><td>Pow </td> <td>Raise normalized pixels to the power <var>value</var>.</td></tr>
3538 <tr><td>RightShift </td> <td>Shift the pixel values right by <var>value</var> bits (i.e., divide pixels by 2<sup><var>value</var></sup>).</td></tr>
3539 <tr><td>RMS</td> <td>Square the pixel and add the <var>value</var>.</td></tr>
3540 <tr><td>RootMeanSquare</td> <td>Square the pixel and add the <var>value</var>.</td></tr>
3541 <tr><td>Set </td> <td>Set pixel equal to <var>value</var>.</td></tr>
3542 <tr><td>Sin, Sine </td> <td>Apply sine to pixels with frequency <var>value</var> with 50% bias added.</td></tr>
3543 <tr><td>Subtract </td> <td>Subtract <var>value</var> from pixels.</td></tr>
3544 <tr><td>Xor </td> <td>Binary XOR of pixels with <var>value.</var></td></tr>
3545
3546 <tr><td> </td><td> </td></tr>
3547
3548 <tr><td>Gaussian-noise</td><td> </td></tr>
3549 <tr><td>Impulse-noise</td><td> </td></tr>
3550 <tr><td>Laplacian-noise</td><td> </td></tr>
Cristy594d2772015-11-15 10:47:42 -05003551 <tr><td>Multiplicative-noise</td> <td>(These are equivalent to the corresponding <a href="command-line-options.html#noise" >-noise</a> operators.)</td></tr>
Cristy882d9f42015-10-29 16:48:39 -04003552 <tr><td>PoissonNoise</td><td> </td></tr>
3553 <tr><td>Uniform-noise</td><td> </td></tr>
3554
3555 <tr><td> </td><td> </td></tr>
3556
3557 <tr><td>Threshold </td> <td>Threshold pixels larger than <var>value</var>.</td></tr>
3558 <tr><td>ThresholdBlack </td> <td>Threshold pixels to zero values equal to or below <var>value</var>.</td></tr>
3559 <tr><td>ThresholdWhite </td> <td>Threshold pixels to maximum values above <var>value</var>. </td></tr>
3560 </tbody>
3561 </table>
3562
Cristy594d2772015-11-15 10:47:42 -05003563<p>The specified functions are applied only to each previously set <a
3564href="command-line-options.html#channel" >-channel</a> in the image. If necessary, the results of the
Cristy882d9f42015-10-29 16:48:39 -04003565calculations are truncated (clipped) to fit in the interval [0, <var>QuantumRange</var>]. The transparency channel of the image is
3566represented as a 'alpha' values (0 = fully transparent), so, for example, a
3567<code>Divide</code> by 2 of the alpha channel will make the image
3568semi-transparent. Append the percent symbol '<code>%</code>' to specify a value
3569as a percentage of the <var>QuantumRange</var>.</p>
3570
3571<p>To print a complete list of <a href="command-line-options.html#evaluate">-evaluate</a> operators, use
3572<a href="command-line-options.html#list">-list evaluate</a>.</p>
3573
3574<p>The results of the <code>Add</code>, <code>Subtract</code> and
Cristy594d2772015-11-15 10:47:42 -05003575<code>Multiply</code> methods can also be achieved using either the <a
3576href="command-line-options.html#level" >-level</a> or the <a href="command-line-options.html#level" >+level</a> operator, with
Cristy882d9f42015-10-29 16:48:39 -04003577appropriate argument, to linearly modify the overall range of color values.
Cristy594d2772015-11-15 10:47:42 -05003578Please note, however, that <a href="command-line-options.html#level" >-level</a> treats transparency as
3579'matte' values (0 = opaque), while <a href="command-line-options.html#level" >-evaluate</a> works with
Cristy882d9f42015-10-29 16:48:39 -04003580'alpha' values.</p>
3581
3582<p><code>AddModulus</code> has been added as of ImageMagick 6.4.8-4 and provides
3583addition modulo the <var>QuantumRange</var>. It is therefore
3584equivalent to <code>Add</code> unless the resulting pixel value is outside the
3585interval [0, <var>QuantumRange</var>]. </p>
3586
3587<p><code>Exp or Exponential</code> has been added as of ImageMagick 6.6.5-1 and
3588works on normalized pixel values. The <var>value</var> used with
3589<code>Exp</code> should be negative so as to produce a decaying exponential
3590function. Non-negative values will always produce results larger unity and
3591thus outside the interval [0, <var>QuantumRange</var>]. The
3592formula is expressed below. </p>
3593
3594<p class="text-center">
3595exp(<var>value</var> × <b><var>u</var></b>)
3596</p>
3597
Cristy594d2772015-11-15 10:47:42 -05003598<p> If the input image is squared, for example, using <a href="command-line-options.html#-function"
3599>-function polynomial "2 0 0"</a>, then a decaying Gaussian function will be
Cristy882d9f42015-10-29 16:48:39 -04003600the result.</p>
3601
3602<p><code>Log</code> has been added as of ImageMagick 6.4.2-1 and works on
3603normalized pixel values. This a <var>scaled</var> log function. The <var>value</var> used with <code>Log</code> provides a <var>scaling
3604factor</var> that adjusts the curvature in the graph of the log function. The
3605formula applied to a normalized value <b><var>u</var></b> is below. </p>
3606
3607<p class="text-center">
3608log(<var>value</var> × <b><var>u</var></b> + 1) / log(<var>value</var> + 1)
3609</p>
3610
3611<p><code>Pow</code> has been added as of ImageMagick 6.4.1-9, and works on
Cristy594d2772015-11-15 10:47:42 -05003612normalized pixel values. Note that <code>Pow</code> is related to the <a
3613href="command-line-options.html#gamma" >-gamma</a> operator. For example, <b>-gamma 2</b> is equivalent
Cristy882d9f42015-10-29 16:48:39 -04003614to <b>-evaluate pow 0.5</b>, i.e., a 'square root' function. The value used
Cristy594d2772015-11-15 10:47:42 -05003615with <a href="command-line-options.html#gamma" >-gamma</a> is simply the reciprocal of the value used
Cristy882d9f42015-10-29 16:48:39 -04003616with <code>Pow</code>.</p>
3617
3618<p><code>Cosine</code> and <code>Sine</code> was added as of IM v6.4.8-8 and
3619converts the image values into a value according to a (co)sine wave function.
3620The synonyms <code>Cos</code> and <code>Sin</code> may also be used. The output
3621is biased 50% and normalized by 50% so as to fit in the respective color value
3622range. The <var>value</var> scaling of the <var>period</var> of the
3623function (its frequency), and thus determines the number of 'waves' that will
3624be generated over the input color range. For example, if the <var>value</var> is 1, the effective period is simply the <var>QuantumRange</var>; but if the <var>value</var> is 2,
3625then the effective period is the <var>half</var> the <var>QuantumRange</var>.</p>
3626
3627<p class="text-center">
36280.5 + 0.5 × cos(2 π <b><var>u</var></b> × <var>value</var>).
3629</p>
3630
Cristy594d2772015-11-15 10:47:42 -05003631<p>See also the <a href="command-line-options.html#function" >-function</a> operator, which is a
Cristy882d9f42015-10-29 16:48:39 -04003632multi-value version of evaluate. </p>
3633
3634<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04003635 <h3><a id="evaluate-sequence"></a>-evaluate-sequence <var>operator</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04003636</div>
3637
3638<p class="magick-description">Alter channel pixels by evaluating an arithmetic, relational, or
3639logical expression over a sequence of images.</p>
3640
Cristy594d2772015-11-15 10:47:42 -05003641<p>To print a complete list of <a
3642href="command-line-options.html#evaluate-sequence">-evaluate-sequence</a> operators, use <a
3643href="command-line-options.html#list">-list evaluate</a>.</p>
Cristy882d9f42015-10-29 16:48:39 -04003644
3645<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04003646 <h3><a id="extent"></a>-extent <var>geometry</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04003647</div>
3648
3649<p class="magick-description">Set the image size and offset.</p>
3650
3651<p>If the image is enlarged, unfilled areas are set to the background color.
3652To position the image, use offsets in the <var>geometry</var>
3653specification or precede with a <a href="command-line-options.html#gravity">-gravity</a> setting. To
Cristy594d2772015-11-15 10:47:42 -05003654specify how to compose the image with the background, use <a href="command-line-options.html#compose"
3655>-compose</a>.</p>
Cristy882d9f42015-10-29 16:48:39 -04003656
3657<p>This command reduces or expands a JPEG image to fit on an 800x600
3658display. If the aspect ratio of the input image isn't exactly 4:3, then the
3659image is centered on an 800x600 black canvas: </p>
3660
Cristy49380402017-06-29 11:24:55 -04003661<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04003662convert input.jpg -resize 800x600 -background black -compose Copy \
3663 -gravity center -extent 800x600 -quality 92 output.jpg
Cristy49380402017-06-29 11:24:55 -04003664</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04003665
3666<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
3667
3668<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04003669 <h3><a id="extract"></a>-extract <var>geometry</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04003670</div>
3671
3672<p class="magick-description">Extract the specified area from image.</p>
3673
3674<p>This option is most useful for extracting a subregion of a very large raw
3675image. Note that these two commands are equivalent:</p>
3676
Cristy49380402017-06-29 11:24:55 -04003677<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04003678convert -size 16000x16000 -depth 8 -extract 640x480+1280+960 \
3679 image.rgb image.png",
3680convert -size 16000x16000 -depth 8 'image.rgb[640x480+1280+960]' \
3681 image.rgb image.png"
Cristy49380402017-06-29 11:24:55 -04003682</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04003683
3684<p>If you omit the offsets, as in</p>
3685
Cristy49380402017-06-29 11:24:55 -04003686<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04003687convert -size 16000x16000 -depth 8 -extract 640x480 \
3688 image.rgb image.png
Cristy49380402017-06-29 11:24:55 -04003689</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04003690
3691<p>the image is <var>resized</var> to the specified dimensions instead,
3692equivalent to:</p>
3693
Cristy49380402017-06-29 11:24:55 -04003694<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04003695convert -size 16000x16000 -depth 8 -resize 640x480 image.rgb image.png
Cristy49380402017-06-29 11:24:55 -04003696</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04003697
3698<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
3699
3700<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04003701 <h3><a id="family"></a>-family <var>fontFamily</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04003702</div>
3703
3704<p class="magick-description">Set a font family for text.</p>
3705
3706<p>This setting suggests a font family that ImageMagick should try to use for
3707rendering text. If the family can be found it is used; if not, a default font
3708(e.g., "Arial") or a family known to be similar is substituted (e.g.,
3709"Courier" might be used if "System" is requested but not found). </p>
3710
Cristy594d2772015-11-15 10:47:42 -05003711<p>For other settings that affect fonts, see the options <a
3712href="command-line-options.html#font">-font</a>, <a href="command-line-options.html#stretch">-stretch</a>, <a
3713href="command-line-options.html#style">-style</a>, and <a href="command-line-options.html#weight">-weight</a>. </p>
Cristy882d9f42015-10-29 16:48:39 -04003714
3715<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04003716 <h3><a id="features"></a>-features <var>distance</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04003717</div>
3718
3719<p class="magick-description">display (co-occurrence matrix) texture measure features for each channel in the image in each of four directions (horizontal, vertical, left and right diagonals) for the specified distance.</p>
3720
Cristy49380402017-06-29 11:24:55 -04003721<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04003722Angular Second Moment Sum Entropy
3723Contrast Entropy
3724Correlation Difference Variance
3725Sum of Squares Variance Difference Entropy
3726Inverse Difference Moment Information Measure of Correlation 1
3727Sum Average Information Measure of Correlation 2
3728Sum Variance Maximum Correlation Coefficient
Cristy49380402017-06-29 11:24:55 -04003729</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04003730
3731<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04003732 <h3><a id="fft"></a>-fft</h3>
Cristy882d9f42015-10-29 16:48:39 -04003733</div>
3734
3735<p class="magick-description">implements the forward discrete Fourier transform (DFT).</p>
3736
3737<p>This option is new as of ImageMagick 6.5.4-3 (and now working for Windows
3738users in ImageMagick 6.6.0-9). It transforms an image from the normal
3739(spatial) domain to the frequency domain. In the frequency domain, an image is
3740represented as a superposition of complex sinusoidal waves of varying
3741amplitudes. The image x and y coordinates are the possible frequencies along
3742the x and y directions, respectively, and the pixel intensity values are
3743complex numbers that correspond to the sinusoidal wave amplitudes. See for
3744example, <a href="http://en.wikipedia.org/wiki/Fourier_transform">Fourier
3745Transform</a>, <a href="http://en.wikipedia.org/wiki/DFT">Discrete Fourier
3746Transform</a> and <a href="http://en.wikipedia.org/wiki/FFT">Fast Fourier
3747Transform</a>.</p>
3748
3749<p>A single image name is provided as output for this option. However, the
3750output result will have two components. It is either a two-frame image or two
3751separate images, depending upon whether the image format specified supports
3752multi-frame images. The reason that we get a dual output result is because the
3753frequency domain represents an image using complex numbers, which cannot be
3754visualized directly. Therefore, the complex values are automagically separated
3755into a two-component image representation. The first component is the
3756magnitude of the complex number and the second is the phase of the complex
Cristy594d2772015-11-15 10:47:42 -05003757number. See for example, <a
3758href="http://en.wikipedia.org/wiki/Complex_numbers">Complex Numbers</a>.</p>
Cristy882d9f42015-10-29 16:48:39 -04003759
3760<p>The magnitude and phase component images must be specified using image
3761formats that do not limit the color or compress the image. Thus, MIFF, TIF,
3762PFM, EXR and PNG are the recommended image formats to use. All of these
3763formats, except PNG support multi-frame images. So for example,</p>
3764
Cristy49380402017-06-29 11:24:55 -04003765<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04003766convert image.png -fft fft_image.miff
Cristy49380402017-06-29 11:24:55 -04003767</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04003768
3769<p>generates a magnitude image as <code>fft_image.miff[0]</code> and a phase
3770image as <code>fft_image.miff[1]</code>. Similarly,</p>
3771
Cristy49380402017-06-29 11:24:55 -04003772<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04003773convert image.png -fft fft_image.png
Cristy49380402017-06-29 11:24:55 -04003774</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04003775
3776<p>generates a magnitude image as <code>fft_image-0.png</code> and a phase image
3777as <code>fft_image-1.png</code>. If you prefer this representation, then you can
Cristy594d2772015-11-15 10:47:42 -05003778force any of the other formats to produce two output images by including <a
3779href="command-line-options.html#adjoin">+adjoin</a> following -fft in the command line.</p>
Cristy882d9f42015-10-29 16:48:39 -04003780
3781<p>The input image can be any size, but if not square and even-dimensioned, it
3782is padded automagically to the larger of the width or height of the input
3783image and to an even number of pixels. The padding will occur at the bottom
3784and/or right sides of the input image. The resulting output magnitude and
Cristy594d2772015-11-15 10:47:42 -05003785phase images is square at this size. The kind of padding relies on the <a
3786href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting.</p>
Cristy882d9f42015-10-29 16:48:39 -04003787
3788<p>Both output components will have dynamic ranges that fit within
3789[0, <var>QuantumRange</var>], so that HDRI need not be enabled.
3790Phase values nominally range from 0 to 2*π, but is scaled to span the full
3791dynamic range. (The first few releases had non-HDRI scaled but HDRI not
3792scaled). The magnitude image is not scaled and thus generally will contain
3793very small values. As such, the image normally will appear totally black. In
3794order to view any detail, the magnitude image typically is enhanced with a log
3795function into what is usually called the spectrum. A log function is used to
3796enhance the darker values more in comparison to the lighter values. This can
3797be done, for example, as follows:</p>
3798
Cristy49380402017-06-29 11:24:55 -04003799<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04003800convert fft_image.miff[0] -contrast-stretch 0 \
3801 -evaluate log 1000 fft_image_spectrum.png"
Cristy49380402017-06-29 11:24:55 -04003802</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04003803
Cristy594d2772015-11-15 10:47:42 -05003804<p>where either <a href="command-line-options.html#contrast-stretch">-contrast-stretch</a> 0 or <a
3805href="command-line-options.html#auto-level">-auto-level</a> is used to scale the image to full dynamic
Cristy882d9f42015-10-29 16:48:39 -04003806range, first. The argument to the <a href="command-line-options.html#evaluate">-evaluate</a> log
3807typically is specified between 100 and 10,000, depending upon the amount of
3808detail that one wants to bring out in the spectrum. Larger values produce more
3809visible detail. Too much detail, however, may hide the important features.</p>
3810
3811<p>The <a href="http://www.fftw.org/">FFTW</a> delegate library is required to
3812use <a href="command-line-options.html#fft">-fft</a>.</p>
3813
3814<p>Use <a href="command-line-options.html#fft">+fft</a> to produce two output images that are the real
3815and imaginary components of the complex valued Fourier transform.</p>
3816
3817<p>However, as the real and imaginary components can contain negative values,
3818this requires that IM be configured with HDRI enabled. In this case, you must
3819use either MIFF, TIF, PFM or MPC formats for the real and imaginary component
3820results, since they are formats that preserve both negative and fractional
3821values without clipping them or truncating the fractional part. With either
3822MIFF or TIF, one should add -define quantum:format=32, to allow those image
3823types to work properly in HDRI mode without clipping.</p>
3824
Cristy594d2772015-11-15 10:47:42 -05003825<p>The real and imaginary component images resulting from <a
3826href="command-line-options.html#fft">+fft</a> are also square, even dimensioned images due to the same
Cristy882d9f42015-10-29 16:48:39 -04003827padding that was discussed above for the magnitude and phase component
3828images.</p>
3829
Cristy594d2772015-11-15 10:47:42 -05003830<p>See the discussion on HDRI implementations of ImageMagick on the page <a
3831href="high-dynamic-range.html" >High Dynamic-Range Images</a>. For more
3832about HDRI go the ImageMagick <a
Cristy364a72f2016-11-04 22:38:41 -04003833href="https://www.imagemagick.org/Usage/basics/#hdri" >Usage</a> pages, <a
Cristy594d2772015-11-15 10:47:42 -05003834href="http://www.fmwconcepts.com/imagemagick/fourier_transforms/fourier.html"
3835>Fred's Fourier Processing With ImageMagick page</a> or this <a
3836 href="http://en.wikipedia.org/wiki/High_dynamic_range_imaging" >Wikipedia</a>
Cristy882d9f42015-10-29 16:48:39 -04003837 entry. </p>
3838
Cristy594d2772015-11-15 10:47:42 -05003839<p>By default the FFT is normalized (and the IFT is not). Use "<code><a href="command-line-options.html#define" >-define</a> fourier:normalize=forward</code> to explicitly normalize the FFT and unnormalize the IFT.</p>
Cristy882d9f42015-10-29 16:48:39 -04003840
3841
3842<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04003843 <h3><a id="fill"></a>-fill <var>color</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04003844</div>
3845
3846<p class="magick-description">color to use when filling a graphic primitive.</p>
3847
3848<p>This option accepts a color name, a hex color, or a numerical RGB, RGBA,
Cristy594d2772015-11-15 10:47:42 -05003849HSL, HSLA, CMYK, or CMYKA specification. See <a href="color.html" >Color Names</a> for
Cristy882d9f42015-10-29 16:48:39 -04003850a description of how to properly specify the color argument.</p>
3851
3852<p>Enclose the color specification in quotation marks to prevent the "#" or
3853the parentheses from being interpreted by your shell.</p>
3854
3855<p>For example,</p>
3856
Cristy49380402017-06-29 11:24:55 -04003857<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04003858-fill blue
3859-fill "#ddddff"
3860-fill "rgb(255,255,255)"
Cristy49380402017-06-29 11:24:55 -04003861</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04003862
3863<p>See <a href="command-line-options.html#draw">-draw</a> for further details.</p>
3864
3865<p>To print a complete list of color names, use the <a href="command-line-options.html#list">-list color</a> option.</p>
3866
3867<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04003868 <h3><a id="filter"></a>-filter <var>type</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04003869</div>
3870
3871<p class="magick-description">Use this <var>type</var> of filter when resizing or distorting an image.</p>
3872
3873<p>Use this option to affect the resizing operation of an image during
Cristy594d2772015-11-15 10:47:42 -05003874operations such as <a href="command-line-options.html#resize">-resize</a> and <a href="command-line-options.html#distort"
3875>-distort</a>. For example you can use a simple resize filter such as:</p>
Cristy882d9f42015-10-29 16:48:39 -04003876
Cristy49380402017-06-29 11:24:55 -04003877<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04003878Point Hermite Cubic
3879Box Gaussian Catrom
3880Triangle Quadratic Mitchell
Cristy49380402017-06-29 11:24:55 -04003881</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04003882
3883<p>The <code>Bessel</code> and <code>Sinc</code> filter is also provided (as well
3884as a faster <code>SincFast</code> equivalent form). However these filters are
3885generally useless on their own as they are infinite filters that are being
3886clipped to the filters support size. Their direct use is not recommended
3887except via expert settings (see below). </p>
3888
3889<p>Instead these special filter functions are typically windowed by a windowing
Cristy594d2772015-11-15 10:47:42 -05003890function that the <a href="command-line-options.html#filter" >-filter</a> setting defines. That is
Cristy882d9f42015-10-29 16:48:39 -04003891using these functions will define a 'Windowed' filter, appropriate to the
3892operator involved. Windowed filters include: </p>
3893
Cristy49380402017-06-29 11:24:55 -04003894<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04003895Lanczos Hamming Parzen
3896Blackman Kaiser Welsh
3897Hanning Bartlett Bohman
Cristy49380402017-06-29 11:24:55 -04003898</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04003899
3900<p>Also one special self-windowing filter is also provided
3901<code>Lagrange</code>, which will automagically re-adjust its function depending
3902on the current 'support' or 'lobes' expert settings (see below).</p>
3903
3904<p>If you do not select a filter with this option, the filter defaults to
3905<code>Mitchell</code> for a colormapped image, an image with a matte channel, or
3906if the image is enlarged. Otherwise the filter default to
3907<code>Lanczos</code>.</p>
3908
3909<p>To print a complete list of resize filters, use the <a href="command-line-options.html#list">-list
3910filter</a> option.</p>
3911
3912<p>You can modify how the filter behaves as it scales your image through the
Cristy594d2772015-11-15 10:47:42 -05003913use of these expert settings (see also <a href="command-line-options.html#define" >-define</a> and <a
3914href="command-line-options.html#set" >-set</a>):-</p>
Cristy882d9f42015-10-29 16:48:39 -04003915
Cristy49380402017-06-29 11:24:55 -04003916<table class="table table-sm table-striped">
Cristy882d9f42015-10-29 16:48:39 -04003917 <tr>
3918 <td>-define filter:blur=<var>factor</var></td>
3919 <td>Scale the X axis of the filter (and its window). Use &gt; 1.0 for
3920 blurry or &lt; 1.0 for sharp. This should only be used with Gaussian and
3921 Gaussian-like filters simple filters, or you may not get the expected
3922 results. </td>
3923 </tr>
3924
3925 <tr>
3926 <td>-define filter:support=<var>radius</var></td>
3927 <td>Set the filter support radius. Defines how large the filter should be and
3928 thus directly defines how slow the filtered resampling process is. All
3929 filters have a default 'preferred' support size. Some filters like
3930 <code>Lagrange</code> and windowed filters adjust themselves depending on
3931 this value. With simple filters this value either does nothing (but slow
3932 the resampling), or will clip the filter function in a detrimental way.
3933 </td>
3934 </tr>
3935
3936 <tr>
3937 <td>-define filter:lobes=<var>count</var></td>
3938 <td>Set the number of lobes to use for the Sinc/Bessel filter. This an
3939 alternative way of specifying the 'support' range of the filter, that is
3940 designed to be more suited to windowed filters, especially when used for
3941 image distorts.</td>
3942 </tr>
3943
3944 <tr>
3945 <td>-define filter:sigma=<var>value</var></td>
3946 <td>The 'sigma' value used to define the <code>Gaussian</code> filter. Default
3947 sigma value is '<code>0.5</code>'. It only effects <code>Gaussian</code> but
3948 does not shrink (but may enlarge) the filter's 'support'. It can be used
3949 to generate very small blurs but without the filter 'missing' pixels due
3950 to using a small support setting. A larger value of '<code>0.707</code>'
3951 (a value of '1/sqrt(2)') is another common setting. </td>
3952 </tr>
3953
3954 <tr>
3955 <td>-define filter:b=<var>b-spline_factor</var></td>
Cristy579a0cb2016-11-26 12:27:17 -05003956 </tr>
3957
Cristy594d2772015-11-15 10:47:42 -05003958 <tr>
Cristy882d9f42015-10-29 16:48:39 -04003959 <td>-define filter:c=<var>keys_alpha_factor</var></td>
3960 <td>Redefine the values used for cubic filters such as <code>Cubic</code>,
3961 <code>Catrom</code>, <code>Mitchel</code>, and <code>Hermite</code>, as well as
3962 the <code>Parzen</code> cubic windowing function. If only one of the values
3963 are defined, the other is set so as to generate a 'Cubic-Keys' filter.
3964 The values meaning was defined by a research paper by
3965 Mitchell-Netravali.</td>
3966 </tr>
3967
3968 <tr>
3969 <td>-define filter:kaiser-beta=<var>value</var></td>
3970 <td>The 'alpha' value used to as part of the Kaiser Windowing function.
3971 Default value is '6.5'. It only effects Kaiser windowing function, and
3972 does not effect any other attributes.
3973 Before ImageMagick v6.7.6-10, this option was known as "filter:alpha", (an
3974 inheritance from the very old "zoom" program). It was changed to bring the
3975 function in line with more modern academic research usage, and better
3976 assign it be more definitive. </td>
3977 </tr>
3978
3979 <tr>
3980 <td>-define filter:kaiser-alpha=<var>value</var></td>
3981 <td>This value when multiplied by 'PI' is equivalent to "kaiser-beta", and
3982 will override that setting. It only effects Kaiser windowing function,
3983 and does not effect any other attributes. </td>
3984 </tr>
3985
3986 <tr>
3987 <td>-define filter:filter=<var>filter_function</var></td>
3988 <td>Use this function directly as the weighting filter. This will allow
3989 you to directly use a windowing function such as <code>Blackman</code>,
3990 as a resampling filter, rather than as its normal usage as a windowing
3991 function. If defined, no windowing function also defined, the window function is set
3992 to <code>Box</code>). Directly specifying <code>Sinc</code> or <code>Jinc</code>
3993 as a filter will also do this. </td>
3994 </tr>
3995
3996 <tr>
3997 <td>-define filter:window=<var>filter_function</var></td>
3998 <td>The IIR (infinite impulse response) filters <code>Sinc</code> and
3999 <code>Jinc</code> are windowed (brought down to zero over the defined
4000 support range) with the given filter. This allows you to specify a filter
4001 function to be used as a windowing function for these IIR filters.
4002 Many of the defined filters are actually windowing functions for these IIR
4003 filters. A typical choices is <code>Box</code>, (which effectively turns
4004 off the windowing function). </td>
4005 </tr>
4006
4007 <tr>
4008 <td>-define filter:win-support=<var>radius</var></td>
4009 <td>Scale windowing function to this size instead. This causes the windowing
4010 (or self-windowing Lagrange filter) to act is if the support window is
4011 larger than what is actually supplied to the calling operator. The filter
4012 however is still clipped to the real support size given. If unset this
4013 will equal the normal filter support size. </td>
4014 </tr>
4015
4016 <tr>
4017 <td>-define filter:verbose=<var>1</var></td>
4018 <td>This causes IM to print information on the final internal filter
4019 selection to standard output. This includes a commented header on the
4020 filter settings being used, and data allowing the filter weights to be
4021 easily graphed. Note however that some filters are internally defined in terms of other filters. The <code>Lanczos</code> filter for example is defined in terms of
4022 a <code>SincFast</code> windowed <code>SincFast</code> filter, while
4023 <code>Mitchell</code> is defined as a general <code>Cubic</code> family filter
4024 with specific 'B' and 'C' settings. </td>
4025 </tr>
4026
4027</table>
4028
4029<p>For example, to get a 8 lobe jinc windowed sinc filter (Genseng filter?):</p>
4030
Cristy49380402017-06-29 11:24:55 -04004031<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04004032convert image.png \
4033 -filter sinc \
4034 -set filter:window=jinc \
4035 -set filter:lobes=8 \
4036 -resize 150% image.jpg"
Cristy49380402017-06-29 11:24:55 -04004037</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04004038
4039<p>Or a raw un-windowed Sinc filter with 4 lobes:</p>
4040
Cristy49380402017-06-29 11:24:55 -04004041<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04004042convert image.png \
4043 -set filter:filter=sinc \
4044 -set filter:lobes=4 \
4045 -resize 150% image.jpg"
Cristy49380402017-06-29 11:24:55 -04004046</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04004047
4048<p>To extract the data for a raw windowing function, combine it with
4049a '<code>Box</code>' filter. For example the '<code>Welch</code> parabolic
4050windowing function. </p>
4051
Cristy49380402017-06-29 11:24:55 -04004052<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04004053convert null: -define filter:filter=Box \
4054 -define filter:window=Welch \
4055 -define filter:support=1.0 \
4056 -define filter:verbose=1 \
Cristy594d2772015-11-15 10:47:42 -05004057 -resize 2 null: > window_welch.dat
Cristy882d9f42015-10-29 16:48:39 -04004058gnuplot
4059 set grid
4060 plot \"window_welch.dat\" with lines
Cristy49380402017-06-29 11:24:55 -04004061</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04004062
4063<p>Note that the use of expert options is provided for image processing experts
4064who have studied and understand how resize filters work. Without this
4065knowledge, and an understanding of the definition of the actual filters
4066involved, using expert settings are more likely to be detrimental to your image
4067resizing.</p>
4068
4069
4070<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004071 <h3><a id="flatten"></a>-flatten</h3>
Cristy882d9f42015-10-29 16:48:39 -04004072</div>
4073
Cristy594d2772015-11-15 10:47:42 -05004074<p class="magick-description">This is a simple alias for the <a href="command-line-options.html#layers" >-layers</a> method "flatten".</p>
Cristy882d9f42015-10-29 16:48:39 -04004075
4076
4077<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004078 <h3><a id="flip"></a>-flip</h3>
Cristy882d9f42015-10-29 16:48:39 -04004079</div>
4080
4081<p class="magick-description">create a <var>mirror image</var></p>
4082
4083<p>reflect the scanlines in the vertical direction. The image will be mirrored
4084upside-down. </p>
4085
4086
4087<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004088 <h3><a id="floodfill"></a>-floodfill {<var>+-</var>}<var>x</var>{<var>+-</var>}<var>y</var> <var>color</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004089</div>
4090
4091<p class="magick-description">floodfill the image with color at the specified offset.</p>
4092
4093<p>Flood fill starts from the given 'seed point' which is not gravity effected.
