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cristyb2cad532015-05-16 13:02:45 +000059<p class="text-center"><a href="command-line-options.html#adaptive-blur">‑adaptive‑blur</a><a href="command-line-options.html#adaptive-resize">‑adaptive‑resize</a><a href="command-line-options.html#adaptive-sharpen">‑adaptive‑sharpen</a><a href="command-line-options.html#adjoin">‑adjoin</a><a href="command-line-options.html#affine">‑affine</a><a href="command-line-options.html#alpha">‑alpha</a><a href="command-line-options.html#annotate">‑annotate</a><a href="command-line-options.html#antialias">‑antialias</a><a href="command-line-options.html#append">‑append</a><a href="command-line-options.html#attenuate">‑attenuate</a><a href="command-line-options.html#authenticate">‑authenticate</a><a href="command-line-options.html#auto-gamma">‑auto‑gamma</a><a href="command-line-options.html#auto-level">‑auto‑level</a><a href="command-line-options.html#auto-orient">‑auto‑orient</a><a href="command-line-options.html#backdrop">‑backdrop</a><a href="command-line-options.html#background">‑background</a><a href="command-line-options.html#bench">‑bench</a><a href="command-line-options.html#bias">‑bias</a><a href="command-line-options.html#black-point-compensation">‑black‑point‑compensation</a><a href="command-line-options.html#black-threshold">‑black‑threshold</a><a href="command-line-options.html#blend">‑blend</a><a href="command-line-options.html#blue-primary">‑blue‑primary</a><a href="command-line-options.html#blue-shift">‑blue‑shift</a><a href="command-line-options.html#blur">‑blur</a><a href="command-line-options.html#border">‑border</a><a href="command-line-options.html#bordercolor">‑bordercolor</a><a href="command-line-options.html#borderwidth">‑borderwidth</a><a href="command-line-options.html#brightness-contrast">‑brightness‑contrast</a><a href="command-line-options.html#cache">‑cache</a><a href="command-line-options.html#canny">‑canny</a><a href="command-line-options.html#caption">‑caption</a><a 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href="command-line-options.html#flatten">‑flatten</a><a href="command-line-options.html#flip">‑flip</a><a href="command-line-options.html#floodfill">‑floodfill</a><a href="command-line-options.html#flop">‑flop</a><a href="command-line-options.html#font">‑font</a><a href="command-line-options.html#foreground">‑foreground</a><a href="command-line-options.html#format">‑format</a><a href="command-line-options.html#format_identify_">‑format[identify]</a><a href="command-line-options.html#frame">‑frame</a><a href="command-line-options.html#frame_import_">‑frame[import]</a><a href="command-line-options.html#function">‑function</a><a href="command-line-options.html#fuzz">‑fuzz</a><a href="command-line-options.html#fx">‑fx</a><a href="command-line-options.html#gamma">‑gamma</a><a href="command-line-options.html#gaussian-blur">‑gaussian‑blur</a><a href="command-line-options.html#geometry">‑geometry</a><a href="command-line-options.html#gravity">‑gravity</a><a 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href="command-line-options.html#polaroid">‑polaroid</a><a href="command-line-options.html#poly">‑poly</a><a href="command-line-options.html#posterize">‑posterize</a><a href="command-line-options.html#precision">‑precision</a><a href="command-line-options.html#preview">‑preview</a><a href="command-line-options.html#print">‑print</a><a href="command-line-options.html#process">‑process</a><a href="command-line-options.html#profile">‑profile</a><a href="command-line-options.html#quality">‑quality</a><a href="command-line-options.html#quantize">‑quantize</a><a href="command-line-options.html#quiet">‑quiet</a><a href="command-line-options.html#radial-blur">‑radial‑blur</a><a href="command-line-options.html#raise">‑raise</a><a href="command-line-options.html#random-threshold">‑random‑threshold</a><a href="command-line-options.html#red-primary">‑red‑primary</a><a href="command-line-options.html#regard-warnings">‑regard‑warnings</a><a href="command-line-options.html#region">‑region</a><a 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href="command-line-options.html#solarize">‑solarize</a><a href="command-line-options.html#sparse-color">‑sparse‑color</a><a href="command-line-options.html#splice">‑splice</a><a href="command-line-options.html#spread">‑spread</a><a href="command-line-options.html#statistic">‑statistic</a><a href="command-line-options.html#stegano">‑stegano</a><a href="command-line-options.html#stereo">‑stereo</a><a href="command-line-options.html#storage-type">‑storage‑type</a><a href="command-line-options.html#stretch">‑stretch</a><a href="command-line-options.html#strip">‑strip</a><a href="command-line-options.html#stroke">‑stroke</a><a href="command-line-options.html#strokewidth">‑strokewidth</a><a href="command-line-options.html#style">‑style</a><a href="command-line-options.html#subimage-search">‑subimage‑search</a><a href="command-line-options.html#swap">‑swap</a><a href="command-line-options.html#swirl">‑swirl</a><a href="command-line-options.html#synchronize">‑synchronize</a><a href="command-line-options.html#taint">‑taint</a><a href="command-line-options.html#text-font">‑text‑font</a><a href="command-line-options.html#texture">‑texture</a><a href="command-line-options.html#threshold">‑threshold</a><a href="command-line-options.html#thumbnail">‑thumbnail</a><a href="command-line-options.html#tile">‑tile</a><a href="command-line-options.html#tile-offset">‑tile‑offset</a><a href="command-line-options.html#tint">‑tint</a><a href="command-line-options.html#title">‑title</a><a href="command-line-options.html#transform">‑transform</a><a href="command-line-options.html#transparent">‑transparent</a><a href="command-line-options.html#transparent-color">‑transparent‑color</a><a href="command-line-options.html#transpose">‑transpose</a><a href="command-line-options.html#transverse">‑transverse</a><a href="command-line-options.html#treedepth">‑treedepth</a><a href="command-line-options.html#trim">‑trim</a><a href="command-line-options.html#type">‑type</a><a href="command-line-options.html#undercolor">‑undercolor</a><a href="command-line-options.html#unique-colors">‑unique‑colors</a><a href="command-line-options.html#units">‑units</a><a href="command-line-options.html#unsharp">‑unsharp</a><a href="command-line-options.html#update">‑update</a><a href="command-line-options.html#verbose">‑verbose</a><a href="command-line-options.html#version">‑version</a><a href="command-line-options.html#view">‑view</a><a href="command-line-options.html#vignette">‑vignette</a><a href="command-line-options.html#virtual-pixel">‑virtual‑pixel</a><a href="command-line-options.html#visual">‑visual</a><a href="command-line-options.html#watermark">‑watermark</a><a href="command-line-options.html#wave">‑wave</a><a href="command-line-options.html#weight">‑weight</a><a href="command-line-options.html#white-point">‑white‑point</a><a href="command-line-options.html#white-threshold">‑white‑threshold</a><a href="command-line-options.html#window">‑window</a><a href="command-line-options.html#window-group">‑window‑group</a><a href="command-line-options.html#write">‑write</a> </p>
cristyad41c0c2012-10-31 00:49:28 +000060
cristyd2432012015-05-04 23:15:15 +000061<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>
62
63<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +000064 <h3 class="magick-header"><a id="adaptive-blur"></a>-adaptive-blur <var>radius</var>[x<var>sigma</var>]</h3>
cristyad41c0c2012-10-31 00:49:28 +000065</div>
66
cristyd2432012015-05-04 23:15:15 +000067<p class="magick-description">Adaptively blur pixels, with decreasing effect near edges.</p>
cristy8ee7f242013-06-20 16:08:44 +000068
cristyd2432012015-05-04 23:15:15 +000069<p>A Gaussian operator of the given radius and standard deviation (<var>sigma</var>) is used. If <var>sigma</var> is not given it
70defaults to 1.</p>
71
72<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +000073 <h3 class="magick-header"><a id="adaptive-resize"></a>-adaptive-resize <var>geometry</var></h3>
cristy149d58c2013-08-07 19:44:54 +000074</div>
cristyd2432012015-05-04 23:15:15 +000075
76<p class="magick-description">Resize the image using data-dependent triangulation.</p>
77
78<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>
cristy82a2ff22015-05-12 16:41:32 +000079option defaults to data-dependent triangulation. Use the <a href="command-line-options.html#filter">-filter</a> to choose a different resampling algorithm.
80Offsets, if present in the geometry string, are ignored, and the <a href="command-line-options.html#gravity">-gravity</a> option has no effect.</p>
cristyd2432012015-05-04 23:15:15 +000081
82<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +000083 <h3 class="magick-header"><a id="adaptive-sharpen"></a>-adaptive-sharpen <var>radius</var>[x<var>sigma</var>]</h3>
cristy149d58c2013-08-07 19:44:54 +000084</div>
cristyd2432012015-05-04 23:15:15 +000085
86<p class="magick-description">Adaptively sharpen pixels, with increasing effect near edges.</p>
87
88<p>A Gaussian operator of the given radius and standard deviation
89(<var>sigma</var>) is used. If <var>sigma</var> is not given it
90defaults to 1.</p>
91
92<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +000093 <h3 class="magick-header"><a id="adjoin"></a>-adjoin</h3>
cristyd2432012015-05-04 23:15:15 +000094</div>
95
96<p class="magick-description">Join images into a single multi-image file.</p>
97
98<p>This option is enabled by default. An attempt is made to save all images of
99an image sequence into the given output file. However, some formats, such as
100JPEG and PNG, do not support more than one image per file, and in that case
101ImageMagick is forced to write each image as a separate file. As such, if
102more than one image needs to be written, the filename given is modified by
103adding a <a href="command-line-options.html#scene">-scene</a> number before the suffix, in order to
104make distinct names for each image. </p>
105
106<p>Use <a href="command-line-options.html#adjoin">+adjoin</a> to force each image to be written to
107separate files, whether or not the file format allows multiple images per file
108(for example, GIF, MIFF, and TIFF). </p>
109
110<p>Including a C-style integer format string in the output filename will
111automagically enable <a href="command-line-options.html#adjoin">+adjoin</a> and are used to specify
112where the <a href="command-line-options.html#scene">-scene</a> number is placed in the filenames. These
113strings, such as '<code>%d</code>' or '<code>%03d</code>', are familiar to those
114who have used the standard <code>printf()</code>' C-library function. As an
115example, the command</p>
116
117<pre>
118convert logo: rose: -morph 15 my%02dmorph.jpg
119</pre>
120
121<p>will create a sequence of 17 images (the two given plus 15 more created by
122<a href="command-line-options.html#morph">-morph</a>), named: my00morph.jpg, my01morph.jpg,
123my02morph.jpg, ..., my16morph.jpg. </p>
124
125<p>In summary, ImageMagick tries to write all images to one file, but will
126save to multiple files, if any of the following conditions exist...</p>
127<ol>
128<li>the output image's file format does not allow multi-image files,</li>
129<li>the <a href="command-line-options.html#adjoin">+adjoin</a> option is given, or</li>
130<li>a printf() integer format string (eg: "%d") is present in the output
131 filename.</li>
132</ol>
133
134
135<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000136 <h3 class="magick-header"><a id="affine"></a>-affine
137 <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>
cristyd2432012015-05-04 23:15:15 +0000138</div>
139
140<p class="magick-description">Set the drawing transformation matrix for combined rotating and scaling.</p>
141
cristy82a2ff22015-05-12 16:41:32 +0000142<p>This option sets a transformation matrix, for use by subsequent <a href="command-line-options.html#draw">-draw</a> or <a href="command-line-options.html#transform">-transform</a> options. </p>
cristyd2432012015-05-04 23:15:15 +0000143
144<p>The matrix entries are entered as comma-separated numeric values either in
145quotes or without spaces. </p>
146
147<p>Internally, the transformation matrix has 3x3 elements, but three of them
148are omitted from the input because they are constant. The new (transformed)
149coordinates (<var>x'</var>, <var>y'</var>) of a pixel at
150position (<var>x</var>, <var>y</var>) in the original
151image are calculated using the following matrix equation.</p>
152
cristyb2cad532015-05-16 13:02:45 +0000153<p class="text-center"><img class="img-thumbnail" alt="affine transformation" src="../images/affine.png"> </p>
cristyd2432012015-05-04 23:15:15 +0000154
155<p> The size of the resulting image is that of the smallest rectangle that
156contains the transformed source image. The parameters
157<var>t<sub>x</sub></var> and <var>t<sub>y</sub></var>
158subsequently shift the image pixels so that those that are moved out of the
159image area are cut off.</p>
160
161<p>The transformation matrix complies with the left-handed pixel coordinate
162system: positive <var>x</var> and <var>y</var> directions
163are rightward and downward, resp.; positive rotation is clockwise.</p>
164
165<p> If the translation coefficients <var>t<sub>x</sub></var> and
166<var>t<sub>y</sub></var> are omitted they default to 0,0. Therefore,
167four parameters suffice for rotation and scaling without translation.</p>
168
169<p>Scaling by the factors <var>s<sub>x</sub></var> and
170<var>s<sub>y</sub></var> in the <var>x</var> and <var>y</var> directions,
171respectively, is accomplished with the following.</p>
172
cristy82a2ff22015-05-12 16:41:32 +0000173<p>See <a href="command-line-options.html#transform">-transform</a>, and the <a href="command-line-options.html#distort">-distort</a> method '<code>Affineprojection</code> for more
cristyd2432012015-05-04 23:15:15 +0000174information </p>
175
176
177<pre>
178-affine <var>s<sub>x</sub></var>,0,0,<var>s<sub>y</sub></var>
179</pre>
180
181<p>Translation by a displacement (<var>t<sub>x</sub></var>, <var>t<sub>y</sub></var>) is accomplished like so:</p>
182
183<pre>
184-affine 1,0,0,1,<var>t<sub>x</sub></var>,<var>t<sub>y</sub></var>
185</pre>
186
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
191<pre>
192-affine <var>c</var>,<var>s</var>,-<var>s</var>,<var>c</var>
193</pre>
194
cristy82a2ff22015-05-12 16:41:32 +0000195<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">-affine</a> operation using the matrix equal to the product of the matrices
cristyd2432012015-05-04 23:15:15 +0000197of the individual transformations.</p>
198
199<p>An attempt is made to detect near-singular transformation matrices. If the
200matrix determinant has a sufficiently small absolute value it is rejected.</p>
201
202<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000203 <h3 class="magick-header"><a id="alpha"></a>-alpha <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +0000204</div>
205
206<p class="magick-description">Gives control of the alpha/matte channel of an image.</p>
207
208<p>Used to set a flag on an image indicating whether or not to use existing alpha
209channel 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>
210
cristyb2cad532015-05-16 13:02:45 +0000211<dl class="dl-horizontal">
212 <dt>Activate</dt>
213 <dd>
214 Enable the image's transparency channel. Note normally Set
cristyd2432012015-05-04 23:15:15 +0000215 should be used instead of this, unless you specifically need to
cristyb2cad532015-05-16 13:02:45 +0000216 preserve existing (but specifically turned Off) transparency
217 channel. </dd>
cristyd2432012015-05-04 23:15:15 +0000218
cristyb2cad532015-05-16 13:02:45 +0000219 <dt>Associate</dt>
220 <dd>
221 associate the alpha channel with the image.</dd>
cristyd2432012015-05-04 23:15:15 +0000222
cristyb2cad532015-05-16 13:02:45 +0000223 <dt>Deactivate</dt>
224 <dd>
cristyd2432012015-05-04 23:15:15 +0000225 Disables the image's transparency channel. Does not delete or change the
cristyb2cad532015-05-16 13:02:45 +0000226 existing data, just turns off the use of that data.</dd>
cristyd2432012015-05-04 23:15:15 +0000227
cristyb2cad532015-05-16 13:02:45 +0000228 <dt>Disassociate</dt>
229 <dd>
230 disassociate the alpha channel from the image.</dd>
cristyd2432012015-05-04 23:15:15 +0000231
cristyb2cad532015-05-16 13:02:45 +0000232 <dt>Set</dt>
233 <dd>
cristyd2432012015-05-04 23:15:15 +0000234 Activates the alpha/matte channel. If it was previously turned off
235 then it also resets the channel to opaque. If the image already had
cristyb2cad532015-05-16 13:02:45 +0000236 the alpha channel turned on, it will have no effect.</dd>
cristyd2432012015-05-04 23:15:15 +0000237
cristyb2cad532015-05-16 13:02:45 +0000238 <dt>Opaque</dt>
239 <dd>
cristyd2432012015-05-04 23:15:15 +0000240 Enables the alpha/matte channel and forces it to be fully opaque.
cristyb2cad532015-05-16 13:02:45 +0000241 </dd>
cristyd2432012015-05-04 23:15:15 +0000242
cristyb2cad532015-05-16 13:02:45 +0000243 <dt>Transparent</dt>
244 <dd>
cristyd2432012015-05-04 23:15:15 +0000245 Activates the alpha/matte channel and forces it to be fully
246 transparent. This effectively creates a fully transparent image the
247 same size as the original and with all its original RGB data still
cristyb2cad532015-05-16 13:02:45 +0000248 intact, but fully transparent. </dd>
cristyd2432012015-05-04 23:15:15 +0000249
cristyb2cad532015-05-16 13:02:45 +0000250 <dt>Extract</dt>
251 <dd>
cristyd2432012015-05-04 23:15:15 +0000252 Copies the alpha channel values into all the color channels and turns
cristyb2cad532015-05-16 13:02:45 +0000253 'Off' the the image's transparency, so as to generate
cristyd2432012015-05-04 23:15:15 +0000254 a gray-scale mask of the image's shape. The alpha channel data is left
cristyb2cad532015-05-16 13:02:45 +0000255 intact just deactivated. This is the inverse of 'Copy'.
256 </dd>
cristyd2432012015-05-04 23:15:15 +0000257
cristyb2cad532015-05-16 13:02:45 +0000258 <dt>Copy</dt>
259 <dd>
260 Turns 'On' the alpha/matte channel, then copies the
cristyd2432012015-05-04 23:15:15 +0000261 gray-scale intensity of the image, into the alpha channel, converting
262 a gray-scale mask into a transparent shaped mask ready to be colored
cristyb2cad532015-05-16 13:02:45 +0000263 appropriately. The color channels are not modified. </dd>
cristyd2432012015-05-04 23:15:15 +0000264
cristyb2cad532015-05-16 13:02:45 +0000265 <dt>Shape</dt>
266 <dd>
267 As per 'Copy' but also colors the resulting shape mask with
cristyd2432012015-05-04 23:15:15 +0000268 the current background color. That is the RGB color channels is
269 replaced, with appropriate alpha shape.
cristyb2cad532015-05-16 13:02:45 +0000270 </dd>
cristyd2432012015-05-04 23:15:15 +0000271
cristyb2cad532015-05-16 13:02:45 +0000272 <dt>Remove</dt>
273 <dd>
cristyd2432012015-05-04 23:15:15 +0000274 Composite the image over the background color.
cristyb2cad532015-05-16 13:02:45 +0000275 </dd>
cristyd2432012015-05-04 23:15:15 +0000276
cristyb2cad532015-05-16 13:02:45 +0000277 <dt>Background</dt>
278 <dd>
cristyd2432012015-05-04 23:15:15 +0000279 Set any fully-transparent pixel to the background color, while leaving
280 it fully-transparent. This can make some image file formats, such as
281 PNG, smaller as the RGB values of transparent pixels are more uniform,
282 and thus can compress better.
cristyb2cad532015-05-16 13:02:45 +0000283 </dd>
284</dl>
cristyd2432012015-05-04 23:15:15 +0000285
286<p>Note that while the obsolete <code>+matte</code> operation was the
cristy82a2ff22015-05-12 16:41:32 +0000287same as "<code><a href="command-line-options.html#alpha">-alpha</a> Off</code>", the <code>
288&gt;-matte</code> operation was the same as "<code><a href="command-line-options.html#alpha">-alpha</a>
289Set</code>" and not "<code><a href="command-line-options.html#alpha">-alpha</a> On</code>". </p>
cristyd2432012015-05-04 23:15:15 +0000290
291
292<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000293 <h3 class="magick-header"><a id="annotate"></a>
cristy82a2ff22015-05-12 16:41:32 +0000294 -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>
cristyd2432012015-05-04 23:15:15 +0000296</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>
cristy82a2ff22015-05-12 16:41:32 +0000305control 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>
cristyd2432012015-05-04 23:15:15 +0000306
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
cristyb2cad532015-05-16 13:02:45 +0000314equation.</p>
315
316<p class="text-center"><img class="img-thumbnail" alt="annotate transformation" src="../images/annotate.png"></p>
cristyd2432012015-05-04 23:15:15 +0000317
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
cristy82a2ff22015-05-12 16:41:32 +0000320probably undesirable. Adding a <a href="command-line-options.html#gravity">-gravity</a> option in this
cristyd2432012015-05-04 23:15:15 +0000321case 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;">
cristy29dc8652015-05-12 16:26:21 +0000329 <h3 class="magick-header"><a id="antialias"></a>-antialias</h3>
cristyd2432012015-05-04 23:15:15 +0000330</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;">
cristy29dc8652015-05-12 16:26:21 +0000341 <h3 class="magick-header"><a id="append"></a>-append</h3>
cristyd2432012015-05-04 23:15:15 +0000342</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
cristy82a2ff22015-05-12 16:41:32 +0000352position relative to each other can be controlled by the current <a href="command-line-options.html#gravity">-gravity</a> setting. </p>
cristyd2432012015-05-04 23:15:15 +0000353
354
355<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000356 <h3 class="magick-header"><a id="attenuate"></a>-attenuate <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +0000357</div>
358
359<p class="magick-description">Lessen (or intensify) when adding noise to an image.</p>
360
361<p>If unset the value is equivalent to 1.0, or a maximum noise addition</p>
362
363<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000364 <h3 class="magick-header"><a id="authenticate"></a>-authenticate <var>password</var></h3>
cristyd2432012015-05-04 23:15:15 +0000365</div>
366
367<p class="magick-description">Decrypt a PDF with a password.</p>
368
369<p>Use this option to supply a <var>password</var> for decrypting
370a PDF that has been encrypted using Microsoft Crypto API (MSC API). The
371encrypting using the MSC API is not supported.</p>
372
373<p>For a different encryption method, see <a href="command-line-options.html#encipher">-encipher</a>
374and <a href="command-line-options.html#decipher">-decipher</a>. </p>
375
376
377<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000378 <h3 class="magick-header"><a id="auto-gamma"></a>-auto-gamma</h3>
cristyd2432012015-05-04 23:15:15 +0000379</div>
380
381<p class="magick-description">Automagically adjust gamma level of image.</p>
382
cristy82a2ff22015-05-12 16:41:32 +0000383<p>This calculates the mean values of an image, then applies a calculated <a href="command-line-options.html#gamma">-gamma</a> adjustment so that is the mean color exists in the
cristyd2432012015-05-04 23:15:15 +0000384image it will get a have a value of 50%. </p>
385
386<p>This means that any solid 'gray' image becomes 50% gray. </p>
387
388<p>This works well for real-life images with little or no extreme dark and
389light areas, but tend to fail for images with large amounts of bright sky or
390dark shadows. It also does not work well for diagrams or cartoon like images.
391</p>
392
cristy82a2ff22015-05-12 16:41:32 +0000393<p>It uses the <a href="command-line-options.html#channel">-channel</a> setting, (including the
cristyd2432012015-05-04 23:15:15 +0000394'<var>sync</var>' flag for channel synchronization), to determine which color
cristy82a2ff22015-05-12 16:41:32 +0000395values is used and modified. As the default <a href="command-line-options.html#channel">-channel</a> setting is '<var>RGB,sync</var>', channels are modified
cristyd2432012015-05-04 23:15:15 +0000396together by the same gamma value, preserving colors. </p>
397
398
399
400<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000401 <h3 class="magick-header"><a id="auto-level"></a>-auto-level</h3>
cristyd2432012015-05-04 23:15:15 +0000402</div>
403
404<p class="magick-description">Automagically adjust color levels of image.</p>
405
406<p>This is a 'perfect' image normalization operator. It finds the exact
cristy82a2ff22015-05-12 16:41:32 +0000407minimum and maximum color values in the image and then applies a <a href="command-line-options.html#level">-level</a> operator to stretch the values to the full range of
cristyd2432012015-05-04 23:15:15 +0000408values. </p>
409
410<p>The operator is not typically used for real-life images, image scans, or
411JPEG format images, as a single 'out-rider' pixel can set a bad min/max values
cristy82a2ff22015-05-12 16:41:32 +0000412for the <a href="command-line-options.html#level">-level</a> operation. On the other hand it is the
cristyd2432012015-05-04 23:15:15 +0000413right operator to use for color stretching gradient images being used to
414generate Color lookup tables, distortion maps, or other 'mathematically'
415defined images. </p>
416
cristy82a2ff22015-05-12 16:41:32 +0000417<p>The operator is very similar to the <a href="command-line-options.html#normalize">-normalize</a>, <a href="command-line-options.html#contrast-stretch">-contrast-stretch</a>, and <a href="command-line-options.html#linear-stretch">-linear-stretch</a> operators, but without 'histogram binning' or 'clipping'
418problems that these operators may have. That is <a href="command-line-options.html#auto-level">-auto-level</a> is the perfect or ideal version these operators. </p>
cristyd2432012015-05-04 23:15:15 +0000419
cristy82a2ff22015-05-12 16:41:32 +0000420<p>It uses the <a href="command-line-options.html#channel">-channel</a> setting, (including the
cristyd2432012015-05-04 23:15:15 +0000421special '<var>sync</var>' flag for channel synchronization), to determine
cristy82a2ff22015-05-12 16:41:32 +0000422which color values are used and modified. As the default <a href="command-line-options.html#channel">+channel</a> setting is '<var>RGB,sync</var>', the
cristyd2432012015-05-04 23:15:15 +0000423'<var>sync</var>' ensures that the color channels will are modified
424together by the same gamma value, preserving colors, and ignoring
425transparency. </p>
426
427
428<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000429 <h3 class="magick-header"><a id="auto-orient"></a>-auto-orient</h3>
cristyd2432012015-05-04 23:15:15 +0000430</div>
431
432<p class="magick-description">adjusts an image so that its orientation is suitable for viewing (i.e. top-left orientation).</p>
433
434<p>This operator reads and resets the EXIF image profile setting 'Orientation'
435and then performs the appropriate 90 degree rotation on the image to orient
436the image, for correct viewing. </p>
437
438<p>This EXIF profile setting is usually set using a gravity sensor in digital
439camera, however photos taken directly downward or upward may not have an
440appropriate value. Also images that have been orientation 'corrected' without
441reseting this setting, may be 'corrected' again resulting in a incorrect
cristy82a2ff22015-05-12 16:41:32 +0000442result. If the EXIF profile was previously stripped, the <a href="command-line-options.html#auto-orient">-auto-orient</a> operator will do nothing. </p>
cristyd2432012015-05-04 23:15:15 +0000443
444
445<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000446 <h3 class="magick-header"><a id="average"></a>-average</h3>
cristyd2432012015-05-04 23:15:15 +0000447</div>
448
449<p class="magick-description">Average a set of images.</p>
450
451<p>An error results if the images are not identically sized.</p>
452
453
454<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000455 <h3 class="magick-header"><a id="backdrop"></a>-backdrop</h3>
cristyd2432012015-05-04 23:15:15 +0000456</div>
457
458<p class="magick-description">Display the image centered on a backdrop.</p>
459
460<p>This backdrop covers the entire workstation screen and is useful for hiding
461other X window activity while viewing the image. The color of the backdrop is
462specified as the background color. The color is specified using the format
463described under the <a href="command-line-options.html#fill">-fill</a> option.</p>
464
465<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000466 <h3 class="magick-header"><a id="background"></a>-background <var>color</var></h3>
cristyd2432012015-05-04 23:15:15 +0000467</div>
468
469<p class="magick-description">Set the background color.</p>
470
cristy82a2ff22015-05-12 16:41:32 +0000471<p>The color is specified using the format described under the <a href="command-line-options.html#fill">-fill</a> option. The default background color (if none is
cristyd2432012015-05-04 23:15:15 +0000472specified or found in the image) is white.</p>
473
474<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000475 <h3 class="magick-header"><a id="bench"></a>-bench <var>iterations</var></h3>
cristyd2432012015-05-04 23:15:15 +0000476</div>
477
478<p class="magick-description">Measure performance.</p>
479
480<p>Repeat the entire command for the given number of <var>iterations</var> and report the user-time and elapsed time. For instance,
481consider the following command and its output. Modify the benchmark with the
482-duration to run the benchmark for a fixed number of seconds and -concurrent
483to run the benchmark in parallel (requires the OpenMP feature).</p>
484
485<pre>
cristyb2cad532015-05-16 13:02:45 +0000486-&gt; convert logo: -resize 1000% -bench 5 logo.png
cristyd2432012015-05-04 23:15:15 +0000487Performance[4]: 5i 0.875657ips 6.880u 0:05.710
488</pre>
489
490<p>In this example, 5 iterations were completed at 0.875657 iterations per
491second, using 4 threads and 6.88 seconds of the user's allotted time, for
492a total elapsed time of 5.71 seconds.</p>
493
494<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000495 <h3 class="magick-header"><a id="bias"></a>-bias <var>value</var>{<var>%</var>}</h3>
cristyd2432012015-05-04 23:15:15 +0000496</div>
497
498<p class="magick-description">Add bias when convolving an image.</p>
499
cristy82a2ff22015-05-12 16:41:32 +0000500<p>This option shifts the output of <a href="command-line-options.html#convolve">‑convolve</a> so that
cristyd2432012015-05-04 23:15:15 +0000501positive and negative results are relative to the specified bias value. </p>
502
503<p>This is important for non-HDRI compilations of ImageMagick when dealing
504with convolutions that contain negative as well as positive values. This is
505especially the case with convolutions involving high pass filters or edge
506detection. Without an output bias, the negative values are clipped at
507zero.</p>
508
cristy82a2ff22015-05-12 16:41:32 +0000509<p>When using an ImageMagick with the HDRI compile-time setting, <a href="command-line-options.html#bias">‑bias</a> is not needed, as ImageMagick is able to store/handle any
cristyd2432012015-05-04 23:15:15 +0000510negative results without clipping to the color value range
511(0..QuantumRange).</p>
512
cristy82a2ff22015-05-12 16:41:32 +0000513<p>See the discussion on HDRI implementations of ImageMagick on the page <a href="high-dynamic-range.html">High Dynamic-Range Images</a>. For more
514about HDRI go the ImageMagick <a href="http://www.imagemagick.org/Usage/basics/#hdri">Usage</a> pages or this
515<a href="http://en.wikipedia.org/wiki/High_dynamic_range_imaging">Wikipedia</a>
cristyd2432012015-05-04 23:15:15 +0000516entry. </p>
517
518<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000519 <h3 class="magick-header"><a id="black-point-compensation"></a>-black-point-compensation</h3>
cristyd2432012015-05-04 23:15:15 +0000520</div>
521
522<p class="magick-description">Use black point compensation.</p>
523
524<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000525 <h3 class="magick-header"><a id="black-threshold"></a>-black-threshold <var>value</var>{<var>%</var>}</h3>
cristyd2432012015-05-04 23:15:15 +0000526</div>
527
528<p class="magick-description">Force to black all pixels below the threshold while leaving all pixels at or above the threshold unchanged.</p>
529
530<p> The threshold value can be given as a percentage or as an absolute integer
531value within [0, <var>QuantumRange</var>] corresponding to the
cristy82a2ff22015-05-12 16:41:32 +0000532desired <a href="command-line-options.html#channel">‑channel</a> value. See <a href="command-line-options.html#threshold">‑threshold</a>for more details on thresholds and resulting values. </p>
cristyd2432012015-05-04 23:15:15 +0000533
534
535<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000536 <h3 class="magick-header"><a id="blend"></a>-blend <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +0000537</div>
538
539<p class="magick-description">blend an image into another by the given absolute value or percent.</p>
540
541<p>Blend will average the images together ('plus') according to the
542percentages given and each pixels transparency. If only a single percentage
543value is given it sets the weight of the composite or 'source' image, while
544the background image is weighted by the exact opposite amount. That is a
545<code>-blend 30%</code> merges 30% of the 'source' image with 70% of the
546'destination' image. Thus it is equivalent to <code>-blend 30x70%</code>.</p>
547
548
549<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000550 <h3 class="magick-header"><a id="blue-primary"></a>-blue-primary <var>x</var>,<var>y</var></h3>
cristyd2432012015-05-04 23:15:15 +0000551</div>
552
553<p class="magick-description">Set the blue chromaticity primary point.</p>
554
555<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000556 <h3 class="magick-header"><a id="blue-shift"></a>-blue-shift <var>factor</var></h3>
cristyd2432012015-05-04 23:15:15 +0000557</div>
558
559<p class="magick-description">simulate a scene at nighttime in the moonlight. Start with a factor of 1.5</p>
560
561<div style="margin: auto;">
562
563<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +0000564 <h3 class="magick-header"><a id="blur"></a>-blur <var>radius</var><br>-blur <var>radius</var>x<var>sigma</var></h3>
cristyd2432012015-05-04 23:15:15 +0000565</div>
566
567<p class="magick-description">Reduce image noise and reduce detail levels.</p>
568
569<p>Convolve the image with a Gaussian or normal distribution using the given
cristy82a2ff22015-05-12 16:41:32 +0000570<var>Sigma</var> value. The formula is:</p>
cristyd2432012015-05-04 23:15:15 +0000571
cristyb2cad532015-05-16 13:02:45 +0000572<p class="text-center"><img class="img-thumbnail" alt="gaussian distribution" width="243px" height="42px" src="../images/gaussian-blur.png"></p>
cristyd2432012015-05-04 23:15:15 +0000573
cristy82a2ff22015-05-12 16:41:32 +0000574<p>The <var>Sigma</var> value is the important argument, and
cristyd2432012015-05-04 23:15:15 +0000575determines the actual amount of blurring that will take place. </p>
576
cristy82a2ff22015-05-12 16:41:32 +0000577<p>The <var>Radius</var> is only used to determine the size of the
cristyd2432012015-05-04 23:15:15 +0000578array which will hold the calculated Gaussian distribution. It should be an
579integer. If not given, or set to zero, IM will calculate the largest possible
580radius that will provide meaningful results for the Gaussian distribution.
581</p>
582
cristy82a2ff22015-05-12 16:41:32 +0000583<p>The larger the <var>Radius</var> the slower the
584operation is. However too small a <var>Radius</var>, and sever
585aliasing effects may result. As a guideline, <var>Radius</var>
586should be at least twice the <var>Sigma</var> value, though three
cristyd2432012015-05-04 23:15:15 +0000587times will produce a more accurate result. </p>
588
589<p>This option differs from <a href="command-line-options.html#gaussian-blur">-gaussian-blur</a> simply
590by taking advantage of the separability properties of the distribution. Here
591we apply a single-dimensional Gaussian matrix in the horizontal direction,
592then repeat the process in the vertical direction.</p>
593
594<p>The <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting will determine how
595pixels which are outside the image proper are blurred into the final result.
596</p>
597
598
599<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000600 <h3 class="magick-header">-blur <var>Width</var>[x<var>Height</var>[+<var>Angle</var>]]</h3>
cristyd2432012015-05-04 23:15:15 +0000601</div>
602
603<p class="magick-description">Variably blur an image according to the overlay mapping.</p>
604
605<p>Each pixel in the overlaid region is replaced with an Elliptical Weighted
606Average (EWA) of the source image, scaled according to the grayscale
607mapping. </p>
608
cristy82a2ff22015-05-12 16:41:32 +0000609<p>The ellipse is weighted with sigma set to the given <var>Width</var> and <var>Height</var>. The <var>Height</var>
610defaults to the <var>Width</var> for a normal circular Gaussian
611weighting. The <var>Angle</var> will rotate the ellipse from
cristyd2432012015-05-04 23:15:15 +0000612horizontal clock-wise. </p>
613
614<p>The <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting will determine how
615pixels which are outside the image proper are blurred into the final result.
616</p>
617
618
619<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000620 <h3 class="magick-header"><a id="border"></a>-border <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +0000621</div>
622
623<p class="magick-description">Surround the image with a border of color. </p>
624
625<p>Set the width and height using the <var>size</var> portion of the
626<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
627ignored. </p>
628
629<p>As of IM 6.7.8-8, the <var>geometry</var> arguments behave as follows:</p>
630
cristyb2cad532015-05-16 13:02:45 +0000631<dl class="dl-horizontal">
632<dt><var>value</var></dt>
633<dd>value is added to both left/right and top/bottom</dd>
634<dt><var>value-x</var><kbd>x</kbd></dt>
635<dd>value-x is added only to left/right and top/bottom are unchanged</dd>
636<dt><kbd>x</kbd><var>value-y</var></dt>
637<dd>value-y is added only to top/bottom and left/right are unchanged</dd>
638<dt><var>value-x</var><kbd>x</kbd><var>value-y</var></dt>
639<dd>value-x is added to left/right and value-y added to top/bottom</dd>
640<dt><var>value-x</var><kbd>x</kbd>0</dt>
641<dd>value-x is added only to left/right and top/bottom are unchanged</dd>
642<dt>0<kbd>x</kbd><var>value-y</var></dt>
643<dd>value-y is added only to top/bottom and left/right are unchanged</dd>
644<dt><var>value</var>%</dt>
645<dd>value % of width is added to left/right and value % of height is added to top/bottom</dd>
646<dt><var>value-x</var><kbd>x</kbd>%</dt>
647<dd>value-x % of width is added to left/right and to top/bottom</dd>
648<dt>x<var>value-y</var>%</dt>
649<dd>value-y % of height is added to top/bottom and to left/right</dd>
650<dt><var>value-x</var>%<kbd>x</kbd><var>value-y</var>%</dt>
651<dd>value-x % of width is added to left/right and value-y % of height is added to top/bottom</dd>
652<dt><var>value-x</var>%<kbd>x</kbd>0%</dt>
653<dd>value-x % of width is added to left/right and top/bottom are unchanged</dd>
654<dt>0%<kbd>x</kbd><var>value-y</var>%</dt>
655<dd>value-y % of height is added to top/bottom and left/right are unchanged</dd>
656</dl>
cristyd2432012015-05-04 23:15:15 +0000657
cristy82a2ff22015-05-12 16:41:32 +0000658<p>Set the border color by preceding with the <a href="command-line-options.html#bordercolor">-bordercolor</a> setting.</p>
cristyd2432012015-05-04 23:15:15 +0000659
cristy82a2ff22015-05-12 16:41:32 +0000660<p>The <a href="command-line-options.html#border">-border</a> operation is affected by the current <a href="command-line-options.html#compose">-compose</a> setting and assumes that this is using the default
cristyd2432012015-05-04 23:15:15 +0000661'<code>Over</code>' composition method. It generates an image of the appropriate
662size colors by the current <a href="command-line-options.html#bordercolor">-bordercolor</a> before
663overlaying the original image in the center of this net image. This means that
664with the default compose method of '<code>Over</code>' any transparent parts may
665be replaced by the current <a href="command-line-options.html#bordercolor">-bordercolor</a> setting.</p>
666<p>See also the <a href="command-line-options.html#frame">-frame</a> option, which has more
667functionality.</p>
668
669<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000670 <h3 class="magick-header"><a id="bordercolor"></a>-bordercolor <var>color</var></h3>
cristyd2432012015-05-04 23:15:15 +0000671</div>
672
673<p class="magick-description">Set the border color.</p>
674
675<p>The color is specified using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p>
676
677<p>The default border color is <code>#DFDFDF</code>, <span style="background-color: #dfdfdf;">this shade of gray</span>.</p>
678
679<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000680 <h3 class="magick-header"><a id="borderwidth"></a>-borderwidth <var>geometry</var> </h3>
cristyd2432012015-05-04 23:15:15 +0000681</div>
682
683<p class="magick-description">Set the border width.</p>
684
685<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +0000686 <h3 class="magick-header"><a id="brightness-contrast"></a>-brightness-contrast <var>brightness</var><br>-brightness-contrast <var>brightness</var>{x<var>contrast</var>}{<var>%</var>}}</h3>
cristyd2432012015-05-04 23:15:15 +0000687</div>
688
689<p class="magick-description">Adjust the brightness and/or contrast of the image.</p>
690
691<p>Brightness and Contrast values apply changes to the input image. They are
692not absolute settings. A brightness or contrast value of zero means no change.
693The range of values is -100 to +100 on each. Positive values increase the
694brightness or contrast and negative values decrease the brightness or contrast.
695To control only contrast, set the brightness=0. To control only brightness,
696set contrast=0 or just leave it off.</p>
697
698<p>You may also use <a href="command-line-options.html#fill">-channel</a> to control which channels to
699apply the brightness and/or contrast change. The default is to apply the same
700transformation to all channels.</p>
701
702<p>Brightness and Contrast arguments are converted to offset and slope of a
703linear transform and applied
704using <a href="command-line-options.html#fill">-function polynomial "slope,offset"</a>.</p>
705
706<p>The slope varies from 0 at contrast=-100 to almost vertical at
707contrast=+100. For brightness=0 and contrast=-100, the result are totally
708midgray. For brightness=0 and contrast=+100, the result will approach but
709not quite reach a threshold at midgray; that is the linear transformation
710is a very steep vertical line at mid gray.</p>
711
712<p>Negative slopes, i.e. negating the image, are not possible with this
713function. All achievable slopes are zero or positive.</p>
714
715<p>The offset varies from -0.5 at brightness=-100 to 0 at brightness=0 to +0.5
716at brightness=+100. Thus, when contrast=0 and brightness=100, the result is
717totally white. Similarly, when contrast=0 and brightness=-100, the result is
718totally black.</p>
719
720<p>As the range of values for the arguments are -100 to +100, adding the '%'
721symbol is no different than leaving it off.</p>
722
723<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000724 <h3 class="magick-header"><a id="cache"></a>-cache <var>threshold</var></h3>
cristyd2432012015-05-04 23:15:15 +0000725</div>
726
cristy82a2ff22015-05-12 16:41:32 +0000727<p class="magick-description">(This option has been replaced by the <a href="command-line-options.html#limit">-limit</a> option).</p>
cristyd2432012015-05-04 23:15:15 +0000728
729<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +0000730 <h3 class="magick-header"><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>
cristyd2432012015-05-04 23:15:15 +0000731</div>
732
733<p class="magick-description">Canny edge detector uses a multi-stage algorithm to detect a wide range of edges in the image.</p>
734
735<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>
736
737<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000738 <h3 class="magick-header"><a id="caption"></a>-caption <var>string</var></h3>
cristyd2432012015-05-04 23:15:15 +0000739</div>
740
741<p class="magick-description">Assign a caption to an image.</p>
742
743<p>This option sets the caption meta-data of an image read in after this
744option has been given. To modify a caption of images already in memory use
745"<code><a href="command-line-options.html#set">-set</a> caption</code>". </p>
746
cristy82a2ff22015-05-12 16:41:32 +0000747<p>The caption can contain special format characters listed in the <a href="escape.html">Format and
cristyd2432012015-05-04 23:15:15 +0000748Print 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
cristy29dc8652015-05-12 16:26:21 +0000761<pre>
762-caption "%m:%f %wx%h" bird.miff
763</pre>
cristyd2432012015-05-04 23:15:15 +0000764
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;">
cristy29dc8652015-05-12 16:26:21 +0000771 <h3 class="magick-header"><a id="cdl"></a>-cdl <var>filename</var></h3>
cristyd2432012015-05-04 23:15:15 +0000772</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
778<pre>
779&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;
792</pre>
793
794<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000795 <h3 class="magick-header"><a id="channel"></a>-channel <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +0000796</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>
cristy29dc8652015-05-12 16:26:21 +0000813<pre>
814-channel Red,Blue
815</pre>
cristyd2432012015-05-04 23:15:15 +0000816<p>or you can use the short hand form</p>
cristy29dc8652015-05-12 16:26:21 +0000817<pre>
818-channel RB
819</pre>
cristyd2432012015-05-04 23:15:15 +0000820
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
cristy82a2ff22015-05-12 16:41:32 +0000826<br>
cristyd2432012015-05-04 23:15:15 +0000827
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 behaviour 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
cristyd2432012015-05-04 23:15:15 +0000859<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
cristy82a2ff22015-05-12 16:41:32 +0000863(depending on the operation being applied). The 'plus' form <a href="command-line-options.html#channel">+channel</a> will reset the value back to this default. </p>
cristyd2432012015-05-04 23:15:15 +0000864
cristy82a2ff22015-05-12 16:41:32 +0000865<p>Options that are affected by the <a href="command-line-options.html#channel">-channel</a> setting
cristyd2432012015-05-04 23:15:15 +0000866include the following.
867
868<a href="command-line-options.html#auto-gamma">-auto-gamma</a>,
869<a href="command-line-options.html#auto-level">-auto-level</a>,
870<a href="command-line-options.html#black-threshold">-black-threshold</a>,
871<a href="command-line-options.html#blur">-blur</a>,
872<a href="command-line-options.html#clamp">-clamp</a>,
873<a href="command-line-options.html#clut">-clut</a>,
874<a href="command-line-options.html#combine">-combine</a>,
875<a href="command-line-options.html#composite">-composite</a> (Mathematical compose methods only),
876<a href="command-line-options.html#convolve">-convolve</a>,
877<a href="command-line-options.html#contrast-stretch">-contrast-stretch</a>,
878<a href="command-line-options.html#evaluate">-evaluate</a>,
879<a href="command-line-options.html#function">-function</a>,
880<a href="command-line-options.html#fx">-fx</a>,
881<a href="command-line-options.html#gaussian-blur">-gaussian-blur</a>,
882<a href="command-line-options.html#hald-clut">-hald-clut</a>,
883<a href="command-line-options.html#motion-blur">-motion-blur</a>,
884<a href="command-line-options.html#morphology">-morphology</a>,
885<a href="command-line-options.html#negate">-negate</a>,
886<a href="command-line-options.html#normalize">-normalize</a>,
887<a href="command-line-options.html#ordered-dither">-ordered-dither</a>,
888<a href="command-line-options.html#radial-blur">-radial-blur</a>,
889<a href="command-line-options.html#random-threshold">-random-threshold</a>,
890<a href="command-line-options.html#separate">-separate</a>,
891<a href="command-line-options.html#threshold">-threshold</a>, and
892<a href="command-line-options.html#white-threshold">-white-threshold</a>.