Cristy594d2772015-11-15 10:47:42 -05004094Any color that matches within <a href="command-line-options.html#fuzz" >-fuzz</a> color distance of the
Cristy882d9f42015-10-29 16:48:39 -04004095given <var>color</var> argument, connected to that 'seed point'
Cristy594d2772015-11-15 10:47:42 -05004096will be replaced with the current <a href="command-line-options.html#fill" >-fill</a> color. </p>
Cristy882d9f42015-10-29 16:48:39 -04004097
4098<p>Note that if the pixel at the 'seed point' does not itself match the given
Cristy594d2772015-11-15 10:47:42 -05004099<var>color</var> (according to <a href="command-line-options.html#fuzz" >-fuzz</a>), then no
Cristy882d9f42015-10-29 16:48:39 -04004100action will be taken. </p>
4101
Cristy594d2772015-11-15 10:47:42 -05004102<p>This operator works more like the <a href="command-line-options.html#opaque" >-opaque</a> option, than
Cristy882d9f42015-10-29 16:48:39 -04004103a more general flood fill that reads the matching color directly at the 'seed
Cristy594d2772015-11-15 10:47:42 -05004104point'. For this form of flood fill, look at <a href="command-line-options.html#draw" >-draw</a> and
Cristy882d9f42015-10-29 16:48:39 -04004105its 'color floodfill' drawing method. </p>
4106
4107
4108<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004109 <h3><a id="flop"></a>-flop</h3>
Cristy882d9f42015-10-29 16:48:39 -04004110</div>
4111
4112<p class="magick-description">create a <var>mirror image</var>.</p>
4113
4114<p>Reflect the scanlines in the horizontal direction, just like the image in
4115a vertical mirror. </p>
4116
4117
4118<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004119 <h3><a id="font"></a>-font <var>name</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004120</div>
4121
4122<p class="magick-description">set the font to use when annotating images with text, or creating labels.</p>
4123
4124<p>To print a complete list of fonts, use the <a href="command-line-options.html#list">-list font</a>
4125option (for versions prior to 6.3.6, use 'type' instead of 'font').</p>
4126
4127<p>In addition to the fonts specified by the above pre-defined list, you can
4128also specify a font from a specific source. For example <code>Arial.ttf</code>
4129is a TrueType font file, <code>ps:helvetica</code> is PostScript font, and
4130<code>x:fixed</code> is X11 font.</p>
4131
Cristy594d2772015-11-15 10:47:42 -05004132<p>For other settings that affect fonts, see the options <a
4133href="command-line-options.html#family">-family</a>, <a href="command-line-options.html#stretch">-stretch</a>, <a
4134href="command-line-options.html#style">-style</a>, and <a href="command-line-options.html#weight">-weight</a>. </p>
Cristy882d9f42015-10-29 16:48:39 -04004135
4136
4137<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004138 <h3><a id="foreground"></a>-foreground <var>color</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004139</div>
4140
4141<p class="magick-description">Define the foreground color for menus.", "display</p>
4142
Cristy594d2772015-11-15 10:47:42 -05004143<p>The color is specified using the format described under the <a
4144href="command-line-options.html#fill">-fill</a> option.</p>
Cristy882d9f42015-10-29 16:48:39 -04004145
4146<p>The default foreground color is black.</p>
4147
4148<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004149 <h3><a id="format"></a>-format <var>type</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004150</div>
4151
4152<p class="magick-description">the image format type.</p>
4153
4154<p>When used with the <code>mogrify</code> utility, this option converts any
4155image to the image <a href="formats.html">format</a> you specify.
Cristy594d2772015-11-15 10:47:42 -05004156For a list of image format types supported by ImageMagick, use <a
4157href="command-line-options.html#list">-list format</a>.</p>
Cristy882d9f42015-10-29 16:48:39 -04004158
4159<p>By default the file is written to its original name. However, if the
4160filename extension matches a supported format, the extension is replaced with
4161the image format type specified with <a href="command-line-options.html#format">-format</a>. For
4162example, if you specify <var>tiff</var> as the format type and the
4163input image filename is <var>image.gif</var>, the output image
4164filename becomes <var>image.tiff</var>.</p>
4165
4166<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004167 <h3><a id="format_identify_"></a>-format <var>string</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004168</div>
4169
4170<p class="magick-description">output formatted image characteristics.</p>
4171
4172<p>See <a href="escape.html">Format and Print Image
4173Properties</a> for an explanation on how to specify the argument to this
4174option.</p>
4175
4176<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004177 <h3><a id="frame"></a>-frame <var>geometry</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004178</div>
4179
4180<p class="magick-description">Surround the image with a border or beveled frame.</p>
4181
Cristyb7f455a2017-03-03 19:30:34 -05004182<p>The color of the border is specified with the <a href="command-line-options.html#mattecolor"
4183>-mattecolor</a> command line option. </p>
Cristy882d9f42015-10-29 16:48:39 -04004184
4185<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. The <var>size</var> portion of the <var>geometry</var> argument indicates the amount of extra width and
4186height that is added to the dimensions of the image. If no offsets are given
4187in the <var>geometry</var> argument, then the border added is
4188a solid color. Offsets <var>x</var> and <var>y</var>, if present, specify that
4189the width and height of the border is partitioned to form an outer bevel of
4190thickness <var>x</var> pixels and an inner bevel of thickness
4191<var>y</var> pixels. Negative offsets make no sense as frame arguments.
4192</p>
4193
Cristy594d2772015-11-15 10:47:42 -05004194<p>The <a href="command-line-options.html#frame">-frame</a> option is affected by the current <a
4195href="command-line-options.html#compose">-compose</a> setting and assumes that this is using the default
Cristy882d9f42015-10-29 16:48:39 -04004196'<code>Over</code>' composition method. It generates an image of the appropriate
4197size with the current <a href="command-line-options.html#bordercolor">-bordercolor</a> setting, and then
Cristy594d2772015-11-15 10:47:42 -05004198draws the frame of four distinct colors close to the current <a
Cristyb7f455a2017-03-03 19:30:34 -05004199href="command-line-options.html#mattecolor">-mattecolor</a>. The original image is then overlaid onto
Cristy882d9f42015-10-29 16:48:39 -04004200center of this image. This means that with the default compose method of
Cristy594d2772015-11-15 10:47:42 -05004201'<code>Over</code>' any transparent parts may be replaced by the current <a
4202href="command-line-options.html#bordercolor">-bordercolor</a> setting.</p>
Cristy882d9f42015-10-29 16:48:39 -04004203
4204<p>The image composition is not
4205affected by the <a href="command-line-options.html#gravity">-gravity</a> option.</p>
4206
4207
4208<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004209 <h3><a id="frame_import_"></a>-frame</h3>
Cristy882d9f42015-10-29 16:48:39 -04004210</div>
4211
4212<p class="magick-description">include the X window frame in the imported image. </p>
4213<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004214 <h3><a id="function"></a>-function <var>function</var> <var>parameters</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004215</div>
4216
4217<p class="magick-description">Apply a function to channel values.</p>
4218
4219<p>This operator performs calculations based on the given arguments to modify
Cristy594d2772015-11-15 10:47:42 -05004220each of the color values for each previously set <a
4221href="command-line-options.html#channel">-channel</a> in the image. See <a
4222href="command-line-options.html#evaluate">-evaluate</a> for details concerning how the results of the
Cristy882d9f42015-10-29 16:48:39 -04004223calculations are handled.</p>
4224
Cristy594d2772015-11-15 10:47:42 -05004225<p>This is can be considered a multi-argument version of the <a
4226href="command-line-options.html#evaluate">-evaluate</a> operator. (Added in
Cristy882d9f42015-10-29 16:48:39 -04004227ImageMagick 6.4.8−8.)</p>
4228
4229<p>Here, <var>parameters</var> is a comma-separated list of
4230numerical values. The number of values varies depending on which <var>function</var> is selected. Choose the <var>function</var> from:</p>
4231
Cristy49380402017-06-29 11:24:55 -04004232<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04004233Polynomial
4234Sinusoid
4235Arcsin
4236Arctan
Cristy49380402017-06-29 11:24:55 -04004237</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04004238
4239<p>To print a complete list of <a href="command-line-options.html#function">-function</a> operators,
4240use <a href="command-line-options.html#list">-list function</a>. Descriptions follow.</p>
4241
Cristy49380402017-06-29 11:24:55 -04004242<dl class="row">
4243 <dt class="col-md-4">Polynomial</dt>
4244 <dd class="col-md-8"><p>The <code>Polynomial</code> function takes an arbitrary number of parameters,
Cristy882d9f42015-10-29 16:48:39 -04004245these being the coefficients of a polynomial, in decreasing order of degree.
4246That is, entering</p>
4247
Cristy49380402017-06-29 11:24:55 -04004248<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04004249-function Polynomial <var>a</var><sub><var>n</var></sub>,<var>a</var><sub><var>n</var>-1</sub>,...<var>a</var><sub>1</sub>,<var>a</var><sub>0</sub>
Cristy49380402017-06-29 11:24:55 -04004250</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04004251
4252<p>will invoke a polynomial function given by</p>
4253
Cristy49380402017-06-29 11:24:55 -04004254<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04004255<var>a</var><sub><var>n</var></sub> <b><var>u</var></b><sup><var>n</var></sup> + <var>a</var><sub><var>n</var>-1</sub> <b><var>u</var></b><sup><var>n</var>-1</sup> + ··· <var>a</var><sub>1</sub> <b><var>u</var></b> + <var>a</var><sub>0</sub>,
Cristy49380402017-06-29 11:24:55 -04004256</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04004257
4258<p>where <b><var>u</var></b> is pixel's original normalized channel value.</p>
4259
4260<p>The <code>Polynomial</code> function can be used in place of <code>Set</code>
4261(the <var>constant</var> polynomial) and <code>Add</code>, <code>Divide</code>,
4262<code>Multiply</code>, and <code>Subtract</code> (some <var>linear</var>
Cristy594d2772015-11-15 10:47:42 -05004263polynomials) of the <a href="command-line-options.html#evaluate">-evaluate</a> operator. The <a
4264href="command-line-options.html#level">-level</a> operator also affects channels linearly. Some
Cristy882d9f42015-10-29 16:48:39 -04004265correspondences follow.</p>
4266
Cristy49380402017-06-29 11:24:55 -04004267<table class="table table-sm table-striped">
Cristy882d9f42015-10-29 16:48:39 -04004268 <tr>
4269 <td>-evaluate Set <var>value</var> </td>
4270 <td>-function Polynomial <var>value</var></td>
4271 <td>(Constant functions; set <var>value</var>×100% gray when channels are RGB.)</td>
4272 </tr>
4273 <tr>
4274 <td>-evaluate Add <var>value</var> </td>
4275 <td>-function Polynomial 1,<var>value</var></td>
4276 </tr>
4277 <tr>
4278 <td>-evaluate Subtract <var>value</var> </td>
4279 <td>-function Polynomial 1,−<var>value</var></td>
4280 </tr>
4281 <tr>
4282 <td>-evaluate Multiply <var>value</var> </td>
4283 <td>-function Polynomial <var>value</var>,0</td>
4284 </tr>
4285 <tr>
4286 <td>+level black% x white%</td>
4287 <td>-function Polynomial A,B</td>
4288 <td>(Reduce contrast. Here, A=(white-black)/100 and B=black/100.)</td>
4289 </tr>
4290</table>
4291
4292<p>The <code>Polynomial</code> function gives great versatility, since
4293polynomials can be used to fit any continuous curve to any degree of accuracy
4294desired.</p>
4295
4296</dd>
Cristy49380402017-06-29 11:24:55 -04004297<dt class="col-md-4">Sinusoid</dt>
4298<dd class="col-md-8">
Cristy882d9f42015-10-29 16:48:39 -04004299<p>The <code>Sinusoid</code> function can be used to vary the channel values
4300sinusoidally by setting frequency, phase shift, amplitude, and a bias. These
4301values are given as one to four parameters, as follows,</p>
4302
Cristy49380402017-06-29 11:24:55 -04004303<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04004304-function <code>Sinusoid</code> <var>freq</var>,[<var>phase</var>,[<var>amp</var>,[<var>bias</var>]]]
Cristy49380402017-06-29 11:24:55 -04004305</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04004306
4307<p>where <var>phase</var> is in degrees. (The domain [0,1] of the function
4308corresponds to 0 through <var>freq</var>×360 degrees.)
4309The result is that if a pixel's normalized channel value is originally
4310<b><var>u</var></b>, its resulting normalized value is given by </p>
4311
Cristy49380402017-06-29 11:24:55 -04004312<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04004313<var>amp</var> * sin(2*π* (<var>freq</var> * <b><var>u</var></b> + <var>phase</var> / 360)) + <var>bias</var>
Cristy49380402017-06-29 11:24:55 -04004314</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04004315
4316<p> For example, the following generates a curve that starts and ends at 0.9
4317(when <b><var>u</var></b>=0 and 1, resp.), oscillating three times between
4318.7−.2=.5 and .7+.2=.9. </p>
4319
Cristy49380402017-06-29 11:24:55 -04004320<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04004321-function Sinusoid 3,-90,.2,.7
Cristy49380402017-06-29 11:24:55 -04004322</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04004323
4324<p>The default values of <var>amp</var> and <var>bias</var> are both .5. The default for <var>phase</var>
4325is 0.</p>
4326
4327<p>The <code>Sinusoid</code> function generalizes <code>Sin</code> and
4328<code>Cos</code> of the <a href="command-line-options.html#evaluate">-evaluate</a> operator by allowing
4329varying amplitude, phase and bias. The correspondence is as follows.</p>
4330
Cristy49380402017-06-29 11:24:55 -04004331<table class="table table-sm table-striped">
Cristy882d9f42015-10-29 16:48:39 -04004332 <tr>
4333 <td>-evaluate Sin <var>freq</var> </td>
4334 <td>-function Sinusoid <var>freq</var>,0 </td>
4335 </tr>
4336 <tr>
4337 <td>-evaluate Cos <var>freq</var> </td>
4338 <td>-function Sinusoid <var>freq</var>,90 </td>
4339 </tr>
4340</table>
4341 </dd>
Cristy49380402017-06-29 11:24:55 -04004342<dt class="col-md-4">ArcSin</dt>
4343<dd class="col-md-8">
Cristy882d9f42015-10-29 16:48:39 -04004344<p>The <code>ArcSin</code> function generates the inverse curve of a Sinusoid,
4345and can be used to generate cylindrical distortion and displacement maps.
4346The curve can be adjusted relative to both the input values and output range
4347of values.</p>
4348
Cristy49380402017-06-29 11:24:55 -04004349<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04004350-function <code>ArcSin</code> <var>width</var>,[<var>center</var>,[<var>range</var>,[<var>bias</var>]]]
Cristy49380402017-06-29 11:24:55 -04004351</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04004352
4353<p>with all values given in terms of normalized color values (0.0 for black,
43541.0 for white). Defaulting to values covering the full range from 0.0 to 1.0
4355for bout input (<var>width</var>), and output (<var>width</var>) values. '<code>1.0,0.5,1.0,0.5</code>' </p>
4356
Cristy49380402017-06-29 11:24:55 -04004357<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04004358<var>range</var>/π * asin( 2/<var>width</var> * ( <b><var>u</var></b> - <var>center</var> ) ) + <var>bias</var>
Cristy49380402017-06-29 11:24:55 -04004359</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04004360
4361</dd>
Cristy49380402017-06-29 11:24:55 -04004362<dt class="col-md-4">ArcTan</dt>
4363<dd class="col-md-8">
Cristy882d9f42015-10-29 16:48:39 -04004364<p>The <code>ArcTan</code> function generates a curve that smooth crosses from
4365limit values at infinities, though a center using the given slope value.
4366All these values can be adjusted via the arguments.</p>
4367
Cristy49380402017-06-29 11:24:55 -04004368<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04004369-function <code>ArcTan</code> <var>slope</var>,[<var>center</var>,[<var>range</var>,[<var>bias</var>]]]
Cristy49380402017-06-29 11:24:55 -04004370</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04004371
4372<p>Defaulting to '<code>1.0,0.5,1.0,0.5</code>'.
4373</p>
4374
Cristy49380402017-06-29 11:24:55 -04004375<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04004376<var>range</var>/π * atan( <var>slope</var>*π * ( <b><var>u</var></b> - <var>center</var> ) ) + <var>bias</var>
Cristy49380402017-06-29 11:24:55 -04004377</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04004378 </dd>
Cristy882d9f42015-10-29 16:48:39 -04004379</dl>
4380
4381
4382
4383<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004384 <h3><a id="fuzz"></a>-fuzz <var>distance</var>{<var>%</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -04004385</div>
4386
4387<p class="magick-description">Colors within this <var>distance</var> are considered equal.</p>
4388
4389<p>A number of algorithms search for a target color. By default the color must
4390be exact. Use this option to match colors that are close to the target color
4391in RGB space. For example, if you want to automagically trim the edges of an
4392image with <a href="command-line-options.html#trim">-trim</a> but the image was scanned and the target
4393background color may differ by a small amount. This option can account for
4394these differences.</p>
4395
4396<p>The <var>distance</var> can be in absolute intensity units or, by
4397appending <code>%</code> as a percentage of the maximum possible intensity (255,
439865535, or 4294967295).</p>
4399
Cristy594d2772015-11-15 10:47:42 -05004400<p>Use <a href="command-line-options.html#fuzz" >+fuzz</a> to reset the fuzz value to 0.</p>
Cristy882d9f42015-10-29 16:48:39 -04004401
4402
4403<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004404 <h3><a id="fx"></a>-fx <var>expression</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004405</div>
4406
4407<p class="magick-description">apply a mathematical expression to an image or image channels.</p>
4408
4409<p>If the first character of <var>expression</var> is <code>@</code>,
4410the expression is read from a file titled by the remaining characters in the
4411string.</p>
4412
4413<p>See <a href="fx.html">FX,
4414The Special Effects Image Operator</a> for a detailed discussion of this
4415option.</p>
4416
4417
4418<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004419 <h3><a id="gamma"></a>-gamma <var>value</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004420</div>
4421
4422<p class="magick-description">level of gamma correction.</p>
4423
4424<p>The same color image displayed on two different workstations may look
4425different due to differences in the display monitor. Use gamma correction to
4426adjust for this color difference. Reasonable values extend from
4427<code>0.8</code> to <code>2.3</code>. Gamma less than 1.0 darkens the image and
4428gamma greater than 1.0 lightens it. Large adjustments to image gamma may
4429result in the loss of some image information if the pixel quantum size is only
4430eight bits (quantum range 0 to 255).</p>
4431
4432<p>Gamma adjusts the image's channel values pixel-by-pixel according to
4433a power law, namely, pow(pixel,1/gamma) or pixel^(1/gamma), where pixel is the
4434normalized or 0 to 1 color value. For example, using a value of gamma=2 is the
4435same as taking the square root of the image.</p>
4436
4437<p>You can apply separate gamma values to the red, green, and blue channels of
4438the image with a gamma value list delimited with commas (e.g.,
4439<code>1.7,2.3,1.2</code>).</p>
4440
4441<p>Use <a href="command-line-options.html#gamma">+gamma <var>value</var></a> to set the
4442image gamma level without actually adjusting the image pixels. This option
4443is useful if the image is of a known gamma but not set as an image attribute
4444(e.g. PNG images). Write the "file gamma" which is the reciprocal of the
4445display gamma; e.g., if your image is sRGB and you want to write a PNG gAMA
4446chunk, use</p>
4447
Cristy49380402017-06-29 11:24:55 -04004448<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04004449convert input.png +gamma .45455 output.png
Cristy49380402017-06-29 11:24:55 -04004450</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04004451
4452<p>(0.45455 is 1/2.2)</p>
4453
4454<p>Note that gamma adjustments are also available via the <a href="command-line-options.html#level">-level</a> operator.</p>
4455
4456<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004457 <h3><a id="gaussian-blur"></a>-gaussian-blur <var>radius</var><br />-gaussian-blur <var>radius</var>x<var>sigma</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004458</div>
4459
4460<p class="magick-description">Blur the image with a Gaussian operator.</p>
4461
4462<p>Convolve the image with a Gaussian or normal distribution using the given
Cristy594d2772015-11-15 10:47:42 -05004463<var >Sigma</var> value. The formula is:</p>
Cristy882d9f42015-10-29 16:48:39 -04004464
Cristy594d2772015-11-15 10:47:42 -05004465<p class="text-center"><img class="img-thumbnail" alt="gaussian distribution" width="243px" height="42px" src="../images/gaussian-blur.png"/> </p>
Cristy882d9f42015-10-29 16:48:39 -04004466
Cristy594d2772015-11-15 10:47:42 -05004467<p>The <var >Sigma</var> value is the important argument, and
Cristy882d9f42015-10-29 16:48:39 -04004468determines the actual amount of blurring that will take place. </p>
4469
Cristy594d2772015-11-15 10:47:42 -05004470<p>The <var >Radius</var> is only used to determine the size of the
Cristy882d9f42015-10-29 16:48:39 -04004471array which will hold the calculated Gaussian distribution. It should be an
4472integer. If not given, or set to zero, IM will calculate the largest possible
4473radius that will provide meaningful results for the Gaussian distribution.
4474</p>
4475
Cristy594d2772015-11-15 10:47:42 -05004476<p>The larger the <var >Radius</var> the radius the slower the
4477operation is. However too small a <var >Radius</var>, and sever
4478aliasing effects may result. As a guideline, <var >Radius</var>
4479should be at least twice the <var >Sigma</var> value, though three
Cristy882d9f42015-10-29 16:48:39 -04004480times will produce a more accurate result. </p>
4481
4482<p>This differs from the faster <a href="command-line-options.html#blur">-blur</a> operator in that a
4483full 2-dimensional convolution is used to generate the weighted average of the
4484neighboring pixels. </p>
4485
4486<p>The <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting will determine how
4487pixels which are outside the image proper are blurred into the final result.
4488</p>
4489
4490
4491<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004492 <h3><a id="geometry"></a>-geometry <var>geometry</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004493</div>
4494
4495<p class="magick-description">Set the preferred size and location of the image.</p>
4496
4497<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
4498
4499<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004500 <h3><a id="gravity"></a>-gravity <var>type</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004501</div>
4502
4503<p class="magick-description">Sets the current gravity suggestion for various other settings and options.</p>
4504
4505<p>Choices include: <code>NorthWest</code>, <code>North</code>,
4506<code>NorthEast</code>, <code>West</code>, <code>Center</code>, <code>East</code>,
Cristy594d2772015-11-15 10:47:42 -05004507<code>SouthWest</code>, <code>South</code>, <code>SouthEast</code>. Use <a
4508href="command-line-options.html#list">-list gravity</a> to get a complete list of <a
4509href="command-line-options.html#gravity">-gravity</a> settings available in your ImageMagick
Cristy882d9f42015-10-29 16:48:39 -04004510installation.</p>
4511
4512<p>The direction you choose specifies where to position text or subimages. For
4513example, a gravity of <code>Center</code> forces the text to be centered within
Cristy776113a2016-04-29 12:01:19 -04004514the image. By default, the image gravity is <code>undefined</code>. See <a
Cristy594d2772015-11-15 10:47:42 -05004515href="command-line-options.html#draw">-draw</a> for more details about graphic primitives. Only the
4516text primitive of <a href="command-line-options.html#draw">-draw</a> is affected by the <a
4517href="command-line-options.html#gravity">-gravity</a> option.</p>
Cristy882d9f42015-10-29 16:48:39 -04004518
4519<p>The <a href="command-line-options.html#gravity">-gravity</a> option is also used in concert with the
4520<a href="command-line-options.html#geometry">-geometry</a> setting and other settings or options that
Cristy594d2772015-11-15 10:47:42 -05004521take <var>geometry</var> as an argument, such as the <a
4522href="command-line-options.html#crop">-crop</a> option. </p>
Cristy882d9f42015-10-29 16:48:39 -04004523
4524<p>If a <a href="command-line-options.html#gravity">-gravity</a> setting occurs before another option
4525or setting having a <var>geometry</var> argument that specifies an
4526offset, the offset is usually applied to the point within the image suggested
4527by the <a href="command-line-options.html#gravity">-gravity</a> argument. Thus, in the following
4528command, for example, suppose the file <code>image.png</code> has dimensions
4529200x100. The offset specified by the argument to <a href="command-line-options.html#region">-region</a>
4530is (−40,+20). The argument to <a href="command-line-options.html#gravity">-gravity</a> is
4531<code>Center</code>, which suggests the midpoint of the image, at the point
4532(100,50). The offset (−40,20) is applied to that point, giving
4533(100−40,50+20)=(60,70), so the specified 10x10 region is located at
4534that point. (In addition, the <a href="command-line-options.html#gravity">-gravity</a> affects the
4535region itself, which is <var>centered</var> at the pixel
4536coordinate (60,70). (See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.)</p>
4537
Cristy49380402017-06-29 11:24:55 -04004538<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04004539convert image.png -gravity Center -region 10x10-40+20 \
4540 -negate output.png
Cristy49380402017-06-29 11:24:55 -04004541</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04004542
Cristy594d2772015-11-15 10:47:42 -05004543<p>When used as an option to <a href="composite.html">composite</a>, <a
4544href="command-line-options.html#gravity">-gravity</a> gives the direction that the image gravitates
Cristy882d9f42015-10-29 16:48:39 -04004545within the composite.</p>
4546
Cristy594d2772015-11-15 10:47:42 -05004547<p>When used as an option to <a href="montage.html">montage</a>, <a
4548href="command-line-options.html#gravity">-gravity</a> gives the direction that an image gravitates
Cristy882d9f42015-10-29 16:48:39 -04004549within a tile. The default gravity is <code>Center</code> for this purpose.</p>
4550
4551
4552<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004553 <h3><a id="grayscale"></a>-grayscale <var>method</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004554</div>
4555
4556<p class="magick-description">convert image to grayscale.</p>
4557
Cristy594d2772015-11-15 10:47:42 -05004558<p>This will use one of the <a href="command-line-options.html#intensity" >-intensity</a> methods to
Cristy882d9f42015-10-29 16:48:39 -04004559convert the given image into a linear-grayscale image. </p>
4560
4561<p>For example, to convert an image to (linear) Rec709Luminance grayscale, type:</p>
4562
Cristy49380402017-06-29 11:24:55 -04004563<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04004564convert in.png -grayscale Rec709Luminance out.png
Cristy49380402017-06-29 11:24:55 -04004565</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04004566
4567<p>which is equivalent to:</p>
4568
Cristy49380402017-06-29 11:24:55 -04004569<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04004570convert in.png -colorspace gray out.png
Cristy49380402017-06-29 11:24:55 -04004571</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04004572
4573<p>Similarly, to convert an image to (non-linear) Rec709Luma grayscale, type:</p>
4574
Cristy49380402017-06-29 11:24:55 -04004575<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04004576convert in.png -grayscale Rec709Luma out.png
Cristy49380402017-06-29 11:24:55 -04004577</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04004578
4579<p>which is equivalent to:</p>
4580
Cristy49380402017-06-29 11:24:55 -04004581<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04004582convert in.png -set colorspace RGB -colorspace gray out.png
Cristy49380402017-06-29 11:24:55 -04004583</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04004584
4585<p>Note that a 'colorspace' intensity method will produce the same result
4586regardless of the current colorpsace of the image. But a 'mathematical'
4587intensity method will depend on the current colorspace the image is currently
4588using. </p>
4589
Cristy594d2772015-11-15 10:47:42 -05004590<p>While this operation uses an <a href="command-line-options.html#intensity" >-intensity</a> method,
4591it does not use or set the <a href="command-line-options.html#intensity" >-intensity</a> setting, so
Cristy882d9f42015-10-29 16:48:39 -04004592will not effect other operations that may use that setting.</p>
4593
4594
4595<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004596 <h3><a id="green-primary"></a>-green-primary <var>x,y</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004597</div>
4598
4599<p class="magick-description">green chromaticity primary point.</p>
4600
4601
4602<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004603 <h3><a id="hald-clut"></a>-hald-clut</h3>
Cristy882d9f42015-10-29 16:48:39 -04004604</div>
4605
4606<p class="magick-description">apply a Hald color lookup table to the image.</p>
4607
4608<p>A Hald color lookup table is a 3-dimensional color cube mapped to 2
4609dimensions. Create it with the <code>HALD:</code> prefix (e.g. HALD:8). You
4610can apply any color transformation to the Hald image and then use this option
4611to apply the transform to the image. </p>
4612
Cristy49380402017-06-29 11:24:55 -04004613<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04004614convert image.png hald.png -hald-clut transform.png
Cristy49380402017-06-29 11:24:55 -04004615</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04004616
4617<p>This option provides a convenient method for you to use Gimp or Photoshop
4618to make color corrections to the Hald CLUT image and subsequently apply them
4619to multiple images using an ImageMagick script. </p>
4620
4621<p>Note that the representation is only of the normal RGB color space and that
4622the whole color value triplet is used for the interpolated lookup of the
Cristy594d2772015-11-15 10:47:42 -05004623represented Hald color cube image. Because of this the operation is not <a
4624href="command-line-options.html#channel" >-channel</a> setting effected, nor can it adjust or modify an
Cristy882d9f42015-10-29 16:48:39 -04004625images transparency or alpha/matte channel.</p>
4626
Cristy594d2772015-11-15 10:47:42 -05004627<p>See also <a href="command-line-options.html#clut" >-clut</a> which provides color value replacement
Cristy769d8892016-01-19 18:11:14 -05004628of the individual color channels, usually involving a simpler grayscale
4629image. E.g: grayscale to color replacement, or modification by a histogram
Cristy882d9f42015-10-29 16:48:39 -04004630mapping. </p>
4631
4632
4633<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004634 <h3><a id="help"></a>-help</h3>
Cristy882d9f42015-10-29 16:48:39 -04004635</div>
4636
4637<p class="magick-description">print usage instructions.</p>
4638
4639<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004640 <h3><a id="highlight-color"></a>-highlight-color <var>color</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004641</div>
4642
4643<p class="magick-description">when comparing images, emphasize pixel differences with this color.</p>
4644
4645<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004646 <h3><a id="hough-lines"></a>-hough-lines <var>width</var>x<var>height</var>{<var>+threshold</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -04004647</div>
4648
4649<p class="magick-description">identify straight lines in the image (e.g. -hough-lines 9x9+195).</p>
4650
4651<p>Use the Hough line detector with any binary edge extracted image to locate and draw any straight lines that it finds.</p>
4652
4653<p>The process accumulates counts for every white pixel in the binary edge image for every possible orientation (for angles from 0 to 179 in 1 deg increments) and distance from the center of the image to the corners (in 1 px increments). It stores the counts in an accumulator matrix of angle vs distance. The size of the accumulator will be 180x(diagonal/2). Next it searches the accumulator for peaks in counts and converts the locations of the peaks to slope and intercept in the normal x,y input image space. The algorithm uses slope/intercepts to find the endpoints clipped to the bounds of the image. The lines are drawn from the given endpoints. The counts are a measure of the length of the lines.</p>.