893</p>
894
cristy82a2ff22015-05-12 16:41:32 +0000895<p>Warning, some operators behave differently when the <a href="command-line-options.html#channel">+channel</a> default setting is in effect, verses ANY user defined <a href="command-line-options.html#channel">-channel</a> setting (including the equivalent of the
cristyd2432012015-05-04 23:15:15 +0000896default). These operators have yet to be made to understand the newer 'Sync'
897flag. </p>
898
899<p>For example <a href="command-line-options.html#threshold">-threshold</a> will by default gray-scale
cristy82a2ff22015-05-12 16:41:32 +0000900the image before thresholding, if no <a href="command-line-options.html#channel">-channel</a> setting
cristyd2432012015-05-04 23:15:15 +0000901has been defined. This is not 'Sync flag controlled, yet. </p>
902
cristy82a2ff22015-05-12 16:41:32 +0000903<p>Also some operators such as <a href="command-line-options.html#blur">-blur</a>, <a href="command-line-options.html#gaussian-blur">-gaussian-blur</a>, will modify their handling of the
904color channels if the '<code>alpha</code>' channel is also enabled by <a href="command-line-options.html#channel">-channel</a>. Generally this done to ensure that
cristyd2432012015-05-04 23:15:15 +0000905fully-transparent colors are treated as being fully-transparent, and thus any
906underlying 'hidden' color has no effect on the final results. Typically
907resulting in 'halo' effects. The newer <a href="command-line-options.html#morphology">-morphology</a>
908convolution equivalents however does have a understanding of the 'Sync' flag
909and will thus handle transparency correctly by default. </p>
910
911<p>As a alpha channel is optional within images, some operators will read the
912color channels of an image as a greyscale alpha mask, when the image has no
cristy82a2ff22015-05-12 16:41:32 +0000913alpha channel present, and the <a href="command-line-options.html#channel">-channel</a> setting tells
914the operator to apply the operation using alpha channels. The <a href="command-line-options.html#clut">-clut</a> operator is a good example of this. </p>
cristyd2432012015-05-04 23:15:15 +0000915
916
917
918<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000919 <h3 class="magick-header"><a id="charcoal"></a>-charcoal <var>factor</var></h3>
cristyd2432012015-05-04 23:15:15 +0000920</div>
921
922<p class="magick-description">Simulate a charcoal drawing.</p>
923
924<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000925 <h3 class="magick-header"><a id="chop"></a>-chop <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +0000926</div>
927
928<p class="magick-description">Remove pixels from the interior of an image.</p>
929
930<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>
931and <var>height</var> given in the of the <var>size</var>
932portion of the <var>geometry</var> argument give the number of
933columns and rows to remove. The <var>offset</var> portion of
934the <var>geometry</var> argument is influenced by
935a <a href="command-line-options.html#gravity">-gravity</a> setting, if present.</p>
936
937<p>The <a href="command-line-options.html#chop">-chop</a> option removes entire rows and columns,
938and moves the remaining corner blocks leftward and upward to close the gaps.</p>
939
940<p>While it can remove internal rows and columns of pixels, it is more
941typically used with as <a href="command-line-options.html#gravity">-gravity</a> setting and zero
cristy82a2ff22015-05-12 16:41:32 +0000942offsets so as to remove a single edge from an image. Compare this to <a href="command-line-options.html#shave">-shave</a> which removes equal numbers of pixels from oppisite
cristyd2432012015-05-04 23:15:15 +0000943sides of the image. </p>
944
cristy82a2ff22015-05-12 16:41:32 +0000945<p>Using <a href="command-line-options.html#chop">-chop</a> effectively undoes the results of a <a href="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>
cristyd2432012015-05-04 23:15:15 +0000946
947<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000948 <h3 class="magick-header"><a id="clamp"></a>-clamp</h3>
cristyd2432012015-05-04 23:15:15 +0000949</div>
950
951<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>
952
953<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000954 <h3 class="magick-header"><a id="clip"></a>-clip</h3>
cristyd2432012015-05-04 23:15:15 +0000955</div>
956
957<p class="magick-description">Apply the clipping path if one is present.</p>
958
959<p>If a clipping path is present, it is applied to subsequent operations.</p>
960
961<p>For example, in the command</p>
962
963<pre>
964convert cockatoo.tif -clip -negate negated.tif
965</pre>
966
967<p>only the pixels within the clipping path are negated.</p>
968
969<p>The <a href="command-line-options.html#clip">-clip</a> feature requires SVG support. If the SVG
970delegate library is not present, the option is ignored.</p>
971
972<p>Use <a href="command-line-options.html#clip">+clip</a> to disable clipping for subsequent operations.</p>
973
974<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000975 <h3 class="magick-header"><a id="clip-mask"></a>-clip-mask</h3>
cristyd2432012015-05-04 23:15:15 +0000976</div>
977
978<p class="magick-description">Clip the image as defined by this mask.</p>
979
980<p>Use the alpha channel of the current image as a mask. Any areas that is
981white is not modified by any of the 'image processing operators' that follow,
982until the mask is removed. Pixels in the black areas of the clip mask are
983modified per the requirements of the operator. </p>
984
985<p>In some ways this is similar to (though not the same) as defining
cristy82a2ff22015-05-12 16:41:32 +0000986a rectangular <a href="command-line-options.html#region">-region</a>, or using the negative of the
987mask (third) image in a three image <a href="command-line-options.html#composite">-composite</a>,
cristyd2432012015-05-04 23:15:15 +0000988operation. </p>
989
990<p>Use <a href="command-line-options.html#clip-mask">+clip-mask</a> to disable clipping for subsequent operations.</p>
991
992<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000993 <h3 class="magick-header"><a id="clip-path"></a>-clip-path <var>id</var></h3>
cristyd2432012015-05-04 23:15:15 +0000994</div>
995
996<p class="magick-description">Clip along a named path from the 8BIM profile.</p>
997
998<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>
999
1000<p>Use <a href="command-line-options.html#clip-path">+clip-path</a> to disable clipping for subsequent operations.</p>
1001
1002<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001003 <h3 class="magick-header"><a id="clone"></a>-clone <var>index(s)</var></h3>
cristyd2432012015-05-04 23:15:15 +00001004</div>
1005
1006<p class="magick-description">make a clone of an image (or images).</p>
1007
1008<p>Inside parenthesis (where the operator is normally used) it will make a
1009clone of the images from the last 'pushed' image sequence, and adds them to
1010the end of the current image sequence. Outside parenthesis
1011(not recommended) it clones the images from the current image sequence. </p>
1012
1013<p>Specify the image by its index in the sequence. The first image is index
10140. Negative indexes are relative to the end of the sequence; for
1015example, <code>−1</code>
1016represents the last image of the sequence. Specify a range of images with a
1017dash (e.g. <code>0−4</code>). Separate multiple indexes with commas but no
1018spaces (e.g. <code>0,2,5</code>). A value of '<code>0−−1</code> will
1019effectively clone all the images. </p>
1020
1021<p>The <a href="command-line-options.html#clone">+clone</a> will simply make a copy of the last image
1022in the image sequence, and is thus equivalent to using a argument of
1023'<code>−1</code>'. </p>
1024
1025<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001026 <h3 class="magick-header"><a id="clut"></a>-clut</h3>
cristyd2432012015-05-04 23:15:15 +00001027</div>
1028
1029<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>
1030
1031<p>The second (LUT) image is ordinarily a gradient image containing the
1032histogram mapping of how each channel should be modified. Typically it is a
1033either a single row or column image of replacement color values. If larger
1034than a single row or column, values are taken from a diagonal line from
1035top-left to bottom-right corners.</p>
1036
cristy82a2ff22015-05-12 16:41:32 +00001037<p>The lookup is further controlled by the <a href="command-line-options.html#interpolate">-interpolate</a> setting, which is especially handy for an
cristyd2432012015-05-04 23:15:15 +00001038LUT which is not the full length needed by the ImageMagick installed Quality
1039(Q) level. Good settings for this are the '<code>bilinear</code>' and
1040'<code>bicubic</code>' interpolation settings, which give smooth color
1041gradients, and the '<code>integer</code>' setting for a direct, unsmoothed
1042lookup of color values. </p>
1043
1044<p>This operator is especially suited to replacing a grayscale image with a
1045specific color gradient from the CLUT image. </p>
1046
1047<p>Only the channel values defined by the <a href="command-line-options.html#channel">-channel</a>
cristy82a2ff22015-05-12 16:41:32 +00001048setting will have their values replaced. In particular, since the default <a href="command-line-options.html#channel">-channel</a> setting is <code>RGB</code>, this means that
1049transparency (alpha/matte channel) is not affected, unless the <a href="command-line-options.html#channel">-channel</a> setting is modified. When the alpha channel is
1050set, it is treated by the <a href="command-line-options.html#clut">-clut</a> operator in the same way
cristyd2432012015-05-04 23:15:15 +00001051as the other channels, implying that alpha/matte values are replaced using the
1052alpha/matte values of the original image. </p>
1053
1054<p>If either the image being modified, or the lookup image, contains no
cristy82a2ff22015-05-12 16:41:32 +00001055transparency (i.e. <a href="command-line-options.html#alpha">-alpha</a> is turned 'off') but the <a href="command-line-options.html#channel">-channel</a> setting includes alpha replacement, then it is
cristyd2432012015-05-04 23:15:15 +00001056assumed that image represents a gray-scale gradient which is used for the
1057replacement alpha values. That is you can use a gray-scale CLUT image to
1058adjust a existing images alpha channel, or you can color a gray-scale image
1059using colors form CLUT containing the desired colors, including transparency.
1060</p>
1061
cristy82a2ff22015-05-12 16:41:32 +00001062<p>See also <a href="command-line-options.html#hald-clut">-hald-clut</a> which replaces colors
cristyd2432012015-05-04 23:15:15 +00001063according to the lookup of the full color RGB value from a 2D representation
1064of a 3D color cube. </p>
1065
1066
1067<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001068 <h3 class="magick-header"><a id="coalesce"></a>-coalesce</h3>
cristyd2432012015-05-04 23:15:15 +00001069</div>
1070
1071<p class="magick-description">Fully define the look of each frame of an GIF animation sequence, to form a 'film strip' animation.</p>
1072
1073<p>Overlay each image in an image sequence according to
1074its <a href="command-line-options.html#dispose">-dispose</a> meta-data, to reproduce the look of
1075an animation at each point in the animation sequence. All images should be
1076the same size, and are assigned appropriate GIF disposal settings for the
1077animation to continue working as expected as a GIF animation. Such frames
1078are more easily viewed and processed than the highly optimized GIF overlay
1079images. </p>
1080
1081<p>The animation can be re-optimized after processing using
1082the <a href="command-line-options.html#layers">-layers</a> method '<code>optimize</code>', although
1083there is no guarantee that the restored GIF animation optimization is
1084better than the original. </p>
1085
1086
1087<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001088 <h3 class="magick-header"><a id="colorize"></a>-colorize <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00001089</div>
1090
cristy82a2ff22015-05-12 16:41:32 +00001091<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>
cristyd2432012015-05-04 23:15:15 +00001092
1093<p>Specify the amount of colorization as a percentage. Separate colorization
1094values can be applied to the red, green, and blue channels of the image with
1095a comma-delimited list of colorization
1096values (e.g., <code>-colorize 0,0,50</code>).</p>
1097
1098<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001099 <h3 class="magick-header"><a id="colormap"></a>-colormap <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00001100</div>
1101
1102<p class="magick-description">Define the colormap type.</p>
1103
1104<p>The <var>type</var> can be <code>shared</code> or <code>private</code>.</p>
1105
1106<p>This option only applies when the default X server visual
1107is <code>PseudoColor</code> or <code>GrayScale</code>. Refer
1108to <a href="command-line-options.html#visual">-visual</a> for more details. By default,
1109a shared colormap is allocated. The image shares colors with
1110other X clients. Some image colors could be approximated,
1111therefore your image may look very different than intended.
1112If <code>private</code> is chosen, the image colors appear exactly
1113as they are defined. However, other clients may go <var>technicolor</var>
1114when the image colormap is installed.</p>
1115
1116<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001117 <h3 class="magick-header"><a id="colors"></a>-colors <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00001118</div>
1119
1120<p class="magick-description">Set the preferred number of colors in the image.</p>
1121
1122<p>The actual number of colors in the image may be less than your request,
1123but never more. Note that this a color reduction option. Images with fewer
1124unique colors than specified by <var>value</var> will have any
1125duplicate or unused colors removed. The ordering of an existing color
1126palette may be altered. When converting an image from color to grayscale,
1127it is more efficient to convert the image to the gray colorspace before
1128reducing the number of colors. Refer to
1129the <a href="quantize.html">
1130color reduction algorithm</a> for more details.</p>
1131
1132<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001133 <h3 class="magick-header"><a id="color-matrix"></a>-color-matrix <var>matrix</var></h3>
cristyd2432012015-05-04 23:15:15 +00001134</div>
1135
1136<p class="magick-description">apply color correction to the image.</p>
1137
1138<p>This option permits saturation changes, hue rotation, luminance to alpha,
1139and various other effects. Although variable-sized transformation matrices
1140can be used, typically one uses a 5x5 matrix for an RGBA image and a 6x6
1141for CMYKA (or RGBA with offsets). The matrix is similar to those used by
1142Adobe Flash except offsets are in column 6 rather than 5 (in support of
1143CMYKA images) and offsets are normalized (divide Flash offset by 255).</p>
1144
1145<p>As an example, to add contrast to an image with offsets, try this command:</p>
1146
1147<pre>
cristy29dc8652015-05-12 16:26:21 +00001148convert kittens.jpg -color-matrix \
1149 " 1.5 0.0 0.0 0.0, 0.0, -0.157 \
1150 0.0 1.5 0.0 0.0, 0.0, -0.157 \
1151 0.0 0.0 1.5 0.0, 0.0, -0.157 \
1152 0.0 0.0 0.0 1.0, 0.0, 0.0 \
1153 0.0 0.0 0.0 0.0, 1.0, 0.0 \
1154 0.0 0.0 0.0 0.0, 0.0, 1.0" kittens.png
cristyd2432012015-05-04 23:15:15 +00001155</pre>
1156<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001157 <h3 class="magick-header"><a id="colorspace"></a>-colorspace <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00001158</div>
1159
1160<p class="magick-description">Set the image colorspace.</p>
1161
1162<p>Choices are:</p>
1163
1164<pre>
cristy29dc8652015-05-12 16:26:21 +00001165CMY CMYK Gray HCL
1166HCLp HSB HSI HSL
1167HSV HWB Lab LCHab
1168LCHuv LMS Log Luv
1169OHTA Rec601YCbCr Rec709YCbCr RGB
1170scRGB sRGB Transparent xyY
1171XYZ YCbCr YCC YDbDr
1172YIQ YPbPr YUV
cristyd2432012015-05-04 23:15:15 +00001173</pre>
1174
1175<p>To print a complete list of colorspaces, use <a href="command-line-options.html#list">-list colorspace</a>.</p>
1176
1177<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>
1178
1179<table class="table table-condensed table-striped">
1180 <caption>Conversion of RGB to Other Color Spaces</caption>
1181 <tr><th valign="middle">CMY</th></tr>
1182 <tr><td valign="middle">C=<var>QuantumRange</var>−R</td></tr>
1183 <tr><td valign="middle">M=<var>QuantumRange</var>−G</td></tr>
1184 <tr><td valign="middle">Y=<var>QuantumRange</var>−B</td></tr>
1185 <tr><th valign="middle">CMYK — starts with CMY from above</th></tr>
1186 <tr><td valign="middle">K=min(C,Y,M)</td></tr>
1187 <tr><td valign="middle">C=<var>QuantumRange</var>*(C−K)/(<var>QuantumRange</var>−K)</td></tr>
1188 <tr><td valign="middle">M=<var>QuantumRange</var>*(M−K)/(<var>QuantumRange</var>−K)</td></tr>
1189 <tr><td valign="middle">Y=<var>QuantumRange</var>*(Y−K)/(<var>QuantumRange</var>−K)</td></tr>
1190
1191 <tr><th valign="middle">Gray</th></tr>
1192 <tr><td valign="middle">Gray = 0.298839*R+0.586811*G+0.114350*B</td></tr>
1193
1194 <tr><th valign="middle">HSB — Hue, Saturation, Brightness; like a cone peak downward</th></tr>
1195 <tr><td valign="middle">H=angle around perimeter (0 to 360 deg); H=0 is red; increasing angles toward green</td></tr>
1196 <tr><td valign="middle">S=distance from axis outward</td></tr>
1197 <tr><td valign="middle">B=distance along axis from bottom upward; B=max(R,G,B); <var>intensity-like</var></td></tr>
1198
1199 <tr><th valign="middle">HSL — Hue, Saturation, Lightness; like a double cone end-to-end with peaks at very top and bottom</th></tr>
1200 <tr><td valign="middle">H=angle around perimeter (0 to 360 deg); H=0 is red; increasing angles toward green</td></tr>
1201 <tr><td valign="middle">S=distance from axis outward</td></tr>
1202 <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>
1203
1204 <tr><th valign="middle">HWB — Hue, Whiteness, Blackness</th></tr>
1205 <tr><td valign="middle">Hue (complicated equation)</td></tr>
1206 <tr><td valign="middle">Whiteness (complicated equation)</td></tr>
1207 <tr><td valign="middle">Blackness (complicated equation)</td></tr>
1208
1209 <tr><th valign="middle">LAB</th></tr>
1210 <tr><td valign="middle">L (complicated equation relating X,Y,Z)</td></tr>
1211 <tr><td valign="middle">A (complicated equation relating X,Y,Z)</td></tr>
1212 <tr><td valign="middle">B (complicated equation relating X,Y,Z)</td></tr>
1213
1214 <tr><th valign="middle">LOG</th></tr>
1215 <tr><td valign="middle">I1 (complicated equation involving logarithm of R)</td></tr>
1216 <tr><td valign="middle">I2 (complicated equation involving logarithm of G)</td></tr>
1217 <tr><td valign="middle">I3 (complicated equation involving logarithm of B)</td></tr>
1218
1219 <tr><th valign="middle">OHTA — approximates principal components transformation</th></tr>
1220 <tr><td valign="middle">I1=0.33333*R+0.33334*G+0.33333*B; <var>intensity-like</var></td></tr>
1221 <tr><td valign="middle">I2=(0.50000*R+0.00000*G−0.50000*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1222 <tr><td valign="middle">I3=(−0.25000*R+0.50000*G−0.25000*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1223
1224 <tr><th valign="middle">Rec601Luma</th></tr>
1225 <tr><td valign="middle">Gray = 0.298839*R+0.586811*G+0.114350*B</td></tr>
1226
1227 <tr><th valign="middle">Rec601YCbCr</th></tr>
1228 <tr><td valign="middle">Y=0.2988390*R+0.5868110*G+0.1143500*B; <var>intensity-like</var></td></tr>
1229 <tr><td valign="middle">Cb=(−0.168736*R-0.331264*G+0.500000*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1230 <tr><td valign="middle">Cr=(0.500000*R−0.418688*G−0.081312*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1231
1232 <tr><th valign="middle">Rec709Luma</th></tr>
1233 <tr><td valign="middle">Gray=0.212656*R+0.715158*G+0.072186*B</td></tr>
1234
1235 <tr><th valign="middle">Rec709YCbCr</th></tr>
1236 <tr><td valign="middle">Y=0.212656*R+0.715158*G+0.072186*B; <var>intensity-like</var></td></tr>
1237 <tr><td valign="middle">Cb=(−0.114572*R−0.385428*G+0.500000*B)+(<var>QuantumRange</var>+1)/2</td></tr>
1238 <tr><td valign="middle">Cr=(0.500000*R−0.454153*G−0.045847*B)+(<var>QuantumRange</var>+1)/2</td></tr>
1239
1240 <tr><th valign="middle">sRGB</th></tr>
1241 <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>
1242 <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>
1243 <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>
1244
1245 <tr><th valign="middle">XYZ</th></tr>
1246 <tr><td valign="middle">X=0.4124564*R+0.3575761*G+0.1804375*B</td></tr>
1247 <tr><td valign="middle">Y=0.2126729*R+0.7151522*G+0.0721750*B</td></tr>
1248 <tr><td valign="middle">Z=0.0193339*R+0.1191920*G+0.9503041*B</td></tr>
1249
1250 <tr><th valign="middle">YCC</th></tr>
1251 <tr><td valign="middle">Y=(0.298839*R+0.586811*G+0.114350*B) (with complicated scaling); <var>intensity-like</var></td></tr>
1252 <tr><td valign="middle">C1=(−0.298839*R−0.586811*G+0.88600*B) (with complicated scaling)</td></tr>
1253 <tr><td valign="middle">C2=(0.70100*R−0.586811*G−0.114350*B) (with complicated scaling)</td></tr>
1254
1255 <tr><th valign="middle">YCbCr</th></tr>
1256 <tr><td valign="middle">Y=0.2988390*R+0.5868110*G+0.1143500*B; <var>intensity-like</var></td></tr>
1257 <tr><td valign="middle">Cb=(−0.168736*R−0.331264*G+0.500000*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1258 <tr><td valign="middle">Cr=(0.500000*R−0.418688*G−0.081312*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1259
1260 <tr><th valign="middle">YIQ</th></tr>
1261 <tr><td valign="middle">Y=0.298839*R+0.586811*G+0.114350*B; <var>intensity-like</var></td></tr>
1262 <tr><td valign="middle">I=(0.59600*R−0.27400*G−0.32200*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1263 <tr><td valign="middle">Q=(0.21100*R−0.52300*G+0.31200*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1264
1265 <tr><th valign="middle">YPbPr</th></tr>
1266 <tr><td valign="middle">Y=0.2988390*R+0.5868110*G+0.1143500*B; <var>intensity-like</var></td></tr>
1267 <tr><td valign="middle">Pb=(−0.168736*R−0.331264*G+0.500000*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1268 <tr><td valign="middle">Pr=(0.500000*R−0.418688*G−0.081312*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1269
1270 <tr><th valign="middle">YUV</th></tr>
1271 <tr><td valign="middle">Y=0.298839*R+0.586811*G+0.114350*B; <var>intensity-like</var></td></tr>
1272 <tr><td valign="middle">U=(−0.14740*R−0.28950*G+0.43690*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1273 <tr><td valign="middle">V=(0.61500*R−0.51500*G−0.10000*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1274</table>
1275
1276<p>Note the scRGB colorspace requires HDRI support otherwise it behaves just like linear RGB.</p>
1277
1278<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001279 <h3 class="magick-header"><a id="combine"></a>-combine</h3>
cristyd2432012015-05-04 23:15:15 +00001280</div>
1281
1282<p class="magick-description">Combine one or more images into a single image.</p>
1283
1284<p>The channels (previously set by <a href="command-line-options.html#channel">-channel</a>) of the
1285combined image are taken from the grayscale values of each image in the
1286sequence, in order. For the default -channel setting of <code>RGB</code>, this
1287means the first image is assigned to the <code>Red</code> channel, the second
1288to the <code>Green</code> channel, the third to the <code>Blue</code>.</p>
1289
cristy82a2ff22015-05-12 16:41:32 +00001290<p>This option can be thought of as the inverse to <a href="command-line-options.html#separate">-separate</a>, so long as the channel settings are the same.
cristyd2432012015-05-04 23:15:15 +00001291Thus, in the following example, the final image should be a copy of the
1292original. </p>
1293
1294<pre>
1295convert original.png -channel RGB -separate sepimage.png
1296convert sepimage-0.png sepimage-1.png sepimage-2.png -channel RGB \
1297 -combine imagecopy.png
1298</pre>
1299
1300<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001301 <h3 class="magick-header"><a id="comment"></a>-comment <var>string</var></h3>
cristyd2432012015-05-04 23:15:15 +00001302</div>
1303
1304<p class="magick-description">Embed a comment in an image.</p>
1305
1306<p>This option sets the comment meta-data of an image read in after this
1307option has been given. To modify a comment of images already in memory use
1308"<code><a href="command-line-options.html#set">-set</a> comment</code>". </p>
1309
cristy82a2ff22015-05-12 16:41:32 +00001310<p>The comment can contain special format characters listed in the <a href="escape.html">Format and
cristyd2432012015-05-04 23:15:15 +00001311Print Image Properties</a>. These attributes are expanded when the comment
1312is finally assigned to the individual images. </p>
1313
1314<p>If the first character of <var>string</var> is <var>@</var>, the image comment is read from a file titled by the
1315remaining characters in the string. Comments read in from a file are literal;
1316no embedded formatting characters are recognized.</p>
1317
1318<p>Comment meta-data are not visible on the image itself. To do that use the
1319<a href="command-line-options.html#annotate">-annotate</a> or <a href="command-line-options.html#draw">-draw</a> options
1320instead.</p>
1321
1322<p>For example,</p>
1323
cristy29dc8652015-05-12 16:26:21 +00001324<pre>
1325-comment "%m:%f %wx%h" bird.miff
1326</pre>
cristyd2432012015-05-04 23:15:15 +00001327
1328<p>produces an image comment of <code>MIFF:bird.miff 512x480</code> (assuming
1329that the image <code>bird.miff</code> has a width of 512 and a height of
1330480.</p>
1331
1332<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001333 <h3 class="magick-header"><a id="compare"></a>-compare</h3>
cristyd2432012015-05-04 23:15:15 +00001334</div>
1335
1336<p class="magick-description">mathematically and visually annotate the difference between an image and its reconstruction</p>
1337
1338<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>
1339
1340<pre>
cristy82a2ff22015-05-12 16:41:32 +00001341convert image.png reference.png -metric RMSE -compare \ <br> difference.png
cristyd2432012015-05-04 23:15:15 +00001342</pre>
1343
1344<p>To get the metric value use the string format "%[distortion]".</p>
1345
1346<pre>
1347convert image.png reference.png -metric RMSE -compare -format \
1348 "%[distortion]" info:
1349</pre>
1350
1351<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001352 <h3 class="magick-header"><a id="complex"></a>-complex <var>operator</var></h3>
cristyd2432012015-05-04 23:15:15 +00001353</div>
1354
1355<p class="magick-description">perform complex mathematics on an image sequence</p>
1356
1357Choose from these operators:
1358
1359<pre>
cristy29dc8652015-05-12 16:26:21 +00001360add
1361conjugate
1362divide
1363magnuitude-phase
1364multiply
1365real-imaginary
1366subtract
cristyd2432012015-05-04 23:15:15 +00001367</pre>
1368
1369<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>
1370
1371<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001372 <h3 class="magick-header"><a id="compose"></a>-compose <var>operator</var></h3>
cristyd2432012015-05-04 23:15:15 +00001373</div>
1374
1375<p class="magick-description">Set the type of image composition.</p>
1376
1377<p>See <a href="compose.html">Alpha Compositing</a> for
1378a detailed discussion of alpha compositing.</p>
1379
1380<p>This setting effects image processing operators that merge two (or more)
1381images together in some way. This includes the operators,
1382<a href="command-line-options.html#composite">-compare</a>,
1383<a href="command-line-options.html#composite">-composite</a>,
1384<a href="command-line-options.html#layers">-layers</a> composite,
1385<a href="command-line-options.html#flatten">-flatten</a>,
1386<a href="command-line-options.html#mosaic">-mosaic</a>,
1387<a href="command-line-options.html#layers">-layers</a> merge,
1388<a href="command-line-options.html#border">-border</a>,
1389<a href="command-line-options.html#frame">-frame</a>,
1390and <a href="command-line-options.html#extent">-extent</a>. </p>
1391
1392<p>It is also one of the primary options for the "<code>composite</code>"
1393command. </p>
1394
1395
1396<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001397 <h3 class="magick-header"><a id="composite"></a>-composite</h3>
cristyd2432012015-05-04 23:15:15 +00001398</div>
1399
1400<p class="magick-description">Perform alpha composition on two images and an optional mask</p>
1401
1402<p>Take the first image 'destination' and overlay the second 'source' image
1403according to the current <a href="command-line-options.html#compose">-compose</a> setting. The location
cristy82a2ff22015-05-12 16:41:32 +00001404of the 'source' or 'overlay' image is controlled according to <a href="command-line-options.html#geometry">-geometry</a>, and <a href="command-line-options.html#geometry">-geometry</a>
cristyd2432012015-05-04 23:15:15 +00001405settings. </p>
1406
1407<p>If a third image is given this is treated as a gray-scale blending 'mask' image
1408relative to the first 'destination' image. This mask is blended with the
1409source image. However for the '<code>displace</code>' compose method, the
1410mask is used to provide a separate Y-displacement image instead. </p>
1411
1412<p>If a <a href="command-line-options.html#compose">-compose</a> method requires extra numerical
cristy82a2ff22015-05-12 16:41:32 +00001413arguments or flags these can be provided by setting the <a href="command-line-options.html#set">-set</a> '<code>option:compose:args</code>'
cristyd2432012015-05-04 23:15:15 +00001414appropriately for the compose method. </p>
1415
1416<p>Some <a href="command-line-options.html#compose">-compose</a> methods can modify the 'destination'
cristy82a2ff22015-05-12 16:41:32 +00001417image outside the overlay area. You can disable this by setting the special <a href="command-line-options.html#set">-set</a> '<code>option:compose:outside-overlay</code>'
cristyd2432012015-05-04 23:15:15 +00001418to '<code>false</code>'. </p>
1419
1420<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>
1421
1422
1423<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001424 <h3 class="magick-header"><a id="compress"></a>-compress <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00001425</div>
1426
1427<p class="magick-description">Use pixel compression specified by <var>type</var> when writing the image.</p>
1428
cristy82a2ff22015-05-12 16:41:32 +00001429<p>Choices are: <code>None</code>, <code>BZip</code>, <code>Fax</code>, <code>Group4</code>, <code>JPEG</code>, <code>JPEG2000</code>, <code>Lossless</code>, <code>LZW</code>, <code>RLE</code> or <code>Zip</code>.</p>
cristyd2432012015-05-04 23:15:15 +00001430
1431<p>To print a complete list of compression types, use <a href="command-line-options.html#list">-list
1432compress</a>.</p>
1433
1434<p>Specify <a href="command-line-options.html#compress">+compress</a> to store the binary image in an
1435uncompressed format. The default is the compression type of the specified
1436image file.</p>
1437
1438<p>If <code>LZW</code> compression is specified but LZW compression has not been
1439enabled, the image data is written in an uncompressed LZW format that can be
1440read by LZW decoders. This may result in larger-than-expected GIF files.</p>
1441
1442<p><code>Lossless</code> refers to lossless JPEG, which is only available if the
1443JPEG library has been patched to support it. Use of lossless JPEG is generally
1444not recommended.</p>
1445
1446<p>
1447When writing an ICO file, you may request that the images be encoded in
1448PNG format, by specifying <code>Zip</code> compression.</p>
1449
1450<p>
1451When writing a JNG file, specify <code>Zip</code> compression to request that
1452the alpha channel be encoded in PNG "IDAT" format, or <code>JPEG</code>
1453to request that it be encoded in JPG "JDAA" format.</p>
1454
1455<p>Use the <a href="command-line-options.html#quality">-quality</a> option to set the compression level
1456to be used by JPEG, PNG, MIFF, and MPEG encoders.