4654
4655<p>The WxH arguments specify the filter size for locating the peaks in the Hough accumulator. The threshold excludes lines whose counts are less than the threshold value.</p>
4656
Cristy594d2772015-11-15 10:47:42 -05004657<p>Use <code><a href="command-line-options.html#background" >-background</a></code> to specify the color of the background onto which the lines will be drawn. The default is black.</p>
Cristy882d9f42015-10-29 16:48:39 -04004658
Cristy594d2772015-11-15 10:47:42 -05004659<p>Use <code><a href="command-line-options.html#fill" >-fill</a></code> to specify the color of the lines. The default is black.</p>
Cristy882d9f42015-10-29 16:48:39 -04004660
Cristy594d2772015-11-15 10:47:42 -05004661<p>Use <code><a href="command-line-options.html#stroke" >-stroke</a></code> and <code><a href="command-line-options.html#strokewidth" >-strokewidth</a></code> to specify the thickness of the lines. The default is black and no strokewidth.</p>
Cristy882d9f42015-10-29 16:48:39 -04004662
4663<p>A text file listing the endpoints and counts may be created by using the suffix, .mvg, for the output image.</p>
4664
Cristy594d2772015-11-15 10:47:42 -05004665<p>Use <code><a href="command-line-options.html#define" >-define</a> hough-lines:accumulator=true</code> to return the accumulator image in addition to the lines image.</p>
Cristy882d9f42015-10-29 16:48:39 -04004666
4667<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004668 <h3><a id="iconGeometry"></a>-iconGeometry <var>geometry</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004669</div>
4670
4671<p class="magick-description">specify the icon geometry.</p>
4672
4673<p>Offsets, if present in the geometry specification, are handled in the same
4674manner as the <a href="command-line-options.html#geometry">-geometry</a> option, using X11 style to
4675handle negative offsets.</p>
4676
4677<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
4678
4679<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004680 <h3><a id="iconic"></a>-iconic</h3>
Cristy882d9f42015-10-29 16:48:39 -04004681</div>
4682
4683<p class="magick-description">start in icon mode in X Windows", 'animate', 'display</p>
4684
4685<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004686 <h3><a id="identify"></a>-identify</h3>
Cristy882d9f42015-10-29 16:48:39 -04004687</div>
4688
4689<p class="magick-description">identify the format and characteristics of the image.</p>
4690
4691<p>This information is printed: image scene number; image name; image size;
4692the image class (<var>DirectClass</var> or <var>PseudoClass</var>); the total number of unique colors; and the
4693number of seconds to read and transform the image. Refer to <a href="miff.html">MIFF</a> for
4694a description of the image class.</p>
4695
4696<p>If <a href="command-line-options.html#colors">-colors</a> is also specified, the total unique colors
Cristy594d2772015-11-15 10:47:42 -05004697in the image and color reduction error values are printed. Refer to <a
Cristy6549abb2016-11-10 08:25:55 -05004698href="http://www.imagemagick.org/www/quantize.html">color
Cristy882d9f42015-10-29 16:48:39 -04004699reduction algorithm</a> for a description of these values.</p>
4700
4701<p>If <a href="command-line-options.html#verbose">-verbose</a> precedes this option, copious
4702amounts of image properties are displayed including image statistics, profiles,
4703image histogram, and others.</p>
4704
4705<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004706 <h3><a id="ift"></a>-ift</h3>
Cristy882d9f42015-10-29 16:48:39 -04004707</div>
4708
4709<p class="magick-description">implements the inverse discrete Fourier transform (DFT).</p>
4710
4711<p>This option is new as of ImageMagick 6.5.4-3 (and now working for Windows
4712users in ImageMagick 6.6.0-9). It transforms a pair of magnitude and phase
4713images from the frequency domain to a single image in the normal or spatial
Cristy594d2772015-11-15 10:47:42 -05004714domain. See for example, <a
4715href="http://en.wikipedia.org/wiki/Fourier_transform">Fourier Transform</a>,
Cristy882d9f42015-10-29 16:48:39 -04004716<a href="http://en.wikipedia.org/wiki/DFT">Discrete Fourier Transform</a> and
4717<a href="http://en.wikipedia.org/wiki/FFT">Fast Fourier Transform</a>.</p>
4718
4719<p>For example, depending upon the image format used to store the result of
4720the <a href="command-line-options.html#fft">-fft</a>, one would use either</p>
4721
Cristy49380402017-06-29 11:24:55 -04004722<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04004723convert fft_image.miff -ift fft_image_ift.png
Cristy49380402017-06-29 11:24:55 -04004724</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04004725
4726<p>or</p>
4727
Cristy49380402017-06-29 11:24:55 -04004728<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04004729convert fft_image-0.png fft_image-1.png -ift fft_image_ift.png
Cristy49380402017-06-29 11:24:55 -04004730</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04004731
4732<p>The resulting image may need to be cropped due to padding introduced when
Cristy594d2772015-11-15 10:47:42 -05004733the original image, prior to the <a href="command-line-options.html#fft">-fft</a> or <a
4734href="command-line-options.html#fft">+fft</a>, was not square or even dimensioned. Any padding is at
Cristy882d9f42015-10-29 16:48:39 -04004735the right and/or bottom sides of the image.</p>
4736
4737<p>The <a href="http://www.fftw.org/">FFTW</a> delegate library is required to
4738use <a href="command-line-options.html#ift">-ift</a>.</p>
4739
4740<p>Use <a href="command-line-options.html#ift">+ift</a> (with HDRI enabled) to transform a pair of real
4741and imaginary images from the frequency domain to a single image in the normal
4742(spatial) domain.</p>
4743
Cristy594d2772015-11-15 10:47:42 -05004744<p>By default the IFT is not normalized (and the FFT is). Use "<code><a href="command-line-options.html#define" >-define</a> fourier:normalize=inverse</code> to explicitly normalize the IFT and unnormalize the FFT.</p>
Cristy882d9f42015-10-29 16:48:39 -04004745
4746<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004747 <h3><a id="immutable"></a>-immutable</h3>
Cristy882d9f42015-10-29 16:48:39 -04004748</div>
4749
4750<p class="magick-description">make image immutable.</p>
4751
4752<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004753 <h3><a id="implode"></a>-implode <var>factor</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004754</div>
4755
4756<p class="magick-description">implode image pixels about the center.</p>
4757
4758<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004759 <h3><a id="insert"></a>-insert <var>index</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004760</div>
4761
4762<p class="magick-description">insert the last image into the image sequence.</p>
4763
4764<p>This option takes last image in the current image sequence and inserts it
4765at the given index. If a negative index is used, the insert position is
4766calculated before the last image is removed from the sequence. As such
4767<code>-insert -1</code> will result in no change to the image sequence.</p>
4768
4769<p>The <code>+insert</code> option is equivalent to <code>-insert -1</code>. In
4770other words, insert the last image, at the end of the current image sequence.
4771Consequently this has no effect on the image sequence order.</p>
4772
4773<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004774 <h3><a id="intensity"></a>-intensity <var>method</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004775</div>
4776
4777<p class="magick-description">method to generate intensity value from pixel.</p>
4778
4779<p>ImageMagick provides a number of methods used in situations where an
4780operator needs to determine a single grayscale value for some purpose, from
4781an image with red, green, and blue pixel components. Typically the linear
4782<code>Rec709Luminance</code> formula is used, which is the same formula used when
4783converting images to <code>-colorspace gray</code>. </p>
4784
4785<p>The following formulas are currently provided, and will first convert
4786the pixel values to linear-RGB or non-linear sRGB colorspace before
4787being applied to calculate the final greyscale value. </p>
4788
Cristy49380402017-06-29 11:24:55 -04004789<dl class="row">
4790<dt class="col-md-4">Rec601Luma</dt><dd class="col-md-8"> 0.298839R' + 0.586811G'+ 0.114350B'</dd>
4791<dt class="col-md-4">Rec601Luminance</dt><dd class="col-md-8"> 0.298839R + 0.586811G + 0.114350B</dd>
4792<dt class="col-md-4">Rec709Luma</dt><dd class="col-md-8"> 0.212656R' + 0.715158G' + 0.072186B'</dd>
4793<dt class="col-md-4">Rec709Luminance</dt><dd class="col-md-8"> 0.212656R + 0.715158G + 0.072186B</dd>
4794<dt class="col-md-4">Brightness</dt><dd class="col-md-8"> max(R', G', B')</dd>
4795<dt class="col-md-4">Lightness</dt><dd class="col-md-8"> (min(R', G', B') + max(R', G', B')) / 2.0</dd>
Cristy882d9f42015-10-29 16:48:39 -04004796</dl>
4797
4798<p>Note that the above R,G,B values is the image's linear-RGB values, while
4799R',G',B' are sRGB non-linear values. </p>
4800
4801<p>These intensity methods are mathematical in nature and will use the
4802current value in the images respective R,G,B channel regardless of
4803what that is, or what colorspace the image is currently using.</p>
4804
Cristy49380402017-06-29 11:24:55 -04004805<dl class="row">
4806<dt class="col-md-4">Average</dt><dd class="col-md-8">(R + G + B) / 3.0</dd>
4807<dt class="col-md-4">MS</dt><dd class="col-md-8">(R^2 + G^2 + B^2) / 3.0</dd>
4808<dt class="col-md-4">RMS</dt><dd class="col-md-8">sqrt( (R^2 + G^2 + B^2) / 3.0 )</dd>
Cristy882d9f42015-10-29 16:48:39 -04004809</dl>
4810
4811<p>These methods are often used for other purposes, such as generating a
Cristy594d2772015-11-15 10:47:42 -05004812grayscale difference image between two color images (using <a href="command-line-options.html#compose"
4813>-compose</a> '<code>Difference</code>' composition. </p>
Cristy882d9f42015-10-29 16:48:39 -04004814
4815<p> For example The 'MS' (Mean Squared) setting is good for minimizing color
4816error comparisions. While... The method 'RMS' (Root Mean Squared) for
4817example is appropriate for calculating color vector distance, from a color
Cristy594d2772015-11-15 10:47:42 -05004818difference image. This is equivalent to the color only component of the <a
4819href="command-line-options.html#fuzz" >-fuzz</a> factor color compare setting. </p>
Cristy882d9f42015-10-29 16:48:39 -04004820
Cristy594d2772015-11-15 10:47:42 -05004821<p>See also <a href="command-line-options.html#grayscale" >-grayscale</a> which applies one of the above
4822grayscaling formula directly to an image without setting the <a
4823href="command-line-options.html#intensity" >-intensity</a> setting.</p>
Cristy882d9f42015-10-29 16:48:39 -04004824
Cristy594d2772015-11-15 10:47:42 -05004825<p>The <a href="command-line-options.html#colorspace" >-colorspace gray</a> image conversion also uses
Cristy882d9f42015-10-29 16:48:39 -04004826the current intensity setting, but will always convert the image to the
4827appropriate sRGB or linear-RGB colorspace before appling the above
4828function.</p>
4829
4830<p>To print a complete list of possible pixel intensity setting methods, use <a href="command-line-options.html#list">-list intensity</a>.</p>
4831
Cristy594d2772015-11-15 10:47:42 -05004832<p>Operators affected by the <a href="command-line-options.html#intensity" >-intensity</a> setting include:</p>
Cristy882d9f42015-10-29 16:48:39 -04004833
Cristy49380402017-06-29 11:24:55 -04004834<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04004835-adaptive-blur
4836-adaptive-sharpen
4837-black-threshold
4838-clut (when mapping greyscale CLUT image to alpha channel if set by -channels)
4839-colors for gray colorspace
4840-compose {LightenIntensity, DarkenIntensity, CopyOpacity, CopyBlack}
4841-contrast-stretch
4842-distort {ErodeIntensity, DilateIntensity}
4843-normalize
4844-random-threshold
4845-selective-blur
4846-shade
4847-threshold
4848-tint
4849-white-threshold
Cristy49380402017-06-29 11:24:55 -04004850</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04004851
4852<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004853 <h3><a id="intent"></a>-intent <var>type</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004854</div>
4855
4856<p class="magick-description">use this type of rendering intent when managing the image color.</p>
4857
4858<p>Use this option to affect the color management operation of an image (see
4859<a href="command-line-options.html#profile">-profile</a>). Choose from these intents: <code>Absolute,
4860Perceptual, Relative, Saturation</code>.</p>
4861
4862<p>The default intent is Perceptual for the sRGB colorspace and undefined for the RGB and gray colorspaces.</p>
4863
4864<p>To print a complete list of rendering intents, use <a href="command-line-options.html#list">-list intent</a>.</p>
4865
4866<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004867 <h3><a id="interlace"></a>-interlace <var>type</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004868</div>
4869
4870<p class="magick-description">the type of interlacing scheme.</p>
4871
4872<p>Choose from:</p>
4873
Cristy49380402017-06-29 11:24:55 -04004874<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04004875none
4876line
4877plane
4878partition
4879JPEG
4880GIF
4881PNG
Cristy49380402017-06-29 11:24:55 -04004882</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04004883
4884<p>This option is used to specify the type of interlacing scheme for raw image
4885formats such as <code>RGB</code> or <code>YUV</code>.</p>
4886
4887<p><code>None</code> means do not interlace (RGBRGBRGBRGBRGBRGB...),</p>
4888
4889<p><code>Line</code> uses scanline interlacing (RRR...GGG...BBB...RRR...GGG...BBB...), and.</p>
4890
4891<p><code>Plane</code> uses plane interlacing (RRRRRR...GGGGGG...BBBBBB...).</p>
4892
4893<p><code>Partition</code> is like plane except the different planes are saved to
4894individual files (e.g. image.R, image.G, and image.B).</p>
4895
4896<p>Use <code>Line</code> or <code>Plane</code> to create an <code>interlaced
4897PNG</code> or <code>GIF</code> or <code>progressive JPEG</code> image.</p>
4898
4899<p>To print a complete list of interlacing schemes, use <a href="command-line-options.html#list">-list
4900interlace</a>.</p>
4901
4902<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004903 <h3><a id="interpolate"></a>-interpolate <var>type</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004904</div>
4905
4906<p class="magick-description">Set the pixel color interpolation method to use when looking up a color based on a floating point or real value.</p>
4907
4908<p>When looking up the color of a pixel using a non-integer floating point
4909value, you typically fall in between the pixel colors defined by the source
4910image. This setting determines how the color is determined from the colors of
4911the pixels surrounding that point. That is how to determine the color of a
4912point that falls between two, or even four different colored pixels. </p>
4913
Cristy49380402017-06-29 11:24:55 -04004914<dl class="row">
4915 <dt class="col-md-4">integer</dt>
4916 <dd class="col-md-8">The color of the top-left pixel (floor function)</dd>
4917 <dt class="col-md-4">nearest-neighbor</dt>
4918 <dd class="col-md-8">The nearest pixel to the lookup point (rounded function)</dd>
4919 <dt class="col-md-4">average</dt>
4920 <dd class="col-md-8">The average color of the surrounding four pixels</dd>
4921 <dt class="col-md-4">bilinear</dt>
4922 <dd class="col-md-8">A double linear interpolation of pixels (the default)</dd>
4923 <dt class="col-md-4">mesh</dt>
4924 <dd class="col-md-8">Divide area into two flat triangular interpolations</dd>
4925 <dt class="col-md-4">bicubic</dt>
4926 <dd class="col-md-8">Fitted bicubic-spines of surrounding 16 pixels</dd>
4927 <dt class="col-md-4">spline</dt>
4928 <dd class="col-md-8">Direct spline curves (colors are blurred)</dd>
4929 <dt class="col-md-4">filter</dt>
4930 <dd class="col-md-8">Use resize <a href="command-line-options.html#filter">-filter</a> settings</dd>
Cristy882d9f42015-10-29 16:48:39 -04004931</dl>
4932
Cristy594d2772015-11-15 10:47:42 -05004933<p>This most important for distortion operators such as <a href="command-line-options.html#distort"
4934>-distort</a>, <a href="command-line-options.html#implode" >-implode</a>, <a href="command-line-options.html#transform"
4935>-transform</a> and <a href="command-line-options.html#fx" >-fx</a>. </p>
Cristy882d9f42015-10-29 16:48:39 -04004936
4937<p>To print a complete list of interpolation methods, use <a href="command-line-options.html#list">-list interpolate</a>.</p>
4938
Cristy594d2772015-11-15 10:47:42 -05004939<p>See also <a href="command-line-options.html#virtual-pixel" >-virtual-pixel</a>, for control of the
Cristy882d9f42015-10-29 16:48:39 -04004940lookup for positions outside the boundaries of the image. </p>
4941
4942
4943<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004944 <h3><a id="interline-spacing"></a>-interline-spacing <var>value</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004945</div>
4946
4947<p class="magick-description">the space between two text lines.</p>
4948
4949<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004950 <h3><a id="interword-spacing"></a>-interword-spacing <var>value</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004951</div>
4952
4953<p class="magick-description">the space between two words.</p>
4954
4955<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004956 <h3><a id="kerning"></a>-kerning <var>value</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004957</div>
4958
4959<p class="magick-description">the space between two letters.</p>
4960
4961<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004962 <h3><a id="kuwahara"></a>-kuwahara <var>radius</var><br />-kuwahara <var>radius</var>x<var>sigma</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004963</div>
4964
4965<p class="magick-description">edge preserving noise reduction filter.</p>
4966
Cristy594d2772015-11-15 10:47:42 -05004967<p>The <var >radius</var> is more important than the <var >sigma</var>. If <var >sigma</var> is left off, it will be computed automatically from the <var >radius</var> as <var >sigma</var>=<var >radius</var>-0.5. The <var >sigma</var> provides a bit of additional smoothing control.</p>
Cristy882d9f42015-10-29 16:48:39 -04004968
4969
4970<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04004971 <h3><a id="label"></a>-label <var>name</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04004972</div>
4973
4974<p class="magick-description">assign a label to an image.</p>
4975
4976<p>Use this option to assign a specific label to the image, as it is read in
Cristy594d2772015-11-15 10:47:42 -05004977or created. You can use the <a href="command-line-options.html#set" >-set</a> operation to re-assign
Cristy882d9f42015-10-29 16:48:39 -04004978a the labels of images already read in. Image formats such as TIFF, PNG,
4979MIFF, supports saving the label information with the image.</p>
4980
4981<p>When saving an image to a <var>PostScript</var> file, any label
4982assigned to an image is used as a header string to print above the postscript
4983image. </p>
4984
4985<p>You can include the image filename, type, width, height, or other image
4986attribute by embedding special format character. See <a href="escape.html">Format and Print Image
4987Properties</a> for details of the percent escape codes.</p>
4988
4989<p>For example,</p>
4990
Cristy49380402017-06-29 11:24:55 -04004991<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04004992-label "%m:%f %wx%h" bird.miff
Cristy49380402017-06-29 11:24:55 -04004993</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04004994
4995<p>assigns an image label of <code>MIFF:bird.miff 512x480</code> to the
4996"<code>bird.miff</code>" image and whose width is 512 and height is 480, as it
4997is read in. If a <a href="command-line-options.html#label">+label</a> option was used instead, any
4998existing label present in the image would be used. You can remove all labels
4999from an image by assigning the empty string. </p>
5000
5001<p>A label is not drawn on the image, but is embedded in the image datastream
5002via <var>Label</var> tag or similar mechanism. If you want the label to be
5003visible on the image itself, use the <a href="command-line-options.html#draw">-draw</a> option, or
5004during the final processing in the creation of an image montage.</p>
5005
5006<p>If the first character of <var>string</var> is <var>@</var>, the image label is read from a file titled by the
5007remaining characters in the string. Labels in a file are literal, no embedded
5008formatting characters are recognized.</p>
5009
5010
5011<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005012 <h3><a id="lat"></a>-lat <var>width</var><br />-lat <var>width</var>x<var>height</var>{<var>+-</var>}<var>offset</var>{<var>%</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -04005013</div>
5014
5015<p class="magick-description">perform local adaptive threshold.</p>
5016
5017<p>Adaptively threshold each pixel based on the value of pixels in a
5018surrounding window. If the current pixel is lighter than this average plus
5019the optional <code>offset</code>, then it is made white, otherwise it is made
5020black. Small variations in pixel values such as found in scanned documents
5021can be ignored if offset is positive. A negative offset will make it more
5022sensitive to those small variations. </p>
5023
5024<p>This is commonly used to threshold images with an uneven background. It is
5025based on the assumption that average color of the small window is the
5026the local background color, from which to separate the foreground color. </p>
5027
5028
5029<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005030 <h3><a id="layers"></a>-layers <var>method</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04005031</div>
5032
5033<p class="magick-description">handle multiple images forming a set of image layers or animation frames.</p>
5034
5035<p>Perform various image operation methods to a ordered sequence of images
5036which may represent either a set of overlaid 'image layers', a GIF disposal
5037animation, or a fully-'coalesced' animation sequence. </p>
5038
Cristy49380402017-06-29 11:24:55 -04005039<table class="table table-sm table-striped">
Cristy882d9f42015-10-29 16:48:39 -04005040 <tbody>
5041 <tr>
5042 <th style="width: 8%">Method</th>
5043 <th>Description</th>
5044 </tr>
5045
5046 <tr>
5047 <td>compare-any</td>
5048 <td>Crop the second and later frames to the smallest rectangle
Cristy594d2772015-11-15 10:47:42 -05005049 that contains all the differences between the two images. No GIF <a
5050 href="command-line-options.html#dispose" >-dispose</a> methods are taken into account. </td>
Cristy882d9f42015-10-29 16:48:39 -04005051 </tr>
5052
Cristy594d2772015-11-15 10:47:42 -05005053 <tr><td></td><td>This exactly the same as the <a href="command-line-options.html#deconstruct"
5054 >-deconstruct</a> operator, and does not preserve animations normal
Cristy882d9f42015-10-29 16:48:39 -04005055 working, especially when animation used layer disposal methods such as
5056 '<code>Previous</code>' or '<code>Background</code>'. </td>
5057 </tr>
5058
5059 <tr>
5060 <td>compare-clear</td>
5061 <td>As '<code>compare-any</code>' but crop to the bounds of any
5062 opaque pixels which become transparent in the second frame. That is the
5063 smallest image needed to mask or erase pixels for the next frame. </td>
5064 </tr>
5065
5066 <tr>
5067 <td>compare-overlay</td>
5068 <td>As '<code>compare-any</code>' but crop to pixels that add
5069 extra color to the next image, as a result of overlaying color pixels.
5070 That is the smallest single overlaid image to add or change colors. </td>
5071 </tr>
5072
Cristy594d2772015-11-15 10:47:42 -05005073 <tr><td></td><td>This can be used with the <a href="command-line-options.html#compose" >-compose</a> alpha
Cristy882d9f42015-10-29 16:48:39 -04005074 composition method '<code>change-mask</code>', to reduce the image to
5075 just the pixels that need to be overlaid. </td>
5076 </tr>
5077
5078 <tr>
5079 <td>coalesce</td>
Cristy594d2772015-11-15 10:47:42 -05005080 <td>Equivalent to a call to the <a href="command-line-options.html#coalesce"
5081 >-coalesce</a> operator. Apply the layer disposal methods set in the
Cristy882d9f42015-10-29 16:48:39 -04005082 current image sequence to form a fully defined animation sequence, as
5083 it should be displayed. Effectively converting a GIF animation into a
5084 'film strip'-like animation. </td>
5085 </tr>
5086
5087 <tr>
5088 <td>composite</td>
5089 <td>Alpha Composition of two image lists, separated by a
5090 "<code>null:</code>" image, with the destination image list first, and
5091 the source images last. An image from each list are composited
5092 together until one list is finished. The separator image and source
5093 image lists are removed. </td>
5094 </tr>
5095
5096
5097 <tr><td></td>
Cristy594d2772015-11-15 10:47:42 -05005098 <td>The <a href="command-line-options.html#geometry" >-geometry</a> offset is adjusted according
5099 to <a href="command-line-options.html#gravity" >-gravity</a> in accordance of the virtual
5100 canvas size of the first image in each list. Unlike a normal <a
5101 href="command-line-options.html#composite" >-composite</a> operation, the canvas offset is also
Cristy882d9f42015-10-29 16:48:39 -04005102 added to the final composite positioning of each image. </td> </tr>
5103
5104 <tr><td></td>
5105 <td>If one of the image lists only contains one image, that image is
5106 applied to all the images in the other image list, regardless of which
5107 list it is. In this case it is the image meta-data of the list which
5108 preserved. </td>
5109 </tr>
5110
5111
5112 <tr>
5113 <td>dispose</td>
5114 <td>This like '<code>coalesce</code>' but shows the look of
5115 the animation after the layer disposal method has been applied, before
5116 the next sub-frame image is overlaid. That is the 'dispose' image that
Cristy594d2772015-11-15 10:47:42 -05005117 results from the application of the GIF <a href="command-line-options.html#dispose"
5118 >-dispose</a> method. This allows you to check what
Cristy882d9f42015-10-29 16:48:39 -04005119 is going wrong with a particular animation you may be developing.
5120 </td>
5121 </tr>
5122
5123 <tr>
5124 <td>flatten</td>
5125 <td>Create a canvas the size of the first images virtual
Cristy594d2772015-11-15 10:47:42 -05005126 canvas using the current <a href="command-line-options.html#background" >-background</a> color,
5127 and <a href="command-line-options.html#compose" >-compose</a> each image in turn onto that
Cristy882d9f42015-10-29 16:48:39 -04005128 canvas. Images falling outside that canvas is clipped. Final
5129 image will have a zero virtual canvas offset. </td>
5130 </tr>
5131
5132 <tr><td></td>
5133 <td>This usually used as one of the final 'image layering' operations
5134 overlaying all the prepared image layers into a final image. </td>
5135 </tr>
5136
5137 <tr><td></td>
5138 <td>For a single image this method can also be used to fillout a virtual
5139 canvas with real pixels, or to underlay an opaque color to remove
5140 transparency from an image.</td>
5141 </tr>
5142
5143
5144 <tr>
5145 <td>merge</td>
5146 <td>As 'flatten' method but merging all the given image
5147 layers to create a new layer image just large enough to hold all the
5148 image without clipping or extra space. The new images virtual offset
5149 will preserve the position of the new layer, even if this offset is
5150 negative. The virtual canvas size of the first image is preserved.
5151 </td>
5152 </tr>
5153
5154 <tr><td></td><td>Caution is advised when handling image layers with
5155 negative offsets as few image file formats handle them correctly.
Cristy594d2772015-11-15 10:47:42 -05005156 Following this operation method with <a href="command-line-options.html#repage" >+repage</a>
Cristy882d9f42015-10-29 16:48:39 -04005157 will remove the layer offset, and create an image in which all the
5158 overlaid image positions relative to each other is preserved, though
5159 not necessarily exactly where you specified them.