1457Use the <a href="command-line-options.html#sampling-factor">-sampling-factor</a> option to set the
1458sampling factor to be used by JPEG, MPEG, and YUV encoders for down-sampling
1459the chroma channels.</p>
1460
1461<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001462 <h3 class="magick-header"><a id="connected-components"></a>-connected-components <var>connectivity</var></h3>
cristyd2432012015-05-04 23:15:15 +00001463</div>
1464
1465<p class="magick-description">connected-components uniquely labeled, choose from 4 or 8 way connectivity.</p>
1466
cristy82a2ff22015-05-12 16:41:32 +00001467<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>
cristyd2432012015-05-04 23:15:15 +00001468
1469<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001470 <h3 class="magick-header"><a id="contrast"></a>-contrast</h3>
cristyd2432012015-05-04 23:15:15 +00001471</div>
1472
1473<p class="magick-description">Enhance or reduce the image contrast.</p>
1474
1475<p>This option enhances the intensity differences between the lighter and
1476darker elements of the image. Use <a href="command-line-options.html#contrast">-contrast</a> to enhance
1477the image or <a href="command-line-options.html#contrast">+contrast</a> to reduce the image
1478contrast.</p>
1479
1480<p>For a more pronounced effect you can repeat the option:</p>
1481
1482<pre>
1483convert rose: -contrast -contrast rose_c2.png
1484</pre>
1485
1486<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00001487 <h3 class="magick-header"><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>
cristyd2432012015-05-04 23:15:15 +00001488</div>
1489
1490<p class="magick-description">Increase the contrast in an image by <var>stretching</var> the range of intensity values.</p>
1491
1492<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
cristy82a2ff22015-05-12 16:41:32 +00001493<var>black-point %</var> pixels and white-out at most <var>white-point %</var> pixels.</p>
cristyd2432012015-05-04 23:15:15 +00001494
cristy82a2ff22015-05-12 16:41:32 +00001495<p>Prior to ImageMagick 6.4.7-0, <a href="command-line-options.html#contrast-stretch">-contrast-stretch</a> will black-out at most <var>black-point</var> pixels and white-out at most <var>total pixels
cristyd2432012015-05-04 23:15:15 +00001496minus 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>
1497
1498<p>Note that <code>-contrast-stretch 0</code> will modify the image such that
1499the 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
cristy82a2ff22015-05-12 16:41:32 +00001500clipping at either end. This is not the same as <a href="command-line-options.html#normalize">-normalize</a>, which is equivalent to <code>-contrast-stretch 0.15x0.05%</code> (or
cristyd2432012015-05-04 23:15:15 +00001501prior to ImageMagick 6.4.7-0, <code>-contrast-stretch 2%x99%</code>).</p>
1502
1503<p>Internally operator works by creating a histogram bin, and then uses that
1504bin to modify the image. As such some colors may be merged together when they
1505originally fell into the same 'bin'. </p>
1506
1507<p>All the channels are normalized in concert by the came amount so as to
cristy82a2ff22015-05-12 16:41:32 +00001508preserve color integrity, when the default <a href="command-line-options.html#channel">+channel</a>
1509setting is in use. Specifying any other <a href="command-line-options.html#channel">-channel</a>
cristyd2432012015-05-04 23:15:15 +00001510setting will normalize the RGB channels independently.</p>
1511
cristy82a2ff22015-05-12 16:41:32 +00001512<p>See also <a href="command-line-options.html#auto-level">-auto-level</a> for a 'perfect'
cristyd2432012015-05-04 23:15:15 +00001513normalization of mathematical images. </p>
1514
1515<p>This operator is under review for re-development. </p>
1516
1517
1518<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001519 <h3 class="magick-header"><a id="convolve"></a>-convolve <var>kernel</var></h3>
cristyd2432012015-05-04 23:15:15 +00001520</div>
1521
1522<p class="magick-description">Convolve an image with a user-supplied convolution kernel.</p>
1523
1524<p>The <var>kernel</var> is a matrix specified as
1525a comma-separated list of integers (with no spaces), ordered left-to right,
1526starting with the top row. Presently, only odd-dimensioned kernels are
1527supported, and therefore the number of entries in the specified <var>kernel</var> must be 3<sup>2</sup>=9, 5<sup>2</sup>=25,
15287<sup>2</sup>=49, etc. </p>
1529
cristy82a2ff22015-05-12 16:41:32 +00001530<p>Note that the <a href="command-line-options.html#convolve">‑convolve</a> operator supports the <a href="command-line-options.html#bias">‑bias</a> setting. This option shifts the convolution so that
cristyd2432012015-05-04 23:15:15 +00001531positive and negative results are relative to a user-specified bias value.
1532This is important for non-HDRI compilations of ImageMagick when dealing with
1533convolutions that contain negative as well as positive values. This is
1534especially the case with convolutions involving high pass filters or edge
1535detection. Without an output bias, the negative values is clipped at zero.
1536</p>
1537
cristy82a2ff22015-05-12 16:41:32 +00001538<p>When using an ImageMagick with the HDRI compile-time setting, <a href="command-line-options.html#bias">‑bias</a> is not needed, as ImageMagick is able to store/handle any
cristyd2432012015-05-04 23:15:15 +00001539negative results without clipping to the color value range (0..QuantumRange).
cristy82a2ff22015-05-12 16:41:32 +00001540See the discussion on HDRI implementations of ImageMagick on the page <a href="high-dynamic-range.html">High
1541Dynamic-Range Images</a>. For more about HDRI go the ImageMagick <a href="http://www.imagemagick.org/Usage/basics/#hdri">Usage</a> pages or this
cristyd2432012015-05-04 23:15:15 +00001542<a href="http://en.wikipedia.org/wiki/High_dynamic_range_imaging">Wikipedia</a>
1543entry. </p>
1544
1545
1546<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001547 <h3 class="magick-header"><a id="crop"></a>-crop <var>geometry</var>{<var>@</var>}{<var>!</var>}</h3>
cristyd2432012015-05-04 23:15:15 +00001548</div>
1549
1550<p class="magick-description">Cut out one or more rectangular regions of the image.</p>
1551
1552<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
1553
1554<p>The <var>width</var> and <var>height</var> of the <var>geometry</var> argument give the size of the image that remains
1555after cropping, and <var>x</var> and <var>y</var> in the
1556<var>offset</var> (if present) gives the location of the top left
1557corner of the cropped image with respect to the original image. To specify the
1558amount to be removed, use <a href="command-line-options.html#shave">-shave</a> instead.</p>
1559
1560<p>If the <var>x</var> and <var>y</var> offsets are
1561present, a single image is generated, consisting of the pixels from the
1562cropping region. The offsets specify the location of the upper left corner of
1563the cropping region measured downward and rightward with respect to the upper
1564left corner of the image. If the <a href="command-line-options.html#gravity">-gravity</a> option is
1565present with <code>NorthEast</code>, <code>East</code>, or <code>SouthEast</code>
1566gravity, it gives the distance leftward from the right edge of the image to
cristy82a2ff22015-05-12 16:41:32 +00001567the right edge of the cropping region. Similarly, if the <a href="command-line-options.html#gravity">-gravity</a> option is present with <code>SouthWest</code>,
cristyd2432012015-05-04 23:15:15 +00001568<code>South</code>, or <code>SouthEast</code> gravity, the distance is measured
1569upward between the bottom edges.</p>
1570
1571<p>If the <var>x</var> and <var>y</var> offsets are
1572omitted, a set of tiles of the specified geometry, covering the entire input
1573image, is generated. The rightmost tiles and the bottom tiles are smaller if
1574the specified geometry extends beyond the dimensions of the input image.</p>
1575
1576<p>You can add the <var>@</var> to the geometry argument to equally divide the image into the number of tiles generated.</p>
1577
1578<p>By adding a exclamation character flag to the geometry argument, the
1579cropped images virtual canvas page size and offset is set as if the
1580geometry argument was a viewport or window. This means the canvas page size
1581is set to exactly the same size you specified, the image offset set
1582relative top left corner of the region cropped. </p>
1583
1584<p>If the cropped image 'missed' the actual image on its virtual canvas, a
1585special single pixel transparent 'missed' image is returned, and a 'crop
1586missed' warning given. </p>
1587
cristy82a2ff22015-05-12 16:41:32 +00001588<p>It might be necessary to <a href="command-line-options.html#repage">+repage</a> the image prior to
cristyd2432012015-05-04 23:15:15 +00001589cropping the image to ensure the crop coordinate frame is relocated to the
1590upper-left corner of the visible image.
1591
cristy82a2ff22015-05-12 16:41:32 +00001592Similarly you may want to use <a href="command-line-options.html#repage">+repage</a> after cropping to
cristyd2432012015-05-04 23:15:15 +00001593remove the page offset that will be left behind. This is especially true when
1594you are going to write to an image format such as PNG that supports an image
1595offset.</p>
1596
1597<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001598 <h3 class="magick-header"><a id="cycle"></a>-cycle <var>amount</var></h3>
cristyd2432012015-05-04 23:15:15 +00001599</div>
1600
1601<p class="magick-description">displace image colormap by amount.</p>
1602
1603<p><var>Amount</var> defines the number of positions each
1604colormap entry is shifted.</p>
1605
1606
1607<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001608 <h3 class="magick-header"><a id="debug"></a>-debug <var>events</var></h3>
cristyd2432012015-05-04 23:15:15 +00001609</div>
1610
1611<p class="magick-description">enable debug printout.</p>
1612
1613<p>The <code>events</code> parameter specifies which events are to be logged. It
1614can be either <code>None</code>, <code>All</code>, <code>Trace</code>, or
1615a comma-separated list consisting of one or more of the following domains:
1616<code>Accelerate</code>, <code>Annotate</code>, <code>Blob</code>, <code>Cache</code>,
1617<code>Coder</code>, <code>Configure</code>, <code>Deprecate</code>,
1618<code>Exception</code>, <code>Locale</code>, <code>Render</code>,
1619<code>Resource</code>, <code>Security</code>, <code>TemporaryFile</code>,
1620<code>Transform</code>, <code>X11</code>, or <code>User</code>. </p>
1621
1622
1623<p>For example, to log cache and blob events, use.</p>
1624
1625<pre>
1626convert -debug "Cache,Blob" rose: rose.png
1627</pre>
1628
1629<p>The <code>User</code> domain is normally empty, but developers can log user
1630events in their private copy of ImageMagick.</p>
1631
1632<p>To print the complete list of debug methods, use <a href="command-line-options.html#list">-list
1633debug</a>.</p>
1634
1635<p>Use the <a href="command-line-options.html#log">-log</a> option to specify the format for debugging
1636output.</p>
1637
1638<p>Use <a href="command-line-options.html#debug">+debug</a> to turn off all logging.</p>
1639
cristy82a2ff22015-05-12 16:41:32 +00001640<p>Debugging may also be set using the <code>MAGICK_DEBUG</code> <a href="resources.html#environment">environment variable</a>. The allowed values for the <code>MAGICK_DEBUG</code>
cristyd2432012015-05-04 23:15:15 +00001641environment variable are the same as for the <a href="command-line-options.html#debug">-debug</a>
1642option.</p>
1643
1644
1645<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001646 <h3 class="magick-header"><a id="decipher"></a>-decipher <var>filename</var></h3>
cristyd2432012015-05-04 23:15:15 +00001647</div>
1648
1649<p class="magick-description">Decipher and restore pixels that were previously transformed by <a href="command-line-options.html#encipher">-encipher</a>.</p>
1650
1651<p>Get the passphrase from the file specified by <var>filename</var>.</p>
1652
cristyea2793e2015-05-31 16:52:26 +00001653<p>For more information, see the webpage, <a href="../www/cipher.html">ImageMagick: Encipher or
cristyd2432012015-05-04 23:15:15 +00001654Decipher an Image</a>.</p>
1655
1656
1657<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001658 <h3 class="magick-header"><a id="deconstruct"></a>-deconstruct</h3>
cristyd2432012015-05-04 23:15:15 +00001659</div>
1660
1661<p class="magick-description">find areas that has changed between images </p>
1662
cristy82a2ff22015-05-12 16:41:32 +00001663<p>Given a sequence of images all the same size, such as produced by <a href="command-line-options.html#coalesce">-coalesce</a>, replace the second and later images, with
cristyd2432012015-05-04 23:15:15 +00001664a smaller image of just the area that changed relative to the previous image.
1665</p>
1666
1667<p>The resulting sequence of images can be used to optimize an animation
1668sequence, though will not work correctly for GIF animations when parts of the
1669animation can go from opaque to transparent. </p>
1670
1671<p>This option is actually equivalent to the <a href="command-line-options.html#layers">-layers</a>
1672method '<code>compare-any</code>'. </p>
1673
1674
1675<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001676 <h3 class="magick-header"><a id="define"></a>-define <var>key</var>{<var>=value</var>}<var>...</var></h3>
cristyd2432012015-05-04 23:15:15 +00001677</div>
1678
1679<p class="magick-description">add specific global settings generally used to control coders and image processing operations.</p>
1680
1681<p>This option creates one or more definitions for coders and decoders to use
1682while reading and writing image data. Definitions are generally used to
1683control image file format coder modules, and image processing operations,
cristy82a2ff22015-05-12 16:41:32 +00001684beyond what is provided by normal means. Defined settings are listed in <a href="command-line-options.html#verbose">-verbose</a> information ("<code>info:</code>" output format)
cristyd2432012015-05-04 23:15:15 +00001685as "Artifacts". </p>
1686
1687<p>If <var>value</var> is missing for a definition, an empty-valued
1688definition of a flag is created with that name. This used to control on/off
1689options. Use <a href="command-line-options.html#define">+define key</a> to remove definitions
1690previously created. Use <a href="command-line-options.html#define">+define "*"</a> to remove all
1691existing definitions.</p>
1692
cristy82a2ff22015-05-12 16:41:32 +00001693<p>The same 'artifact' settings can also be defined using the <a href="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
cristyd2432012015-05-04 23:15:15 +00001694Properties</a> in the defined value. </p>
1695
1696<p>The <var>option</var> and <var>key</var> are case-independent (they are
1697converted to lowercase for use within the decoders) while the <var>value</var>
1698is case-dependent.</p>
1699
1700<p>Such settings are global in scope, and affect all images and operations. </p>
1701
1702<p>The following definitions are just some of the artifacts that are
1703available:</p>
1704
cristy29dc8652015-05-12 16:26:21 +00001705<table class="table table-condensed table-striped">
1706 <tr>
1707 <td>bmp:format=<var>value</var></td>
1708 <td> valid values are <var>bmp2</var>, <var>bmp3</var>,
cristyd2432012015-05-04 23:15:15 +00001709 and <var>bmp4</var>. This option can be useful when the
1710 method of prepending "BMP2:" to the output filename is inconvenient or
cristy29dc8652015-05-12 16:26:21 +00001711 is not available, such as when using the <a href="mogrify.html">mogrify</a> utility.</td>
1712 </tr>
cristyd2432012015-05-04 23:15:15 +00001713
cristy29dc8652015-05-12 16:26:21 +00001714 <tr>
1715 <td>complex:snr=<var>value</var></td>
cristy82a2ff22015-05-12 16:41:32 +00001716 <td>Set the divide SNR constant<a href="command-line-options.html#complex">-complex</a></td>
cristy29dc8652015-05-12 16:26:21 +00001717 </tr>
cristyd2432012015-05-04 23:15:15 +00001718
cristy29dc8652015-05-12 16:26:21 +00001719 <tr>
1720 <td>compose:args=<var>arguments</var></td>
1721 <td>Sets certain compose argument values when using convert ... -compose ...
cristy82a2ff22015-05-12 16:41:32 +00001722 -composite. See <a href="compose.html">Image Composition</a></td>
cristy29dc8652015-05-12 16:26:21 +00001723 </tr>
cristyd2432012015-05-04 23:15:15 +00001724
cristy29dc8652015-05-12 16:26:21 +00001725 <tr>
1726 <td>convolve:scale=<var>{kernel_scale}[!^] [,{origin_addition}] [%]</var></td>
1727 <td>Defines the kernel scaling. The special flag ! automatically scales to
cristyd2432012015-05-04 23:15:15 +00001728 full dynamic range. The ! flag can be used in combination with a factor or
1729 percent. The factor or percent is then applied after the automatic scaling.
1730 An example is 50%!. This produces a result 50% darker than full dynamic
1731 range scaling. The ^ flag assures the kernel is 'zero-summing', for
1732 example when some values are positive and some are negative as in edge
1733 detection kernels. The origin addition adds that value to the center
1734 pixel of the kernel. This produces and effect that is like adding the image
1735 that many times to the result of the filtered image. The typical value
1736 is 1 so that the original image is added to the result of the convolution.
cristy29dc8652015-05-12 16:26:21 +00001737 The default is 0.</td>
1738 </tr>
cristyd2432012015-05-04 23:15:15 +00001739
cristy29dc8652015-05-12 16:26:21 +00001740 <tr>
1741 <td>convolve:showkernel=<var>1</var></td>
cristy82a2ff22015-05-12 16:41:32 +00001742 <td>Outputs (to 'standard error') all the information about a specified <a href="command-line-options.html#morphology">-morphology convolve</a> kernel.</td>
cristy29dc8652015-05-12 16:26:21 +00001743 </tr>
cristyd2432012015-05-04 23:15:15 +00001744
cristy29dc8652015-05-12 16:26:21 +00001745 <tr>
1746 <td>dcm:display-range=<var>reset</var></td>
1747 <td>Sets the display range to the minimum and maximum pixel values for the
1748 DCM image format.</td>
1749 </tr>
cristyd2432012015-05-04 23:15:15 +00001750
cristy29dc8652015-05-12 16:26:21 +00001751 <tr>
1752 <td>dds:cluster-fit=<var>true|false</var></td>
1753 <td>Enables the dds cluster-fit.</td>
1754 </tr>
cristyd2432012015-05-04 23:15:15 +00001755
cristy29dc8652015-05-12 16:26:21 +00001756 <tr>
1757 <td>dds:compression=<var>dxt1|dxt5|none</var></td>
1758 <td>Sets the dds compression.</td>
1759 </tr>
cristyd2432012015-05-04 23:15:15 +00001760
cristy29dc8652015-05-12 16:26:21 +00001761 <tr>
1762 <td>dds:mipmaps=<var>value</var></td>
1763 <td>Sets the dds number of mipmaps.</td>
1764 </tr>
cristyd2432012015-05-04 23:15:15 +00001765
cristy29dc8652015-05-12 16:26:21 +00001766 <tr>
1767 <td>dds:weight-by-alpha=<var>true|false</var></td>
1768 <td>Enables the dds alpha weighting.</td>
1769 </tr>
cristyd2432012015-05-04 23:15:15 +00001770
cristy29dc8652015-05-12 16:26:21 +00001771 <tr>
1772 <td>delegate:bimodal=<var>true</var></td>
1773 <td>Specifies direct conversion from Postscript to PDF.</td>
1774 </tr>
cristyd2432012015-05-04 23:15:15 +00001775
cristy29dc8652015-05-12 16:26:21 +00001776 <tr>
1777 <td>distort:scale=<var>value</var></td>
cristy82a2ff22015-05-12 16:41:32 +00001778 <td>Sets the output scaling factor for use with <a href="command-line-options.html#distort">-distort</a></td>
cristy29dc8652015-05-12 16:26:21 +00001779 </tr>
cristyd2432012015-05-04 23:15:15 +00001780
cristy29dc8652015-05-12 16:26:21 +00001781 <tr>
1782 <td>distort:viewport=<var>WxH+X+Y</var></td>
1783 <td>Sets the viewport for use with <a href="command-line-options.html#distort">-distort</a></td>
1784 </tr>
cristyd2432012015-05-04 23:15:15 +00001785
cristy29dc8652015-05-12 16:26:21 +00001786 <tr>
1787 <td>dot:layout-engine=<var>value</var></td>
1788 <td>Specifies the layout engine for the DOT image format (e.g.
1789 <code>neato</code>).</td>
1790 </tr>
cristyd2432012015-05-04 23:15:15 +00001791
cristy29dc8652015-05-12 16:26:21 +00001792 <tr>
1793 <td>filter:option=<var>value</var></td>
1794 <td>Set a filter option for use with <a href="command-line-options.html#resize">-resize</a>.
1795 See <a href="command-line-options.html#filter">-filter</a> for details.</td>
1796 </tr>
cristyd2432012015-05-04 23:15:15 +00001797
cristy29dc8652015-05-12 16:26:21 +00001798 <tr>
1799 <td>fourier:normalize=<var>inverse</var></td>
1800 <td>Sets the location for the FFT/IFT normalization as use by
cristyd2432012015-05-04 23:15:15 +00001801 <a href="command-line-options.html#fft">+-fft</a> and <a href="command-line-options.html#ift">+-ift</a>. The default is
cristy29dc8652015-05-12 16:26:21 +00001802 forward.</td>
1803 </tr>
cristyd2432012015-05-04 23:15:15 +00001804
cristy29dc8652015-05-12 16:26:21 +00001805 <tr>
1806 <td>icon:auto-resize</td>
1807 <td>Automatically stores multiple sizes when writing an ico image
1808 (requires a 256x256 input image).</td>
1809 </tr>
cristyd2432012015-05-04 23:15:15 +00001810
cristy29dc8652015-05-12 16:26:21 +00001811 <tr>
1812 <td>jp2:layer-number=<var>value</var></td>
1813 <td>Sets the maximum number of quality layers to decode. Same for JPT, JC2,
1814 and J2K</td>
1815 </tr>
cristyd2432012015-05-04 23:15:15 +00001816
cristy29dc8652015-05-12 16:26:21 +00001817 <tr>
1818 <td>jp2:number-resolutions=<var>value</var></td>
1819 <td>Sets the number of resolutions to encode.Same for JPT, JC2, and J2K</td>
1820 </tr>
cristyd2432012015-05-04 23:15:15 +00001821
cristy29dc8652015-05-12 16:26:21 +00001822 <tr>
1823 <td>jp2:progression-order=<var>value</var></td>
1824 <td>choose from LRCP, RLCP, RPCL, PCRL or CPRL. Same for JPT, JC2, and
1825 J2K</td>
1826 </tr>
cristyd2432012015-05-04 23:15:15 +00001827
cristy29dc8652015-05-12 16:26:21 +00001828 <tr>
1829 <td>jp2:quality=<var>value,value...</var></td>
1830 <td>Sets the quality layer PSNR, given in dB. The order is from left to
cristyd2432012015-05-04 23:15:15 +00001831 right in ascending order. The default is a single lossless quality layer.
cristy29dc8652015-05-12 16:26:21 +00001832 Same for JPT, JC2, and J2K</td>
1833 </tr>
cristyd2432012015-05-04 23:15:15 +00001834
cristy29dc8652015-05-12 16:26:21 +00001835 <tr>
1836 <td>jp2:rate=<var>value</var></td>
1837 <td>Specify the compression factor to use while writing JPEG-2000 files. The
cristyd2432012015-05-04 23:15:15 +00001838 compression factor is the reciprocal of the compression ratio. The valid
1839 range is 0.0 to 1.0, with 1.0 indicating lossless compression. If defined,
1840 this value overrides the -quality setting. A quality setting of 75
cristy29dc8652015-05-12 16:26:21 +00001841 results in a rate value of 0.06641. Same for JPT, JC2, and J2K</td>
1842 </tr>
cristyd2432012015-05-04 23:15:15 +00001843
cristy29dc8652015-05-12 16:26:21 +00001844 <tr>
1845 <td>jp2:reduce-factor=<var>value</var></td>
1846 <td>Sets the number of highest resolution levels to be discarded.Same for
1847 JPT, JC2, and J2K</td>
1848 </tr>
cristyd2432012015-05-04 23:15:15 +00001849
cristy29dc8652015-05-12 16:26:21 +00001850 <tr>
1851 <td>jpeg:block-smoothing=<var>on|off</var></td>
cristyb2cad532015-05-16 13:02:45 +00001852 <td>&amp;nbsp</td>
1853 </tr>
cristyd2432012015-05-04 23:15:15 +00001854
cristyb2cad532015-05-16 13:02:45 +00001855 <tr>
cristy29dc8652015-05-12 16:26:21 +00001856 <td>jpeg:colors=<var>value</var></td>
1857 <td>Set the desired number of colors and let the JPEG encoder do the
1858 quantizing.</td>
1859 </tr>
cristyd2432012015-05-04 23:15:15 +00001860
cristy29dc8652015-05-12 16:26:21 +00001861 <tr>
1862 <td>jpeg:dct-method=<var>value</var></td>
1863 <td>Choose from <code>default</code>, <code>fastest</code>,
1864 <code>float</code>, <code>ifast</code>, and <code>islow</code>.</td>
1865 </tr>
cristyd2432012015-05-04 23:15:15 +00001866
cristy29dc8652015-05-12 16:26:21 +00001867 <tr>
1868 <td>jpeg:extent=<var>value</var></td>
1869 <td>Restrict the maximum JPEG file size, for example <code>-define
cristyd2432012015-05-04 23:15:15 +00001870 jpeg:extent=400KB</code>. The JPEG encoder will search for the highest
1871 compression quality level that results in an output file that does not
1872 exceed the value. The <code>-quality</code> option is ignored if it
cristy29dc8652015-05-12 16:26:21 +00001873 is also present.</td>
1874 </tr>
cristyd2432012015-05-04 23:15:15 +00001875
cristy29dc8652015-05-12 16:26:21 +00001876 <tr>
1877 <td>jpeg:fancy-upsampling=<var>on|off</var></td>
cristyb2cad532015-05-16 13:02:45 +00001878 <td>&amp;nbsp</td>
1879 </tr>
cristyd2432012015-05-04 23:15:15 +00001880
cristyb2cad532015-05-16 13:02:45 +00001881 <tr>
cristy29dc8652015-05-12 16:26:21 +00001882 <td>jpeg:optimize-coding=<var>on|off</var></td>
cristyb2cad532015-05-16 13:02:45 +00001883 <td>&amp;nbsp</td>
1884 </tr>
cristyd2432012015-05-04 23:15:15 +00001885
cristyb2cad532015-05-16 13:02:45 +00001886 <tr>
cristy29dc8652015-05-12 16:26:21 +00001887 <td>jpeg:q-table=<var>table</var></td>
cristyb2cad532015-05-16 13:02:45 +00001888 <td>&amp;nbsp</td>
1889 </tr>
cristyd2432012015-05-04 23:15:15 +00001890
cristyb2cad532015-05-16 13:02:45 +00001891 <tr>
cristy29dc8652015-05-12 16:26:21 +00001892 <td>jpeg:sampling-factor=<var>sampling-factor-string</var></td>
cristyb2cad532015-05-16 13:02:45 +00001893 <td>&amp;nbsp</td>
1894 </tr>
cristyd2432012015-05-04 23:15:15 +00001895
cristyb2cad532015-05-16 13:02:45 +00001896 <tr>
cristy29dc8652015-05-12 16:26:21 +00001897 <td>jpeg:size=<var>geometry</var></td>
1898 <td>Set the size hint of a JPEG image, for
cristyd2432012015-05-04 23:15:15 +00001899 example, <code>-define jpeg:size=128x128</code>.
1900 It is most useful for increasing performance and reducing the memory
cristy29dc8652015-05-12 16:26:21 +00001901 requirements when reducing the size of a large JPEG image.</td>
1902 </tr>
cristyd2432012015-05-04 23:15:15 +00001903
cristy29dc8652015-05-12 16:26:21 +00001904 <tr>
1905 <td>json:features</td>
1906 <td>includes features in verbose information</td>
1907 </tr>
cristyd2432012015-05-04 23:15:15 +00001908
cristy29dc8652015-05-12 16:26:21 +00001909 <tr>
1910 <td>json:limit</td>
cristyb2cad532015-05-16 13:02:45 +00001911 <td>&amp;nbsp</td>
1912 </tr>
cristyd2432012015-05-04 23:15:15 +00001913
cristyb2cad532015-05-16 13:02:45 +00001914 <tr>
cristy29dc8652015-05-12 16:26:21 +00001915 <td>json:locate</td>
cristyb2cad532015-05-16 13:02:45 +00001916 <td>&amp;nbsp</td>
1917 </tr>
cristyd2432012015-05-04 23:15:15 +00001918
cristyb2cad532015-05-16 13:02:45 +00001919 <tr>
cristy29dc8652015-05-12 16:26:21 +00001920 <td>json:moments</td>
1921 <td>includes image moments in verbose information</td>
1922 </tr>
cristyd2432012015-05-04 23:15:15 +00001923
cristy29dc8652015-05-12 16:26:21 +00001924 <tr>
1925 <td>mng:need-cacheoff</td>
1926 <td>turn playback caching off for streaming MNG.</td>
1927 </tr>
cristyd2432012015-05-04 23:15:15 +00001928
cristy29dc8652015-05-12 16:26:21 +00001929 <tr>
1930 <td>morphology:compose=<var>compose-method</var></td>
cristy82a2ff22015-05-12 16:41:32 +00001931 <td>Specifies how to merge results generated by multiple<a href="command-line-options.html#morphology">-morphology</a> kernel. The default is none. One
cristyd2432012015-05-04 23:15:15 +00001932 typical value is 'lighten' as used, for example, with the sobel edge
cristy29dc8652015-05-12 16:26:21 +00001933 kernels. </td>
1934 </tr>
cristyd2432012015-05-04 23:15:15 +00001935
cristy29dc8652015-05-12 16:26:21 +00001936 <tr>
1937 <td>morphology:showkernel=<var>1</var></td>
cristy82a2ff22015-05-12 16:41:32 +00001938 <td>Outputs (to 'standard error') all the information about a generated <a href="command-line-options.html#morphology">-morphology</a> kernel.</td>
cristy29dc8652015-05-12 16:26:21 +00001939 </tr>
cristyd2432012015-05-04 23:15:15 +00001940
cristy29dc8652015-05-12 16:26:21 +00001941 <tr>
1942 <td>pcl:fit-to-page=<var>true</var></td>
cristyd2432012015-05-04 23:15:15 +00001943
cristy82a2ff22015-05-12 16:41:32 +00001944 </tr><tr>
cristy29dc8652015-05-12 16:26:21 +00001945 <td>pdf:fit-page=<var>geometry</var></td>
1946 <td> geometry specifies the scaling dimensions for resizing when the PDF is
cristyd2432012015-05-04 23:15:15 +00001947 being read. The geometry is either WxH{%} or page size. No offsets are
cristy29dc8652015-05-12 16:26:21 +00001948 allowed. (introduced in IM 6.8.8-8)</td>
1949 </tr>
cristyd2432012015-05-04 23:15:15 +00001950
cristy29dc8652015-05-12 16:26:21 +00001951 <tr>
1952 <td>pdf:fit-to-page=<var>true</var></td>
cristyb2cad532015-05-16 13:02:45 +00001953 <td>&amp;nbsp</td>
1954 </tr>
cristyd2432012015-05-04 23:15:15 +00001955
cristyb2cad532015-05-16 13:02:45 +00001956 <tr>
cristy29dc8652015-05-12 16:26:21 +00001957 <td>pdf:use-cropbox=<var>true</var></td>
cristyb2cad532015-05-16 13:02:45 +00001958 <td>&amp;nbsp</td>
1959 </tr>
cristyd2432012015-05-04 23:15:15 +00001960
cristyb2cad532015-05-16 13:02:45 +00001961 <tr>
cristy29dc8652015-05-12 16:26:21 +00001962 <td>pdf:use-trimbox=<var>true</var></td>
cristyb2cad532015-05-16 13:02:45 +00001963 <td>&amp;nbsp</td>
1964 </tr>
cristyd2432012015-05-04 23:15:15 +00001965
cristyb2cad532015-05-16 13:02:45 +00001966 <tr>
cristy29dc8652015-05-12 16:26:21 +00001967 <td>png:bit-depth=<var>value</var></td>
cristyb2cad532015-05-16 13:02:45 +00001968 <td>&amp;nbsp</td>
1969 </tr>
1970 <tr>
cristy29dc8652015-05-12 16:26:21 +00001971 <td>png:color-type=<var>value</var></td>
1972 <td>desired bit-depth and color-type for PNG output. You can force the PNG
cristyd2432012015-05-04 23:15:15 +00001973 encoder to use a different bit-depth and color-type than it would have
1974 normally selected, but only if this does not cause any loss of image
1975 quality. Any attempt to reduce image quality is treated as an error and no
1976 PNG file is written. E.g., if you have a 1-bit black-and-white image, you
1977 can use these "defines" to cause it to be written as an 8-bit grayscale,
1978 indexed, or even a 64-bit RGBA. But if you have a 16-million color image,
1979 you cannot force it to be written as a grayscale or indexed PNG. If you
1980 wish to do this, you must use the appropriate <a href="command-line-options.html#depth">-depth</a>,
1981 <a href="command-line-options.html#colors">-colors</a>, or <a href="command-line-options.html#type">-type</a> directives to
1982 reduce the image quality prior to using the PNG encoder. Note that in
1983 indexed PNG files, "bit-depth" refers to the number of bits per index,
1984 which can be 1, 2, 4, or 8. In such files, the color samples always have
cristy29dc8652015-05-12 16:26:21 +00001985 8-bit depth.</td>
1986 </tr>
cristyd2432012015-05-04 23:15:15 +00001987
cristy29dc8652015-05-12 16:26:21 +00001988 <tr>
1989 <td>png:compression-filter=<var>value</var></td>
1990 <td> valid values are 0 through 9. 0-4 are the corresponding PNG filters,
cristyd2432012015-05-04 23:15:15 +00001991 5 means adaptive filtering except for images with a colormap, 6 means
1992 adaptive filtering for all images, 7 means MNG "loco" compression, 8 means
1993 Z_RLE strategy with adaptive filtering, and 9 means Z_RLE strategy with no
cristy29dc8652015-05-12 16:26:21 +00001994 filtering.</td>
1995 </tr>
cristyd2432012015-05-04 23:15:15 +00001996
cristy29dc8652015-05-12 16:26:21 +00001997 <tr>
1998 <td>png:compression-level=<var>value</var></td>
1999 <td> valid values are 0 through 9, with 0 providing the least but fastest
2000 compression and 9 usually providing the best and always the slowest.</td>
2001 </tr>
cristyd2432012015-05-04 23:15:15 +00002002
cristy29dc8652015-05-12 16:26:21 +00002003 <tr>
2004 <td>png:compression-strategy=<var>value</var></td>
2005 <td> valid values are 0 through 4, meaning default, filtered, huffman_only,
cristyd2432012015-05-04 23:15:15 +00002006 rle, and fixed ZLIB compression strategy. If you are using an old zlib
2007 that does not support Z_RLE (before 1.2.0) or Z_FIXED (before 1.2.2.2),
2008 values 3 and 4, respectively, will use the zlib default strategy
cristy29dc8652015-05-12 16:26:21 +00002009 instead.</td>
2010 </tr>
cristyd2432012015-05-04 23:15:15 +00002011
cristy29dc8652015-05-12 16:26:21 +00002012 <tr>
2013 <td>png:format=<var>value</var></td>
2014 <td> valid values are <var>png8</var>, <var>png24</var>,
cristyd2432012015-05-04 23:15:15 +00002015 <var>png32</var>, <var>png48</var>,
2016 <var>png64</var>, and <var>png00</var>.
2017 This property can be useful for specifying
2018 the specific PNG format to be used, when the usual method of prepending the
2019 format name to the output filename is inconvenient, such as when writing
2020 a PNG-encoded ICO file or when using <a href="mogrify.html">mogrify</a>.
2021 Value = <var>png8</var> reduces the number of colors to 256,
2022 only one of which may be fully transparent, if necessary. The other
2023 values do not force any reduction of quality; it is an error to request
2024 a format that cannot represent the image data without loss (except that
2025 it is allowed to reduce the bit-depth from 16 to 8 for all formats).
2026 Value = <var>png24</var> and <var>png48</var>
2027 allow transparency, only if a single color is fully transparent and that
2028 color does not also appear in an opaque pixel; such transparency is
2029 written in a PNG <code>tRNS</code> chunk.
2030 Value = <var>png00</var> causes the image to inherit its
2031 color-type and bit-depth from the input image, if the input was also
cristy29dc8652015-05-12 16:26:21 +00002032 a PNG.</td>
2033 </tr>
cristyd2432012015-05-04 23:15:15 +00002034
cristy29dc8652015-05-12 16:26:21 +00002035 <tr>
2036 <td>png:exclude-chunk=<var>value</var></td>
cristyd2432012015-05-04 23:15:15 +00002037
cristy82a2ff22015-05-12 16:41:32 +00002038 </tr><tr>
cristy29dc8652015-05-12 16:26:21 +00002039 <td>png:include-chunk=<var>value</var></td>
2040 <td>ancillary chunks to be excluded from or included in PNG output.
cristyd2432012015-05-04 23:15:15 +00002041
2042 <p>The <var>value</var> can be the name of a PNG chunk-type such
2043 as <var>bKGD</var>, a comma-separated list of chunk-names
2044 (which can include the word <var>date</var>, the word
2045 <var>all</var>, or the word <var>none</var>).
2046 Although PNG chunk-names are case-dependent, you can use all lowercase
2047 names if you prefer.</p>
2048
2049 <p>The "include-chunk" and "exclude-chunk" lists only affect the behavior
2050 of the PNG encoder and have no effect on the PNG decoder.</p>
2051
2052 <p>As a special case, if the <code>sRGB</code> chunk is excluded and
2053 the <code>gAMA</code> chunk is included, the <code>gAMA</code> chunk will
2054 only be written if gamma is not 1/2.2, since most decoders assume
2055 sRGB and gamma=1/2.2 when no colorspace information is included in
2056 the PNG file. Because the list is processed from left to right, you
2057 can achieve this with a single define:</p>
2058
2059<pre>
cristy29dc8652015-05-12 16:26:21 +00002060-define png:include-chunk=none,gAMA
cristyd2432012015-05-04 23:15:15 +00002061</pre>
2062
2063 <p>As a special case, if the <code>sRGB</code> chunk is not excluded and
2064 the PNG encoder recognizes that the image contains the sRGB ICC profile,
2065 the PNG encoder will write the <code>sRGB</code> chunk instead of the
2066 entire ICC profile. To force the PNG encoder to write the sRGB
2067 profile as an <code>iCCP</code> chunk in the output PNG instead of the
2068 <code>sRGB</code> chunk, exclude the <code>sRGB</code> chunk.</p>
2069
2070 <p>The critical PNG chunks <code>IHDR</code>, <code>PLTE</code>,
2071 <code>IDAT</code>, and <code>IEND</code> cannot be excluded. Any such
2072 entries appearing in the list will be ignored.</p>
2073
2074 <p>If the ancillary PNG <code>tRNS</code> chunk is excluded and the
2075 image has transparency, the PNG colortype is forced to be 4 or 6
2076 (GRAY_ALPHA or RGBA). If the image is not transparent, then the
2077 <code>tRNS</code> chunk isn't written anyhow, and there is no effect
2078 on the PNG colortype of the output image.</p>
2079
2080 <p>The <a href="command-line-options.html#strip">-strip</a> option does the equivalent of the
2081 following for PNG output:</p>
2082
2083<pre>
cristy29dc8652015-05-12 16:26:21 +00002084-define png:exclude-chunk=EXIF,iCCP,iTXt,sRGB,tEXt,zCCP,zTXt,date
cristyd2432012015-05-04 23:15:15 +00002085</pre>
2086
2087 <p>The default behavior is to include all known PNG ancillary chunks
2088 plus ImageMagick's private <code>vpAg</code> ("virtual page") chunk,
2089 and to exclude all PNG chunks that are unknown to ImageMagick,
2090 regardless of their PNG "copy-safe" status as described in the
2091 PNG specification.</p>
2092
2093 <p>Any chunk names that are not known to ImageMagick are ignored
2094 if they appear in either the "include-chunk" or "exclude-chunk" list.
2095 The ancillary chunks currently known to ImageMagick are
2096 <code>bKGD</code>, <code>cHRM</code>, <code>gAMA</code>, <code>iCCP</code>,
2097 <code>oFFs</code>, <code>pHYs</code>, <code>sRGB</code>, <code>tEXt</code>,
2098 <code>tRNS</code>, <code>vpAg</code>, and <code>zTXt</code>.</p>
2099
2100 <p>You can also put <code>date</code> in the list to include or exclude
2101 the "Date:create" and "Date:modify" text chunks that ImageMagick normally
cristy29dc8652015-05-12 16:26:21 +00002102 inserts in the output PNG.</p></td>
2103 </tr>
cristyd2432012015-05-04 23:15:15 +00002104
cristy29dc8652015-05-12 16:26:21 +00002105 <tr>
2106 <td>png:preserve-colormap[=<var>true</var>]</td>
cristy82a2ff22015-05-12 16:41:32 +00002107 <td>Use the existing image-&gt;colormap. Normally the PNG encoder will
cristyd2432012015-05-04 23:15:15 +00002108 try to optimize the palette, eliminating unused entries and putting
2109 the transparent colors first. If this flag is set, that behavior
cristy29dc8652015-05-12 16:26:21 +00002110 is suppressed.</td>
2111 </tr>
cristyd2432012015-05-04 23:15:15 +00002112
cristy29dc8652015-05-12 16:26:21 +00002113 <tr>
2114 <td>png:preserve-iCCP[=<var>true</var>]</td>
2115 <td>By default, the PNG decoder and encoder examine any ICC profile
cristyd2432012015-05-04 23:15:15 +00002116 that is present, either from an <code>iCCP</code> chunk in the PNG
2117 input or supplied via an option, and if the profile is recognized
2118 to be the sRGB profile, converts it to the <code>sRGB</code> chunk.
2119 You can use <code>-define png:preserve-iCCP</code> to prevent
2120 this from happening; in such cases the <code>iCCP</code> chunk
2121 will be read or written and no <code>sRGB</code> chunk will be
2122 written. There are some ICC profiles that claim to be sRGB but
2123 have various errors that cause them to be rejected by libpng16; such
2124 profiles are recognized anyhow and converted to the <code>sRGB</code>
2125 chunk, but are rejected if the <code>-define png:preserve-iCCP</code>
2126 is present. Note that not all "sRGB" ICC profiles are recognized
cristy29dc8652015-05-12 16:26:21 +00002127 yet; we will add them to the list as we encounter them.</td>
2128 </tr>
cristyd2432012015-05-04 23:15:15 +00002129
cristy29dc8652015-05-12 16:26:21 +00002130 <tr>
2131 <td>png:swap-bytes[=<var>true</var>]</td>
2132 <td>The PNG specification requires that any multi-byte integers be stored in
cristyd2432012015-05-04 23:15:15 +00002133 network byte order (MSB-LSB endian). This option allows you to
2134 fix any invalid PNG files that have 16-bit samples stored incorrectly
2135 in little-endian order (LSB-MSB). The "-define png:swap-bytes" option
2136 must appear before the input filename on the commandline. The swapping
cristy29dc8652015-05-12 16:26:21 +00002137 is done during the libpng decoding operation.</td>
2138 </tr>
cristyd2432012015-05-04 23:15:15 +00002139
cristy29dc8652015-05-12 16:26:21 +00002140 <tr>
2141 <td>profile:skip=<var>name1,name2,...</var></td>
2142 <td>Skip the named profile[s] when reading the image. Use skip="*" to
cristyd2432012015-05-04 23:15:15 +00002143 skip all named profiles in the image. Many named profiles exist,
cristy29dc8652015-05-12 16:26:21 +00002144 including ICC, EXIF, APP1, IPTC, XMP, and others.</td>
2145 </tr>
cristyd2432012015-05-04 23:15:15 +00002146
cristy29dc8652015-05-12 16:26:21 +00002147 <tr>
2148 <td>ps:imagemask</td>
2149 <td>If the ps:imagemask flag is defined, the PS3 and EPS3 coders will create
cristyd2432012015-05-04 23:15:15 +00002150 Postscript files that render bilevel images with the Postscript imagemask
cristy29dc8652015-05-12 16:26:21 +00002151 operator instead of the image operator.</td>
2152 </tr>
cristyd2432012015-05-04 23:15:15 +00002153
cristy29dc8652015-05-12 16:26:21 +00002154 <tr>
2155 <td>quantum:format=<var>type</var></td>
2156 <td>Set the type to <code>floating-point</code> to specify a floating-point
cristyd2432012015-05-04 23:15:15 +00002157 format for raw files (e.g. GRAY:) or for MIFF and TIFF images in HDRI mode
2158 to preserve negative values. If <a href="command-line-options.html#depth">-depth</a> 16 is
2159 included, the result is a single precision floating point format.