5160 </td>
5161 </tr>
5162
5163 <tr><td></td><td>See also 'trim-bounds' below which is closely related but
5164 without doing the'flatten' to merge the images together. </td>
5165 </tr>
5166
5167 <tr>
5168 <td>mosaic</td>
5169 <td>As 'flatten' method but expanding the initial canvas size
5170 of the first image in a positive direction only so as to hold all the
5171 image layers. However as a virtual canvas is 'locked' to the origin,
5172 by its own definition, image layers with a negative offsets will still
5173 become clipped by the top and left edges. See 'merge' or 'trim-bounds'
5174 if this could be a problem. </td>
5175
5176 </tr>
5177
5178 <tr><td></td><td>This method is commonly used to layout individual image
5179 using various offset but without knowing the final canvas size. The
5180 resulting image will, like 'flatten' not have any virtual offset, so
5181 can be saved to any image file format. </td>
5182 </tr>
5183
5184
5185 <tr>
5186 <td>optimize</td>
5187 <td>Optimize a coalesced animation, into GIF animation using
5188 a number of general techniques. This currently a short cut to
5189 apply both the '<code>optimize-frame</code>', and
5190 '<code>optimize-transparency</code>' methods but may be expanded to
5191 include other optimization methods as they are developed. </td>
5192 </tr>
5193
5194 <tr>
5195 <td>optimize-frame</td>
5196 <td>Optimize a coalesced animation, into GIF animation by
5197 reducing the number of pixels per frame as much as possible by
5198 attempting to pick the best layer disposal method to use, while ensuring
5199 the result will continue to animate properly. </td>
5200 </tr>
5201
5202 <tr><td></td><td> There is no guarantee that the best optimization is found.
5203 But then no reasonably fast GIF optimization algorithm can do this.
5204 However this does seem to do better than most other GIF frame
5205 optimizers seen. </td>
5206 </tr>
5207
5208 <tr>
5209 <td>optimize-plus</td>
5210 <td>As '<code>optimize-frame</code>' but attempt to improve the
5211 overall optimization by adding extra frames to the animation, without
5212 changing the final look or timing of the animation. The frames are
5213 added to attempt to separate the clearing of pixels from the
5214 overlaying of new additional pixels from one animation frame to the
5215 next. If this does not improve the optimization (for the next frame
5216 only), it will fall back to the results of the previous normal
5217 '<code>optimize-frame</code>' technique. </td>
5218 </tr>
5219
5220 <tr><td></td><td>There is the possibility that the change in the disposal
5221 style will result in a worsening in the optimization of later frames,
5222 though this is unlikely. In other words there no guarantee that it is
5223 better than the normal '<code>optimize-frame</code>' technique. For some
5224 animations however you can get a vast improvement in the final
5225 animation size. </td>
5226 </tr>
5227
5228 <tr>
5229 <td>optimize-transparency</td>
5230 <td>Given a GIF animation, replace any pixel in the sub-frame
5231 overlay images with transparency, if it does not change the resulting
Cristy594d2772015-11-15 10:47:42 -05005232 animation by more than the current <a href="command-line-options.html#fuzz" >-fuzz</a> factor.
Cristy882d9f42015-10-29 16:48:39 -04005233 </td>
5234 </tr>
5235
5236 <tr><td></td><td>This should allow a existing frame optimized GIF animation
5237 to compress into a smaller file size due to larger areas of one
5238 (transparent) color rather than a pattern of multiple colors repeating
5239 the current disposed image of the last frame. </td>
5240 </tr>
5241
5242 <tr>
5243 <td>remove-dups</td>
5244 <td>Remove (and merge time delays) of duplicate consecutive
5245 images, so as to simplify layer overlays of coalesced animations.
5246 </td>
5247 </tr>
5248
5249 <tr><td></td><td>Usually this a result of using a constant time delay
5250 across the whole animation, or after a larger animation was split into
5251 smaller sub-animations. The duplicate frames could also have been
5252 used as part of some frame optimization methods. </td>
5253 </tr>
5254
5255 <tr>
5256 <td>remove-zero</td>
5257 <td>Remove any image with a zero time delay, unless ALL the
5258 images have a zero time delay (and is not a proper timed animation, a
5259 warning is then issued). </td>
5260 </tr>
5261
5262 <tr><td></td><td>In a GIF animation, such images are usually frames which
5263 provide partial intermediary updates between the frames that are
5264 actually displayed to users. These frames are usually added for
5265 improved frame optimization in GIF animations. </td>
5266 </tr>
5267
5268 <tr>
5269 <td>trim-bounds</td>
5270 <td>Find the bounds of all the images in the current
5271 image sequence, then adjust the offsets so all images are contained on
5272 a minimal positive canvas. None of the image data is modified or
5273 merged, only the individual image virtual canvas size and offset.
5274 All the images is given the same canvas size, and and will have
5275 a positive offset, but will remain in the same position relative to
5276 each other. As a result of the minimal canvas size at least one image
5277 will touch every edge of that canvas. The image data touching those
5278 edges however may be transparent. </td>
5279 </tr>
5280
5281 <tr><td></td><td>The result is much like if you used 'merge' followed by a
Cristy594d2772015-11-15 10:47:42 -05005282 <a href="command-line-options.html#repage" >+repage</a> option, except that all the images
Cristy882d9f42015-10-29 16:48:39 -04005283 have been kept separate. If 'flatten' is used after using
5284 'trim-bounds' you will get the same result. </td>
5285 </tr>
5286
5287 </tbody>
5288</table>
5289
5290<p>To print a complete list of layer types, use <a href="command-line-options.html#list">-list layers</a>.</p>
5291
Cristy594d2772015-11-15 10:47:42 -05005292<p>The operators <a href="command-line-options.html#coalesce" >-coalesce</a>, <a href="command-line-options.html#deconstruct"
5293>-deconstruct</a>, <a href="command-line-options.html#flatten" >-flatten</a>, and <a href="command-line-options.html#mosaic"
5294>-mosaic</a> are only aliases for the above methods and may be depreciated in
5295the future. Also see <a href="command-line-options.html#page" >-page</a>, <a href="command-line-options.html#repage"
5296>-repage</a> operators, the <a href="command-line-options.html#compose" >-compose</a> setting, and the
5297GIF <a href="command-line-options.html#dispose" >-dispose</a> and <a href="command-line-options.html#delay" >-delay</a>
Cristy882d9f42015-10-29 16:48:39 -04005298settings. </p>
5299
5300
5301<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005302 <h3><a id="level"></a>-level <var>black_point</var>{,<var>white_point</var>}{<var>%</var>}{,<var>gamma</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -04005303</div>
5304
5305<p class="magick-description">adjust the level of image channels.</p>
5306
5307<p>Given one, two or three values delimited with commas: black-point,
5308white-point, gamma (for example: 10,250,1.0 or 2%,98%,0.5). The black and
5309white points range from 0 to <var>QuantumRange</var>, or from 0 to
5310100%; if the white point is omitted it is set to (<var>QuantumRange</var> - black_point), so as to center contrast changes.
5311If a <code>%</code> sign is present anywhere in the string, both black and white
Cristy594d2772015-11-15 10:47:42 -05005312points are percentages of the full color range. Gamma will do a <a
5313href="command-line-options.html#gamma">-gamma</a> adjustment of the values. If it is omitted, the
Cristy882d9f42015-10-29 16:48:39 -04005314default of 1.0 (no gamma correction) is assumed.</p>
5315
5316<p>In normal usage (<code>-level</code>) the image values are stretched so that
5317the given '<code>black_point</code>' value in the original image is set to zero
5318(or black), while the given '<code>white_point</code>' value is set to <var>QuantumRange</var> (or white). This provides you with direct
5319contrast adjustments to the image. The '<code>gamma</code>' of the resulting
5320image will then be adjusted. </p>
5321
5322<p>From ImageMagick v6.4.1-9 using the plus form of the operator
5323(<code>+level</code>) or adding the special '!' flag anywhere in the argument
5324list, will cause the operator to do the reverse of the level adjustment. That
5325is a zero, or <var>QuantumRange</var> value (black, and white, resp.)
5326in the original image, is adjusted to the given level values, allowing you to
5327de-contrast, or compress the channel values within the image. The
5328'<code>gamma</code>' is adjusted before the level adjustment to de-contrast the
5329image is made. </p>
5330
5331<p>Only the channels defined by the current <a href="command-line-options.html#channel">-channel</a>
5332setting are adjusted (defaults to RGB color channels only), allowing you to
5333limit the effect of this operator. </p>
5334
5335<p>Please note that the transparency channel is treated as 'matte'
5336values (0 is opaque) and not as 'alpha' values (0 is transparent).</p>
5337
5338
5339<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005340 <h3><a id="level-colors"></a>-level-colors {<var>black_color</var>}{,}{<var>white_color</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -04005341</div>
5342
5343<p class="magick-description">adjust the level of an image using the provided dash separated colors.</p>
5344
5345<p>This function is exactly like <a href="command-line-options.html#level">-level</a>, except that the
5346value value for each color channel is determined by the
5347'<code>black_color</code>' and '<code>white_color</code>' colors given (as
5348described under the <a href="command-line-options.html#fill">-fill</a> option). </p>
5349
5350<p>This effectually means the colors provided to <code>-level-colors</code>
5351is mapped to become 'black' and 'white' respectively, with all the other
5352colors linearly adjusted (or clipped) to match that change. Each channel is
5353adjusted separately using the channel values of the colors specified. </p>
5354
5355<p>On the other hand the plus form of the operator (<code>+level-colors</code>)
5356will map the image color 'black' and 'white' to the given colors
5357respectively, resulting in a gradient (de-contrasting) tint of the image to
Cristy769d8892016-01-19 18:11:14 -05005358those colors. This can also be used to convert a plain grayscale image into a
Cristy882d9f42015-10-29 16:48:39 -04005359one using the gradient of colors specified. </p>
5360
5361<p>By supplying a single color with a comma separator either before or after
5362that color, will just replace the respective 'black' or 'white' point
5363respectively. But if no comma separator is provided, the given color is
5364used for both the black and white color points, making the operator either
5365threshold the images around that color (- form) or set all colors to that
5366color (+ form). </p>
5367
5368
5369<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005370 <h3><a id="limit"></a>-limit <var>type value</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04005371</div>
5372
5373<p class="magick-description">Set the pixel cache resource limit.</p>
5374
Cristye09ed312016-03-06 08:07:39 -05005375<p>Choose from: <code>width</code>, <code>height</code>, <code>area</code>, <code>memory</code>, <code>map</code>, <code>disk</code>, <code>file</code>, <code>thread</code>, <code>throttle</code>, or <code>time</code>.</p>
Cristy882d9f42015-10-29 16:48:39 -04005376
5377<p>The value for <code>file</code> is in number of files. The other limits are
5378in bytes. Define arguments for the memory, map, area, and disk resource limits
5379with SI prefixes (.e.g 100MB).</p>
5380
5381<p>By default the limits are 768 files, 3GB of image area, 1.5GiB memory, 3GiB
5382memory map, and 18.45EB of disk. These limits are adjusted relative to the
5383available resources on your computer if this information is available. When
5384any limit is reached, ImageMagick fails in some fashion but attempts to take
5385compensating actions, if possible. For example, the following limits
5386memory:</p>
5387
Cristy49380402017-06-29 11:24:55 -04005388<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04005389-limit memory 32MiB -limit map 64MiB
Cristy49380402017-06-29 11:24:55 -04005390</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04005391
5392<p>Use <a href="command-line-options.html#list">-list resource</a> to list the current limits. For example, our system shows these limits:</p>
5393
Cristy49380402017-06-29 11:24:55 -04005394<pre><code>
Cristy594d2772015-11-15 10:47:42 -05005395-> identify -list resource
Cristy882d9f42015-10-29 16:48:39 -04005396Resource limits:
5397 Width: 100MP
5398 Height: 100MP
5399 Area: 25.181GB
5400 Memory: 11.726GiB
5401 Map: 23.452GiB
5402 Disk: unlimited
5403 File: 768
5404 Thread: 12
5405 Throttle: 0
5406 Time: unlimited
Cristy49380402017-06-29 11:24:55 -04005407</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04005408
5409<p>Requests for pixel storage to keep intermediate images are satisfied by one
5410of three resource categories: in-memory pool, memory-mapped files pool, and
Cristy594d2772015-11-15 10:47:42 -05005411disk pool (in that order) depending on the <a href="command-line-options.html#limit">&#x2011;limit</a> settings
Cristy882d9f42015-10-29 16:48:39 -04005412and whether the system honors a resource request. If the total size of
5413allocated pixel storage in the given pool reaches the corresponding limit, the
5414request is passed to the next pool. Additionally, requests that exceed the
5415<code>area</code> limit automagically are allocated on disk.</p>
5416
5417<p>To illustrate how ImageMagick utilizes resource limits, consider a typical
5418image resource request. First, ImageMagick tries to allocate the pixels in
5419memory. The request might be denied if the resource request exceeds the
5420<code>memory</code> limit or if the system does not honor the request. If
5421a memory request is not honored, the pixels are allocated to disk and the file
5422is memory-mapped. However, if the allocation request exceeds the
5423<code>map</code> limit, the resource allocation goes to disk. In all cases, if
5424the resource request exceeds the <code>area</code> limit, the pixels are
5425automagically cached to disk. If the disk has a hard limit, the program
5426fails.</p>
5427
5428<p>In most cases you simply do not need to concern yourself with resource
5429limits. ImageMagick chooses reasonable defaults and most images do not tax
5430your computer resources. Where limits do come in handy is when you process
5431images that are large or on shared systems where ImageMagick can consume all
5432or most of the available memory. In this case, the ImageMagick workflow slows
5433other processes or, in extreme cases, brings the system to a halt. Under
5434these circumstances, setting limits give some assurances that the ImageMagick
5435workflow will not interfere with other concurrent uses of the computer. For
5436example, assume you have a web interface that processes images uploaded from
5437the Internet. To assure ImageMagick does not exceed 10MiB of memory you can
5438simply set the area limit to 10MiB:</p>
5439
Cristy49380402017-06-29 11:24:55 -04005440<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04005441-limit area 10MB
Cristy49380402017-06-29 11:24:55 -04005442</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04005443
5444<p>Now whenever a large image is processed, the pixels are automagically
5445cached to disk instead of memory. This of course implies that large images
5446typically process very slowly, simply because pixel processing in memory can
5447be an order of magnitude faster than on disk. Because your web site users
5448might inadvertently upload a huge image to process, you should set a disk
5449limit as well:</p>
5450
Cristy49380402017-06-29 11:24:55 -04005451<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04005452-limit area 10MB -limit disk 500MB
Cristy49380402017-06-29 11:24:55 -04005453</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04005454
5455<p>Here ImageMagick stops processing if an image requires more than 500MB of disk storage.</p>
5456
5457<p>In addition to command-line resource limit option, resources can be set
Cristy594d2772015-11-15 10:47:42 -05005458with <a href="resources.html#environment" >environment variables</a>. Set the
Cristy882d9f42015-10-29 16:48:39 -04005459environment variables <code>MAGICK_AREA_LIMIT</code>,
5460<code>MAGICK_DISK_LIMIT</code>, <code>MAGICK_FILE_LIMIT</code>,
5461<code>MAGICK_MEMORY_LIMIT</code>, <code>MAGICK_MAP_LIMIT</code>,
5462<code>MAGICK_THREAD_LIMIT</code>, <code>MAGICK_TIME_LIMIT</code> for limits of
5463image area, disk space, open files, heap memory, memory map, number of threads
5464of execution, and maximum elapsed time in seconds respectively.</p>
5465
5466<p> Inquisitive users can try adding <a href="command-line-options.html#debug">-debug cache</a> to
5467their commands and then scouring the generated output for references to the
5468pixel cache, in order to determine how the pixel cache was allocated and how
5469resources were consumed. Advanced Unix/Linux users can pipe that output
5470through <code>grep memory|open|destroy|disk</code> for more readable sifting.
5471</p>
5472
5473<p>For more about ImageMagick's use of resources, see the section <b>Cache
Cristy594d2772015-11-15 10:47:42 -05005474Storage and Resource Requirements</b> on the <a href="architecture.html#cache
5475">Architecture</a> page. </p>
Cristy882d9f42015-10-29 16:48:39 -04005476
5477<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005478 <h3><a id="linear-stretch"></a>-linear-stretch <var>black-point</var><br />-linear-stretch <var>black-point</var>{x<var>white-point</var>}{<var>%</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -04005479</div>
5480
5481<p class="magick-description">Linear with saturation stretch.</p>
5482
Cristy594d2772015-11-15 10:47:42 -05005483<p>This is very similar to <a href="command-line-options.html#contrast-stretch" >-contrast-stretch</a>,
Cristy882d9f42015-10-29 16:48:39 -04005484and uses a 'histogram bin' to determine the range of color values that needs to
Cristy594d2772015-11-15 10:47:42 -05005485be stretched. However it then stretches those colors using the <a
5486href="command-line-options.html#level" >-level</a> operator.</p>
Cristy882d9f42015-10-29 16:48:39 -04005487
5488<p>As such while the initial determination may have 'binning' round off
5489effects, the image colors are stretched mathematically, rather than using the
5490histogram bins. This makes the operator more accurate. </p>
5491
Cristy594d2772015-11-15 10:47:42 -05005492<p>note however that a <a href="command-line-options.html#linear-stretch" >-linear-stretch</a> of
Cristy882d9f42015-10-29 16:48:39 -04005493'<code>0</code>' does nothing, while a value of '<code>1</code>' does a near
5494perfect stretch of the color range. </p>
5495
Cristy594d2772015-11-15 10:47:42 -05005496<p>See also <a href="command-line-options.html#auto-level" >-auto-level</a> for a 'perfect'
Cristy882d9f42015-10-29 16:48:39 -04005497normalization of mathematical images. </p>
5498
5499<p>This operator is under review for re-development. </p>
5500
5501
5502<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005503 <h3><a id="linewidth"></a>-linewidth</h3>
Cristy882d9f42015-10-29 16:48:39 -04005504</div>
5505
5506<p class="magick-description">the line width for subsequent draw operations.</p>
5507
5508<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005509 <h3><a id="liquid-rescale"></a>-liquid-rescale <var>geometry</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04005510</div>
5511
5512<p class="magick-description">rescale image with seam-carving.</p>
5513
5514<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
5515
5516<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005517 <h3><a id="list"></a>-list <var>type</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04005518</div>
5519
5520<p class="magick-description">Print a list of supported arguments for various options or settings. Choose from these list types:</p>
5521
Cristy49380402017-06-29 11:24:55 -04005522<pre class="pre-scrollable"><code>
Cristy882d9f42015-10-29 16:48:39 -04005523Align
5524Alpha
5525Boolean
5526Cache
5527Channel
5528Class
5529ClipPath
5530Coder
5531Color
5532Colorspace
5533Command
5534Complex
5535Compose
5536Compress
5537Configure
5538DataType
5539Debug
5540Decoration
5541Delegate
5542Direction
5543Dispose
5544Distort
5545Dither
5546Endian
5547Evaluate
5548FillRule
5549Filter
5550Font
5551Format
5552Function
5553Gravity
5554Intensity
5555Intent
5556Interlace
5557Interpolate
5558Kernel
5559Layers
5560LineCap
5561LineJoin
5562List
5563Locale
5564LogEvent
5565Log
5566Magic
5567Method
5568Metric
5569Mime
5570Mode
5571Morphology
5572Module
5573Noise
5574Orientation
5575PixelIntensity
5576Policy
5577PolicyDomain
5578PolicyRights
5579Preview
5580Primitive
5581QuantumFormat
5582Resource
5583SparseColor
5584Statistic
5585Storage
5586Stretch
5587Style
5588Threshold
5589Type
5590Units
5591Validate
5592VirtualPixel
Cristy49380402017-06-29 11:24:55 -04005593</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04005594
5595<p>These lists vary depending on your version of ImageMagick. Use "<code>-list
5596list</code>" to get a complete listing of all the "<code>-list</code>" arguments
5597available:</p>
5598
Cristy49380402017-06-29 11:24:55 -04005599<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04005600identify -list list
Cristy49380402017-06-29 11:24:55 -04005601</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04005602
5603<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005604 <h3><a id="log"></a>-log <var>string</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04005605</div>
5606
5607<p class="magick-description">Specify format for debug log.</p>
5608
Cristy594d2772015-11-15 10:47:42 -05005609<p>This option specifies the format for the log printed when the <a
5610href="command-line-options.html#debug">-debug</a> option is active.</p>
Cristy882d9f42015-10-29 16:48:39 -04005611
5612<p>You can display the following components by embedding special format
5613characters:</p>
5614
Cristy49380402017-06-29 11:24:55 -04005615<dl class="row">
5616<dt class="col-md-4">%d</dt><dd class="col-md-8">domain</dd>
5617<dt class="col-md-4">%e</dt><dd class="col-md-8">event</dd>
5618<dt class="col-md-4">%f</dt><dd class="col-md-8">function</dd>
5619<dt class="col-md-4">%l</dt><dd class="col-md-8">line</dd>
5620<dt class="col-md-4">%m</dt><dd class="col-md-8">module</dd>
5621<dt class="col-md-4">%p</dt><dd class="col-md-8">process ID</dd>
5622<dt class="col-md-4">%r</dt><dd class="col-md-8">real CPU time</dd>
5623<dt class="col-md-4">%t</dt><dd class="col-md-8">wall clock time</dd>
5624<dt class="col-md-4">%u</dt><dd class="col-md-8">user CPU time</dd>
5625<dt class="col-md-4">%%</dt><dd class="col-md-8">percent sign</dd>
5626<dt class="col-md-4">\n</dt><dd class="col-md-8">newline</dd>
5627<dt class="col-md-4">\r</dt><dd class="col-md-8">carriage return</dd>
Cristy882d9f42015-10-29 16:48:39 -04005628</dl>
5629
5630<p>For example:</p>
5631
Cristy49380402017-06-29 11:24:55 -04005632<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04005633convert -debug coders -log "%u %m:%l %e" in.gif out.png
Cristy49380402017-06-29 11:24:55 -04005634</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04005635
5636<p>The default behavior is to print all of the components.</p>
5637
5638<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005639 <h3><a id="loop"></a>-loop <var>iterations</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04005640</div>
5641
5642<p class="magick-description">add Netscape loop extension to your GIF animation.</p>
5643
5644<p>Set iterations to zero to repeat the animation an infinite number of times,
5645otherwise the animation repeats itself up to <var>iterations</var>
5646times.</p>
5647
5648<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005649 <h3><a id="lowlight-color"></a>-lowlight-color <var>color</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04005650</div>
5651
5652<p class="magick-description">when comparing images, de-emphasize pixel differences with this color.</p>
5653
5654<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005655 <h3><a id="magnify"></a>-magnify</h3>
Cristy882d9f42015-10-29 16:48:39 -04005656</div>
5657
5658<p class="magick-description">double the size of the image with pixel art scaling.</p>
5659
5660
5661<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005662 <h3><a id="map"></a>-map <var>type</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04005663</div>
5664
5665<p class="magick-description">Display image using this <var>type</var>.</p>
5666
5667<p>Choose from these <var>Standard Colormap</var> types:</p>
5668
Cristy49380402017-06-29 11:24:55 -04005669<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04005670best
5671default
5672gray
5673red
5674green
5675blue
Cristy49380402017-06-29 11:24:55 -04005676</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04005677
5678<p>The <var>X server</var> must support the <var>Standard
5679Colormap</var> you choose, otherwise an error occurs. Use <code>list</code> as
5680the type and <code>display</code> searches the list of colormap types in
5681<code>top-to-bottom</code> order until one is located. See <var>xstdcmap(1)</var> for one way of creating Standard Colormaps.</p>
5682
5683
5684<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005685 <h3><a id="map_stream_"></a>-map <var>components</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04005686</div>
5687
5688<p class="magick-description">pixel map.</p>
5689
5690<p>Here are the valid components of a map:</p>
5691
Cristy49380402017-06-29 11:24:55 -04005692<dl class="row">
5693<dt class="col-md-4">r</dt><dd class="col-md-8"> red pixel component</dd>
5694<dt class="col-md-4">g</dt><dd class="col-md-8"> green pixel component</dd>
5695<dt class="col-md-4">b</dt><dd class="col-md-8"> blue pixel component</dd>
5696<dt class="col-md-4">a</dt><dd class="col-md-8"> alpha pixel component (0 is transparent)</dd>
5697<dt class="col-md-4">o</dt><dd class="col-md-8"> opacity pixel component (0 is opaque)</dd>
5698<dt class="col-md-4">i</dt><dd class="col-md-8"> grayscale intensity pixel component</dd>
5699<dt class="col-md-4">c</dt><dd class="col-md-8"> cyan pixel component</dd>
5700<dt class="col-md-4">m</dt><dd class="col-md-8"> magenta pixel component</dd>
5701<dt class="col-md-4">y</dt><dd class="col-md-8"> yellow pixel component</dd>
5702<dt class="col-md-4">k</dt><dd class="col-md-8"> black pixel component</dd>
5703<dt class="col-md-4">p</dt><dd class="col-md-8"> pad component (always 0)</dd>
Cristy882d9f42015-10-29 16:48:39 -04005704</dl>
5705
5706<p>You can specify as many of these components as needed in any order (e.g.
5707bgr). The components can repeat as well (e.g. rgbr).</p>
5708
5709
5710<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005711 <h3><a id="mattecolor"></a>-mattecolor <var>color</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04005712</div>
5713
5714<p class="magick-description">Specify the color to be used with the <a href="command-line-options.html#frame">-frame</a> option.</p>
5715
5716<p>The color is specified using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p>
5717
Cristy594d2772015-11-15 10:47:42 -05005718<p>The default matte color is <code>#BDBDBD</code>, <span
5719style="background-color: #bdbdbd;">this shade of gray</span>.</p>
Cristy882d9f42015-10-29 16:48:39 -04005720
5721<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005722 <h3><a id="maximum"></a>-maximum</h3>
Cristy882d9f42015-10-29 16:48:39 -04005723</div>
5724
5725<p class="magick-description">return the maximum intensity of an image sequence.</p>
5726
5727<p>Select the 'maximum' value from all the surrounding pixels. </p>
5728
Cristy594d2772015-11-15 10:47:42 -05005729<p>This is legacy option from the <a href="command-line-options.html#statistic" >method</a> of the same
Cristy882d9f42015-10-29 16:48:39 -04005730name. </p>
5731
5732<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005733 <h3><a id="median"></a>-median <var>geometry</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04005734</div>
5735
5736<p class="magick-description">apply a median filter to the image.</p>
5737
5738<p>Select the 'middle' value from all the surrounding pixels. </p>
5739
Cristy594d2772015-11-15 10:47:42 -05005740<p>This is legacy option from the <a href="command-line-options.html#statistic" >method</a> of the same
Cristy882d9f42015-10-29 16:48:39 -04005741name. </p>
5742
5743<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005744 <h3><a id="mean-shift"></a>-mean-shift <var>width</var>x<var>height</var>{<var>+distance</var>{%}</h3>
Cristy882d9f42015-10-29 16:48:39 -04005745</div>
5746
5747<p class="magick-description">image noise removal and color reduction/segmentation (e.g. -mean-shift 7x7+10%).</p>
5748
5749<p><var>width</var>x<var>height</var> is the window size and <var>distance</var> is the color distance measured in the range 0 to 1 or 0 to 100%</p>
5750
5751<p>The mean shift algorithm is iterative and thus slower the larger the window size. For each pixel, it gets all the pixels in the window centered at the pixel and excludes those that are outside the <var>radius=sqrt((width-1)(height-1)/4)</var> surrounding the pixel. From those pixels, it finds which of them are within the specified squared color distance from the current mean. It then computes a new x,y centroid from those coordinates and a new mean. This new x,y centroid is used as the center for a new window. This process is iterated until it converges and the final mean is then used to replace the original pixel value. It repeats this process for the next pixel, etc, until it processes all pixels in the image. Results are better when using other colorspaces rather than RGB. Recommend YIQ, YUV or YCbCr, which seem to give equivalent results.</p>
5752
5753<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005754 <h3><a id="metric"></a>-metric <var>type</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04005755</div>
5756
5757<p class="magick-description">Output to STDERR a measure of the differences between images according to the <var>type</var> given metric.</p>
5758
5759<p>Choose from:</p>
5760
Cristy49380402017-06-29 11:24:55 -04005761<dl class="row">
5762<dt class="col-md-4">AE</dt><dd class="col-md-8"> absolute error count, number of different pixels (-fuzz effected)</dd>
5763<dt class="col-md-4">FUZZ</dt><dd class="col-md-8"> mean color distance</dd>
5764<dt class="col-md-4">MAE</dt><dd class="col-md-8"> mean absolute error (normalized), average channel error distance</dd>
5765<dt class="col-md-4">MEPP</dt><dd class="col-md-8"> mean error per pixel (normalized mean error, normalized peak error)</dd>
5766<dt class="col-md-4">MSE</dt><dd class="col-md-8"> mean error squared, average of the channel error squared</dd>
5767<dt class="col-md-4">NCC</dt><dd class="col-md-8"> normalized cross correlation</dd>
5768<dt class="col-md-4">PAE</dt><dd class="col-md-8"> peak absolute (normalized peak absolute)</dd>
5769<dt class="col-md-4">PHASH</dt><dd class="col-md-8"> perceptual hash for the sRGB and HCLp colorspaces. Specify an alternative colorspace with <code>-define phash:colorspaces=<var>colorspace,colorspace,...</var></code></dd>
5770<dt class="col-md-4">PSNR</dt><dd class="col-md-8"> peak signal to noise ratio</dd>
5771<dt class="col-md-4">RMSE</dt><dd class="col-md-8"> root mean squared (normalized root mean squared)</dd>
Cristy882d9f42015-10-29 16:48:39 -04005772</dl>
5773
5774<p>Control the '<code>AE</code>', or absolute count of pixels that are different,
Cristy594d2772015-11-15 10:47:42 -05005775with the <a href="command-line-options.html#fuzz" >-fuzz</a> factor (ignore pixels which
Cristy882d9f42015-10-29 16:48:39 -04005776only changed by a small amount). Use '<code>PAE</code>' to find the
Cristy594d2772015-11-15 10:47:42 -05005777size of the <a href="command-line-options.html#fuzz" >-fuzz</a> factor needed to make all pixels
Cristy882d9f42015-10-29 16:48:39 -04005778'similar', while '<code>MAE</code>' determines the factor needed
5779for about half the pixels to be similar. </p>
5780
5781<p>The '<code>MEPP</code>' metric returns three different metrics
5782('<code>MAE</code>', '<code>MAE</code>' normalized, and '<code>PAE</code>'
5783normalized) from a single comparison run. </p>
5784
5785<p>To print a complete list of metrics, use the <a href="command-line-options.html#list">-list
5786metric</a> option.</p>
5787
5788
5789<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005790 <h3><a id="minimum"></a>-minimum</h3>
Cristy882d9f42015-10-29 16:48:39 -04005791</div>
5792
5793<p class="magick-description">return the minimum intensity of an image sequence.</p>
5794
5795<p>Select the 'minimal' value from all the surrounding pixels. </p>
5796
Cristy594d2772015-11-15 10:47:42 -05005797<p>This is legacy option from the <a href="command-line-options.html#statistic" >method</a> of the same
Cristy882d9f42015-10-29 16:48:39 -04005798name. </p>
5799
5800
5801
5802<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005803 <h3><a id="mode"></a>-mode <var>geometry</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04005804</div>
5805
5806<p class="magick-description">make each pixel the \'predominant color\' of the neighborhood.'</p>
5807
5808<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005809 <h3>-mode <var>value</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04005810</div>
5811
5812<p class="magick-description">Mode of operation.</p>
5813
5814<p>Choose the <var>value</var> from these styles: <code>Frame,
5815Unframe, or Concatenate</code></p>
5816
Cristy594d2772015-11-15 10:47:42 -05005817<p>Use the <a href="command-line-options.html#list" >-list</a> option with a '<code>Mode</code>' argument
5818for a list of <a href="command-line-options.html#mode" >-mode</a> arguments available in your
Cristy882d9f42015-10-29 16:48:39 -04005819ImageMagick installation.</p>
5820
5821
5822<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005823 <h3><a id="modulate"></a>-modulate <var>brightness</var>[,<var>saturation</var>,<var>hue</var>]</h3>
Cristy882d9f42015-10-29 16:48:39 -04005824</div>
5825
5826<p class="magick-description">Vary the <var>brightness</var>, <var>saturation</var>, and <var>hue</var> of an image.</p>
5827
5828<p>The arguments are given as a percentages of variation. A value of 100 means
5829no change, and any missing values are taken to mean 100.</p>
5830
5831<p>The <var>brightness</var> is a multiplier of the overall
5832brightness of the image, so 0 means pure black, 50 is half as bright, 200 is
5833twice as bright. To invert its meaning <a href="command-line-options.html#negate">-negate</a> the image
5834before and after. </p>
5835
5836<p>The <var>saturation</var> controls the amount of color in an
5837image. For example, 0 produce a grayscale image, while a large value such as
5838200 produce a very colorful, 'cartoonish' color.</p>
5839
5840<p>The <var>hue</var> argument causes a "rotation" of the colors
5841within the image by the amount specified. For example, 50 results in
5842a counter-clockwise rotation of 90, mapping red shades to purple, and so on.
5843A value of either 0 or 200 results in a complete 180 degree rotation of the
5844image. Using a value of 300 is a 360 degree rotation resulting in no change to
5845the original image. </p>
5846
5847<p>For example, to increase the color brightness by 20% and decrease the color
Cristy594d2772015-11-15 10:47:42 -05005848saturation by 10% and leave the hue unchanged, use <a
5849href="command-line-options.html#modulate">-modulate 120,90</a>.</p>
Cristy882d9f42015-10-29 16:48:39 -04005850
Cristy594d2772015-11-15 10:47:42 -05005851<p>Use <a href="command-line-options.html#set">-set</a> attribute of '<code
5852>option:modulate:colorspace</code>' to specify which colorspace to
Cristy882d9f42015-10-29 16:48:39 -04005853modulate. Choose from <code>HCL</code>, <code>HCLp</code>, <code>HSB</code>, <code>HSI</code>, <code>HSL</code> (the default), <code>HSV</code>, <code>HWB</code>, or <code>LCH</code> (LCHuv). For example,</p>
5854
Cristy49380402017-06-29 11:24:55 -04005855<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04005856convert image.png -set option:modulate:colorspace hsb -modulate 120,90 modulate.png
Cristy49380402017-06-29 11:24:55 -04005857</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04005858
5859<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005860 <h3><a id="moments"></a>-moments</h3>
Cristy882d9f42015-10-29 16:48:39 -04005861</div>
5862
5863<p class="magick-description">report image moments and perceptual hash.</p>
5864
5865
5866<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005867 <h3><a id="monitor"></a>-monitor</h3>
Cristy882d9f42015-10-29 16:48:39 -04005868</div>
5869
5870<p class="magick-description">monitor progress.</p>
5871
5872
5873<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005874 <h3><a id="monochrome"></a>-monochrome</h3>
Cristy882d9f42015-10-29 16:48:39 -04005875</div>
5876
5877<p class="magick-description">transform the image to black and white.</p>
5878
5879<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005880 <h3><a id="morph"></a>-morph <var>frames</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04005881</div>
5882
5883<p class="magick-description">morphs an image sequence.</p>
5884
5885<p>Both the image pixels and size are linearly interpolated to give the
5886appearance of a metamorphosis from one image to the next, over all the images
Cristy594d2772015-11-15 10:47:42 -05005887in the current image list. The added images are the equivalent of a <a
5888href="command-line-options.html#blend">-blend</a> composition. The <var>frames</var>
Cristy882d9f42015-10-29 16:48:39 -04005889argument determine how many images to interpolate between each image. </p>
5890
5891
5892<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005893 <h3><a id="morphology"></a>-morphology</h3>
5894 <h3>-morphology <var>method</var> <var>kernel</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04005895</div>
5896
5897<p class="magick-description">apply a morphology method to the image.</p>
5898
Cristy594d2772015-11-15 10:47:42 -05005899<p>Until I get around to writing an option summary for this, see <a
Cristy364a72f2016-11-04 22:38:41 -04005900href="https://www.imagemagick.org/Usage/morphology/" >IM Usage Examples,
Cristy882d9f42015-10-29 16:48:39 -04005901Morphology</a>. </p>
5902
5903
5904<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005905 <h3><a id="mosaic"></a>-mosaic</h3>
Cristy882d9f42015-10-29 16:48:39 -04005906</div>
5907
Cristy594d2772015-11-15 10:47:42 -05005908<p class="magick-description">an simple alias for the <a href="command-line-options.html#layers" >-layers</a> method "mosaic"</p>
Cristy882d9f42015-10-29 16:48:39 -04005909
5910
5911<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005912 <h3><a id="motion-blur"></a>-motion-blur <var>radius</var><br />-motion-blur <var>radius</var>x<var>sigma</var>+<var>angle</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04005913</div>
5914
5915<p class="magick-description">simulate motion blur.</p>
5916
5917<p>Blur with the given radius, standard deviation (sigma), and angle. The
5918angle given is the angle toward which the image is blurred. That is the
5919direction people would consider the object is coming from. </p>
5920
5921<p>Note that the blur is not uniform distribution, giving the motion a
5922definite sense of direction of movement. </p>
5923
5924<p>The <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting will determine how
5925pixels which are outside the image proper are blurred into the final result.
5926</p>
5927
5928<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005929 <h3><a id="name"></a>-name</h3>
Cristy882d9f42015-10-29 16:48:39 -04005930</div>
5931
5932<p class="magick-description">name an image.</p>
5933<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005934 <h3><a id="negate"></a>-negate</h3>
Cristy882d9f42015-10-29 16:48:39 -04005935</div>
5936
5937<p class="magick-description">replace each pixel with its complementary color.</p>
5938
5939<p>The red, green, and blue intensities of an image are negated. White becomes
5940black, yellow becomes blue, etc. Use <a href="command-line-options.html#negate">+negate</a> to only
5941negate the grayscale pixels of the image.</p>
5942
5943<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005944 <h3><a id="noise"></a>-noise <var>geometry</var><br/>
Cristy882d9f42015-10-29 16:48:39 -04005945 +noise <var>type</var></h3>
5946</div>
5947
5948<p class="magick-description">Add or reduce noise in an image.</p>
5949
5950<p>The principal function of noise peak elimination filter is to smooth the
5951objects within an image without losing edge information and without creating
5952undesired structures. The central idea of the algorithm is to replace a pixel
5953with its next neighbor in value within a pixel window, if this pixel has been
5954found to be noise. A pixel is defined as noise if and only if this pixel is
5955a maximum or minimum within the pixel window.</p>
5956
5957<p>Use <code><a href="command-line-options.html#noise">-noise</a> <var>radius</var></code> to
5958specify the width of the neighborhood when reducing noise. This is equivalent
Cristy594d2772015-11-15 10:47:42 -05005959to using a <code><a href="command-line-options.html#statistic" >-statistic</a> NonPeak</code> operation,
Cristy882d9f42015-10-29 16:48:39 -04005960which should be used in preference.</p>
5961
5962<p>Use <a href="command-line-options.html#noise">+noise</a> followed by a noise <var>type</var> to add noise to an image. Choose from these noise
5963types:</p>
5964
Cristy49380402017-06-29 11:24:55 -04005965<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04005966Gaussian
5967Impulse
5968Laplacian
5969Multiplicative
5970Poisson
5971Random
5972Uniform
Cristy49380402017-06-29 11:24:55 -04005973</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04005974
Cristy594d2772015-11-15 10:47:42 -05005975<p>The amount of noise added can be controlled by the <code><a
5976href="command-line-options.html#attenuate" >-attenuate</a></code> setting. If unset the value is
Cristy882d9f42015-10-29 16:48:39 -04005977equivalent to 1.0, or a maximum noise addition.</p>
5978
5979<p>Note that Random will replace the image with noise rather than add noise to the image. Use Uniform, if you wish to add random noise to the image.</p>
5980
5981<p>To print a complete list of noises, use the <a href="command-line-options.html#list">-list noise</a> option.</p>
5982
5983<p>Also see the <a href="command-line-options.html#evaluate">-evaluate</a> noise functions that allows
5984the use of a controlling value to specify the amount of noise that should be
5985added to an image. </p>
5986
5987
5988<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04005989 <h3><a id="normalize"></a>-normalize</h3>
Cristy882d9f42015-10-29 16:48:39 -04005990</div>
5991
5992<p class="magick-description">Increase the contrast in an image by <var>stretching</var> the range of intensity values.</p>
5993
5994<p>The intensity values are stretched to cover the entire range of possible
5995values. While doing so, black-out at most <var>2%</var> of the pixels and
5996white-out at most <var>1%</var> of the pixels.</p>
5997
Cristy594d2772015-11-15 10:47:42 -05005998<p>Note that as of ImageMagick 6.4.7-0, <a href="command-line-options.html#normalize" >-normalize</a>
5999is equivalent to <a href="command-line-options.html#contrast-stretch" >-contrast-stretch 2%x1%</a>.
6000(Before this version, it was equivalent to <a href="command-line-options.html#contrast-stretch"
6001>-contrast-stretch 2%x99%</a>).</p>
Cristy882d9f42015-10-29 16:48:39 -04006002
Cristy769d8892016-01-19 18:11:14 -05006003<p>All the channels are normalized in concert by the same amount so as to
Cristy594d2772015-11-15 10:47:42 -05006004preserve color integrity, when the default <a href="command-line-options.html#channel" >+channel</a>
6005setting is in use. Specifying any other <a href="command-line-options.html#channel" >-channel</a>
Cristy882d9f42015-10-29 16:48:39 -04006006setting will normalize the RGB channels independently.</p>
6007
Cristy594d2772015-11-15 10:47:42 -05006008<p>See <a href="command-line-options.html#contrast-stretch" >-contrast-stretch</a> for more details.
6009Also see <a href="command-line-options.html#auto-level" >-auto-level</a> for a 'perfect' normalization
Cristy882d9f42015-10-29 16:48:39 -04006010that is better suited to mathematically generated images. </p>
6011
6012<p>This operator is under review for re-development. </p>
6013
6014
6015<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006016 <h3><a id="opaque"></a>-opaque <var>color</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006017</div>
6018
6019<p class="magick-description">change this color to the fill color within the image.</p>
6020
6021<p>The <var>color</var> argument is defined using the format
Cristy594d2772015-11-15 10:47:42 -05006022described under the <a href="command-line-options.html#fill" >-fill</a> option. The <a href="command-line-options.html#fuzz"
6023>-fuzz</a> setting can be used to match and replace colors similar to the one
Cristy882d9f42015-10-29 16:48:39 -04006024given.</p>
6025
6026<p>Use <a href="command-line-options.html#opaque">+opaque</a> to paint any pixel that does not match
6027the target color. </p>
6028
6029<p>The <a href="command-line-options.html#transparent">-transparent</a> operator is exactly the same
Cristy594d2772015-11-15 10:47:42 -05006030as <a href="command-line-options.html#opaque" >-opaque</a> but replaces the matching color with
Cristy882d9f42015-10-29 16:48:39 -04006031transparency rather than the current <a href="command-line-options.html#fill">-fill</a> color setting.
6032To ensure that it can do this it also ensures that the image has an alpha
Cristy594d2772015-11-15 10:47:42 -05006033channel enabled, as per "<code><a href="command-line-options.html#alpha" >-alpha</a> set</code>", for
6034the new transparent colors, and does not require you to modify the <a
6035href="command-line-options.html#channel">-channel</a> to enable alpha channel handling. </p>
Cristy882d9f42015-10-29 16:48:39 -04006036
6037
6038<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006039 <h3><a id="ordered-dither"></a>-ordered-dither <var>threshold_map</var>{,<var>level</var>...}</h3>
Cristy882d9f42015-10-29 16:48:39 -04006040</div>
6041
6042<p class="magick-description">dither the image using a pre-defined ordered dither <var>threshold map</var> specified, and a uniform color map with the
6043given number of <var>levels</var> per color channel.</p>
6044
6045<p>You can choose from these standard threshold maps:</p>
6046
Cristy49380402017-06-29 11:24:55 -04006047<pre class="pre-scrollable"><code>
Cristy882d9f42015-10-29 16:48:39 -04006048threshold 1x1 Threshold 1x1 (non-dither)
6049checks 2x1 Checkerboard 2x1 (dither)
6050o2x2 2x2 Ordered 2x2 (dispersed)
6051o3x3 3x3 Ordered 3x3 (dispersed)
6052o4x4 4x4 Ordered 4x4 (dispersed)
6053o8x8 8x8 Ordered 8x8 (dispersed)
6054h3x4a 4x1 Halftone 4x4 (angled)
6055h6x6a 6x1 Halftone 6x6 (angled)
6056h8x8a 8x1 Halftone 8x8 (angled)
6057h3x4o Halftone 4x4 (orthogonal)
6058h6x6o Halftone 6x6 (orthogonal)
6059h8x8o Halftone 8x8 (orthogonal)
6060h36x16o Halftone 16x16 (orthogonal)
6061c5x5b c5x5 Circles 5x5 (black)
6062c5x5w Circles 5x5 (white)
6063c6x6b c6x6 Circles 6x6 (black)
6064c6x6w Circles 6x6 (white)
6065c7x7b c7x7 Circles 7x7 (black)
6066c7x7w Circles 7x7 (white)
Cristy49380402017-06-29 11:24:55 -04006067</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04006068
6069<p> The <code>threshold</code> generated a simple 50% threshold of the image.
Cristy594d2772015-11-15 10:47:42 -05006070This could be used with <var >level</var> to do the equivalent of <a
6071href="command-line-options.html#posterize" >-posterize</a> to reduce an image to basic primary colors.
Cristy882d9f42015-10-29 16:48:39 -04006072</p>
6073
6074<p>The <code>checks</code> pattern produces a 3 level checkerboard dither
6075pattern. That is a grayscale will become a pattern of solid black, solid
6076white, and mid-tone colors into a checkerboard pattern of black and white.
6077</p>
6078
Cristy594d2772015-11-15 10:47:42 -05006079<p>You can define your own <var >threshold map</var> for ordered
Cristy882d9f42015-10-29 16:48:39 -04006080dithering and halftoning your images, in either personal or system
Cristy594d2772015-11-15 10:47:42 -05006081<code>thresholds.xml</code> XML file. See <a href="resources.html" >Resources</a>
Cristy882d9f42015-10-29 16:48:39 -04006082for more details of configuration files. </p>
6083
6084<p>To print a complete list of the thresholds that have been defined, use the
Cristy594d2772015-11-15 10:47:42 -05006085<a href="command-line-options.html#list" >-list threshold</a> option.</p>
Cristy882d9f42015-10-29 16:48:39 -04006086
6087<p>Note that at this time the same threshold dithering map is used for all
6088color channels, no attempt is made to offset or rotate the map for different
6089channels is made, to create an offset printing effect. Also as the maps are
6090simple threshold levels, the halftone and circle maps will create incomplete
6091circles along the edges of a colored area. Also all the effects are purely
6092on/off boolean effects, without anti-aliasing to make the circles smooth
6093looking. Large dots can be made to look better with a small amount of blurring
6094after being created. </p>
6095
6096
6097<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006098 <h3><a id="orient"></a>-orient <var>image orientation</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006099</div>
6100
6101<p class="magick-description">specify orientation of a digital camera image.</p>
6102
6103<p>Choose from these orientations:</p>
6104
Cristy49380402017-06-29 11:24:55 -04006105<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04006106bottom-left right-top
6107bottom-right top-left
6108left-bottom top-right
6109left-top undefined
6110right-bottom
Cristy49380402017-06-29 11:24:55 -04006111</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04006112
Cristy594d2772015-11-15 10:47:42 -05006113<p>To print a complete list of orientations, use the <a href="command-line-options.html#list" >-list
Cristy882d9f42015-10-29 16:48:39 -04006114orientation</a> option.</p>
6115
6116
6117<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006118 <h3><a id="page"></a>-page <var>geometry</var><br/>
Cristy594d2772015-11-15 10:47:42 -05006119 -page <var>media</var>[<var>offset</var>][{<var>^!&lt;&gt;</var>}]<br/>
Cristy882d9f42015-10-29 16:48:39 -04006120 +page
6121 </h3>
6122</div>
6123
6124<p class="magick-description">Set the size and location of an image on the larger virtual canvas.</p>
6125
6126<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
6127
6128<p>For convenience you can specify the page size using <var>media</var> (see below). Offsets can then be added as with other
Cristy594d2772015-11-15 10:47:42 -05006129<var>geometry</var> arguments (e.g. <a
6130href="command-line-options.html#page">-page</a> <code>Letter+43+43</code>).</p>
Cristy882d9f42015-10-29 16:48:39 -04006131
6132<p>Use <var>media</var> as shorthand to specify the dimensions (<var>width</var>x<var>height</var>) of the <var>PostScript</var> page in dots per inch or a TEXT page in pixels.
6133The choices for a PostScript page are:</p>
6134
Cristy49380402017-06-29 11:24:55 -04006135<dl class="row">
6136<dt class="col-md-4"> 11x17 </dt> <dd class="col-md-8"> 792 x 1224</dd>
6137<dt class="col-md-4"> Ledger </dt> <dd class="col-md-8"> 1224 x 792</dd>
6138<dt class="col-md-4"> Legal </dt> <dd class="col-md-8"> 612 x 1008</dd>
6139<dt class="col-md-4"> Letter </dt> <dd class="col-md-8"> 612 x 792</dd>
6140<dt class="col-md-4"> LetterSmall</dt> <dd class="col-md-8"> 612 x 792</dd>
6141<dt class="col-md-4"> ArchE </dt> <dd class="col-md-8"> 2592 x 3456</dd>
6142<dt class="col-md-4"> ArchD </dt> <dd class="col-md-8"> 1728 x 2592</dd>
6143<dt class="col-md-4"> ArchC </dt> <dd class="col-md-8"> 1296 x 1728</dd>
6144<dt class="col-md-4"> ArchB </dt> <dd class="col-md-8"> 864 x 1296</dd>
6145<dt class="col-md-4"> ArchA </dt> <dd class="col-md-8"> 648 x 864</dd>
6146<dt class="col-md-4"> A0 </dt> <dd class="col-md-8"> 2380 x 3368</dd>
6147<dt class="col-md-4"> A1 </dt> <dd class="col-md-8"> 1684 x 2380</dd>
6148<dt class="col-md-4"> A2 </dt> <dd class="col-md-8"> 1190 x 1684</dd>
6149<dt class="col-md-4"> A3 </dt> <dd class="col-md-8"> 842 x 1190</dd>
6150<dt class="col-md-4"> A4 </dt> <dd class="col-md-8"> 595 x 842</dd>
6151<dt class="col-md-4"> A4Small </dt> <dd class="col-md-8"> 595 x 842</dd>
6152<dt class="col-md-4"> A5 </dt> <dd class="col-md-8"> 421 x 595</dd>
6153<dt class="col-md-4"> A6 </dt> <dd class="col-md-8"> 297 x 421</dd>
6154<dt class="col-md-4"> A7 </dt> <dd class="col-md-8"> 210 x 297</dd>
6155<dt class="col-md-4"> A8 </dt> <dd class="col-md-8"> 148 x 210</dd>
6156<dt class="col-md-4"> A9 </dt> <dd class="col-md-8"> 105 x 148</dd>
6157<dt class="col-md-4"> A10 </dt> <dd class="col-md-8"> 74 x 105</dd>
6158<dt class="col-md-4"> B0 </dt> <dd class="col-md-8"> 2836 x 4008</dd>
6159<dt class="col-md-4"> B1 </dt> <dd class="col-md-8"> 2004 x 2836</dd>
6160<dt class="col-md-4"> B2 </dt> <dd class="col-md-8"> 1418 x 2004</dd>
6161<dt class="col-md-4"> B3 </dt> <dd class="col-md-8"> 1002 x 1418</dd>
6162<dt class="col-md-4"> B4 </dt> <dd class="col-md-8"> 709 x 1002</dd>
6163<dt class="col-md-4"> B5 </dt> <dd class="col-md-8"> 501 x 709</dd>
6164<dt class="col-md-4"> C0 </dt> <dd class="col-md-8"> 2600 x 3677</dd>
6165<dt class="col-md-4"> C1 </dt> <dd class="col-md-8"> 1837 x 2600</dd>
6166<dt class="col-md-4"> C2 </dt> <dd class="col-md-8"> 1298 x 1837</dd>
6167<dt class="col-md-4"> C3 </dt> <dd class="col-md-8"> 918 x 1298</dd>
6168<dt class="col-md-4"> C4 </dt> <dd class="col-md-8"> 649 x 918</dd>
6169<dt class="col-md-4"> C5 </dt> <dd class="col-md-8"> 459 x 649</dd>
6170<dt class="col-md-4"> C6 </dt> <dd class="col-md-8"> 323 x 459</dd>
6171<dt class="col-md-4"> Flsa </dt> <dd class="col-md-8"> 612 x 936</dd>
6172<dt class="col-md-4"> Flse </dt> <dd class="col-md-8"> 612 x 936</dd>
6173<dt class="col-md-4"> HalfLetter </dt> <dd class="col-md-8"> 396 x 612</dd>
Cristy882d9f42015-10-29 16:48:39 -04006174</dl>
6175
6176<p>This option is also used to place subimages when writing to a multi-image
6177format that supports offsets, such as GIF89 and MNG. When used for this
6178purpose the offsets are always measured from the top left corner of the canvas
6179and are not affected by the <a href="command-line-options.html#gravity">-gravity</a> option. To
6180position a GIF or MNG image, use <a href="command-line-options.html#page">-page</a><var>{+-}x{+-}y</var> (e.g. -page +100+200). When writing to a MNG
6181file, a <a href="command-line-options.html#page">-page</a> option appearing ahead of the first image in
6182the sequence with nonzero width and height defines the width and height values
6183that are written in the <code>MHDR</code> chunk. Otherwise, the MNG width and
6184height are computed from the bounding box that contains all images in the
6185sequence. When writing a GIF89 file, only the bounding box method is used to
6186determine its dimensions.</p>
6187
Cristy594d2772015-11-15 10:47:42 -05006188<p>For a PostScript page, the image is sized as in <a
6189href="command-line-options.html#geometry">-geometry</a> but positioned relative to the <var>lower
6190left-hand corner</var> of the page by {+-}<code>x</code><var>offset</var>{+-}<code>y</code> <var>offset</var>. Use <a
6191href="command-line-options.html#page">-page 612x792</a>, for example, to center the image within the
Cristy882d9f42015-10-29 16:48:39 -04006192page. If the image size exceeds the PostScript page, it is reduced to fit the
6193page. The default gravity for the <a href="command-line-options.html#page">-page</a> option is <var>NorthWest</var>, i.e., positive <code>x</code> and <code>y</code> <var>offset</var> are measured rightward and downward from the top left
6194corner of the page, unless the <a href="command-line-options.html#gravity">-gravity</a> option is
6195present with a value other than <var>NorthWest</var>.</p>
6196
6197<p>The default page dimensions for a TEXT image is 612x792.</p>
6198
6199<p>This option is used in concert with <a href="command-line-options.html#density">-density</a>.</p>
6200
6201<p>Use <a href="command-line-options.html#page">+page</a> to remove the page settings for an image.</p>
6202
6203<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006204 <h3><a id="paint"></a>-paint <var>radius</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006205</div>
6206
6207<p class="magick-description">simulate an oil painting.</p>
6208
6209<p>Each pixel is replaced by the most frequent color in a circular
6210neighborhood whose width is specified with <var>radius</var>.</p>
6211
6212<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006213 <h3><a id="path"></a>-path <var>path</var></h3></div>
Cristy882d9f42015-10-29 16:48:39 -04006214
6215<p class="magick-description">write images to this path on disk.</p>
6216
6217<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006218 <h3><a id="pause_animate_"></a>-pause <var>seconds</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006219</div>
6220
6221<p class="magick-description">Pause between animation loops</p>
6222
6223<p>Pause for the specified number of seconds before repeating the animation.</p>
6224
6225<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006226 <h3><a id="pause_import_"></a>-pause <var>seconds</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006227</div>
6228
6229<p class="magick-description">Pause between snapshots.</p>
6230
6231<p>Pause for the specified number of seconds before taking the next snapshot.</p>
6232
6233<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006234 <h3><a id="perceptible"></a>-perceptible <var>epsilon</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006235</div>
6236
6237<p class="magick-description">set each pixel whose value is less than |<var>epsilon</var>| to <var>-epsilon</var> or <var>epsilon</var> (whichever is closer) otherwise the pixel value remains unchanged.</p>
6238
6239<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006240 <h3><a id="ping"></a>-ping</h3>
Cristy882d9f42015-10-29 16:48:39 -04006241</div>
6242
6243<p class="magick-description">efficiently determine image characteristics.</p>
6244
6245<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006246 <h3><a id="pointsize"></a>-pointsize <var>value</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006247</div>
6248
6249<p class="magick-description">pointsize of the PostScript, OPTION1, or TrueType font.</p>
6250
6251<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006252 <h3><a id="polaroid"></a>-polaroid <var>angle</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006253</div>
6254
6255<p class="magick-description">simulate a Polaroid picture.</p>
6256
6257<p>Use <code>+polaroid</code> to rotate the image at a random angle between -15 and +15 degrees.</p>
6258
6259<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006260 <h3><a id="poly"></a>-poly <var>"wt,exp ..."</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006261</div>
6262
6263<p class="magick-description">combines multiple images according to a weighted sum of polynomials; one floating point weight (coefficient) and one floating point polynomial exponent (power) for each image expressed as comma separated pairs.</p>
6264
6265<p> The weights should typically be fractions between -1 and 1. But the sum of weights should be 1 or at least between 0 and 1 to avoid clamping in non-hdri mode at black and white.</p>
6266
6267<p>The exponents may be positive, negative or zero. A negative exponent is equivalent to 1 divided by the image raised to the corresponding positive exponent. A zero exponent always produces 1 scaled by quantumrange to white, i.e. wt*white, no matter what the image.</p>
6268
6269<p>The format is: <var>output = wt1*image1^exp1 + wt2*image2^exp2 </var>...</p>
6270
6271<p>Some simple uses are:</p>
6272<ul>
6273<li>A weighted sum of each image provided all weights add to unity and all exponents=1. If the the weights are all equal to 1/(number of images), then this is equivalent to <a href="command-line-options.html#profile">-evaluate-sequence</a> <var>mean</var>.</li>
6274<li>The sum of squares of two or more images, provided the weights are equal (and sum to 1 to avoid clamping) and the exponents equal 2.</li>
6275</ul>
6276
6277<p>Note that one may add a constant color to the expression simply by using xc:somecolor for one of the images and specifying the desired weight and exponent equal to 0.</p>
6278
6279<p>Similarly one may add white to the expression by simply using null: (or xc:white) for one of the images with the appropriate weight and exponent equal to 0.</p>
6280
6281
6282<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006283 <h3><a id="posterize"></a>-posterize <var>levels</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006284</div>
6285
6286<p class="magick-description">reduce the image to a limited number of color levels per channel.</p>
6287
6288<p>Very low values of <var>levels</var>, e.g., 2, 3, 4, have the most
6289visible effect.</p>
6290
6291<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006292 <h3><a id="precision"></a>-precision <var>value</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006293</div>
6294
6295<p class="magick-description">set the maximum number of significant digits to be printed.</p>
6296
6297<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006298 <h3><a id="preview"></a>-preview <var>type</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006299</div>
6300
6301<p class="magick-description">image preview type.</p>
6302
6303<p>Use this option to affect the preview operation of an image (e.g.