2160 If <a href="command-line-options.html#depth">-depth</a> 32 is included, the result is
cristy29dc8652015-05-12 16:26:21 +00002161 double precision floating point format.</td>
2162 </tr>
cristyd2432012015-05-04 23:15:15 +00002163
cristy29dc8652015-05-12 16:26:21 +00002164 <tr>
2165 <td>quantum:polarity=<var>photometric-interpretation</var></td>
2166 <td>Set the photometric-interpretation of an image (typically for TIFF image
cristyd2432012015-05-04 23:15:15 +00002167 file format) to either <code>min-is-black</code> (default) or
cristy29dc8652015-05-12 16:26:21 +00002168 <code>min-is-white</code>.</td>
2169 </tr>
cristyd2432012015-05-04 23:15:15 +00002170
cristy29dc8652015-05-12 16:26:21 +00002171 <tr>
2172 <td>sample:offset=<var>geometry</var></td>
2173 <td>Location of the sampling point within the sub-region being sampled,
cristy82a2ff22015-05-12 16:41:32 +00002174 expressed as percentages (see <a href="command-line-options.html#sample">-sample</a>).</td>
cristy29dc8652015-05-12 16:26:21 +00002175 </tr>
cristyd2432012015-05-04 23:15:15 +00002176
cristy29dc8652015-05-12 16:26:21 +00002177 <tr>
2178 <td>showkernel=<var>1</var></td>
cristy82a2ff22015-05-12 16:41:32 +00002179 <td>Outputs (to 'standard error') all the information about a generated <a href="command-line-options.html#morphology">-morphology</a> kernel.</td>
cristy29dc8652015-05-12 16:26:21 +00002180 </tr>
cristyd2432012015-05-04 23:15:15 +00002181
cristy29dc8652015-05-12 16:26:21 +00002182 <tr>
2183 <td>stream:buffer-size=<var>value</var></td>
2184 <td>Set the stream buffer size. Select 0 for unbuffered I/O.</td>
2185 </tr>
cristyd2432012015-05-04 23:15:15 +00002186
cristy29dc8652015-05-12 16:26:21 +00002187 <tr>
2188 <td>tiff:alpha=<var>associated|unassociated|unspecified</var></td>
2189 <td>Specify the alpha extra samples as associated, unassociated or unspecified </td>
2190 </tr>
cristyd2432012015-05-04 23:15:15 +00002191
cristy29dc8652015-05-12 16:26:21 +00002192 <tr>
2193 <td>tiff:endian=<var>msb|lsb</var></td>
cristyb2cad532015-05-16 13:02:45 +00002194 <td>&amp;nbsp</td>
2195 </tr>
cristyd2432012015-05-04 23:15:15 +00002196
cristyb2cad532015-05-16 13:02:45 +00002197 <tr>
cristy29dc8652015-05-12 16:26:21 +00002198 <td>tiff:exif-properties=<var>false</var></td>
2199 <td>Skips reading the EXIF properties.</td>
2200 </tr>
cristyd2432012015-05-04 23:15:15 +00002201
cristy29dc8652015-05-12 16:26:21 +00002202 <tr>
2203 <td>tiff:fill-order=<var>msb|lsb</var></td>
cristyb2cad532015-05-16 13:02:45 +00002204 <td>&amp;nbsp</td>
2205 </tr>
cristyd2432012015-05-04 23:15:15 +00002206
cristyb2cad532015-05-16 13:02:45 +00002207 <tr>
cristy29dc8652015-05-12 16:26:21 +00002208 <td>tiff:ignore-tags=<var>comma-separate-list-of-tag-IDs</var></td>
2209 <td>Allows one or more tag ID values to be ignored.</td>
2210 </tr>
cristyd2432012015-05-04 23:15:15 +00002211
cristy29dc8652015-05-12 16:26:21 +00002212 <tr>
2213 <td>tiff:rows-per-strip=<var>value</var></td>
2214 <td>Sets the number of rows per strip</td>
2215 </tr>
cristyd2432012015-05-04 23:15:15 +00002216
cristy29dc8652015-05-12 16:26:21 +00002217 <tr>
2218 <td>tiff:tile-geometry=<var>WxH</var></td>
2219 <td>Sets the tile size for pyramid tiffs. Requires the suffix
2220 PTIF: before the outputname</td>
2221 </tr>
2222</table>
cristyd2432012015-05-04 23:15:15 +00002223
2224<p>For example, to create a postscript file that will render only the black
2225pixels of a bilevel image, use:</p>
2226
2227<pre>
2228convert bilevel.tif -define ps:imagemask eps3:stencil.ps
2229</pre>
2230
2231<p>Set attributes of the image registry by prefixing the value with
2232<code>registry:</code>. For example, to set a temporary path to put work files,
2233use:</p>
2234
cristy29dc8652015-05-12 16:26:21 +00002235<pre>
cristyd2432012015-05-04 23:15:15 +00002236-define registry:temporary-path=/data/tmp
cristy29dc8652015-05-12 16:26:21 +00002237</pre>
cristyd2432012015-05-04 23:15:15 +00002238
2239<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00002240 <h3 class="magick-header"><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>
cristyd2432012015-05-04 23:15:15 +00002241</div>
2242
2243<p class="magick-description">display the next image after pausing.</p>
2244
2245<p>This option is useful for regulating the animation of image sequences
2246<var>ticks/ticks-per-second</var> seconds must expire before the display of the
2247next image. The default is no delay between each showing of the image
2248sequence. The default ticks-per-second is 100.</p>
2249
2250<p>Use <code>&gt;</code> to change the image delay <var>only</var> if its current
2251value exceeds the given delay. <code>&lt;</code> changes the image delay
2252<var>only</var> if current value is less than the given delay. For example, if
2253you specify <code>30&gt;</code> and the image delay is 20, the image delay does
2254not change. However, if the image delay is 40 or 50, the delay it is changed
2255to 30. Enclose the given delay in quotation marks to prevent the
2256<code>&lt;</code> or <code>&gt;</code> from being interpreted by your shell as
2257a file redirection.</p>
2258
2259
2260<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002261 <h3 class="magick-header"><a id="delete"></a>-delete <var>indexes</var></h3>
cristyd2432012015-05-04 23:15:15 +00002262</div>
2263
2264<p class="magick-description">delete the images specified by index, from the image sequence.</p>
2265
2266<p>Specify the image by its index in the sequence. The first image is index
22670. Negative indexes are relative to the end of the sequence, for example, -1
2268represents the last image of the sequence. Specify a range of images with
2269a dash (e.g. 0-4). Separate indexes with a comma (e.g. 0,2). Use
2270<code>+delete</code> to delete the last image in the current image sequence.</p>
2271
2272
2273<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00002274 <h3 class="magick-header"><a id="density"></a>-density <var>width</var><br>-density <var>width</var>x<var>height</var></h3>
cristyd2432012015-05-04 23:15:15 +00002275</div>
2276
2277<p class="magick-description">Set the horizontal and vertical resolution of an image for rendering to devices.</p>
2278
2279<p>This option specifies the image resolution to store while encoding a raster
2280image or the canvas resolution while rendering (reading) vector formats such
2281as Postscript, PDF, WMF, and SVG into a raster image. Image resolution
2282provides the unit of measure to apply when rendering to an output device or
cristy82a2ff22015-05-12 16:41:32 +00002283raster image. The default unit of measure is in dots per inch (DPI). The <a href="command-line-options.html#units">-units</a> option may be used to select dots per centimeter
cristyd2432012015-05-04 23:15:15 +00002284instead.</p>
2285
2286<p>The default resolution is 72 dots per inch, which is equivalent to one
2287point per pixel (Macintosh and Postscript standard). Computer screens are
2288normally 72 or 96 dots per inch, while printers typically support 150, 300,
2289600, or 1200 dots per inch. To determine the resolution of your display, use
2290a ruler to measure the width of your screen in inches, and divide by the
2291number of horizontal pixels (1024 on a 1024x768 display).</p>
2292
2293<p>If the file format supports it, this option may be used to update the
2294stored image resolution. Note that Photoshop stores and obtains image
2295resolution from a proprietary embedded profile. If this profile is not
2296stripped from the image, then Photoshop will continue to treat the image using
2297its former resolution, ignoring the image resolution specified in the standard
2298file header.</p>
2299
2300<p>The <a href="command-line-options.html#density">-density</a> option sets an <var>attribute</var> and
2301does not alter the underlying raster image. It may be used to adjust the
2302rendered size for desktop publishing purposes by adjusting the scale applied
2303to the pixels. To resize the image so that it is the same size at a different
2304resolution, use the <a href="command-line-options.html#resample">-resample</a> option.</p>
2305
2306<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002307 <h3 class="magick-header"><a id="depth"></a>-depth <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00002308</div>
2309
2310<p class="magick-description">depth of the image.</p>
2311
2312<p>This the number of bits in a color sample within a pixel. Use this option
2313to specify the depth of raw images whose depth is unknown such as GRAY, RGB,
2314or CMYK, or to change the depth of any image after it has been read.</p>
2315
2316<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002317 <h3 class="magick-header"><a id="descend"></a>-descend</h3>
cristyd2432012015-05-04 23:15:15 +00002318</div>
2319
2320<p class="magick-description">obtain image by descending window hierarchy.</p>
2321
2322<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002323 <h3 class="magick-header"><a id="deskew"></a>-deskew <var>threshold</var></h3>
cristyd2432012015-05-04 23:15:15 +00002324</div>
2325
2326<p class="magick-description">straighten an image. A threshold of 40% works for most images.</p>
2327
2328<p>Use <a href="command-line-options.html#set">-set</a> <code>option:deskew:auto-crop
2329<var>width</var></code> to auto crop the image. The set argument is the pixel
2330width of the image background (e.g 40).</p>
2331
2332<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002333 <h3 class="magick-header"><a id="despeckle"></a>-despeckle</h3>
cristyd2432012015-05-04 23:15:15 +00002334</div>
2335
2336<p class="magick-description">reduce the speckles within an image.</p>
2337
2338<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002339 <h3 class="magick-header"><a id="direction"></a>-direction <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00002340</div>
2341
2342<p class="magick-description">render text right-to-left or left-to-right.</p>
2343
2344<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00002345 <h3 class="magick-header"><a id="displace"></a>-displace <var>horizontal-scale</var><br>-displace <var>horizontal-scale</var>x<var>vertical-scale</var></h3>
cristyd2432012015-05-04 23:15:15 +00002346</div>
2347
2348<p class="magick-description">shift image pixels as defined by a displacement map.</p>
2349
2350<p>With this option, the 'overlay' image, and optionally the 'mask' image,
2351is used as a displacement map, which is used to displace the lookup of
2352what part of the 'background' image is seen at each point of the overlaid
2353area. Much like the displacement map is a 'lens' that redirects light shining
2354through it so as to present a distorted view the original 'background' image
2355behind it. </p>
2356
2357<p>Any perfect grey areas of the displacement map produce a zero
2358displacement of the image. Black areas produce the given maximum negative
2359displacement of the lookup point, while white produce a maximum positive
2360displacement of the lookup. </p>
2361
2362<p>Note that it is the lookup of the 'background' that is displaced, not a
2363displacement of the image itself. As such an area of the displacement map
2364containing 'white' will have the lookup point 'shifted' by a positive amount,
2365and thus generating a copy of the destination image to the right/downward from
2366the correct position. That is the image will look like it may have been
2367'shifted' in a negative left/upward direction. Understanding this is a very
2368important in understanding how displacement maps work. </p>
2369
2370<p>The given arguments define the maximum amount of displacement in pixels
2371that a particular map can produce. If the displacement scale is large enough
2372it is also possible to lookup parts of the 'background' image that lie well
2373outside the bounds of the displacement map itself. That is you could very
2374easily copy a section of the original image from outside the overlay area
2375into the overlay area. </p>
2376
2377<p>The '%' flag makes the displacement scale relative to the size of the
2378overlay image (100% = half width/height of image). Using '!' switches
2379percentage arguments to refer to the destination image size instead.
2380these flags were added as of IM v6.5.3-5.</p>
2381
2382<p>Normally a single grayscale displacement map is provided, which with the
2383given scaling values will determine a single direction (vector) in which
2384displacements can occur (positively or negatively). However, if you also
2385specify a third image which is normally used as a <var>mask</var>,
2386the <var>composite image</var> is used for horizontal X
2387displacement, while the <var>mask image</var> is used for vertical Y
2388displacement. This allows you to define completely different displacement
2389values for the X and Y directions, and allowing you to lookup any point within
2390the <var>scale</var> bounds. In other words each pixel can lookup
2391any other nearby pixel, producing complex 2 dimensional displacements, rather
2392than a simple 1 dimensional vector displacements. </p>
2393
2394<p>Alternatively rather than supplying two separate images, as of IM v6.4.4-0,
2395you can use the 'red' channel of the overlay image to specify the horizontal
2396or X displacement, and the 'green' channel for the vertical or Y displacement.
2397</p>
2398
2399<p>As of IM v6.5.3-5 any alpha channel in the overlay image is used as a
2400mask the transparency of the destination image. However areas outside the
2401overlaid areas will not be effected. </p>
2402
2403
2404<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002405 <h3 class="magick-header"><a id="display"></a>-display <var>host:display[.screen]</var></h3>
cristyd2432012015-05-04 23:15:15 +00002406</div>
2407
2408<p class="magick-description">Specifies the X server to contact.</p>
2409
2410<p>This option is used with convert for obtaining image or font from this
2411X server. See <var>X(1)</var>.</p>
2412
2413<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002414 <h3 class="magick-header"><a id="dispose"></a>-dispose <var>method</var></h3>
cristyd2432012015-05-04 23:15:15 +00002415</div>
2416
2417<p class="magick-description">define the GIF disposal image setting for images that are being created or read in. </p>
2418
2419<p>The layer disposal method defines the way each the displayed image is to be
2420modified after the current 'frame' of an animation has finished being
2421displayed (after its 'delay' period), but before the next frame on an
2422animation is to be overlaid onto the display. </p>
2423
2424<p>Here are the valid methods:</p>
2425
cristy29dc8652015-05-12 16:26:21 +00002426<dl class="dl-horizontal">
2427<dt>Undefined</dt><dd>0: No disposal specified (equivalent to '<code>none</code>').</dd>
2428<dt>None</dt><dd>1: Do not dispose, just overlay next frame image.</dd>
2429<dt>Background</dt><dd>2: Clear the frame area with the background color.</dd>
2430<dt>Previous</dt><dd>3: Clear to the image prior to this frames overlay.</dd>
2431</dl>
cristyd2432012015-05-04 23:15:15 +00002432
2433<p>You can also use the numbers given above, which is what the GIF format
2434uses internally to represent the above settings. </p>
2435
2436<p>To print a complete list of dispose methods, use <a href="command-line-options.html#list">-list dispose</a>.</p>
2437
cristy82a2ff22015-05-12 16:41:32 +00002438<p>Use <a href="command-line-options.html#dispose">+dispose</a>, turn off the setting and prevent
cristyd2432012015-05-04 23:15:15 +00002439resetting the layer disposal methods of images being read in. </p>
2440
2441<p>Use <a href="command-line-options.html#set">-set</a> '<code>dispose</code>' method to set the image
2442disposal method for images already in memory.</p>
2443
2444<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002445 <h3 class="magick-header"><a id="dissimilarity-threshold"></a>-dissimilarity-threshold <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00002446</div>
2447
2448<p class="magick-description">maximum RMSE for subimage match (default 0.2).</p>
2449
2450
2451<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002452 <h3 class="magick-header"><a id="dissolve"></a>-dissolve <var>src_percent</var>[x<var>dst_percent</var>]</h3>
cristyd2432012015-05-04 23:15:15 +00002453</div>
2454
2455<p class="magick-description">dissolve an image into another by the given percent.</p>
2456
2457<p>The opacity of the composite image is multiplied by the given percent, then
2458it is composited 'over' the main image. If <var>src_percent</var>
2459is greater than 100, start dissolving the main image so it becomes
2460transparent at a value of '<code>200</code>'. If both percentages
2461are given, each image are dissolved to the percentages given. </p>
2462
2463<p>Note that dissolve percentages do not add, two opaque images dissolved
2464'50,50', produce a 75% transparency. For a 50% + 50% blending of the two
2465images, you would need to use dissolve values of '50,100'. </p>
2466
2467<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002468 <h3 class="magick-header"><a id="distort"></a>-distort <var>method arguments</var></h3>
cristyd2432012015-05-04 23:15:15 +00002469</div>
2470
2471<p class="magick-description">distort an image, using the given <var>method</var> and its required <var>arguments</var>.</p>
2472
2473<p>The <var>arguments</var> is a single string containing a list
2474of floating point numbers separated by commas or spaces. The number of
2475and meaning of the floating point values depends on the distortion <var>method</var> being used. </p>
2476
2477<p>Choose from these distortion types:</p>
2478
2479<table class="table table-condensed table-striped">
2480 <tr>
2481 <th style="width: 8%">Method</th>
2482 <th>Description</th>
2483 </tr>
2484
2485 <tr>
cristyb2cad532015-05-16 13:02:45 +00002486 <td>ScaleRotateTranslate <br> SRT</td>
cristyd2432012015-05-04 23:15:15 +00002487 <td>
2488 Distort image by first scaling and rotating about a given 'center',
2489 before translating that 'center' to the new location, in that order. It
cristyb2cad532015-05-16 13:02:45 +00002490 is an alternative method of specifying a 'Affine' type of
cristyd2432012015-05-04 23:15:15 +00002491 distortion, but without shearing effects. It also provides a good way
2492 of rotating and displacing a smaller image for tiling onto a larger
cristy82a2ff22015-05-12 16:41:32 +00002493 background (IE 2-dimensional animations). <br>
cristyd2432012015-05-04 23:15:15 +00002494
2495 The number of arguments determine the specific meaning of each
cristy82a2ff22015-05-12 16:41:32 +00002496 argument for the scales, rotation, and translation operations. <br>
cristyd2432012015-05-04 23:15:15 +00002497
cristyb2cad532015-05-16 13:02:45 +00002498 <dl class="dl-horizontal">
2499 <dt>2:</dt><dd><var>Scale Angle</var></dd>
2500 <dt>3:</dt><dd><var>X,Y Angle</var></dd>
2501 <dt>4:</dt><dd><var>X,Y Scale Angle</var></dd>
2502 <dt>5:</dt> <dd><var>X,Y ScaleX,ScaleY Angle</var></dd>
2503 <dt>6:</dt> <dd><var>X,Y Scale Angle NewX,NewY</var></dd>
2504 <dt>7:</dt> <dd><var>X,Y ScaleX,ScaleY Angle NewX,NewY</var></dd>
2505 </dl>
cristyd2432012015-05-04 23:15:15 +00002506
2507 This is actually an alternative way of specifying a 2 dimensional linear
cristyb2cad532015-05-16 13:02:45 +00002508 'Affine' or 'AffineProjection' distortion. </td> </tr>
cristyd2432012015-05-04 23:15:15 +00002509
2510 <tr>
cristyb2cad532015-05-16 13:02:45 +00002511 <td>Affine</td>
cristyd2432012015-05-04 23:15:15 +00002512 <td>
2513 Distort the image linearly by moving a list of at least 3 or more sets
2514 of control points (as defined below). Ideally 3 sets or 12 floating
2515 point values are given allowing the image to be linearly scaled,
2516 rotated, sheared, and translated, according to those three points. See
cristyb2cad532015-05-16 13:02:45 +00002517 also the related 'AffineProjection' and 'SRT'
cristy82a2ff22015-05-12 16:41:32 +00002518 distortions. <br>
cristyd2432012015-05-04 23:15:15 +00002519
2520 More than 3 sets given control point pairs (12 numbers) is least
2521 squares fitted to best match a linear affine distortion. If only 2
2522 control point pairs (8 numbers) are given a two point image translation
2523 rotation and scaling is performed, without any possible shearing,
2524 flipping or changes in aspect ratio to the resulting image. If only one
2525 control point pair is provides the image is only translated, (which may
cristy82a2ff22015-05-12 16:41:32 +00002526 be a floating point non-integer translation). <br>
cristyd2432012015-05-04 23:15:15 +00002527
2528 This distortion does not include any form of perspective distortion.
2529 </td>
2530
2531 </tr>
2532
2533 <tr>
cristyb2cad532015-05-16 13:02:45 +00002534 <td>AffineProjection</td>
cristyd2432012015-05-04 23:15:15 +00002535 <td>
2536 Linearly distort an image using the given Affine Matrix of 6
2537 pre-calculated coefficients forming a set of Affine Equations to map
2538 the source image to the destination image.
2539
cristyb2cad532015-05-16 13:02:45 +00002540 <p class="text-center"><var>
cristyd2432012015-05-04 23:15:15 +00002541 s<sub>x</sub>, r<sub>x</sub>,
2542 r<sub>y</sub>, s<sub>y</sub>,
2543 t<sub>x</sub>, t<sub>y</sub>
cristyb2cad532015-05-16 13:02:45 +00002544 </var></p>
cristyd2432012015-05-04 23:15:15 +00002545
cristy82a2ff22015-05-12 16:41:32 +00002546 See <a href="command-line-options.html#affine">-affine</a> setting for more detail, and
2547 meanings of these coefficients. <br>
cristyd2432012015-05-04 23:15:15 +00002548
cristyb2cad532015-05-16 13:02:45 +00002549 The distortions 'Affine' and 'SRT' provide
cristyd2432012015-05-04 23:15:15 +00002550 alternative methods of defining this distortion, with ImageMagick doing
2551 the calculations needed to generate the required coefficients. You can
cristy82a2ff22015-05-12 16:41:32 +00002552 see the internally generated coefficients, by using a <a href="command-line-options.html#verbose">-verbose</a> setting with those other variants. </td>
cristyd2432012015-05-04 23:15:15 +00002553
2554 </tr>
2555
2556 <tr>
cristyb2cad532015-05-16 13:02:45 +00002557 <td>BilinearForward<br>
2558 BilinearReverse</td>
cristyd2432012015-05-04 23:15:15 +00002559 <td>
2560 Bilinear Distortion, given a minimum of 4 sets of coordinate pairs, or
2561 16 values (see below). Not that lines may not appear straight after
2562 distortion, though the distance between coordinates will remain
cristy82a2ff22015-05-12 16:41:32 +00002563 consistent. <br>
cristyd2432012015-05-04 23:15:15 +00002564
cristyb2cad532015-05-16 13:02:45 +00002565 The 'BilinearForward' is used to map rectangles to any
2566 quadrilateral, while the 'BilinearReverse' form maps any
cristyd2432012015-05-04 23:15:15 +00002567 quadrilateral to a rectangle, while preserving the straight line edges
cristy82a2ff22015-05-12 16:41:32 +00002568 in each case. <br>
cristyd2432012015-05-04 23:15:15 +00002569
cristyb2cad532015-05-16 13:02:45 +00002570 Note that 'BilinearForward' can generate invalid pixels
cristy82a2ff22015-05-12 16:41:32 +00002571 which will be colored using the <a href="command-line-options.html#mattecolor">-mattecolor</a>
cristyd2432012015-05-04 23:15:15 +00002572 color setting. Also if the quadrilateral becomes 'flipped' the image
cristy82a2ff22015-05-12 16:41:32 +00002573 may disappear. <br>
cristyd2432012015-05-04 23:15:15 +00002574
2575 There are future plans to produce a true Bilinear distortion that will
2576 attempt to map any quadrilateral to any other quadrilateral, while
2577 preserving edges (and edge distance ratios).
2578
2579 </td>
2580 </tr>
2581
2582 <tr>
cristyb2cad532015-05-16 13:02:45 +00002583 <td>Perspective</td>
cristyd2432012015-05-04 23:15:15 +00002584 <td>
2585 Perspective distort the images, using a list of 4 or more sets of
2586 control points (as defined below). More that 4 sets (16 numbers) of
2587 control points provide least squares fitting for more accurate
2588 distortions (for the purposes of image registration and panorama
cristyb2cad532015-05-16 13:02:45 +00002589 effects). Less than 4 sets will fall back to a 'Affine'
cristy82a2ff22015-05-12 16:41:32 +00002590 linear distortion. <br>
cristyd2432012015-05-04 23:15:15 +00002591
2592 Perspective Distorted images ensures that straight lines remain
2593 straight, but the scale of the distorted image will vary. The horizon
2594 is anti-aliased, and the 'sky' color may be set using the
cristy82a2ff22015-05-12 16:41:32 +00002595 <a href="command-line-options.html#mattecolor">-mattecolor</a> setting. </td>
cristyd2432012015-05-04 23:15:15 +00002596 </tr>
2597
2598 <tr>
cristyb2cad532015-05-16 13:02:45 +00002599 <td>PerspectiveProjection </td>
cristyd2432012015-05-04 23:15:15 +00002600 <td>
cristyb2cad532015-05-16 13:02:45 +00002601 Do a 'Perspective' distortion biased on a set of 8
cristyd2432012015-05-04 23:15:15 +00002602 pre-calculated coefficients. You can get these coefficients by looking
cristy82a2ff22015-05-12 16:41:32 +00002603 at the <a href="command-line-options.html#verbose">-verbose</a> output of a
cristyb2cad532015-05-16 13:02:45 +00002604 'Perspective' distortion, or by calculating them yourself.
cristyd2432012015-05-04 23:15:15 +00002605 If the last two perspective scaling coefficients are zero, the
2606 remaining 6 represents a transposed 'Affine Matrix'. </td>
2607
2608 </tr>
2609
2610 <tr>
cristyb2cad532015-05-16 13:02:45 +00002611 <td>Arc</td>
cristyd2432012015-05-04 23:15:15 +00002612 <td>
2613 Arc the image (variation of polar mapping) over the angle given around
cristyb2cad532015-05-16 13:02:45 +00002614 a circle.
2615
2616 <p></p><dl class="dl-horizontal">
2617 <dt>arc_angle</dt>
2618 <dd>The angle over which to arc the image side-to-side</dd>
2619 <dt>rotate_angle</dt>
2620 <dd>Angle to rotate resulting image from vertical center</dd>
2621 <dt>top_radius</dt>
2622 <dd>Set top edge of source image at this radius</dd>
2623 <dt>bottom_radius </dt>
2624 <dd>Set bottom edge to this radius (radial scaling)</dd>
2625 </dl>
cristyd2432012015-05-04 23:15:15 +00002626
2627 The resulting image is always resized to best fit the resulting image,
cristy82a2ff22015-05-12 16:41:32 +00002628 (as if using <a href="command-line-options.html#distort">+distort</a>) while attempting to
cristyd2432012015-05-04 23:15:15 +00002629 preserve scale and aspect ratio of the original image as much as
2630 possible with the arguments given by the user. All four arguments will
cristy82a2ff22015-05-12 16:41:32 +00002631 be needed to change the overall aspect ratio of an 'Arc'ed image. <br>
cristyd2432012015-05-04 23:15:15 +00002632
2633 This a variation of a polar distortion designed to try to preserve the
2634 aspect ratio of the image rather than direct Cartesian to Polar
2635 conversion. </td>
2636 </tr>
2637
2638 <tr>
cristyb2cad532015-05-16 13:02:45 +00002639 <td>Polar</td>
cristyd2432012015-05-04 23:15:15 +00002640 <td>
cristyb2cad532015-05-16 13:02:45 +00002641 Like 'Arc' but do a complete Cartesian to Polar mapping of
cristyd2432012015-05-04 23:15:15 +00002642 the image. that is the height of the input image is mapped to the
2643 radius limits, while the width is wrapped around between the
cristy82a2ff22015-05-12 16:41:32 +00002644 angle limits. <br>
cristyd2432012015-05-04 23:15:15 +00002645
cristy82a2ff22015-05-12 16:41:32 +00002646 Arguments: <var>Rmax,Rmin CenterX,CenterY, start,end_angle</var> <br>
cristyd2432012015-05-04 23:15:15 +00002647
2648 All arguments are optional. With <var>Rmin</var> defaulting to zero, the
2649 center to the center of the image, and the angles going from -180 (top)
2650 to +180 (top). If <var>Rmax</var> is given the special value of
cristyb2cad532015-05-16 13:02:45 +00002651 '0', the the distance from the center to the nearest edge
cristyd2432012015-05-04 23:15:15 +00002652 is used for the radius of the output image, which will ensure the whole
2653 image is visible (though scaled smaller). However a special value of
cristyb2cad532015-05-16 13:02:45 +00002654 '-1' will use the distance from the center to the furthest
cristyd2432012015-05-04 23:15:15 +00002655 corner, This may 'clip' the corners from the input rectangular image,
cristyb2cad532015-05-16 13:02:45 +00002656 but will generate the exact reverse of a 'DePolar' with
cristy82a2ff22015-05-12 16:41:32 +00002657 the same arguments. <br>
cristyd2432012015-05-04 23:15:15 +00002658
cristy82a2ff22015-05-12 16:41:32 +00002659 If the plus form of distort (<a href="command-line-options.html#distort">+distort</a>) is used
cristyb2cad532015-05-16 13:02:45 +00002660 output image center will default to 0,0 of the virtual
cristyd2432012015-05-04 23:15:15 +00002661 canvas, and the image size adjusted to ensure the whole input image is
2662 made visible in the output image on the virtual canvas. </td>
2663
2664 </tr>
2665
2666 <tr>
cristyb2cad532015-05-16 13:02:45 +00002667 <td>DePolar</td>
cristyd2432012015-05-04 23:15:15 +00002668 <td>
cristyb2cad532015-05-16 13:02:45 +00002669 Uses the same arguments and meanings as a 'Polar' distortion
cristy82a2ff22015-05-12 16:41:32 +00002670 but generates the reverse Polar to Cartesian distortion. <br>
cristyd2432012015-05-04 23:15:15 +00002671
cristyb2cad532015-05-16 13:02:45 +00002672 The special <var>Rmax</var> setting of '0' may however clip
cristyd2432012015-05-04 23:15:15 +00002673 the corners of the input image. However using the special
cristyb2cad532015-05-16 13:02:45 +00002674 <var>Rmax</var> setting of '-1' (maximum center to corner
cristyd2432012015-05-04 23:15:15 +00002675 distance) will ensure the whole distorted image is preserved in the
cristyb2cad532015-05-16 13:02:45 +00002676 generated result, so that the same argument to 'Polar' will
cristyd2432012015-05-04 23:15:15 +00002677 reverse the distortion re-producing the original.