6304<code>convert file.png -preview Gamma Preview:gamma.png</code>). Choose from
6305these previews:</p>
6306
Cristy49380402017-06-29 11:24:55 -04006307<pre class="pre-scrollable"><code>
Cristy882d9f42015-10-29 16:48:39 -04006308AddNoise
6309Blur
6310Brightness
6311Charcoal
6312Despeckle
6313Dull
6314EdgeDetect
6315Gamma
6316Grayscale
6317Hue
6318Implode
6319JPEG
6320OilPaint
6321Quantize
6322Raise
6323ReduceNoise
6324Roll
6325Rotate
6326Saturation
6327Segment
6328Shade
6329Sharpen
6330Shear
6331Solarize
6332Spiff
6333Spread
6334Swirl
6335Threshold
6336Wave
Cristy49380402017-06-29 11:24:55 -04006337</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04006338
6339<p>To print a complete list of previews, use the <a href="command-line-options.html#list">-list preview</a> option.</p>
6340
6341<p>The default preview is <code>JPEG</code>.</p>
6342
6343<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006344 <h3><a id="print"></a>-print <var>string</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006345</div>
6346
6347<p class="magick-description">interpret string and print to console.</p>
6348
6349<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006350 <h3><a id="process"></a>-process <var>command</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006351</div>
6352
6353<p class="magick-description">process the image with a custom image filter.</p>
6354
6355<p>The command arguments has the form <code>"module arg1 arg2 arg3 ...
6356argN"</code> where <code>module</code> is the name of the module to invoke (e.g.
6357"Analyze") and arg1 arg2 arg3 ... argN are an arbitrary number of arguments to
6358pass to the process module.</p>
6359
6360<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006361 <h3><a id="profile"></a>-profile <var>filename</var><br/>
Cristy882d9f42015-10-29 16:48:39 -04006362 +profile <var>profile_name</var></h3>
6363</div>
6364
6365<p class="magick-description">Manage ICM, IPTC, or generic profiles in an image.</p>
6366
6367<p>Using <a href="command-line-options.html#profile">-profile</a> <var>filename</var> adds an
6368ICM (ICC color management), IPTC (newswire information), or a generic profile
6369to the image.</p>
6370
6371<p>Use <a href="command-line-options.html#profile">+profile <var>profile_name</var></a> to
6372remove the indicated profile. ImageMagick uses standard filename globbing, so
6373wildcard expressions may be used to remove more than one profile. Here we
6374remove all profiles from the image except for the XMP profile: <code>+profile
6375"!xmp,*"</code>. </p>
6376
6377<p>Use <code>identify -verbose</code> to find out which profiles are in the
6378image file. Use <a href="command-line-options.html#strip">-strip</a> to remove all profiles (and
6379comments).</p>
6380
6381<p>To extract a profile, the <a href="command-line-options.html#profile">-profile</a> option is not
6382used. Instead, simply write the file to an image format such as <var>APP1, 8BIM, ICM,</var> or <var>IPTC</var>.</p>
6383
6384<p>For example, to extract the Exif data (which is stored in JPEG files in the
6385<var>APP1</var> profile), use.</p>
6386
Cristy49380402017-06-29 11:24:55 -04006387<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04006388convert cockatoo.jpg profile.exif
Cristy49380402017-06-29 11:24:55 -04006389</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04006390
6391<p>It is important to note that results may depend on whether or not the
Cristy594d2772015-11-15 10:47:42 -05006392original image already has an included profile. Also, keep in mind that <a
6393href="command-line-options.html#profile">-profile</a> is an "operator" (as opposed to a "setting") and
Cristy882d9f42015-10-29 16:48:39 -04006394therefore a conversion is made each time it is encountered, in order, in the
6395command-line. For instance, in the following example, if the original image is
6396CMYK with profile, a CMYK-CMYK-RGB conversion results.</p>
6397
Cristy49380402017-06-29 11:24:55 -04006398<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04006399convert CMYK.tif -profile "CMYK.icc" -profile "RGB.icc" RGB.tiff
Cristy49380402017-06-29 11:24:55 -04006400</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04006401
6402<p>Furthermore, since ICC profiles are not necessarily symmetric, extra
6403conversion steps can yield unwanted results. CMYK profiles are often very
6404asymmetric since they involve 3−&gt;4 and 4−&gt;3 channel mapping.
6405</p>
6406
6407<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006408 <h3><a id="quality"></a>-quality <var>value</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006409</div>
6410
6411<p class="magick-description">JPEG/MIFF/PNG compression level.</p>
6412
6413<p>For the JPEG and MPEG image formats, quality is 1 (lowest image quality and
6414highest compression) to 100 (best quality but least effective compression).
6415The default is to use the estimated quality of your input image if it can
6416be determined, otherwise 92. When the quality is greater than 90, then the
6417chroma channels are not downsampled.
6418Use the <a href="command-line-options.html#sampling-factor">-sampling-factor</a> option to specify the
6419factors for chroma downsampling.</p>
6420
6421<p>For the JPEG-2000 image format, quality is mapped using a non-linear
6422equation to the compression ratio required by the Jasper library. This
6423non-linear equation is intended to loosely approximate the quality provided by
6424the JPEG v1 format. The default quality value 100, a request for non-lossy
6425compression. A quality of 75 results in a request for 16:1 compression.</p>
6426
6427<p>For the MNG and PNG image formats, the quality value sets the zlib
6428compression level (quality / 10) and filter-type (quality % 10). The default
6429PNG "quality" is 75, which means compression level 7 with adaptive PNG
6430filtering, unless the image has a color map, in which case it means
6431compression level 7 with no PNG filtering.</p>
6432
6433<p>For compression level 0 (quality value less than 10), the Huffman-only
6434strategy is used, which is fastest but not necessarily the worst
6435compression.</p>
6436
6437<p>If filter-type is 4 or less, the specified PNG filter-type is used for
6438all scanlines:</p>
6439
Cristy49380402017-06-29 11:24:55 -04006440<dl class="row">
6441<dt class="col-md-4">0</dt><dd class="col-md-8">none</dd>
6442<dt class="col-md-4">1</dt><dd class="col-md-8">sub</dd>
6443<dt class="col-md-4">2</dt><dd class="col-md-8">up</dd>
6444<dt class="col-md-4">3</dt><dd class="col-md-8">average</dd>
6445<dt class="col-md-4">4</dt><dd class="col-md-8">Paeth</dd>
Cristy882d9f42015-10-29 16:48:39 -04006446</dl>
6447
6448<p>If filter-type is 5, adaptive filtering is used when quality is greater
6449than 50 and the image does not have a color map, otherwise no filtering is
6450used.</p>
6451
6452<p>If filter-type is 6, adaptive filtering
6453with <var>minimum-sum-of-absolute-values</var> is used.</p>
6454
6455<p>Only if the output is MNG, if filter-type is 7, the LOCO color
6456transformation (intrapixel differencing) and adaptive filtering
6457with <var>minimum-sum-of-absolute-values</var> are used.</p>
6458
6459<p>If the filter-type is 8 the zlib Z_RLE compression strategy (or the
6460Z_HUFFMAN_ONLY strategy, when compression level is 0) is used with
6461adaptive PNG filtering.</p>
6462
6463<p>If the filter-type is 9 the zlib Z_RLE compression strategy (or the
6464Z_HUFFMAN_ONLY strategy, when compression level is 0) is used with
6465no PNG filtering.</p>
6466
6467<p>The quality setting has no effect on the appearance or signature of PNG
6468and MNG images, since the compression is always lossless.</p>
6469
6470<p>Not all combinations of compression level, strategy, and PNG filter type
6471can be obtained using the -quality option. For more precise control,
6472you can use the PNG:compression-level=N, PNG:compression-strategy=N, and
6473PNG:compression-filter=N defines, respectively, instead.
6474See <a href="command-line-options.html#define">-define</a>. Values from the defines take precedence
6475over values from the -quality option.</p>
6476
6477<p>For further information, see
6478the <a href="http://www.w3.org/pub/WWW/TR">PNG</a> specification.</p>
6479
6480<p>For the MIFF and TIFF image formats, quality/10 is the <a href="command-line-options.html#compress">Zip/BZip</a> compression level, which is 0 (worst but fastest compression) to 9 (best but slowest). It has no effect on the image appearance, since the compression is always lossless.</p>
6481
6482<p>For the BPG image format, quality/2 is the actual BPG compression level (range from 0 to 51).</p>
6483
6484<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006485 <h3><a id="quantize"></a>-quantize <var>colorspace</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006486</div>
6487
6488<p class="magick-description">reduce colors using this colorspace.</p>
6489
6490<p>This setting defines the colorspace used to sort out and reduce the number
Cristy594d2772015-11-15 10:47:42 -05006491of colors needed by an image (for later dithering) by operators such as <a
6492href="command-line-options.html#colors" >-colors</a>, Note that color reduction also happens
Cristy882d9f42015-10-29 16:48:39 -04006493automatically when saving images to color-limited image file formats, such as
6494GIF, and PNG8.</p>
6495
6496
6497<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006498 <h3><a id="quiet"></a>-quiet</h3>
Cristy882d9f42015-10-29 16:48:39 -04006499</div>
6500
6501<p class="magick-description">suppress all warning messages. Error messages are still reported.</p>
6502
6503<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006504 <h3><a id="radial-blur"></a>-radial-blur <var>angle</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006505</div>
6506
6507<p class="magick-description">Blur around the center of the image.</p>
6508
6509<p>Note that this is actually a rotational blur rather than a radial and as
6510such actually mis-named. </p>
6511
6512<p>The <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting will determine how
6513pixels which are outside the image proper are blurred into the final result.
6514</p>
6515
6516
6517<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006518 <h3><a id="raise"></a>-raise <var>thickness</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006519</div>
6520
6521<p class="magick-description">Lighten or darken image edges.</p>
6522
6523<p>This will create a 3-D effect. Use <a href="command-line-options.html#raise">-raise</a> to create
6524a raised effect, otherwise use <a href="command-line-options.html#raise">+raise</a>. </p>
6525
Cristy594d2772015-11-15 10:47:42 -05006526<p>Unlike the similar <a href="command-line-options.html#frame">-frame</a> option, <a
6527href="command-line-options.html#raise">-raise</a> does not alter the dimensions of the image.</p>
Cristy882d9f42015-10-29 16:48:39 -04006528
6529<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006530 <h3><a id="random-threshold"></a>-random-threshold <var>low</var>x<var>high</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006531</div>
6532
6533<p class="magick-description">Apply a random threshold to the image.</p>
6534
6535<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006536 <h3><a id="read-mask"></a>-read-mask
Cristye0779712016-07-30 17:25:22 -04006537<var>filename</var></h3>
6538</div>
6539
6540<p class="magick-description">Prevent updates to image pixels specified by the mask.</p>
6541
6542<p>This the same as using a mask used for composite masking operations, with
6543grayscale values causing blended updates of the image the mask is attached to.
6544</p>
6545
6546<p>Use <a href="command-line-options.html#read-mask">+read-mask</a> to remove the mask from images.</p>
6547
6548<p>Also see <a href="command-line-options.html#clip-mask">-clip-mask</a> which work in the same way,
6549but with strict boolean masking. </p>
6550
6551<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006552 <h3><a id="red-primary"></a>-red-primary <var>x,y</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006553</div>
6554
6555<p class="magick-description">Set the red chromaticity primary point.</p>
6556
6557<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006558 <h3><a id="regard-warnings"></a>-regard-warnings</h3>
Cristy882d9f42015-10-29 16:48:39 -04006559</div>
6560
6561<p class="magick-description">Pay attention to warning messages.</p>
6562
6563<p>This option causes some warnings in some image formats to be treated
6564as errors. </p>
6565
6566<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006567 <h3><a id="remap"></a>-remap <var>filename</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006568</div>
6569
6570<p class="magick-description">Reduce the number of colors in an image to the colors used by this image.</p>
6571
6572<p>If the <a href="command-line-options.html#dither">-dither</a> setting is enabled (the default) then
6573the given colors are dithered over the image as necessary, otherwise the closest
6574color (in RGB colorspace) is selected to replace that pixel in the image. </p>
6575
6576<p>As a side effect of applying a <a href="command-line-options.html#remap">-remap</a> of colors across all
6577images in the current image sequence, all the images will have the same color
6578table. That means that when saved to a file format such as GIF, it will use
6579that color table as a single common or global color table, for all the images,
6580without requiring extra local color tables. </p>
6581
6582<p>Use <a href="command-line-options.html#remap">+remap</a> to reduce all images in the current image
6583sequence to use a common color map over all the images. This equivalent to
6584appending all the images together (without extra background colors) and color
6585reducing those images using <a href="command-line-options.html#colors">-colors</a> with a 256 color
6586limit, then <a href="command-line-options.html#remap">-remap</a> those colors over the original list of
6587images. This ensures all the images follow a single color map. </p>
6588
Cristy594d2772015-11-15 10:47:42 -05006589<p>If the number of colors over all the images is less than 256, then <a
6590href="command-line-options.html#remap">+remap</a> should not perform any color reduction or dithering, as
Cristy882d9f42015-10-29 16:48:39 -04006591no color changes are needed. In that case, its only effect is to force the use
Cristy594d2772015-11-15 10:47:42 -05006592of a global color table. This recommended after using either <a
6593href="command-line-options.html#colors">-colors</a> or <a href="command-line-options.html#ordered-dither">-ordered-dither</a> to
Cristy882d9f42015-10-29 16:48:39 -04006594reduce the number of colors in an animated image sequence. </p>
6595
6596<p>Note, the remap image colormap has at most 8-bits of precision. Deeper color maps are automagically coalesced with other colors to meet this requirement.</p>
6597
6598<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006599 <h3><a id="region"></a>-region <var>geometry</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006600</div>
6601
6602<p class="magick-description">Set a region in which subsequent operations apply.</p>
6603
6604<p>The <var>x</var> and <var>y</var> offsets are treated
6605in the same manner as in <a href="command-line-options.html#crop">-crop</a>.</p>
6606
6607<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
6608
6609<p>Use <code>+region</code> to remove any previously set regions.</p>
6610
Cristy882d9f42015-10-29 16:48:39 -04006611<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006612 <h3><a id="remote"></a>-remote</h3>
Cristy882d9f42015-10-29 16:48:39 -04006613</div>
6614
6615<p class="magick-description">perform a remote operation.</p>
6616
6617<p>The only command recognized is the name of an image file to load.</p>
6618
6619<p>If you have more than one <a href="display.html">display</a> application
6620running simultaneously, use the <a href="command-line-options.html#window"> window</a> option to
6621specify which application to control.</p>
6622
6623<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006624 <h3><a id="render"></a>-render</h3>
Cristy882d9f42015-10-29 16:48:39 -04006625</div>
6626
6627<p class="magick-description">render vector operations.</p>
6628
6629<p>Use <a href="command-line-options.html#render">+render</a> to turn off rendering vector operations.
6630This useful when saving the result to vector formats such as MVG or SVG.</p>
6631
6632<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006633<h3><a id="repage"></a>-repage <var>geometry</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006634</div>
6635
6636<p class="magick-description">Adjust the canvas and offset information of the image.</p>
6637
6638<p>This option is like <a href="command-line-options.html#page">-page</a> but acts as an image operator
6639rather than a setting. You can separately set the canvas size or the offset
6640of the image on that canvas by only providing those components. </p>
6641
6642<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
6643
6644<p>If a <code>!</code> flag is given the offset given is added to the existing
6645offset to move the image relative to its previous position. This useful for
6646animation sequences. </p>
6647
6648<p>A given a canvas size of zero such as '<code>0x0</code>' forces it to
6649recalculate the canvas size so the image (at its current offset) will appear
6650completely on that canvas (unless it has a negative offset).</p>
6651
6652<p>Use <a href="command-line-options.html#repage">+repage</a> to completely remove/reset the virtual
6653canvas meta-data from the images. </p>
6654
6655<p>The <a href="command-line-options.html#set">-set</a> '<code>page</code>' option can be used to
6656directly assign virtual canvas meta-data. </p>
6657
6658
6659<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006660 <h3><a id="resample"></a>-resample <var>horizontal</var>x<var>vertical</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006661</div>
6662
6663<p class="magick-description">Resample image to specified horizontal and vertical resolution.</p>
6664
6665<p>Resize the image so that its rendered size remains the same as the original
6666at the specified target resolution. For example, if a 300 DPI image renders at
66673 inches by 2 inches on a 300 DPI device, when the image has been resampled to
666872 DPI, it will render at 3 inches by 2 inches on a 72 DPI device. Note that
6669only a small number of image formats (e.g. JPEG, PNG, and TIFF) are capable of
6670storing the image resolution. For formats which do not support an image
Cristy594d2772015-11-15 10:47:42 -05006671resolution, the original resolution of the image must be specified via <a
6672href="command-line-options.html#density">-density</a> on the command line prior to specifying the
Cristy882d9f42015-10-29 16:48:39 -04006673resample resolution.</p>
6674
6675<p>Note that Photoshop stores and obtains image resolution from a proprietary
6676embedded profile. If this profile exists in the image, then Photoshop will
6677continue to treat the image using its former resolution, ignoring the image
6678resolution specified in the standard file header.</p>
6679
6680<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006681 <h3><a id="resize"></a>-resize <var>geometry</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006682</div>
6683
6684<p class="magick-description">Resize an image.</p>
6685
6686<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. Offsets, if present in the geometry string, are
6687ignored, and the <a href="command-line-options.html#gravity">-gravity</a> option has no effect.</p>
6688
6689<p>If the <a href="command-line-options.html#filter">-filter</a> option
Cristy594d2772015-11-15 10:47:42 -05006690or <code>-define filter:option=value</code> precedes the <a
6691href="command-line-options.html#resize">-resize</a> option, the image is resized with the specified
Cristy882d9f42015-10-29 16:48:39 -04006692filter.</p>
6693
6694<p>Many image processing algorithms assume your image is in a linear-light
6695coding. If your image is gamma-corrected, you can remove the nonlinear gamma
6696correction, apply the transform, then restore it like this:</p>
6697
Cristy49380402017-06-29 11:24:55 -04006698<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04006699convert portrait.jpg -gamma .45455 -resize 25% -gamma 2.2 \
6700 -quality 92 passport.jpg
Cristy49380402017-06-29 11:24:55 -04006701</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04006702
6703<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006704 <h3><a id="respect-parentheses"></a>-respect-parentheses</h3>
Cristy882d9f42015-10-29 16:48:39 -04006705</div>
6706
6707<p class="magick-description">settings remain in effect until parenthesis boundary.</p>
6708
6709<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006710 <h3><a id="reverse"></a>-reverse</h3>
Cristy882d9f42015-10-29 16:48:39 -04006711</div>
6712
6713<p class="magick-description">Reverse the order of images in the current image list.</p>
6714
6715
6716<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006717 <h3><a id="roll"></a>-roll {<var>+-</var>}<var>x</var>{<var>+-</var>}<var>y</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006718</div>
6719
6720<p class="magick-description">roll an image vertically or horizontally by the amount given.</p>
6721
6722<p>A negative <var>x</var> offset rolls the image right-to-left.
6723A negative <var>y</var> offset rolls the image bottom-to-top.</p>
6724
6725
6726<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006727 <h3><a id="rotate"></a>-rotate <var>degrees</var>{<var>&lt;</var>}{<var>&gt;</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -04006728</div>
6729
6730<p class="magick-description">Apply Paeth image rotation (using shear operations) to the image.</p>
6731
6732<p>Use <code>&gt;</code> to rotate the image only if its width exceeds the
6733height. <code>&lt;</code> rotates the image <var>only</var> if its width is less
6734than the height. For example, if you specify <code>-rotate "-90&gt;"</code> and
6735the image size is 480x640, the image is not rotated. However, if the image is
6736640x480, it is rotated by -90 degrees. If you use <code>&gt;</code> or
6737<code>&lt;</code>, enclose it in quotation marks to prevent it from being
6738misinterpreted as a file redirection.</p>
6739
6740<p>Empty triangles in the corners, left over from rotating the image, are
6741filled with the <code>background</code> color. </p>
6742
6743<p>See also the <a href="command-line-options.html#distort">-distort</a> operator and specifically the
6744'<code>ScaleRotateTranslate</code>' distort method. </p>
6745
6746
6747<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006748 <h3><a id="sample"></a>-sample <var>geometry</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006749</div>
6750
6751<p class="magick-description">minify / magnify the image with pixel subsampling and pixel replication, respectively.</p>
6752
6753<p>Change the image size simply by directly sampling the pixels original
6754from the image. When magnifying, pixels are replicated in blocks. When
6755minifying, pixels are sub-sampled (i.e., some rows and columns are skipped
6756over). </p>
6757
6758<p>The results are thus equivalent to using <a href="command-line-options.html#resize">-resize</a> with
6759a <a href="command-line-options.html#filter">-filter</a> setting of <code>point</code> (nearest
6760neighbor), though <a href="command-line-options.html#sample">-sample</a> is a lot faster, as it
6761avoids all the filter processing of the image. As such it completely ignores
6762the current <a href="command-line-options.html#filter">-filter</a> setting. </p>
6763
6764<p>The key feature of the <a href="command-line-options.html#sample">-sample</a> is that no new colors
6765will be added to the resulting image, though some colors may disappear. </p>
6766
6767<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. Offsets, if present in the geometry string, are
6768ignored, unlike <a href="command-line-options.html#resize">-resize</a>. </p>
6769
6770
6771<p>The actual sampling point is the middle of the sub-region being sampled.
6772As such a single pixel sampling of an image will take the middle pixel, (or
Cristy594d2772015-11-15 10:47:42 -05006773top-left-middle if image has even dimensions). However the <a
6774href="command-line-options.html#define">-define</a> '<code>sample:offset</code>' can be set to modify
Cristy882d9f42015-10-29 16:48:39 -04006775this position some other location within each sub-region being sampled, as
6776a percentage offset.</p>
6777
6778<p>By default this value is '<code>50</code>' for the midpoint, but could be set
6779to '<code>0</code>' for top-left, '<code>100</code>' for bottom-right, or with
6780separate X and Y offsets such as '<code>0x50</code>' for left-middle edge of
6781sampling sub-region.</p>
6782
6783
6784<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006785 <h3><a id="sampling-factor"></a>-sampling-factor <var>horizontal-factor</var>x<var>vertical-factor</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006786</div>
6787
6788<p class="magick-description">sampling factors used by JPEG or MPEG-2 encoder and YUV decoder/encoder.</p>
6789
6790<p>This option specifies the sampling factors to be used by the JPEG encoder
6791for chroma downsampling. If this option is omitted, the JPEG library will use
6792its own default values. When reading or writing the YUV format and when
Cristy594d2772015-11-15 10:47:42 -05006793writing the M2V (MPEG-2) format, use <a
6794href="command-line-options.html#sampling-factor">-sampling-factor 2x1</a> or <a
6795href="command-line-options.html#sampling-factor">-sampling-factor 4:2:2</a> to specify the 4:2:2
Cristy882d9f42015-10-29 16:48:39 -04006796downsampling method.</p>
6797
6798<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006799 <h3><a id="scale"></a>-scale <var>geometry</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006800</div>
6801
6802<p class="magick-description">minify / magnify the image with pixel block averaging and pixel replication, respectively.</p>
6803
6804<p>Change the image size simply by replacing pixels by averaging pixels
6805together when minifying, or replacing pixels when magnifying. </p>
6806
6807<p>The results are thus equivalent to using <a href="command-line-options.html#resize">-resize</a> with
6808a <a href="command-line-options.html#filter">-filter</a> setting of <code>box</code>. Though it is a lot
6809faster, as it avoids all the filter processing of the image. As such it
6810completely ignores the current <a href="command-line-options.html#filter">-filter</a> setting. </p>
6811
6812<p>If when shrinking (minifying) images the original image is some integer
6813multiple of the new image size, the number of pixels averaged together to
6814produce the new pixel color is the same across the whole image. This is
6815a special case known as 'binning' and is often used as a method of reducing
6816noise in image such as those generated by digital cameras, especially in low
6817light conditions. </p>
6818
6819
6820<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006821 <h3><a id="scene"></a>-scene <var>value</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006822</div>
6823
6824<p class="magick-description">set scene number.</p>
6825
6826<p>This option sets the scene number of an image or the first image in an image sequence.</p>
6827
6828<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006829 <h3><a id="screen"></a>-screen</h3>
Cristy882d9f42015-10-29 16:48:39 -04006830</div>
6831
6832<p class="magick-description">specify the screen to capture.</p>
6833
6834<p>This option indicates that the GetImage request used to obtain the image
6835should be done on the root window, rather than directly on the specified
6836window. In this way, you can obtain pieces of other windows that overlap the
6837specified window, and more importantly, you can capture menus or other popups
6838that are independent windows but appear over the specified window.</p>
6839
6840<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006841 <h3><a id="seed"></a>-seed</h3>
Cristy882d9f42015-10-29 16:48:39 -04006842</div>
6843
6844<p class="magick-description">seed a new sequence of pseudo-random numbers</p>
6845
6846<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006847 <h3><a id="segment"></a>-segment <var>cluster-threshold</var>x<var>smoothing-threshold</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006848</div>
6849
6850<p class="magick-description">segment the colors of an image.</p>
6851
6852<p>Segment an image by analyzing the histograms of the color components and
6853identifying units that are homogeneous with the fuzzy c-means technique. This
6854is part of the ImageMagick color quantization routines. </p>
6855
6856<p>Specify <var>cluster threshold</var> as the number of pixels in
6857each cluster that must exceed the cluster threshold to be considered valid.
6858<var>Smoothing threshold</var> eliminates noise in the second
6859derivative of the histogram. As the value is increased, you can expect
6860a smoother second derivative. The default is 1.5.</p>
6861
6862<p>If the <a href="command-line-options.html#verbose">-verbose</a> setting is defined, a detailed report
6863of the color clusters is returned.</p>
6864
6865
6866<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006867 <h3><a id="selective-blur"></a>-selective-blur <var>radius</var><br />-selective-blur <var>radius</var>x<var>sigma</var>{<var>+threshold</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -04006868</div>
6869
6870<p class="magick-description">Selectively blur pixels within a contrast threshold.</p>
6871
6872<p>Blurs those pixels that are less than or equal to the threshold in
6873contrast. The threshold may be expressed as a fraction of <var>QuantumRange</var> or as a percentage.</p>
6874
6875<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006876 <h3><a id="separate"></a>-separate</h3>
Cristy882d9f42015-10-29 16:48:39 -04006877</div>
6878
6879<p class="magick-description">separate an image channel into a grayscale image. Specify the channel with <a href="command-line-options.html#channel">-channel</a>.</p>
6880
6881<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006882 <h3><a id="sepia-tone"></a>-sepia-tone <var>percent-threshold</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006883</div>
6884
6885<p class="magick-description">simulate a sepia-toned photo.</p>
6886
6887<p>Specify <var>threshold</var> as the percent threshold of the intensity (0 - 99.9%).</p>
6888
6889<p>This option applies a special effect to the image, similar to the effect
6890achieved in a photo darkroom by sepia toning. Threshold ranges from 0 to <var>QuantumRange</var> and is a measure of the extent of the sepia
6891toning. A threshold of 80% is a good starting point for a reasonable
6892tone.</p>
6893
6894
6895
6896<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04006897 <h3><a id="set"></a>-set <var>key value</var></h3>
6898 <h3>+set <var>key</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04006899</div>
6900
6901<p class="magick-description">sets image attributes and properties for images in the current image sequence.</p>
6902
6903<p>This will assign (or modify) specific settings attached to all the images
6904in the current image sequence. Using the <a href="command-line-options.html#set">+set</a> form of the
6905option will either remove, or reset that setting to a default state, as
6906appropriate. </p>
6907
6908<p>For example, it will modify specific well known image meta-data
Cristy594d2772015-11-15 10:47:42 -05006909'attributes' such as those normally overridden by: the options <a
6910href="command-line-options.html#delay" >-delay</a>, <a href="command-line-options.html#dispose" >-dispose</a>, and <a
6911href="command-line-options.html#page" >-page</a>, <a href="command-line-options.html#colorspace" >-colorspace</a>; generally
Cristy882d9f42015-10-29 16:48:39 -04006912assigned before the image is read in, by using a <var>key</var> of
6913the same name. </p>
6914
6915<p>If the given <var>key</var> does not match a specific known
6916'attribute ', such as shown above, the setting is stored as a a free form
Cristy594d2772015-11-15 10:47:42 -05006917'property' string. Such settings are listed in <a href="command-line-options.html#verbose"
6918>-verbose</a> information ("<code>info:</code>" output format) as "Properties".