2678
2679 Note that as this distortion requires the area resampling of a circular
2680 arc, which can not be handled by the builtin EWA resampling function.
2681 As such the normal EWA filters are turned off. It is recommended some
2682 form of 'super-sampling' image processing technique be used to produce
2683 a high quality result. </td>
2684
2685 </tr>
2686
2687 <tr>
cristyb2cad532015-05-16 13:02:45 +00002688 <td>Barrel</td>
cristyd2432012015-05-04 23:15:15 +00002689 <td>
cristy82a2ff22015-05-12 16:41:32 +00002690 Given the four coefficients (A,B,C,D) as defined by <a href="http://wiki.panotools.org/Lens_correction_model">Helmut
cristyd2432012015-05-04 23:15:15 +00002691 Dersch</a>, perform a barrel or pin-cushion distortion appropriate to
2692 correct radial lens distortions. That is in photographs, make straight
cristy82a2ff22015-05-12 16:41:32 +00002693 lines straight again. <br>
cristyd2432012015-05-04 23:15:15 +00002694
cristyb2cad532015-05-16 13:02:45 +00002695 <p class="text-center">Arguments: <var>A B C</var> [ <var>D</var> [
cristy82a2ff22015-05-12 16:41:32 +00002696 <var>X</var> , <var>Y</var> ] ] <br>
cristyd2432012015-05-04 23:15:15 +00002697 or <var>A<sub>x</sub> B<sub>x</sub> C<sub>x</sub> D<sub>x</sub>
2698 A<sub>y</sub> B<sub>y</sub> C<sub>y</sub> D<sub>y</sub></var>
cristyb2cad532015-05-16 13:02:45 +00002699 [ <var>X</var> , <var>Y</var> ] </p>
2700 So that it forms the function
2701 <p class="text-center">Rsrc = r * ( <var>A</var>*r<sup>3</sup> + <var>B</var>*r<sup>2</sup> +
2702 <var>C</var>*r + <var>D</var> )</p>
cristyd2432012015-05-04 23:15:15 +00002703
2704 Where <var>X</var>,<var>Y</var> is the optional center of the distortion
cristy82a2ff22015-05-12 16:41:32 +00002705 (defaulting to the center of the image). <br>
cristyd2432012015-05-04 23:15:15 +00002706 The second form is typically used to distort images, rather than
cristy82a2ff22015-05-12 16:41:32 +00002707 correct lens distortions. <br>
cristyd2432012015-05-04 23:15:15 +00002708 </td>
2709
2710 </tr>
2711
2712 <tr>
cristyb2cad532015-05-16 13:02:45 +00002713 <td>BarrelInverse</td>
cristyd2432012015-05-04 23:15:15 +00002714 <td>
cristyb2cad532015-05-16 13:02:45 +00002715 This is very similar to 'Barrel' with the same set of
cristyd2432012015-05-04 23:15:15 +00002716 arguments, and argument handling. However it uses the inverse
2717 of the radial polynomial,
cristyb2cad532015-05-16 13:02:45 +00002718 so that it forms the function
2719 <p class="text-center">Rsrc = r / ( <var>A</var>*r<sup>3</sup> + <var>B</var>*r<sup>2</sup> +
2720 <var>C</var>*r + <var>D</var> )</p>
2721 Note that this is not the reverse of the 'Barrel'
cristyd2432012015-05-04 23:15:15 +00002722 distortion, just a different barrel-like radial distortion method.
2723
2724 </td>
2725 </tr>
2726
2727 <tr>
cristyb2cad532015-05-16 13:02:45 +00002728 <td>Shepards</td>
cristyd2432012015-05-04 23:15:15 +00002729 <td>
2730 Distort the given list control points (any number) using an Inverse
cristy82a2ff22015-05-12 16:41:32 +00002731 Squared Distance Interpolation Method (<a href="http://en.wikipedia.org/wiki/Shepard%27s_method">Shepards
cristyd2432012015-05-04 23:15:15 +00002732 Method</a>). The control points in effect do 'localized' displacement
2733 of the image around the given control point (preserving the look and
2734 the rotation of the area near the control points. For best results
2735 extra control points should be added to 'lock' the positions of the
2736 corners, edges and other unchanging parts of the image, to prevent
cristy82a2ff22015-05-12 16:41:32 +00002737 their movement. <br>
cristyd2432012015-05-04 23:15:15 +00002738
2739 The distortion has been likened to 'taffy pulling' using nails, or
2740 pins' stuck in a block of 'jelly' which is then moved to the new
cristy82a2ff22015-05-12 16:41:32 +00002741 position, distorting the surface of the jelly. <br>
cristyd2432012015-05-04 23:15:15 +00002742
cristy82a2ff22015-05-12 16:41:32 +00002743 Internally it is equivalent to generating a displacement map (see <a href="command-line-options.html#displace">-displace</a>) for source image color look-up using
2744 the <a href="command-line-options.html#sparse-color">-sparse-color</a> method of the same name.
cristyd2432012015-05-04 23:15:15 +00002745
2746 </td>
2747 </tr>
2748
2749</table>
2750
2751<p>To print a complete list of distortion methods, use <a href="command-line-options.html#list">-list
2752distort</a>.</p>
2753
2754<p>Many of the above distortion methods such as '<code>Affine</code>',
2755'<code>Perspective</code>', and '<code>Shepards</code>' use a list control points
2756defining how these points in the given image should be distorted in the
2757destination image. Each set of four floating point values represent a source
2758image coordinate, followed immediately by the destination image coordinate.
2759This produces a list of values such as...</p>
cristyb2cad532015-05-16 13:02:45 +00002760<p class="text-center"><var>
cristyd2432012015-05-04 23:15:15 +00002761 U<sub>1</sub>,V<sub>1</sub> X<sub>1</sub>,Y<sub>1</sub>
2762 U<sub>2</sub>,V<sub>2</sub> X<sub>2</sub>,Y<sub>2</sub>
2763 U<sub>3</sub>,V<sub>3</sub> X<sub>3</sub>,Y<sub>3</sub>
2764 ...
2765 U<sub>n</sub>,V<sub>n</sub> X<sub>n</sub>,Y<sub>n</sub>
cristyb2cad532015-05-16 13:02:45 +00002766</var></p>
cristyd2432012015-05-04 23:15:15 +00002767<p>where <var>U,V</var> on the source image is mapped to <var>X,Y</var> on the
2768destination image. </p>
2769
2770<p>For example, to warp an image using '<code>perspective</code>' distortion,
2771needs a list of at least 4 sets of coordinates, or 16 numbers. Here is the
2772perspective distortion of the built-in "rose:" image. Note how spaces were
2773used to group the 4 sets of coordinate pairs, to make it easier to read and
2774understand.</p>
2775
2776<pre>
2777convert rose: -virtual-pixel black \
cristy29dc8652015-05-12 16:26:21 +00002778 -distort Perspective '0,0,0,0 0,45,0,45 69,0,60,10 69,45,60,35' \
2779 rose_3d_rotated.gif"
cristyd2432012015-05-04 23:15:15 +00002780</pre>
2781
2782<p>If more that the required number of coordinate pairs are given for
2783a distortion, the distortion method is 'least squares' fitted to produce the
2784best result for all the coordinate pairs given. If less than the ideal number
2785of points are given, the distort will generally fall back to a simpler form of
2786distortion that can handles the smaller number of coordinates (usually a linear
2787'<code>Affine</code>' distortion). </p>
2788
2789<p>By using more coordinates you can make use of image registration tool to
2790find matching coordinate pairs in overlapping images, so as to improve the
2791'fit' of the distortion. Of course a bad coordinate pair can also make the
2792'fit' worse. Caution is always advised. </p>
2793
2794<p>Colors are acquired from the source image according to a cylindrical
cristy82a2ff22015-05-12 16:41:32 +00002795resampling <a href="command-line-options.html#filter">-filter</a>, using a special technique known as
cristyd2432012015-05-04 23:15:15 +00002796EWA resampling. This produces very high quality results, especially when
2797images become smaller (minified) in the output, which is very common when
2798using '<code>perspective</code>' distortion. For example here we view
2799a infinitely tiled 'plane' all the way to the horizon. </p>
2800
2801<pre>
2802convert -size 90x90 pattern:checkerboard -normalize -virtual-pixel tile \
cristy29dc8652015-05-12 16:26:21 +00002803 -distort perspective '0,0,5,45 89,0,45,46 0,89,0,89 89,89,89,89' \
2804 checks_tiled.jpg
cristyd2432012015-05-04 23:15:15 +00002805</pre>
2806
2807<p>Note that a infinitely tiled perspective images involving the horizon can
2808be very slow, because of the number of pixels that are compressed to generate
2809each individual pixel close to the 'horizon'. You can turn off EWA
cristy82a2ff22015-05-12 16:41:32 +00002810resampling, by specifing the special <a href="command-line-options.html#filter">-filter</a> setting of
cristyd2432012015-05-04 23:15:15 +00002811'<code>point</code>' (recommended if you plan to use super-sampling instead).
2812</p>
2813
2814<p>If an image generates <i>invalid pixels</i>, such as the 'sky' in the last
cristy82a2ff22015-05-12 16:41:32 +00002815example, <a href="command-line-options.html#distort">-distort</a> will use the current <a href="command-line-options.html#mattecolor">-mattecolor</a> setting for these pixels. If you do not
cristyd2432012015-05-04 23:15:15 +00002816what these pixels to be visible, set the color to match the rest of the
2817ground. </p>
2818
2819<p>The output image size will by default be the same as the input image. This
2820means that if the part of the distorted image falls outside the viewed area of
2821the 'distorted space', those parts is clipped and lost. However if you use
cristy82a2ff22015-05-12 16:41:32 +00002822the plus form of the operator (<a href="command-line-options.html#distort">+distort</a>) the operator
cristyd2432012015-05-04 23:15:15 +00002823will attempt (if possible) to show the whole of the distorted image, while
2824retaining a correct 'virtual canvas' offset, for image layering. This offset
cristy82a2ff22015-05-12 16:41:32 +00002825may need to be removed using <a href="command-line-options.html#repage">+repage</a>, to remove if it
cristyd2432012015-05-04 23:15:15 +00002826is unwanted. </p>
2827
cristy82a2ff22015-05-12 16:41:32 +00002828<p>Setting <a href="command-line-options.html#verbose">-verbose</a> setting, will cause <a href="command-line-options.html#distort">-distort</a> to attempt to output the internal coefficients,
2829and the <a href="command-line-options.html#fx">-fx</a> equivalent to the distortion, for expert study,
cristyd2432012015-05-04 23:15:15 +00002830and debugging purposes. This many not be available for all distorts. </p>
2831
cristy82a2ff22015-05-12 16:41:32 +00002832<p>You can alternatively specify a special "<code><a href="command-line-options.html#define">-define</a> distort:viewport={geometry_string}</code>" setting which will
cristyd2432012015-05-04 23:15:15 +00002833specify the size and the offset of the generated 'viewport' image of the
2834distorted image space.</p>
2835
cristy82a2ff22015-05-12 16:41:32 +00002836<p>Setting a "<code><a href="command-line-options.html#define">-define</a>
cristyd2432012015-05-04 23:15:15 +00002837distort:scale={scale_factor}</code>" will scale the output image (viewport or
2838otherwise) by that factor without changing the viewed contents of the
2839distorted image. This can be used either for 'super-sampling' the image for
2840a higher quality result, or for panning and zooming around the image (with
2841appropriate viewport changes, or post-distort cropping and resizing). </p>
2842
cristy82a2ff22015-05-12 16:41:32 +00002843<p>Setting "<code><a href="command-line-options.html#define">-define</a> resample:verbose=1</code>"
cristyd2432012015-05-04 23:15:15 +00002844will output the cylindrical filter lookup table created by the EWA (Elliptical
2845Weighted Average) resampling algorithm. Note this table uses a squared radius
2846lookup value. This is typically only used for debugging EWA resampling. </p>
2847
2848
2849<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002850 <h3 class="magick-header"><a id="distribute-cache"></a>-distribute-cache <var>port</var></h3>
cristyd2432012015-05-04 23:15:15 +00002851</div>
2852
2853<p class="magick-description">launch a distributed pixel cache server. </p>
2854
2855<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002856 <h3 class="magick-header"><a id="dither"></a>-dither <var>method</var></h3>
cristyd2432012015-05-04 23:15:15 +00002857</div>
2858
2859<p class="magick-description">Apply a Riemersma or Floyd-Steinberg error diffusion dither to
2860images when general color reduction is applied via an option, or automagically
2861when saving to specific formats. This enabled by default.</p>
2862
2863<p>Dithering places two or more colors in neighboring pixels so that to the
2864eye a closer approximation of the images original color is reproduced. This
2865reduces the number of colors needed to reproduce the image but at the cost of
2866a lower level pattern of colors. Error diffusion dithers can use any set of
2867colors (generated or user defined) to an image. </p>
2868
2869<p>Dithering is turned on by default, to turn it off use the plus form of the
2870setting, <a href="command-line-options.html#dither">+dither</a>. This will also also render PostScript
2871without text or graphic aliasing. Disabling dithering often (but not always)
2872leads to faster process, a smaller number of colors, but more cartoon like
2873image coloring. Generally resulting in 'color banding' effects in areas with
2874color gradients. </p>
2875
cristy82a2ff22015-05-12 16:41:32 +00002876<p>The color reduction operators <a href="command-line-options.html#colors">-colors</a>, <a href="command-line-options.html#monochrome">-monochrome</a>, <a href="command-line-options.html#remap%20">-remap</a>, and <a href="command-line-options.html#posterize">-posterize</a>, apply dithering to images using the reduced
cristyd2432012015-05-04 23:15:15 +00002877color set they created. These operators are also used as part of automatic
2878color reduction when saving images to formats with limited color support, such
2879as <code>GIF:</code>, <code>XBM:</code>, and others, so dithering may also be used
2880in these cases. </p>
2881
2882<p>Alternatively you can use <a href="command-line-options.html#random-threshold">-random-threshold</a>
cristy82a2ff22015-05-12 16:41:32 +00002883to generate purely random dither. Or use <a href="command-line-options.html#ordered-dither">-ordered-dither</a> to apply threshold mapped dither
cristyd2432012015-05-04 23:15:15 +00002884patterns, using uniform color maps, rather than specific color maps. </p>
2885
2886
2887<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002888 <h3 class="magick-header"><a id="draw"></a>-draw <var>string</var></h3>
cristyd2432012015-05-04 23:15:15 +00002889</div>
2890
2891<p class="magick-description">Annotate an image with one or more graphic primitives.</p>
2892
2893<p>Use this option to annotate or decorate an image with one or more graphic
2894primitives. The primitives include shapes, text, transformations, and pixel
2895operations.</p>
2896
2897<p>The shape primitives:</p>
2898
cristyb2cad532015-05-16 13:02:45 +00002899<dl class="dl-horizontal">
2900<dt>point</dt><dd> x,y</dd>
2901<dt>line</dt><dd> x0,y0 x1,y1</dd>
2902<dt>rectangle</dt><dd> x0,y0 x1,y1</dd>
2903<dt>roundRectangle</dt><dd> x0,y0 x1,y1 wc,hc</dd>
2904<dt>arc</dt><dd> x0,y0 x1,y1 a0,a1</dd>
2905<dt>ellipse</dt><dd> x0,y0 rx,ry a0,a1</dd>
2906<dt>circle</dt><dd> x0,y0 x1,y1</dd>
2907<dt>polyline</dt><dd> x0,y0 ... xn,yn</dd>
2908<dt>polygon</dt><dd> x0,y0 ... xn,yn</dd>
2909<dt>bezier</dt><dd> x0,y0 ... xn,yn</dd>
2910<dt>path</dt><dd>specification </dd>
2911<dt>image</dt><dd> operator x0,y0 w,h filename</dd>
2912</dl>
cristyd2432012015-05-04 23:15:15 +00002913
2914<p>The text primitive:</p>
2915
cristyb2cad532015-05-16 13:02:45 +00002916<dl class="dl-horizontal">
2917<dt>text</dt><dd>x0,y0 string</dd>
2918</dl>
cristyd2432012015-05-04 23:15:15 +00002919<p>The text gravity primitive:</p>
2920
cristyb2cad532015-05-16 13:02:45 +00002921<dl class="dl-horizontal">
2922<dt>gravity</dt><dd>NorthWest, North, NorthEast, West, Center, East, SouthWest, South, or SouthEast</dd>
2923</dl>
cristyd2432012015-05-04 23:15:15 +00002924
2925<p>The text gravity primitive only affects the placement of text and does not
cristy82a2ff22015-05-12 16:41:32 +00002926interact with the other primitives. It is equivalent to using the <a href="command-line-options.html#gravity">-gravity</a> command-line option, except that it is limited in
cristyd2432012015-05-04 23:15:15 +00002927scope to the <a href="command-line-options.html#draw">-draw</a> option in which it appears.</p>
2928
2929<p>The transformation primitives:</p>
2930
cristyb2cad532015-05-16 13:02:45 +00002931<dl class="dl-horizontal">
2932<dt>rotate</dt><dd>degrees</dd>
2933<dt>translate</dt><dd>dx,dy</dd>
2934<dt>scale</dt><dd>sx,sy</dd>
2935<dt>skewX</dt><dd>degrees</dd>
2936<dt>skewY</dt><dd>degrees</dd>
2937</dl>
cristyd2432012015-05-04 23:15:15 +00002938
2939<p>The pixel operation primitives:</p>
2940
cristyb2cad532015-05-16 13:02:45 +00002941<dl class="dl-horizontal">
2942<dt>color</dt><dd>x0,y0 method</dd>
2943<dt>matte</dt><dd>x0,y0 method</dd>
2944</dl>
cristyd2432012015-05-04 23:15:15 +00002945
cristy82a2ff22015-05-12 16:41:32 +00002946<p>The shape primitives are drawn in the color specified by the preceding <a href="command-line-options.html#fill">-fill</a> setting. For unfilled shapes, use <a href="command-line-options.html#fill">-fill none</a>. You can optionally control the stroke (the
2947"outline" of a shape) with the <a href="command-line-options.html#stroke">-stroke</a> and <a href="command-line-options.html#strokewidth">-strokewidth</a> settings.</p>
cristyd2432012015-05-04 23:15:15 +00002948
2949<p>A <code>point</code> primitive is specified by a single <var>point</var> in the
2950pixel plane, that is, by an ordered pair of integer coordinates,
2951<var>x</var>,<var>y</var>. (As it involves only a single pixel, a <code>point</code>
cristy82a2ff22015-05-12 16:41:32 +00002952primitive is not affected by <a href="command-line-options.html#stroke">-stroke</a> or <a href="command-line-options.html#strokewidth">-strokewidth</a>.)</p>
cristyd2432012015-05-04 23:15:15 +00002953
2954<p>A <code>line</code> primitive requires a start point and end point.</p>
2955
2956<p>A <code>rectangle</code> primitive is specified by the pair of points at the
2957upper left and lower right corners.</p>
2958
2959<p>A <code>roundRectangle</code> primitive takes the same corner points as
2960a <code>rectangle</code> followed by the width and height of the rounded corners
2961to be removed.</p>
2962
2963<p>The <code>circle</code> primitive makes a disk (filled) or circle (unfilled).
2964Give the center and any point on the perimeter (boundary).</p>
2965
2966<p>The <code>arc</code> primitive is used to inscribe an elliptical segment in
2967to a given rectangle. An <code>arc</code> requires the two corners used for
2968<code>rectangle</code> (see above) followed by the start and end angles of the
2969arc of the segment segment (e.g. 130,30 200,100 45,90). The start and end
2970points produced are then joined with a line segment and the resulting segment
2971of an ellipse is filled.</p>
2972
2973<p>Use <code>ellipse</code> to draw a partial (or whole) ellipse. Give the
2974center point, the horizontal and vertical "radii" (the <var>semi-axes</var> of
2975the ellipse) and start and end angles in degrees (e.g. 100,100 100,150
29760,360).</p>
2977
2978<p>The <code>polyline</code> and <code>polygon</code> primitives require three or
2979more points to define their perimeters. A <code>polyline</code> is simply
2980a <code>polygon</code> in which the final point is not stroked to the start
cristy82a2ff22015-05-12 16:41:32 +00002981point. When unfilled, this is a <var>polygonal line</var>. If the <a href="command-line-options.html#stroke">-stroke</a> setting is <code>none</code> (the default), then
cristyd2432012015-05-04 23:15:15 +00002982a <code>polyline</code> is identical to a <code>polygon</code>. </p>
2983
2984<p>A <var>coordinate</var> is a pair of integers separated by a space or
2985optional comma. </p>
2986
2987<p>As an example, to define a circle centered at 100,100 that extends to
2988150,150 use:</p>
2989
cristy29dc8652015-05-12 16:26:21 +00002990<pre>
2991-draw 'circle 100,100 150,150'
2992</pre>
cristyd2432012015-05-04 23:15:15 +00002993
2994<p>The <code>Bezier</code> primitive creates a spline curve and requires three
2995or points to define its shape. The first and last points are the
2996<var>knots</var> and these points are attained by the curve, while any
2997intermediate coordinates are <var>control points</var>. If two control points
2998are specified, the line between each end knot and its sequentially respective
2999control point determines the tangent direction of the curve at that end. If
3000one control point is specified, the lines from the end knots to the one
3001control point determines the tangent directions of the curve at each end. If
3002more than two control points are specified, then the additional control points
3003act in combination to determine the intermediate shape of the curve. In order
3004to draw complex curves, it is highly recommended either to use the
3005<code>path</code> primitive or to draw multiple four-point bezier segments with
3006the start and end knots of each successive segment repeated. For example:</p>
3007
cristy29dc8652015-05-12 16:26:21 +00003008<pre>
3009-draw 'bezier 20,50 45,100 45,0 70,50'
3010-draw 'bezier 70,50 95,100 95,0 120,50'
3011</pre>
cristyd2432012015-05-04 23:15:15 +00003012
3013<p>A <code>path</code> represents an outline of an object, defined in terms of
3014moveto (set a new current point), lineto (draw a straight line), curveto (draw
3015a Bezier curve), arc (elliptical or circular arc) and closepath (close the
3016current shape by drawing a line to the last moveto) elements. Compound paths
3017(i.e., a path with subpaths, each consisting of a single moveto followed by
3018one or more line or curve operations) are possible to allow effects such as
cristy82a2ff22015-05-12 16:41:32 +00003019<var>donut holes</var> in objects. (See <a href="http://www.w3.org/TR/SVG/paths.html">Paths</a>.)</p>
cristyd2432012015-05-04 23:15:15 +00003020
3021<p>Use <code>image</code> to composite an image with another image. Follow the
3022image keyword with the composite operator, image location, image size, and
3023filename:</p>
3024
cristy29dc8652015-05-12 16:26:21 +00003025<pre>
3026-draw 'image SrcOver 100,100 225,225 image.jpg'
3027</pre>
cristyd2432012015-05-04 23:15:15 +00003028
3029<p>You can use 0,0 for the image size, which means to use the actual
3030dimensions found in the image header. Otherwise, it is scaled to the given
3031dimensions. See <a href="compose.html">Alpha Compositing</a> for
3032a detailed discussion of alpha composition methods that are available. </p>
3033
3034<p>The "special augmented compose operators" such as "dissolve" that require
3035arguments cannot be used at present with the <code>-draw image</code> option.