Cristy882d9f42015-10-29 16:48:39 -04006919</p>
6920
6921<p>This includes string 'properties' that are set by and assigned to images
Cristy594d2772015-11-15 10:47:42 -05006922using the options <a href="command-line-options.html#comment" >-comment</a>, <a href="command-line-options.html#label"
6923>-label</a>, <a href="command-line-options.html#caption" >-caption</a>. These options actually assign
6924a global 'artifact' which are automatically assigned (and any <a href="escape.html" >Format Percent
Cristy882d9f42015-10-29 16:48:39 -04006925Escapes</a> expanded) to images as they are read in. For example:</p>
6926
Cristy49380402017-06-29 11:24:55 -04006927<pre><code>
Cristy594d2772015-11-15 10:47:42 -05006928-> convert rose: -set comment 'Rose is a rose is a rose is a rose' rose.png
Cristy882d9f42015-10-29 16:48:39 -04006929identify -format %c rose.png
6930Rose is a rose is a rose is a rose
Cristy49380402017-06-29 11:24:55 -04006931</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04006932
Cristy594d2772015-11-15 10:47:42 -05006933<p>The set value can also make use of <a href="escape.html" >Format and Print Image
Cristy882d9f42015-10-29 16:48:39 -04006934Properties</a> in the defined value. For example:</p>
6935
Cristy49380402017-06-29 11:24:55 -04006936<pre><code>
Cristy594d2772015-11-15 10:47:42 -05006937-> convert rose: -set origsize '%wx%h' -resize 50% \
Cristy882d9f42015-10-29 16:48:39 -04006938 -format 'Old size = %[origsize] New size = %wx%h' info:
6939Old size = 70x46 New size = 35x23
Cristy49380402017-06-29 11:24:55 -04006940</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04006941
6942<p>Other well known 'properties' that are available include:
6943'<code>date:create</code>' and '<code>date:modify</code>' and
6944'<code>signature</code>'. </p>
6945
6946<p>The <a href="command-line-options.html#repage">-repage</a> operator will also allow you to modify
6947the '<code>page</code>' attribute of an image for images already in memory (also
6948see <a href="command-line-options.html#repage">-page</a>). However it is designed to provide a finer
6949control of the sub-parts of this 'attribute'. The <a href="command-line-options.html#set">-set page</a>
6950option will only provide a direct, unmodified assignment of '<code>page</code>'
6951attribute. </p>
6952
6953<p>This option can also associate a colorspace or profile with your image.
6954For example,</p>
6955
Cristy49380402017-06-29 11:24:55 -04006956<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04006957convert image.psd -set profile ISOcoated_v2_eci.icc image-icc.psd
Cristy49380402017-06-29 11:24:55 -04006958</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04006959
6960<p>Some 'properties' must be defined in a specific way to be used. For
6961example only 'properties' prefixed with "<code>filename:</code>" can be used to
6962modify the output filename of an image. For example</p>
6963
Cristy49380402017-06-29 11:24:55 -04006964<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04006965convert rose: -set filename:mysize '%wx%h' 'rose_%[filename:mysize].png'
Cristy49380402017-06-29 11:24:55 -04006966</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04006967
6968<p>If the setting value is prefixed with "<code>option:</code>" the setting will
Cristy594d2772015-11-15 10:47:42 -05006969be saved as a global "Artifact" exactly as if it was set using the <a
6970href="command-line-options.html#define" >-define</a> option. As such settings are global in scope, they
Cristy882d9f42015-10-29 16:48:39 -04006971can be used to pass 'attributes' and 'properties' of one specific image,
6972in a way that allows you to use them in a completely different image, even if
6973the original image has long since been modified or destroyed. For example: </p>
6974
Cristy49380402017-06-29 11:24:55 -04006975<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04006976convert rose: -set option:rosesize '%wx%h' -delete 0 \
6977 label:'%[rosesize]' label_size_of_rose.gif"
Cristy49380402017-06-29 11:24:55 -04006978</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04006979
Cristy594d2772015-11-15 10:47:42 -05006980<p>Note that <a href="escape.html" >Format Percent Escapes</a> will only match
Cristy882d9f42015-10-29 16:48:39 -04006981a 'artifact' if the given <var>key</var> does not match an existing
6982'attribute' or 'property'. </p>
6983
6984<p>You can set the attributes of the image registry by prefixing the value
6985with <code>registry:</code>.</p>
6986
6987<p>The <a href="command-line-options.html#set">-set profile</a> option can also be used to inject
6988previously-formatted ancillary chunks into the output PNG file, using
6989the commandline option as shown below or by setting the profile via a
6990programming interface:</p>
6991
Cristy49380402017-06-29 11:24:55 -04006992<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04006993convert in.png -set profile PNG-chunk-x:&lt;filename&gt; out.png
Cristy49380402017-06-29 11:24:55 -04006994</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04006995
6996<p>where <var>x</var> is a location flag and
6997<var>filename</var> is a file containing the chunk
6998name in the first 4 bytes, then a colon (":"), followed by the chunk data.
6999This encoder will compute the chunk length and CRC, so those must not
7000be included in the file.</p>
7001
7002<p>"x" can be "b" (before PLTE), "m" (middle, i.e., between PLTE and IDAT),
7003or "e" (end, i.e., after IDAT). If you want to write multiple chunks
7004of the same type, then add a short unique string after the "x" to prevent
7005subsequent profiles from overwriting the preceding ones, e.g.,</p>
7006
7007
Cristy49380402017-06-29 11:24:55 -04007008<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04007009convert in.png -set profile PNG-chunk-b01:file01 \
7010 -profile PNG-chunk-b02:file02 out.png
Cristy49380402017-06-29 11:24:55 -04007011</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04007012
7013<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007014 <h3><a id="shade"></a>-shade <var>azimuth</var>x<var>elevation</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007015</div>
7016
7017<p class="magick-description">shade the image using a distant light source.</p>
7018
7019<p>Specify <var>azimuth</var> and <var>elevation</var> as
7020the position of the light source. Use <a href="command-line-options.html#shade">+shade</a> to return
7021the shading results as a grayscale image.</p>
7022
7023<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007024 <h3><a id="shadow"></a>-shadow <var>percent-opacity</var>{x<var>sigma</var>}{<var>+-</var>}<var>x</var>{<var>+-</var>}<var>y</var>{<var>%</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -04007025</div>
7026
7027<p class="magick-description">simulate an image shadow.</p>
7028
7029<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007030 <h3><a
Cristy594d2772015-11-15 10:47:42 -05007031id="shared-memory"></a>-shared-memory</h3>
Cristy882d9f42015-10-29 16:48:39 -04007032</div>
7033
7034<p class="magick-description">use shared memory.</p>
7035
7036<p>This option specifies whether the utility should attempt to use shared
7037memory for pixmaps. ImageMagick must be compiled with shared memory support,
7038and the display must support the <var>MIT-SHM</var> extension.
7039Otherwise, this option is ignored. The default is <code>True</code>.</p>
7040
7041<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007042 <h3><a id="sharpen"></a>-sharpen <var>radius</var><br />-sharpen <var>radius</var>x<var>sigma</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007043</div>
7044
7045<p class="magick-description">sharpen the image.</p>
7046
7047<p>Use a Gaussian operator of the given radius and standard deviation (sigma).</p>
7048
7049<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007050 <h3><a id="shave"></a>-shave <var>geometry</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007051</div>
7052
7053<p class="magick-description">Shave pixels from the image edges.</p>
7054
7055<p>The <var>size</var> portion of the <var>geometry</var>
7056argument specifies the width of the region to be removed from both sides of
7057the image and the height of the regions to be removed from top and bottom.
7058Offsets are ignored.</p>
7059
7060<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
7061
7062<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007063 <h3><a id="shear"></a>-shear <var>Xdegrees</var>[x<var>Ydegrees</var>]</h3>
Cristy882d9f42015-10-29 16:48:39 -04007064</div>
7065
7066<p class="magick-description">Shear the image along the x-axis and/or y-axis.</p>
7067
7068<p>The shear angles may be positive, negative, or zero. When <var>Ydegrees</var> is omitted it defaults to 0. When both angles are
7069given, the horizontal component of the shear is performed before the vertical
7070component.</p>
7071
7072<p>Shearing slides one edge of an image along the x-axis or y-axis (i.e.,
7073horizontally or vertically, respectively),creating a parallelogram. The amount
7074of each is controlled by the respective shear angle. For horizontal shears,
7075<var>Xdegrees</var> is measured clockwise relative to "up" (the
7076negative y-axis), sliding the top edge to the right when 0°&lt;<var>Xdegrees</var>&lt;90° and to the left when 90°&lt;<var>Xdegrees</var>&lt;180°. For vertical shears <var>Ydegrees</var> is measured clockwise relative to "right" (the
7077positive x-axis), sliding the right edge down when 0°&lt;<var>Ydegrees</var>&lt;90° and up when 90°&lt;<var>Ydegrees</var>&lt;180°.</p>
7078
7079<p>Empty triangles left over from shearing the image are filled with the color
7080defined by the <a href="command-line-options.html#fill">-background</a> option. The color is specified
7081using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p>
7082
7083<p>The horizontal shear is performed before the vertical part. This is
7084important to note, since horizontal and vertical shears do not
7085<var>commute</var>, i.e., the order matters in a sequence of shears. For
7086example, the following two commands are not equivalent.</p>
7087
Cristy49380402017-06-29 11:24:55 -04007088<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04007089convert logo: -shear 20x0 -shear 0x60 logo-sheared.png
7090convert logo: -shear 0x60 -shear 20x0 logo-sheared.png
Cristy49380402017-06-29 11:24:55 -04007091</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04007092
7093<p>The first of the two commands above is equivalent to the following, except
7094for the amount of empty space created; the command that follows generates
7095a smaller image, and so is a better choice in terms of time and space.</p>
7096
Cristy49380402017-06-29 11:24:55 -04007097<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04007098convert logo: -shear 20x60 logo-sheared.png
Cristy49380402017-06-29 11:24:55 -04007099</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04007100
7101<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007102 <h3><a id="sigmoidal-contrast"></a>-sigmoidal-contrast <var>contrast</var>x<var>mid-point</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007103</div>
7104
7105<p class="magick-description">increase the contrast without saturating highlights or shadows.</p>
7106
7107<p>Increase the contrast of the image using a sigmoidal transfer function
7108without saturating highlights or shadows. <var>Contrast</var>
7109indicates how much to increase the contrast. For example, 0 is none, 3 is
7110typical and 20 is a lot.
7111</p>
7112
7113<p>The <var>mid-point</var> indicates where the maximum change
7114'slope' in contrast should fall in the resultant image (0 is white; 50% is
7115middle-gray; 100% is black). </p>
7116
7117<p>By default the image contrast is increased, use <var>+sigmoidal-contrast</var> to decrease the contrast.</p>
7118
7119<p>To achieve the equivalent of a sigmoidal brightness change (similar to
7120a gamma adjustment), you would use <var>-sigmoidal-contrast
7121{brightness}x0%</var> to increase brightness and <var>+sigmoidal-contrast {brightness}x0%</var> to decrease brightness.
7122Note the use of '0' fo rthe mid-point of the sigmoidal curve. </p>
7123
7124<p>Using a very high <var>contrast</var> will produce a sort of
7125'smoothed thresholding' of the image. Not as sharp (with high aliasing
7126effects) of a true threshold, but with tapered gray-levels around the threshold
7127<var>mid-point</var>. </p>
7128
7129<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007130 <h3><a id="silent"></a>-silent</h3>
Cristyf650f4f2016-04-01 10:53:07 -04007131
7132
Cristy882d9f42015-10-29 16:48:39 -04007133</div>
7134
Cristyf650f4f2016-04-01 10:53:07 -04007135<p class="magick-description">operate silently. This option is only used
7136by the <a href="import.html">import</a> tool.</p>
Cristy882d9f42015-10-29 16:48:39 -04007137
7138<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007139 <h3><a id="similarity-threshold"></a>-similarity-threshold <var>value</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007140</div>
7141
7142<p class="magick-description">minimum RMSE for subimage match.</p>
7143
7144<p>If this setting is used, then the search will stop as soon as it finds a match whose metric is less than or equal to the value. A partially filled second output image will result. Using a value of zero, will cause the search to stop at the first perfect match it finds. If this setting is left off, then the search will proceed to completion or as limited by <var>-dissimilarity-threshold</var>.</p>
7145
7146<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007147 <h3><a id="size"></a>-size <var>width</var>[x<var>height</var>][<var>+offset</var>]</h3>
Cristy882d9f42015-10-29 16:48:39 -04007148</div>
7149
7150<p class="magick-description">set the width and height of the image.</p>
7151
7152<p>Use this option to specify the width and height of raw images whose
7153dimensions are unknown such as <code>GRAY</code>, <code>RGB</code>, or
Cristy594d2772015-11-15 10:47:42 -05007154<code>CMYK</code>. In addition to width and height, use <a
7155href="command-line-options.html#size">-size</a> with an offset to skip any header information in the
Cristy882d9f42015-10-29 16:48:39 -04007156image or tell the number of colors in a <code>MAP</code> image file, (e.g. -size
7157640x512+256).</p>
7158
7159<p>For Photo CD images, choose from these sizes:</p>
7160
Cristy49380402017-06-29 11:24:55 -04007161<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04007162192x128
7163384x256
7164768x512
71651536x1024
71663072x2048
Cristy49380402017-06-29 11:24:55 -04007167</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04007168
7169<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007170 <h3><a id="sketch"></a>-sketch <var>radius</var><br />-sketch <var>radius</var>x<var>sigma</var>+<var>angle</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007171</div>
7172
7173<p class="magick-description">simulate a pencil sketch.</p>
7174
7175<p>Sketch with the given radius, standard deviation (sigma), and angle. The
7176angle given is the angle toward which the image is sketched. That is the
7177direction people would consider the object is coming from. </p>
7178
7179<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007180 <h3><a id="smush"></a>-smush <var>offset</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007181</div>
7182
Cristybc232422016-11-22 07:46:18 -05007183<p class="magick-description">appends an image sequence together ignoring transparency.</p>
7184
7185<p>Smush is a more flexible version of <a href="command-line-options.html#append">-append</a>, joining the images in the sequence top-to-bottom (<a href="command-line-options.html#smush">-smush</a>) or left-to-right (<a href="command-line-options.html#smush">+smush</a>), with a gap between images according to the specified offset.</p>
7186
7187<p>If the offset is negative, images will overlap by that amount.</p>
7188
7189<p><a href="command-line-options.html#smush">-smush</a> respects <a href="command-line-options.html#gravity">-gravity</a>. Any empty space will be filled with the <a href="command-line-options.html#background">-background</a> color.</p>
7190
7191<p>For zero offset and transparent images, the non-transparent parts of the two images will be aligned as close as possible without overlapping.</p>
Cristy882d9f42015-10-29 16:48:39 -04007192
7193<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007194 <h3><a id="snaps"></a>-snaps <var>value</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007195</div>
7196
7197<p class="magick-description">Set the number of screen snapshots.</p>
7198
7199<p>Use this option to grab more than one image from the X server screen, to create an animation sequence.</p>
7200
7201<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007202 <h3><a id="solarize"></a>-solarize <var>percent-threshold</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007203</div>
7204
7205<p class="magick-description">negate all pixels above the threshold level.</p>
7206
7207<p>Specify <var>factor</var> as the percent threshold of the intensity (0 - 99.9%).</p>
7208
7209<p>This option produces a <var>solarization</var> effect seen when
7210exposing a photographic film to light during the development process.</p>
7211
7212<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007213 <h3><a id="sparse-color"></a>-sparse-color <var>method</var> '<var>x</var>,<var>y</var> <var>color</var> ...'</h3>
Cristy882d9f42015-10-29 16:48:39 -04007214</div>
7215
7216<p class="magick-description"> color the given image using the specified points of color, and filling the other intervening colors using the given methods. </p>
7217
7218
Cristy49380402017-06-29 11:24:55 -04007219<dl class="row">
7220 <dt class="col-md-4">barycentric</dt>
7221 <dd class="col-md-8">three point triangle of color given 3 points.
Cristy882d9f42015-10-29 16:48:39 -04007222 Giving only 2 points will form a linear gradient between those points.
7223 The gradient generated extends beyond the triangle created by those
7224 3 points. </dd>
Cristy49380402017-06-29 11:24:55 -04007225 <dt class="col-md-4">bilinear</dt>
7226 <dd class="col-md-8">Like barycentric but for 4 points. Less than 4 points
Cristy882d9f42015-10-29 16:48:39 -04007227 fall back to barycentric. </dd>
Cristy49380402017-06-29 11:24:55 -04007228 <dt class="col-md-4">voronoi</dt>
7229 <dd class="col-md-8">Simply map each pixel to the to nearest color point
Cristy882d9f42015-10-29 16:48:39 -04007230 given. The result are polygonal 'cells' of solid color. </dd>
Cristy49380402017-06-29 11:24:55 -04007231 <dt class="col-md-4">manhatten</dt>
7232 <dd class="col-md-8">Like voronoi, but resulting polygonal 'cells' are mapped to a fixed coordinate system.</dd>
7233 <dt class="col-md-4">shepards</dt>
7234 <dd class="col-md-8">Colors points biased on the ratio of inverse distance
Cristy882d9f42015-10-29 16:48:39 -04007235 squared. Generating spots of color in a sea of the average of
7236 colors. </dd>
Cristy49380402017-06-29 11:24:55 -04007237 <dt class="col-md-4">inverse</dt>
7238 <dd class="col-md-8">Colors points biased on the ratio of inverse distance.
Cristy882d9f42015-10-29 16:48:39 -04007239 This generates sharper points of color rather than rounded spots of
7240 '<code>shepards</code>' Generating spots of color in a sea of the
7241 average of colors. </dd>
7242</dl>
7243
7244<p>The points are placed according to the images location on the virtual
Cristy594d2772015-11-15 10:47:42 -05007245canvas (<a href="command-line-options.html#page" >-page</a> or <a href="command-line-options.html#repage" >-repage</a>
Cristy882d9f42015-10-29 16:48:39 -04007246offset), and do not actually have to exist on the given image, but may be
7247some point beyond the edge of the image. All points are floating point values.
7248</p>
7249
Cristy594d2772015-11-15 10:47:42 -05007250<p>Only the color channels defined by the <a href="command-line-options.html#channel" >-channel</a> are
Cristy882d9f42015-10-29 16:48:39 -04007251modified, which means that by default matte/alpha transparency channel is not
7252effected. Typically transparency channel is turned off either before or after
7253the operation. </p>
7254
7255<p>Of course if some color points are transparent to generate a transparent
7256gradient, then the image also requires transparency enabled to store the
7257values. </p>
7258
7259<p>All the above methods when given a single point of color will replace all
7260the colors in the image with the color given, regardless of the point. This is
7261logical, and provides an alternative technique to recolor an image to some
7262default value. </p>
7263
7264
7265<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007266 <h3><a id="splice"></a>-splice <var>geometry</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007267</div>
7268
7269<p class="magick-description">Splice the current background color into the image.</p>
7270
Cristy594d2772015-11-15 10:47:42 -05007271<p>This will add rows and columns of the current <a
7272href="command-line-options.html#background">-background</a> color into the given image according to the
Cristy882d9f42015-10-29 16:48:39 -04007273given <a href="command-line-options.html#gravity">-gravity</a> geometry setting. See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. Essentially <a href="command-line-options.html#splice">-splice</a> will divide the
7274image into four quadrants, separating them by the inserted rows and columns.
7275</p>
7276
7277<p>If a dimension of geometry is zero no rows or columns will be added for that
Cristy594d2772015-11-15 10:47:42 -05007278dimension. Similarly using a zero offset with the appropriate <a
7279href="command-line-options.html#gravity">-gravity</a> setting will add rows and columns to the edges of
7280the image, padding the image only along that one edge. Edge padding is what <a
7281href="command-line-options.html#splice">-splice</a> is most commonly used for. </p>
Cristy882d9f42015-10-29 16:48:39 -04007282
Cristy594d2772015-11-15 10:47:42 -05007283<p>If the exact same <var>geometry</var> and <a
7284href="command-line-options.html#gravity">-gravity</a> is later used with <a href="command-line-options.html#chop">-chop</a> the
Cristy882d9f42015-10-29 16:48:39 -04007285added added all splices removed. </p>
7286
7287<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007288 <h3><a id="spread"></a>-spread <var>amount</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007289</div>
7290
7291<p class="magick-description">displace image pixels by a random amount.</p>
7292
7293<p>The argument <var>amount</var> defines the size of the
7294neighborhood around each pixel from which to choose a candidate pixel to
7295blend.</p>
7296
7297<p>The lookup is controlled by the <a href="command-line-options.html#interpolate">-interpolate</a> setting.</p>
7298
7299<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007300 <h3><a id="statistic"></a>-statistic <var>type</var> <var>geometry</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007301</div>
7302
7303<p class="magick-description">replace each pixel with corresponding statistic from the neighborhood.</p>
7304
7305<p>Choose from these statistic types:</p>
Cristy49380402017-06-29 11:24:55 -04007306<dl class="row">
7307<dt class="col-md-4">Gradient</dt><dd class="col-md-8">maximum difference (max - min) value in neighborhood</dd>
7308<dt class="col-md-4">Maximum</dt><dd class="col-md-8">maximum value per channel in neighborhood</dd>
7309<dt class="col-md-4">Minimum</dt><dd class="col-md-8">minimum value per channel in neighborhood</dd>
7310<dt class="col-md-4">Mean</dt><dd class="col-md-8">average value per channel in neighborhood</dd>
7311<dt class="col-md-4">Median</dt><dd class="col-md-8">median value per channel in neighborhood</dd>
7312<dt class="col-md-4">Mode</dt><dd class="col-md-8">mode (most frequent) value per channel in neighborhood</dd>
7313<dt class="col-md-4">Nonpeak</dt><dd class="col-md-8">value just before or after the median value per channel in neighborhood</dd>
7314<dt class="col-md-4">RMS</dt><dd class="col-md-8">root mean square value per channel in neighborhood</dd>
7315<dt class="col-md-4">StandardDeviation</dt><dd class="col-md-8"> standard deviation value per channel in neighborhood</dd>
Cristy882d9f42015-10-29 16:48:39 -04007316</dl>
7317
7318<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007319 <h3><a id="stegano"></a>-stegano <var>offset</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007320</div>
7321
7322<p class="magick-description">hide watermark within an image.</p>
7323
7324<p>Use an offset to start the image hiding some number of pixels from the
7325beginning of the image. Note this offset and the image size. You will need
7326this information to recover the steganographic image (e.g. display -size
7327320x256+35 stegano:image.png).</p>
7328
7329<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007330 <h3><a id="stereo"></a>-stereo <var>+x</var>{<var>+y</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -04007331</div>
7332
7333<p class="magick-description">composite two images to create a red / cyan stereo anaglyph.</p>
7334
7335<p>The left side of the stereo pair (second image) is saved as the red channel of the output image. The right side (first image) is saved as the green and blue channels. Red-green stereo glasses are required to properly view the stereo image.</p>
7336
7337<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007338 <h3><a id="storage-type"></a>-storage-type <var>type</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007339</div>
7340
7341<p class="magick-description">pixel storage type. Here are the valid types:</p>
7342
Cristy49380402017-06-29 11:24:55 -04007343<dl class="row">
7344<dt class="col-md-4">char</dt><dd class="col-md-8">unsigned characters</dd>
7345<dt class="col-md-4">double</dt><dd class="col-md-8">doubles</dd>
7346<dt class="col-md-4">float</dt><dd class="col-md-8">floats</dd>
7347<dt class="col-md-4">integer</dt><dd class="col-md-8">integers</dd>
7348<dt class="col-md-4">long</dt><dd class="col-md-8">longs</dd>
7349<dt class="col-md-4">quantum</dt><dd class="col-md-8">pixels in the native depth of your ImageMagick distribution</dd>
7350<dt class="col-md-4">short</dt><dd class="col-md-8">unsigned shorts</dd>
Cristy882d9f42015-10-29 16:48:39 -04007351</dl>
7352
7353<p>Float and double types are normalized from 0.0 to 1.0 otherwise the pixels
7354values range from 0 to the maximum value the storage type can support.</p>
7355
7356<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007357 <h3><a id="stretch"></a>-stretch <var>fontStretch</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007358</div>
7359
7360<p class="magick-description">Set a type of stretch style for fonts.</p>
7361
7362<p>This setting suggests a type of stretch that ImageMagick should try to
7363apply to the currently selected font family. Select <var>fontStretch</var> from the following.</p>
7364
Cristy49380402017-06-29 11:24:55 -04007365<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04007366Any
7367Condensed
7368Expanded
7369ExtraCondensed
7370ExtraExpanded
7371Normal
7372SemiCondensed
7373SemiExpanded
7374UltraCondensed
7375UltraExpanded
Cristy49380402017-06-29 11:24:55 -04007376</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04007377
7378<p>To print a complete list of stretch types, use <a href="command-line-options.html#list">-list
7379stretch</a>.</p>
7380
Cristy594d2772015-11-15 10:47:42 -05007381<p>For other settings that affect fonts, see the options <a
7382href="command-line-options.html#font">-font</a>, <a href="command-line-options.html#family">-family</a>, <a
7383href="command-line-options.html#style">-style</a>, and <a href="command-line-options.html#weight">-weight</a>. </p>
Cristy882d9f42015-10-29 16:48:39 -04007384
7385<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007386 <h3><a id="strip"></a>-strip</h3>
Cristy882d9f42015-10-29 16:48:39 -04007387</div>
7388
Cristy776113a2016-04-29 12:01:19 -04007389<p class="magick-description">strip the image of any profiles, comments or these PNG chunks: bKGD,cHRM,EXIF,gAMA,iCCP,iTXt,sRGB,tEXt,zCCP,zTXt,date.</p>
Cristy882d9f42015-10-29 16:48:39 -04007390
7391<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007392 <h3><a id="stroke"></a>-stroke <var>color</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007393</div>
7394
7395<p class="magick-description">color to use when stroking a graphic primitive.</p>
7396
7397<p>The color is specified using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p>
7398
7399<p>See <a href="command-line-options.html#draw">-draw</a> for further details.</p>
7400
7401<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007402 <h3><a id="strokewidth"></a>-strokewidth <var>value</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007403</div>
7404
7405<p class="magick-description">set the stroke width.</p>
7406
7407<p>See <a href="command-line-options.html#draw">-draw</a> for further details.</p>
7408
7409<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007410 <h3><a id="style"></a>-style <var>fontStyle</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007411</div>
7412
7413<p class="magick-description">Set a font style for text.</p>
7414
7415<p>This setting suggests a font style that ImageMagick should try to apply to
7416the currently selected font family. Select <var>fontStyle</var> from
7417the following.</p>
7418
Cristy49380402017-06-29 11:24:55 -04007419<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04007420Any
7421Italic
7422Normal
7423Oblique
Cristy49380402017-06-29 11:24:55 -04007424</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04007425
Cristy594d2772015-11-15 10:47:42 -05007426<p>For other settings that affect fonts, see the options <a
7427href="command-line-options.html#font">-font</a>, <a href="command-line-options.html#family">-family</a>, <a
7428href="command-line-options.html#stretch">-stretch</a>, and <a href="command-line-options.html#weight">-weight</a>. </p>
Cristy882d9f42015-10-29 16:48:39 -04007429
7430<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007431 <h3><a id="subimage-search"></a>-subimage-search</h3>
Cristy882d9f42015-10-29 16:48:39 -04007432</div>
7433
7434<p class="magick-description">search for subimage.</p>
7435
7436<p>This option is required to have compare search for the best match location
7437of a small image within a larger image. This search will produce two images
7438(or two frames). The first is the "difference" image and the second will
7439be the "match score" image.</p>
7440
7441<p>The "match-score" image is smaller containing a pixel for ever possible
7442position of the top-left corner of the given sub-image. that is its size will
7443be the size of the larger_image - sub_image + 1. The brightest location in
7444this image is the location s the locate on the best match that is also
7445reported. Note that this may or may not be a perfect match, and the actual
7446brightness will reflect this. Other bright 'peaks' can be used to locate other
7447possible matching locations. </p>
7448
7449<p>Note that the search will try to compare the sub-image at every possible
7450location in the larger image, as such it can be very slow. The smaller the
7451sub-image the faster this search is. </p>
7452
7453
7454<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007455 <h3><a id="swap"></a>-swap <var>index,index</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007456</div>
7457
7458<p class="magick-description">Swap the positions of two images in the image sequence.</p>
7459
7460<p>For example, <a href="command-line-options.html#swap">-swap 0,2</a> swaps the first and the third
7461images in the current image sequence. Use <a href="command-line-options.html#swap">+swap</a> to switch
7462the last two images in the sequence.</p>
7463
7464<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007465 <h3><a id="swirl"></a>-swirl <var>degrees</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007466</div>
7467
7468<p class="magick-description">swirl image pixels about the center.</p>
7469
7470<p><var>Degrees</var> defines the tightness of the swirl.</p>
7471
7472<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007473 <h3><a id="synchronize"></a>-synchronize</h3>
Cristy882d9f42015-10-29 16:48:39 -04007474</div>
7475
7476<p class="magick-description">synchronize image to storage device.</p>
7477
7478<p>Set to "true" to ensure all image data is fully flushed and synchronized
7479to disk. There is a performance penalty, but the benefits include ensuring a
7480valid image file in the event of a system crash and early reporting if there
7481is not enough disk space for the image pixel cache.</p>
7482
7483<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007484 <h3><a id="taint"></a>-taint</h3>
Cristy882d9f42015-10-29 16:48:39 -04007485</div>
7486
7487<p class="magick-description">Mark the image as modified.</p>
7488
7489<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007490 <h3><a id="text-font"></a>-text-font <var>name</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007491</div>
7492
7493<p class="magick-description">font for writing fixed-width text.</p>
7494
7495<p>Specifies the name of the preferred font to use in fixed (typewriter style)
7496formatted text. The default is 14 point <var>Courier</var>.</p>
7497
7498<p>You can tag a font to specify whether it is a PostScript, TrueType, or
7499OPTION1 font. For example, <code>Courier.ttf</code> is a TrueType font and
7500<code>x:fixed</code> is OPTION1.</p>
7501
7502<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007503 <h3><a id="texture"></a>-texture <var>filename</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007504</div>
7505
7506<p class="magick-description">name of texture to tile onto the image background.</p>
7507
7508<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007509 <h3><a id="threshold"></a>-threshold <var>value</var>{<var>%</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -04007510</div>
7511
7512<!-- {<var>green,blue,opacity</var>}
7513<p>If the green or blue value is omitted, these channels use the same value as
7514the first one provided. If all three color values are the same, the result is
7515a bi-level image. If the opacity threshold is omitted, OpaqueOpacity is used
7516and any partially transparent pixel becomes fully transparent.</p>
7517-->
7518
7519<p class="magick-description">Apply simultaneous black/white threshold to the image.</p>
7520
Cristy594d2772015-11-15 10:47:42 -05007521<p>Any pixel values (more specifically, those channels set using <a href="command-line-options.html#channel">&#x2011;channel</a>) that exceed the specified threshold are reassigned the
Cristy882d9f42015-10-29 16:48:39 -04007522maximum channel value, while all other values are assigned the minimum.</p>
7523
7524<p> The threshold value can be given as a percentage or as an absolute integer
7525value corresponding to the desired channel value. When given as an integer,
7526the minimum attainable value is 0 (corresponding to black when all channels
7527are affected), but the maximum value (corresponding to white) is that of the
7528<code>quantum depth</code> of the particular build of ImageMagick, and is
7529therefore dependent on the installation. For that reason, a reasonable
7530recommendation for most applications is to specify the threshold values as
7531a percentage. </p>
7532
7533<p> The following would force pixels with red values above 50% to have 100%
7534red values, while those at or below 50% red would be set to 0 in the red
7535channel. The green, blue, and alpha channels (if present) would be unchanged.
7536</p>
7537
Cristy49380402017-06-29 11:24:55 -04007538<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04007539convert in.png -channel red -threshold 50% out.png
Cristy49380402017-06-29 11:24:55 -04007540</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04007541
7542<p>As (possibly) impractical but instructive examples, the following would
7543generate an all-black and an all-white image with the same dimensions as the
7544input image.</p>
7545
7546
Cristy49380402017-06-29 11:24:55 -04007547<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04007548convert in.png -threshold 100% black.png
7549convert in.png -threshold -1 white.png
Cristy49380402017-06-29 11:24:55 -04007550</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04007551
7552<p>Note that the values of the transparency channel is treated as 'matte'
7553values (0 is opaque) and not as 'alpha' values (0 is transparent).</p>
7554
Cristy594d2772015-11-15 10:47:42 -05007555<p> See also <a href="command-line-options.html#black-threshold">&#x2011;black&#x2011;threshold</a> and <a href="command-line-options.html#white-threshold">&#x2011;white&#x2011;threshold</a>.
Cristy882d9f42015-10-29 16:48:39 -04007556</p>
7557
7558<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007559 <h3><a id="thumbnail"></a>-thumbnail <var>geometry</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007560</div>
7561
7562<p class="magick-description">Create a thumbnail of the image.</p>
7563
7564<p>This is similar to <a href="command-line-options.html#resize">-resize</a>, except it is optimized
7565for speed and any image profile, other than a color profile, is removed to
Cristy594d2772015-11-15 10:47:42 -05007566reduce the thumbnail size. To strip the color profiles as well, add <a
7567href="command-line-options.html#strip">-strip</a> just before of after this option.</p>
Cristy882d9f42015-10-29 16:48:39 -04007568
7569<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
7570
7571<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007572 <h3><a id="tile"></a>-tile <var>filename</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007573</div>
7574
7575<p class="magick-description">Set the tile image used for filling a subsequent graphic primitive.</p>
7576
7577<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007578 <h3>-tile <var>geometry</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007579</div>
7580
7581<p class="magick-description">Specify the layout of images.</p>
7582
7583<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
7584
7585<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007586 <h3>-tile</h3>
Cristy882d9f42015-10-29 16:48:39 -04007587</div>
7588
7589<p class="magick-description">Specifies that a subsequent composite operation is repeated across and down image.</p>
7590
7591<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007592 <h3><a id="tile-offset"></a>-tile-offset {<var>+-</var>}<var>x</var>{<var>+-</var>}<var>y</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007593</div>
7594
7595<p class="magick-description">Specify the offset for tile images, relative to the background image it is tiled on.</p>
7596
Cristy594d2772015-11-15 10:47:42 -05007597<p>This should be set before the tiling image is set by <a href="command-line-options.html#tile"
7598>-tile</a> or <a href="command-line-options.html#texture" >-texture</a>, or directly applied for
Cristy882d9f42015-10-29 16:48:39 -04007599creating a tiled canvas using <code>TILE:</code> or <code>PATTERN:</code> input
7600formats. </p>
7601
Cristy594d2772015-11-15 10:47:42 -05007602<p>Internally ImageMagick does a <a href="command-line-options.html#roll" >-roll</a> of the tile image
Cristy882d9f42015-10-29 16:48:39 -04007603by the arguments given when the tile image is set. </p>
7604
7605<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007606 <h3><a id="tint"></a>-tint <var>value</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007607</div>
7608
7609<p class="magick-description">Tint the image with the fill color.</p>
7610
7611<p>Tint the image with the fill color.</p>
7612
7613<p>Specify the amount of tinting as a percentage. Pure colors like black,
7614white red, yellow, will not be affected by -tint. Only mid-range colors such
7615as the various shades of grey.</p>
7616
7617<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007618 <h3><a id="title"></a>-title <var>string</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007619</div>
7620
7621<p class="magick-description">Assign a title to displayed image.", "animate", "display", "montage</p>
7622
7623<p>Use this option to assign a specific title to the image. This assigned to
7624the image window and is typically displayed in the window title bar.
7625Optionally you can include the image filename, type, width, height, Exif data,
7626or other image attribute by embedding special format characters described
7627under the <a href="command-line-options.html#format">-format</a> option.</p>
7628
7629<p>For example,</p>
7630
Cristy49380402017-06-29 11:24:55 -04007631<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04007632-title "%m:%f %wx%h"
Cristy49380402017-06-29 11:24:55 -04007633</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04007634
7635<p>produces an image title of <code>MIFF:bird.miff 512x480</code> for an image
7636titled <code>bird.miff</code> and whose width is 512 and height is 480.</p>
7637
7638
7639<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007640 <h3><a id="transform"></a>-transform</h3>
Cristy882d9f42015-10-29 16:48:39 -04007641</div>
7642
7643<p class="magick-description">transform the image.</p>
7644
7645<p>This option applies the transformation matrix from a previous <a href="command-line-options.html#affine">-affine</a> option.</p>
7646
Cristy49380402017-06-29 11:24:55 -04007647<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04007648convert -affine 2,2,-2,2,0,0 -transform bird.ppm bird.jpg
Cristy49380402017-06-29 11:24:55 -04007649</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04007650
7651
Cristy594d2772015-11-15 10:47:42 -05007652<p>This operator has been now been superseded by the <a
7653href="command-line-options.html#distort">-distort</a> '<code>AffineProjection</code>' method. </p>
Cristy882d9f42015-10-29 16:48:39 -04007654
7655
7656<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007657 <h3><a id="transparent"></a>-transparent <var>color</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007658</div>
7659
7660<p class="magick-description">Make this color transparent within the image.</p>
7661
7662<p>The <var>color</var> argument is defined using the format
Cristy594d2772015-11-15 10:47:42 -05007663described under the <a href="command-line-options.html#fill">-fill</a> option. The <a href="command-line-options.html#fuzz"
7664>-fuzz</a> setting can be used to match and replace colors similar to the one
Cristy882d9f42015-10-29 16:48:39 -04007665given. </p>
7666
Cristy594d2772015-11-15 10:47:42 -05007667<p>Use <a href="command-line-options.html#transparent" >+transparent</a> to invert the pixels matched.
Cristy882d9f42015-10-29 16:48:39 -04007668that is make all non-matching colors transparent. </p>
7669
Cristy594d2772015-11-15 10:47:42 -05007670<p>The <a href="command-line-options.html#opaque">-opaque</a> operator is exactly the same as <a
7671href="command-line-options.html#transparent" >-transparent</a> but replaces the matching color with the
Cristy882d9f42015-10-29 16:48:39 -04007672current <a href="command-line-options.html#fill">-fill</a> color setting, rather than transparent.
Cristy594d2772015-11-15 10:47:42 -05007673However the <a href="command-line-options.html#transparent" >-transparent</a> operator also ensures
7674that the image has an alpha channel enabled, as per "<code><a href="command-line-options.html#alpha"
7675>-alpha</a> set</code>", and does not require you to modify the <a
7676href="command-line-options.html#channel">-channel</a> to enable alpha channel handling. </p>
Cristy882d9f42015-10-29 16:48:39 -04007677
7678<p>Note that this does not define the color as being the 'transparency color'
Cristy594d2772015-11-15 10:47:42 -05007679used for color-mapped image formats, such as GIF. For that use <a
7680href="command-line-options.html#transparent-color" >-transparent-color</a> </p>
Cristy882d9f42015-10-29 16:48:39 -04007681
7682
7683<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007684 <h3><a id="transparent-color"></a>-transparent-color <var>color</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007685</div>
7686
7687<p class="magick-description">Set the transparent color.</p>
7688
7689<p>Sometimes this is used for saving to image formats such as
7690GIF and PNG8 which uses this color to represent boolean transparency. This
7691does not make a color transparent, it only defines what color the transparent
Cristy594d2772015-11-15 10:47:42 -05007692color is in the color palette of the saved image. Use <a
7693href="command-line-options.html#transparent">-transparent</a> to make an opaque color transparent.</p>
Cristy882d9f42015-10-29 16:48:39 -04007694
7695<p>This option allows you to have both an opaque visible color, as well as a
7696transparent color of the same color value without conflict. That is, you can
7697use the same color for both the transparent and opaque color areas within an
7698image. This, in turn, frees to you to select a transparent color that is
7699appropriate when an image is displayed by an application that does not handle a
7700transparent color index, while allowing ImageMagick to correctly handle images of this
7701type. </p>
7702
7703<p>The default transparent color is <code>#00000000</code>, which is fully transparent black.</p>
7704
7705<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007706 <h3><a id="transpose"></a>-transpose</h3>
Cristy882d9f42015-10-29 16:48:39 -04007707</div>
7708
7709<p class="magick-description">Mirror the image along the top-left to bottom-right diagonal.</p>
7710
7711<p> This option mathematically transposes the pixel array. It is equivalent to the sequence <code>-flip -rotate 90</code>.
7712</p>
7713
7714<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007715 <h3><a id="transverse"></a>-transverse</h3>
Cristy882d9f42015-10-29 16:48:39 -04007716</div>
7717
7718<p class="magick-description">Mirror the image along the images bottom-left top-right diagonal. Equivalent to the operations <code>-flop -rotate 90</code>.</p>
7719
7720
7721<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007722 <h3><a id="treedepth"></a>-treedepth <var>value</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007723</div>
7724
7725<p class="magick-description">tree depth for the color reduction algorithm.</p>
7726
7727<p>Normally, this integer value is zero or one. A value of zero or one causes
7728the use of an optimal tree depth for the color reduction algorithm.</p>
7729
7730<p>An optimal depth generally allows the best representation of the source
7731image with the fastest computational speed and the least amount of memory.
7732However, the default depth is inappropriate for some images. To assure the
7733best representation, try values between 2 and 8 for this parameter. Refer to
Cristy6549abb2016-11-10 08:25:55 -05007734the <a href="http://www.imagemagick.org/www/quantize.html"
Cristy594d2772015-11-15 10:47:42 -05007735>color reduction algorithm</a> for more details.</p>
Cristy882d9f42015-10-29 16:48:39 -04007736
7737<p>The <a href="command-line-options.html#colors">-colors</a> or <a href="command-line-options.html#monochrome">-monochrome</a>
7738option, or writing to an image format which requires color reduction, is
7739required for this option to take effect.</p>
7740
7741<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007742 <h3><a id="trim"></a>-trim</h3>
Cristy882d9f42015-10-29 16:48:39 -04007743</div>
7744
7745<p class="magick-description">trim an image.</p>
7746
7747<p>This option removes any edges that are exactly the same color as the corner
7748pixels. Use <a href="command-line-options.html#fuzz">-fuzz</a> to make <a href="command-line-options.html#trim">-trim</a> remove
7749edges that are nearly the same color as the corner pixels.</p>
7750
7751<p>The page or virtual canvas information of the image is preserved allowing
7752you to extract the result of the <a href="command-line-options.html#trim">-trim</a> operation from the
7753image. Use a <a href="command-line-options.html#repage">+repage</a> to remove the virtual canvas page
7754information if it is unwanted.</p>
7755
7756<p>If the trimmed image 'disappears' an warning is produced, and a special
7757single pixel transparent 'missed' image is returned, in the same way as when a
7758<a href="command-line-options.html#crop">-crop</a> operation 'misses' the image proper. </p>
7759
7760
7761<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007762 <h3><a id="type"></a>-type <var>type</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007763</div>
7764
7765<p class="magick-description">the image type.</p> <p>Choose from: <code>Bilevel</code>,
7766<code>Grayscale</code>, <code>GrayscaleMatte</code>, <code>Palette</code>,
7767<code>PaletteMatte</code>, <code>TrueColor</code>, <code>TrueColorMatte</code>,
7768<code>ColorSeparation</code>, or <code>ColorSeparationMatte</code>.</p>
7769
7770<p>Normally, when a format supports different subformats such as grayscale and
Cristy594d2772015-11-15 10:47:42 -05007771truecolor, the encoder will try to choose an efficient subformat. The <a
7772href="command-line-options.html#type">-type</a> option can be used to override this behavior. For
Cristy882d9f42015-10-29 16:48:39 -04007773example, to prevent a JPEG from being written in grayscale format even though
7774only gray pixels are present, use.</p>
7775
Cristy49380402017-06-29 11:24:55 -04007776<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04007777convert bird.png -type TrueColor bird.jpg
Cristy49380402017-06-29 11:24:55 -04007778</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04007779
7780<p>Similarly, use <a href="command-line-options.html#type">-type TrueColorMatte</a> to force the
7781encoder to write an alpha channel even though the image is opaque, if the
7782output format supports transparency.</p>
7783
7784<p>Use <a href="command-line-options.html#type">-type optimize</a> to ensure the image is written in the smallest possible file size.</p>
7785
7786<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007787 <h3><a id="undercolor"></a>-undercolor <var>color</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007788</div>
7789
7790<p class="magick-description">set the color of the annotation bounding box.</p>
7791
7792<p>The color is specified using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p>
7793
7794<p>See <a href="command-line-options.html#draw">-draw</a> for further details.</p>
7795
7796
7797<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007798 <h3><a id="update"></a>-update <var>seconds</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007799</div>
7800
7801<p class="magick-description">detect when image file is modified and redisplay.</p>
7802
7803<p>Suppose that while you are displaying an image the file that is currently
7804displayed is over-written. <code>display</code> will automagically detect that
7805the input file has been changed and update the displayed image
7806accordingly.</p>
7807
7808
7809<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007810 <h3><a id="unique-colors"></a>-unique-colors</h3>
Cristy882d9f42015-10-29 16:48:39 -04007811</div>
7812
7813<p class="magick-description">discard all but one of any pixel color.</p>
7814
7815
7816<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007817 <h3><a id="units"></a>-units <var>type</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007818</div>
7819
7820<p class="magick-description">the units of image resolution.</p>
7821
7822<p>Choose from: <code>Undefined</code>, <code>PixelsPerInch</code>, or
7823<code>PixelsPerCentimeter</code>. This option is normally used in conjunction
7824with the <a href="command-line-options.html#density">-density</a> option.</p>
7825
7826
7827<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007828 <h3><a id="unsharp"></a>-unsharp <var>radius</var><br />-unsharp <var>radius</var>x<var>sigma</var>{<var>+gain</var>}{<var>+threshold</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -04007829</div>
7830
7831<p class="magick-description">sharpen the image with an unsharp mask operator.</p>
7832
7833<p>The <a href="command-line-options.html#unsharp">-unsharp</a> option sharpens an image. The image is
7834convolved with a Gaussian operator of the given radius and standard deviation
7835(sigma). For reasonable results, radius should be larger than sigma. Use
7836a radius of 0 to have the method select a suitable radius.</p>
7837
7838<p>The parameters are:</p>
7839
Cristy49380402017-06-29 11:24:55 -04007840<dl class="row">
7841<dt class="col-md-4">radius</dt>
7842<dd class="col-md-8">The radius of the Gaussian, in pixels, not counting the center pixel (default 0).</dd>
7843<dt class="col-md-4">sigma</dt>
7844<dd class="col-md-8">The standard deviation of the Gaussian, in pixels (default 1.0).</dd>
7845<dt class="col-md-4">gain</dt>
7846<dd class="col-md-8">The fraction of the difference between the original and the blur image that is added back into the original (default 1.0).</dd>
7847<dt class="col-md-4">threshold</dt>
7848<dd class="col-md-8">The threshold, as a fraction of <var>QuantumRange</var>, needed to apply the difference amount (default 0.05).</dd>
Cristy882d9f42015-10-29 16:48:39 -04007849</dl>
7850
7851<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007852 <h3><a id="verbose"></a>-verbose</h3>
Cristy882d9f42015-10-29 16:48:39 -04007853</div>
7854
7855<p class="magick-description">print detailed information about the image when this option precedes the <a href="command-line-options.html#identify">-identify</a> option or <code>info:</code>.</p>
7856
7857
7858<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007859 <h3><a id="version"></a>-version</h3>
Cristy882d9f42015-10-29 16:48:39 -04007860</div>
7861
7862<p class="magick-description">print ImageMagick version string and exit.</p>
7863
7864
7865<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007866 <h3><a id="view"></a>-view <var>string</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007867</div>
7868
7869<p class="magick-description">FlashPix viewing parameters.</p>
7870
7871
7872<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007873 <h3><a id="vignette"></a>-vignette <var>radius</var>{x<var>sigma</var>}{<var>+-</var>}<var>x</var>{<var>+-</var>}<var>y</var>{<var>%</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -04007874</div>
7875
7876<p class="magick-description">soften the edges of the image in vignette style.</p>
7877
7878<p>The vignette effect rolloff is controlled by radiusxsigma. For nominal rolloff, this would be set to 0xsigma. A value of 0x0 will produce a circle/ellipse with no rolloff. The arguments x and y control the size of the circle. Larger values decrease the radii and smaller values increase the radii. Values of +0+0 will generate a circle/ellipse the same size as the image. The default values for x and y are 10% of the corresponding image dimension. Thus, the radii will be decreased by 10%, i.e., the diameters of the circle/ellipse will be 80% of the corresponding image dimension.</p>
7879
7880<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007881 <h3><a id="virtual-pixel"></a>-virtual-pixel <var>method</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007882</div>
7883
7884<p class="magick-description">Specify contents of <var>virtual pixels</var>.</p>
7885
7886<p>This option defines what color source should be used if and when a color
7887lookup completely 'misses' the source image. The color(s) that appear to
7888surround the source image. Generally this color is derived from the source
7889image, but could also be set to a specify background color. </p>
7890
7891<p>Choose from these methods:</p>
7892
Cristy49380402017-06-29 11:24:55 -04007893<dl class="row">
7894<dt class="col-md-4">background</dt><dd class="col-md-8">the area surrounding the image is the background color</dd>
7895<dt class="col-md-4">black</dt><dd class="col-md-8">the area surrounding the image is black</dd>
7896<dt class="col-md-4">checker-tile</dt><dd class="col-md-8">alternate squares with image and background color</dd>
7897<dt class="col-md-4">dither</dt><dd class="col-md-8">non-random 32x32 dithered pattern</dd>
7898<dt class="col-md-4">edge</dt><dd class="col-md-8">extend the edge pixel toward infinity</dd>
7899<dt class="col-md-4">gray</dt><dd class="col-md-8">the area surrounding the image is gray</dd>
7900<dt class="col-md-4">horizontal-tile</dt><dd class="col-md-8">horizontally tile the image, background color above/below</dd>
7901<dt class="col-md-4">horizontal-tile-edge</dt><dd class="col-md-8">horizontally tile the image and replicate the side edge pixels</dd>
7902<dt class="col-md-4">mirror</dt><dd class="col-md-8">mirror tile the image</dd>
7903<dt class="col-md-4">random</dt><dd class="col-md-8">choose a random pixel from the image</dd>
7904<dt class="col-md-4">tile</dt><dd class="col-md-8">tile the image (default)</dd>
7905<dt class="col-md-4">transparent</dt><dd class="col-md-8">the area surrounding the image is transparent blackness</dd>
7906<dt class="col-md-4">vertical-tile</dt><dd class="col-md-8">vertically tile the image, sides are background color</dd>
7907<dt class="col-md-4">vertical-tile-edge</dt><dd class="col-md-8">vertically tile the image and replicate the side edge pixels</dd>
7908<dt class="col-md-4">white</dt><dd class="col-md-8">the area surrounding the image is white</dd>
Cristy882d9f42015-10-29 16:48:39 -04007909</dl>
7910
7911<p>The default value is "edge".</p>
7912
Cristy594d2772015-11-15 10:47:42 -05007913<p>This most important for distortion operators such as <a href="command-line-options.html#distort"
7914>-distort</a>, <a href="command-line-options.html#implode" >-implode</a>, and <a href="command-line-options.html#fx" >-fx</a>.
Cristy882d9f42015-10-29 16:48:39 -04007915However it also effects operations that may access pixels just outside the
Cristy594d2772015-11-15 10:47:42 -05007916image proper, such as <a href="command-line-options.html#convolve">-convolve</a>, <a
7917href="command-line-options.html#blur">-blur</a>, and <a href="command-line-options.html#sharpen">-sharpen</a>. </p>
Cristy882d9f42015-10-29 16:48:39 -04007918
Cristy594d2772015-11-15 10:47:42 -05007919<p>To print a complete list of virtual pixel types, use the <a
7920href="command-line-options.html#list">-list virtual-pixel</a> option.</p>
Cristy882d9f42015-10-29 16:48:39 -04007921
7922
7923<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007924 <h3><a id="visual"></a>-visual <var>type</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007925</div>
7926
7927<p class="magick-description">Animate images using this X visual type.", 'animate', 'display'</p>
7928
7929<p>Choose from these visual classes:</p>
7930
Cristy49380402017-06-29 11:24:55 -04007931<pre><code>
Cristy882d9f42015-10-29 16:48:39 -04007932StaticGray TrueColor
7933GrayScale DirectColor
7934StaticColor default
7935PseudoColor visual id
Cristy49380402017-06-29 11:24:55 -04007936</code></pre>
Cristy882d9f42015-10-29 16:48:39 -04007937
7938<p>The X server must support the visual you choose, otherwise an error occurs.
7939If a visual is not specified, the visual class that can display the most
7940simultaneous colors on the default screen is chosen.</p>
7941
7942
7943<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007944 <h3><a id="watermark"></a>-watermark <var>brightness</var>x<var>saturation</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007945</div>
7946
7947<p class="magick-description">Watermark an image using the given percentages of brightness and saturation.</p>
7948
7949<p>Take a grayscale image (with alpha mask) and modify the destination image's
7950brightness according to watermark image's grayscale value and the
7951<var>brightness</var> percentage. The destinations color saturation
7952attribute is just direct modified by the <var>saturation</var>
7953percentage, which defaults to 100 percent (no color change). </p>
7954
7955
7956<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007957 <h3><a id="wave"></a>-wave <var>amplitude</var><br />-wave <var>amplitude</var>x<var>wavelength</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007958</div>
7959
7960<p class="magick-description">Shear the columns of an image into a sine wave.</p>
7961
Cristye09ed312016-03-06 08:07:39 -05007962<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007963 <h3><a id="wavelet-denoise"></a>-wavelet-denoise <var>threshold</var><br />-wavelet-denoise <var>threshold</var>x<var>softness</var></h3>
Cristye09ed312016-03-06 08:07:39 -05007964</div>
7965
7966<p class="magick-description">removes noise from the image using a wavelet transform. The threshold is the value below which everything is considered noise and ranges from 0.0 (none) to QuantumRange or use percent (e.g. 5%). Softness attenuates the threshold and typically ranges from 0.0 (none) to 1.0. The higher the value the more noise that remains in the image.</p>
Cristy882d9f42015-10-29 16:48:39 -04007967
7968<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04007969 <h3><a id="weight"></a>-weight <var>fontWeight</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04007970</div>
7971
7972<p class="magick-description">Set a font weight for text.</p>
7973
7974<p>This setting suggests a font weight that ImageMagick should try to apply to
7975the currently selected font family. Use a positive integer for
7976<var>fontWeight</var> or select from the following.</p>
7977
Cristy49380402017-06-29 11:24:55 -04007978<dl class="row">
7979<dt class="col-md-4">Thin </dt>
7980<dd class="col-md-8">Same as <var>fontWeight</var> = 100.</dd>
7981<dt class="col-md-4">ExtraLight </dt>
7982<dd class="col-md-8">Same as <var>fontWeight</var> = 200.</dd>
7983<dt class="col-md-4">Light </dt>
7984<dd class="col-md-8">Same as <var>fontWeight</var> = 300.</dd>
7985<dt class="col-md-4">Normal </dt>
7986<dd class="col-md-8">Same as <var>fontWeight</var> = 400.</dd>
7987<dt class="col-md-4">Medium </dt>
7988<dd class="col-md-8">Same as <var>fontWeight</var> = 500.</dd>
7989<dt class="col-md-4">DemiBold </dt>
7990<dd class="col-md-8">Same as <var>fontWeight</var> = 600.</dd>
7991<dt class="col-md-4">Bold </dt>
7992<dd class="col-md-8">Same as <var>fontWeight</var> = 700.</dd>
7993<dt class="col-md-4">ExtraBold </dt>
7994<dd class="col-md-8">Same as <var>fontWeight</var> = 800.</dd>
7995<dt class="col-md-4">Heavy </dt>
7996<dd class="col-md-8">Same as <var>fontWeight</var> = 900.</dd>
Cristy882d9f42015-10-29 16:48:39 -04007997</dl>
Cristy594d2772015-11-15 10:47:42 -05007998<br/>
Cristy882d9f42015-10-29 16:48:39 -04007999
8000<p>To print a complete list of weight types, use <a href="command-line-options.html#list">-list weight</a>.</p>
8001
Cristy594d2772015-11-15 10:47:42 -05008002<p>For other settings that affect fonts, see the options <a
8003href="command-line-options.html#font">-font</a>, <a href="command-line-options.html#family">-family</a>, <a
8004href="command-line-options.html#stretch">-stretch</a>, and <a href="command-line-options.html#style">-style</a>. </p>
Cristy882d9f42015-10-29 16:48:39 -04008005
8006<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04008007 <h3><a id="white-point"></a>-white-point <var>x,y</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04008008</div>
8009
8010<p class="magick-description">chromaticity white point.</p>
8011
8012<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04008013 <h3><a id="white-threshold"></a>-white-threshold <var>value</var>{<var>%</var>}</h3>
Cristy882d9f42015-10-29 16:48:39 -04008014</div>
8015
8016<p class="magick-description">Force to white all pixels above the threshold while leaving all pixels at or below the threshold unchanged.</p>
8017
8018<p> The threshold value can be given as a percentage or as an absolute integer
8019value within [0, <var>QuantumRange</var>] corresponding to the
Cristy594d2772015-11-15 10:47:42 -05008020desired <a href="command-line-options.html#channel">&#x2011;channel</a> value. See <a href="command-line-options.html#threshold">&#x2011;threshold</a>for more details on thresholds and resulting values. </p>
Cristy882d9f42015-10-29 16:48:39 -04008021
8022<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04008023 <h3><a id="window"></a>-window <var>id</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04008024</div>
8025
8026<p class="magick-description">Make the image the background of a window.", 'animate', 'display'</p>
8027
8028<p><var>id</var> can be a window id or name. Specify <code>root</code>
8029to select X's root window as the target window.</p>
8030
8031<p>By default the image is tiled onto the background of the target window. If
8032<code>backdrop</code> or <a href="command-line-options.html#geometry">-resize</a> are specified, the
8033image is surrounded by the background color. Refer to <code>X RESOURCES</code>
8034for details.</p>
8035
8036<p>The image will not display on the root window if the image has more unique
Cristy594d2772015-11-15 10:47:42 -05008037colors than the target window colormap allows. Use <a
8038href="command-line-options.html#colors">-colors</a> to reduce the number of colors.</p>
Cristy882d9f42015-10-29 16:48:39 -04008039
8040<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04008041 <h3><a id="window-group"></a>-window-group</h3>
Cristy882d9f42015-10-29 16:48:39 -04008042</div>
8043
8044<p class="magick-description">specify the window group.</p>
8045
8046<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04008047 <h3><a id="write"></a>-write <var>filename</var></h3>
Cristy882d9f42015-10-29 16:48:39 -04008048</div>
8049
8050<p class="magick-description">write an image sequence.</p>
8051
8052<p>The image sequence preceding the <a href="command-line-options.html#write">-write</a> <var>filename</var> option is written out, and processing continues with the same image in its current state if there are additional options. To restore the image to its original state after writing it, use the <a href="command-line-options.html#write">+write</a> <var>filename</var> option.</p>
8053
8054<p>Use <a href="command-line-options.html#compress">-compress</a> to specify the type of image compression.</p>
Cristye0779712016-07-30 17:25:22 -04008055
8056<div style="margin: auto;">
Cristy49380402017-06-29 11:24:55 -04008057 <h3><a id="write-mask"></a>-write-mask <var>filename</var></h3>
Cristye0779712016-07-30 17:25:22 -04008058</div>
8059
8060<p class="magick-description">Prevent updates to image pixels specified by the mask.</p>
8061
8062<p>This the same as using a mask used for composite masking operations, with
8063grayscale values causing blended updates of the image the mask is attached to.
8064</p>
8065
8066<p>Use <a href="command-line-options.html#write-mask">+write-mask</a> to remove the mask from images.</p>
8067
8068<p>Also see <a href="command-line-options.html#clip-mask">-clip-mask</a> which work in the same way,
8069but with strict boolean masking. </p>
Cristy882d9f42015-10-29 16:48:39 -04008070</div>
8071</div>
8072
8073
Cristye93be682015-11-26 09:07:51 -05008074
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