3036 </p>
3037
3038<p>Use <code>text</code> to annotate an image with text. Follow the text
3039coordinates with a string. If the string has embedded spaces, enclose it in
3040single or double quotes.</p>
3041
3042<p>For example, the following annotates the image with <code>Works like
3043magick!</code> for an image titled <code>bird.miff</code>. </p>
3044
cristy29dc8652015-05-12 16:26:21 +00003045<pre>
3046-draw "text 100,100 'Works like magick!' "
3047</pre>
cristyd2432012015-05-04 23:15:15 +00003048
3049<p>See the <a href="command-line-options.html#annotate">-annotate</a> option for another convenient way
3050to annotate an image with text.</p>
3051
3052<p>The <code>rotate</code> primitive rotates subsequent shape primitives and
cristy82a2ff22015-05-12 16:41:32 +00003053text primitives about the origin of the main image. If the <a href="command-line-options.html#region">-region</a> option precedes the <a href="command-line-options.html#draw">-draw</a>
cristyd2432012015-05-04 23:15:15 +00003054option, the origin for transformations is the upper left corner of the
3055region.</p>
3056
3057<p>The <code>translate</code> primitive translates subsequent shape and text
3058primitives.</p>
3059
3060<p>The <code>scale</code> primitive scales them.</p>
3061
3062<p>The <code>skewX</code> and <code>skewY</code> primitives skew them with respect
3063to the origin of the main image or the region.</p>
3064
3065<p>The transformations modify the current affine matrix, which is initialized
3066from the initial affine matrix defined by the <a href="command-line-options.html#affine">-affine</a>
3067option. Transformations are cumulative within the <a href="command-line-options.html#draw">-draw</a>
3068option. The initial affine matrix is not affected; that matrix is only changed
3069by the appearance of another <a href="command-line-options.html#affine">-affine</a> option. If another
3070<a href="command-line-options.html#draw">-draw</a> option appears, the current affine matrix is
3071reinitialized from the initial affine matrix.</p>
3072
3073<p>Use the <code>color</code> primitive to change the color of a pixel to the
3074fill color (see <a href="command-line-options.html#fill">-fill</a>). Follow the pixel coordinate with
3075a method:</p>
3076
3077<pre>
cristy29dc8652015-05-12 16:26:21 +00003078point
3079replace
3080floodfill
3081filltoborder
3082reset
cristyd2432012015-05-04 23:15:15 +00003083</pre>
3084
3085<p>Consider the target pixel as that specified by your coordinate. The
3086<code>point</code> method recolors the target pixel. The <code>replace</code>
3087method recolors any pixel that matches the color of the target pixel.
3088<code>Floodfill</code> recolors any pixel that matches the color of the target
3089pixel and is a neighbor, whereas <code>filltoborder</code> recolors any neighbor
3090pixel that is not the border color. Finally, <code>reset</code> recolors all
3091pixels.</p>
3092
3093<p>Use <code>matte</code> to the change the pixel matte value to transparent.
3094Follow the pixel coordinate with a method (see the <code>color</code> primitive
3095for a description of methods). The <code>point</code> method changes the matte
3096value of the target pixel. The <code>replace</code> method changes the matte
3097value of any pixel that matches the color of the target pixel.
3098<code>Floodfill</code> changes the matte value of any pixel that matches the
3099color of the target pixel and is a neighbor, whereas <code>filltoborder</code>
cristy82a2ff22015-05-12 16:41:32 +00003100changes the matte value of any neighbor pixel that is not the border color (<a href="command-line-options.html#bordercolor">-bordercolor</a>). Finally <code>reset</code> changes the
cristyd2432012015-05-04 23:15:15 +00003101matte value of all pixels.</p>
3102
cristy82a2ff22015-05-12 16:41:32 +00003103<p>You can set the primitive color, font, and font bounding box color with <a href="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>
cristyd2432012015-05-04 23:15:15 +00003104respectively. Options are processed in command line order so be sure to use
3105these options <var>before</var> the <a href="command-line-options.html#draw">-draw</a> option.</p>
3106
3107<p>Strings that begin with a number must be quoted (e.g. use '1.png' rather
3108than 1.png).</p>
3109
cristy82a2ff22015-05-12 16:41:32 +00003110<p>Drawing primitives conform to the <a href="magick-vector-graphics.html">Magick
cristyd2432012015-05-04 23:15:15 +00003111Vector Graphics</a> format.</p>
3112
3113
3114<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003115 <h3 class="magick-header"><a id="duplicate"></a>-duplicate <var>count,indexes</var></h3>
cristyd2432012015-05-04 23:15:15 +00003116</div>
3117
3118<p class="magick-description">duplicate an image one or more times.</p>
3119
3120<p>Specify the count and the image to duplicate by its index in the sequence.
3121The first image is index 0. Negative indexes are relative to the end of the
3122sequence, for example, -1 represents the last image of the sequence. Specify
3123a range of images with a dash (e.g. 0-4). Separate indexes with a comma (e.g.
31240,2). Use <code>+duplicate</code> to duplicate the last image in the current
3125image sequence.</p>
3126
3127<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003128 <h3 class="magick-header"><a id="edge"></a>-edge <var>radius</var></h3>
cristyd2432012015-05-04 23:15:15 +00003129</div>
3130
3131<p class="magick-description">detect edges within an image.</p>
3132
3133<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003134 <h3 class="magick-header"><a id="emboss"></a>-emboss <var>radius</var></h3>
cristyd2432012015-05-04 23:15:15 +00003135</div>
3136
3137<p class="magick-description">emboss an image.</p>
3138
3139<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003140 <h3 class="magick-header"><a id="encipher"></a>-encipher <var>filename</var></h3>
cristyd2432012015-05-04 23:15:15 +00003141</div>
3142
3143<p class="magick-description">Encipher pixels for later deciphering by <a href="command-line-options.html#decipher">-decipher</a>.</p>
3144
3145<p>Get the passphrase from the file specified by <var>filename</var>.</p>
3146
cristyea2793e2015-05-31 16:52:26 +00003147<p>For more information, see the webpage, <a href="../www/cipher.html">ImageMagick: Encipher or
cristyd2432012015-05-04 23:15:15 +00003148Decipher an Image</a>.</p>
3149
3150
3151
3152<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003153 <h3 class="magick-header"><a id="encoding"></a>-encoding <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00003154</div>
3155
3156<p class="magick-description">specify the text encoding.</p>
3157
cristyb2cad532015-05-16 13:02:45 +00003158<p>Choose from</p>
3159
3160<pre>
3161AdobeCustom AdobeExpert
3162AdobeStandard AppleRoman
3163BIG5 GB2312
3164Latin 2 None
3165SJIScode Symbol
3166Unicode Wansung
3167</pre>
cristyd2432012015-05-04 23:15:15 +00003168
3169<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003170 <h3 class="magick-header"><a id="endian"></a>-endian <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00003171</div>
3172
3173<p class="magick-description">Specify endianness (<code>MSB</code> or <code>LSB</code>) of the image.</p>
3174
3175<p>To print a complete list of endian types, use the <a href="command-line-options.html#list">-list endian</a> option.</p>
3176
3177<p>Use <a href="command-line-options.html#endian">+endian</a> to revert to unspecified endianness.</p>
3178
3179
3180<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003181 <h3 class="magick-header"><a id="enhance"></a>-enhance</h3>
cristyd2432012015-05-04 23:15:15 +00003182</div>
3183
3184<p class="magick-description">Apply a digital filter to enhance a noisy image.</p>
3185
3186
3187<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003188 <h3 class="magick-header"><a id="equalize"></a>-equalize</h3>
cristyd2432012015-05-04 23:15:15 +00003189</div>
3190
3191<p class="magick-description">perform histogram equalization on the image channel-by-channel.</p>
3192
3193<p>To perform histogram equalization on all channels in concert, transform the
3194image into some other color space, such as HSL, OHTA, YIQ or YUV, then
3195equalize the appropriate intensity-like channel, then convert back to RGB.</p>
3196
3197<p>For example using HSL, we have: ... <code>-colorspace HSL -channel lightness
3198-equalize -colorspace RGB</code> ...</p>
3199
3200<p>For YIQ, YUV and OHTA use the red channel. For example, OHTA is a principal
3201components transformation that puts most of the information in the first
3202channel. Here we have ... <code>-colorspace OHTA -channel red -equalize
3203-colorspace RGB</code> ...</p>
3204
3205<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003206 <h3 class="magick-header"><a id="evaluate"></a>-evaluate <var>operator value</var></h3>
cristyd2432012015-05-04 23:15:15 +00003207</div>
3208
3209<p class="magick-description">Alter channel pixels by evaluating an arithmetic, relational, or logical expression.</p>
3210
cristy82a2ff22015-05-12 16:41:32 +00003211<p>(See the <a href="command-line-options.html#function">-function</a> operator for some
3212multi-parameter functions. See the <a href="command-line-options.html#fx">-fx</a> operator if more
cristyd2432012015-05-04 23:15:15 +00003213elaborate calculations are needed.)</p>
3214
3215<p>The behaviors of each <var>operator</var> are summarized in the
3216following list. For brevity, the numerical value of a "pixel" referred to
3217below is the value of the corresponding channel of that pixel, while
3218a "normalized pixel" is that number divided by the maximum
3219(installation-dependent) value <var>QuantumRange</var>. (If
3220normalized pixels are used, they are restored, following the other
3221calculations, to the full range by multiplying by <var>QuantumRange</var>.)</p>
3222
3223<table class="table table-condensed table-striped">
cristy82a2ff22015-05-12 16:41:32 +00003224 <col width="25%">
3225 <col width="75%">
cristyd2432012015-05-04 23:15:15 +00003226 <thead>
3227 <tr>
3228 <th><var>operator</var></th>
3229 <th>Summary (see further below for details)</th>
3230 </tr>
3231 </thead>
3232 <tbody>
3233
3234 <tr><td>Abs </td> <td>Add <var>value</var> to pixels and return absolute value. </td></tr>
3235 <tr><td>Add </td> <td>Add <var>value</var> to pixels. </td></tr>
3236 <tr><td>AddModulus </td> <td>Add <var>value</var> to pixels modulo <var>QuantumRange</var>.</td></tr>
3237 <tr><td>And </td> <td>Binary AND of pixels with <var>value</var>.</td></tr>
3238 <tr><td>Cos, Cosine </td> <td>Apply cosine to pixels with frequency <var>value</var> with 50% bias added.</td></tr>
3239 <tr><td>Divide </td> <td>Divide pixels by <var>value</var>.</td></tr>
3240 <tr><td>Exp </td> <td>base-e exponential function</td></tr>
3241 <tr><td>Exponential </td> <td>base-e exponential function</td></tr>
3242 <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>
3243 <tr><td>Log </td> <td>Apply scaled logarithm to normalized pixels.</td></tr>
cristyea2793e2015-05-31 16:52:26 +00003244 <tr><td>Max </td> <td>Clip pixels at upper bound <var>value</var>.</td></tr>
cristyd2432012015-05-04 23:15:15 +00003245 <tr><td>Mean </td> <td>Add the <var>value</var> and divide by 2.</td></tr>
3246 <tr><td>Median </td> <td>Choose the median value from an image sequence.</td></tr>
cristyea2793e2015-05-31 16:52:26 +00003247 <tr><td>Min </td> <td>Clip pixels at lower bound <var>value</var>.</td></tr>
cristyd2432012015-05-04 23:15:15 +00003248 <tr><td>Multiply </td> <td>Multiply pixels by <var>value</var>.</td></tr>
3249 <tr><td>Or </td> <td>Binary OR of pixels with <var>value</var>.</td></tr>
3250 <tr><td>Pow </td> <td>Raise normalized pixels to the power <var>value</var>.</td></tr>
3251 <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>
3252 <tr><td>RMS</td> <td>Square the pixel and add the <var>value</var>.</td></tr>
3253 <tr><td>RootMeanSquare</td> <td>Square the pixel and add the <var>value</var>.</td></tr>
3254 <tr><td>Set </td> <td>Set pixel equal to <var>value</var>.</td></tr>
3255 <tr><td>Sin, Sine </td> <td>Apply sine to pixels with frequency <var>value</var> with 50% bias added.</td></tr>
3256 <tr><td>Subtract </td> <td>Subtract <var>value</var> from pixels.</td></tr>
3257 <tr><td>Xor </td> <td>Binary XOR of pixels with <var>value.</var></td></tr>
3258
cristya1890f02015-05-15 23:32:44 +00003259 <tr><td> </td><td> </td></tr>
cristyd2432012015-05-04 23:15:15 +00003260
cristy29dc8652015-05-12 16:26:21 +00003261 <tr><td>Gaussian-noise</td><td> </td></tr>
3262 <tr><td>Impulse-noise</td><td> </td></tr>
3263 <tr><td>Laplacian-noise</td><td> </td></tr>
cristy82a2ff22015-05-12 16:41:32 +00003264 <tr><td>Multiplicative-noise</td> <td>(These are equivalent to the corresponding <a href="command-line-options.html#noise">-noise</a> operators.)</td></tr>
cristy29dc8652015-05-12 16:26:21 +00003265 <tr><td>PoissonNoise</td><td> </td></tr>
3266 <tr><td>Uniform-noise</td><td> </td></tr>
cristyd2432012015-05-04 23:15:15 +00003267
cristya1890f02015-05-15 23:32:44 +00003268 <tr><td> </td><td> </td></tr>
cristyd2432012015-05-04 23:15:15 +00003269
3270 <tr><td>Threshold </td> <td>Threshold pixels larger than <var>value</var>.</td></tr>
3271 <tr><td>ThresholdBlack </td> <td>Threshold pixels to zero values equal to or below <var>value</var>.</td></tr>
3272 <tr><td>ThresholdWhite </td> <td>Threshold pixels to maximum values above <var>value</var>. </td></tr>
3273 </tbody>
3274 </table>
3275
cristy82a2ff22015-05-12 16:41:32 +00003276<p>The specified functions are applied only to each previously set <a href="command-line-options.html#channel">-channel</a> in the image. If necessary, the results of the
cristyd2432012015-05-04 23:15:15 +00003277calculations are truncated (clipped) to fit in the interval [0, <var>QuantumRange</var>]. The transparency channel of the image is
3278represented as a 'alpha' values (0 = fully transparent), so, for example, a
3279<code>Divide</code> by 2 of the alpha channel will make the image
3280semi-transparent. Append the percent symbol '<code>%</code>' to specify a value
3281as a percentage of the <var>QuantumRange</var>.</p>
3282
3283<p>To print a complete list of <a href="command-line-options.html#evaluate">-evaluate</a> operators, use
3284<a href="command-line-options.html#list">-list evaluate</a>.</p>
3285
3286<p>The results of the <code>Add</code>, <code>Subtract</code> and
cristy82a2ff22015-05-12 16:41:32 +00003287<code>Multiply</code> methods can also be achieved using either the <a href="command-line-options.html#level">-level</a> or the <a href="command-line-options.html#level">+level</a> operator, with
cristyd2432012015-05-04 23:15:15 +00003288appropriate argument, to linearly modify the overall range of color values.
cristy82a2ff22015-05-12 16:41:32 +00003289Please note, however, that <a href="command-line-options.html#level">-level</a> treats transparency as
3290'matte' values (0 = opaque), while <a href="command-line-options.html#level">-evaluate</a> works with
cristyd2432012015-05-04 23:15:15 +00003291'alpha' values.</p>
3292
3293<p><code>AddModulus</code> has been added as of ImageMagick 6.4.8-4 and provides
3294addition modulo the <var>QuantumRange</var>. It is therefore
3295equivalent to <code>Add</code> unless the resulting pixel value is outside the
3296interval [0, <var>QuantumRange</var>]. </p>
3297
3298<p><code>Exp or Exponential</code> has been added as of ImageMagick 6.6.5-1 and
3299works on normalized pixel values. The <var>value</var> used with
3300<code>Exp</code> should be negative so as to produce a decaying exponential
3301function. Non-negative values will always produce results larger unity and
3302thus outside the interval [0, <var>QuantumRange</var>]. The
3303formula is expressed below. </p>
3304
cristya1890f02015-05-15 23:32:44 +00003305<p class="text-center">
3306exp(<var>value</var> × <b><var>u</var></b>)
3307</p>
cristyd2432012015-05-04 23:15:15 +00003308
cristy82a2ff22015-05-12 16:41:32 +00003309<p> If the input image is squared, for example, using <a href="command-line-options.html#-function">-function polynomial "2 0 0"</a>, then a decaying Gaussian function will be
cristyd2432012015-05-04 23:15:15 +00003310the result.</p>
3311
3312<p><code>Log</code> has been added as of ImageMagick 6.4.2-1 and works on
3313normalized pixel values. This a <var>scaled</var> log function. The <var>value</var> used with <code>Log</code> provides a <var>scaling
3314factor</var> that adjusts the curvature in the graph of the log function. The
3315formula applied to a normalized value <b><var>u</var></b> is below. </p>
3316
cristya1890f02015-05-15 23:32:44 +00003317<p class="text-center">
3318log(<var>value</var> × <b><var>u</var></b> + 1) / log(<var>value</var> + 1)
3319</p>
cristyd2432012015-05-04 23:15:15 +00003320
3321<p><code>Pow</code> has been added as of ImageMagick 6.4.1-9, and works on
cristy82a2ff22015-05-12 16:41:32 +00003322normalized pixel values. Note that <code>Pow</code> is related to the <a href="command-line-options.html#gamma">-gamma</a> operator. For example, <b>-gamma 2</b> is equivalent
cristyd2432012015-05-04 23:15:15 +00003323to <b>-evaluate pow 0.5</b>, i.e., a 'square root' function. The value used
cristy82a2ff22015-05-12 16:41:32 +00003324with <a href="command-line-options.html#gamma">-gamma</a> is simply the reciprocal of the value used
cristyd2432012015-05-04 23:15:15 +00003325with <code>Pow</code>.</p>
3326
3327<p><code>Cosine</code> and <code>Sine</code> was added as of IM v6.4.8-8 and
3328converts the image values into a value according to a (co)sine wave function.
3329The synonyms <code>Cos</code> and <code>Sin</code> may also be used. The output
3330is biased 50% and normalized by 50% so as to fit in the respective color value
3331range. The <var>value</var> scaling of the <var>period</var> of the
3332function (its frequency), and thus determines the number of 'waves' that will
3333be 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,
3334then the effective period is the <var>half</var> the <var>QuantumRange</var>.</p>
3335
cristya1890f02015-05-15 23:32:44 +00003336<p class="text-center">
33370.5 + 0.5 × cos(2 π <b><var>u</var></b> × <var>value</var>).
3338</p>
cristyd2432012015-05-04 23:15:15 +00003339
cristy82a2ff22015-05-12 16:41:32 +00003340<p>See also the <a href="command-line-options.html#function">-function</a> operator, which is a
cristyd2432012015-05-04 23:15:15 +00003341multi-value version of evaluate. </p>
3342
3343<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003344 <h3 class="magick-header"><a id="evaluate-sequence"></a>-evaluate-sequence <var>operator</var></h3>
cristyd2432012015-05-04 23:15:15 +00003345</div>
3346
3347<p class="magick-description">Alter channel pixels by evaluating an arithmetic, relational, or
3348logical expression over a sequence of images.</p>
3349
cristy82a2ff22015-05-12 16:41:32 +00003350<p>To print a complete list of <a href="command-line-options.html#evaluate-sequence">-evaluate-sequence</a> operators, use <a href="command-line-options.html#list">-list evaluate</a>.</p>
cristyd2432012015-05-04 23:15:15 +00003351
3352<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003353 <h3 class="magick-header"><a id="extent"></a>-extent <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00003354</div>
3355
3356<p class="magick-description">Set the image size and offset.</p>
3357
3358<p>If the image is enlarged, unfilled areas are set to the background color.
3359To position the image, use offsets in the <var>geometry</var>
3360specification or precede with a <a href="command-line-options.html#gravity">-gravity</a> setting. To
cristy82a2ff22015-05-12 16:41:32 +00003361specify how to compose the image with the background, use <a href="command-line-options.html#compose">-compose</a>.</p>
cristyd2432012015-05-04 23:15:15 +00003362
3363<p>This command reduces or expands a JPEG image to fit on an 800x600
3364display. If the aspect ratio of the input image isn't exactly 4:3, then the
3365image is centered on an 800x600 black canvas: </p>
3366
3367<pre>
3368convert input.jpg -resize 800x600 -background black -compose Copy \
3369 -gravity center -extent 800x600 -quality 92 output.jpg
3370</pre>
3371
3372<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
3373
3374<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003375 <h3 class="magick-header"><a id="extract"></a>-extract <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00003376</div>
3377
3378<p class="magick-description">Extract the specified area from image.</p>
3379
3380<p>This option is most useful for extracting a subregion of a very large raw
3381image. Note that these two commands are equivalent:</p>
3382
3383<pre>
3384convert -size 16000x16000 -depth 8 -extract 640x480+1280+960 \
3385 image.rgb image.png",
3386convert -size 16000x16000 -depth 8 'image.rgb[640x480+1280+960]' \
3387 image.rgb image.png"
3388</pre>
3389
3390<p>If you omit the offsets, as in</p>
3391
3392<pre>
3393convert -size 16000x16000 -depth 8 -extract 640x480 \
3394 image.rgb image.png
3395</pre>
3396
3397<p>the image is <var>resized</var> to the specified dimensions instead,
3398equivalent to:</p>
3399
3400<pre>
3401convert -size 16000x16000 -depth 8 -resize 640x480 image.rgb image.png
3402</pre>
3403
3404<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
3405
3406<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003407 <h3 class="magick-header"><a id="family"></a>-family <var>fontFamily</var></h3>
cristyd2432012015-05-04 23:15:15 +00003408</div>
3409
3410<p class="magick-description">Set a font family for text.</p>
3411
3412<p>This setting suggests a font family that ImageMagick should try to use for
3413rendering text. If the family can be found it is used; if not, a default font
3414(e.g., "Arial") or a family known to be similar is substituted (e.g.,
3415"Courier" might be used if "System" is requested but not found). </p>
3416
cristy82a2ff22015-05-12 16:41:32 +00003417<p>For other settings that affect fonts, see the options <a href="command-line-options.html#font">-font</a>, <a href="command-line-options.html#stretch">-stretch</a>, <a href="command-line-options.html#style">-style</a>, and <a href="command-line-options.html#weight">-weight</a>. </p>
cristyd2432012015-05-04 23:15:15 +00003418
3419<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003420 <h3 class="magick-header"><a id="features"></a>-features <var>distance</var></h3>
cristyd2432012015-05-04 23:15:15 +00003421</div>
3422
3423<p class="magick-description">display (cooccurrence 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>
3424
3425<pre>
cristyb2cad532015-05-16 13:02:45 +00003426Angular Second Moment Sum Entropy
3427Contrast Entropy
3428Correlation Difference Variance
3429Sum of Squares Variance Difference Entropy
3430Inverse Difference Moment Information Measure of Correlation 1
3431Sum Average Information Measure of Correlation 2
3432Sum Variance Maximum Correlation Coefficient
cristyd2432012015-05-04 23:15:15 +00003433</pre>
3434
cristyd2432012015-05-04 23:15:15 +00003435<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003436 <h3 class="magick-header"><a id="fft"></a>-fft</h3>
cristyd2432012015-05-04 23:15:15 +00003437</div>
3438
3439<p class="magick-description">implements the forward discrete Fourier transform (DFT).</p>
3440
3441<p>This option is new as of ImageMagick 6.5.4-3 (and now working for Windows
3442users in ImageMagick 6.6.0-9). It transforms an image from the normal
3443(spatial) domain to the frequency domain. In the frequency domain, an image is
3444represented as a superposition of complex sinusoidal waves of varying
3445amplitudes. The image x and y coordinates are the possible frequencies along
3446the x and y directions, respectively, and the pixel intensity values are
3447complex numbers that correspond to the sinusoidal wave amplitudes. See for
3448example, <a href="http://en.wikipedia.org/wiki/Fourier_transform">Fourier
3449Transform</a>, <a href="http://en.wikipedia.org/wiki/DFT">Discrete Fourier
3450Transform</a> and <a href="http://en.wikipedia.org/wiki/FFT">Fast Fourier
3451Transform</a>.</p>
3452
3453<p>A single image name is provided as output for this option. However, the
3454output result will have two components. It is either a two-frame image or two
3455separate images, depending upon whether the image format specified supports
3456multi-frame images. The reason that we get a dual output result is because the
3457frequency domain represents an image using complex numbers, which cannot be
3458visualized directly. Therefore, the complex values are automagically separated
3459into a two-component image representation. The first component is the
3460magnitude of the complex number and the second is the phase of the complex
cristy82a2ff22015-05-12 16:41:32 +00003461number. See for example, <a href="http://en.wikipedia.org/wiki/Complex_numbers">Complex Numbers</a>.</p>
cristyd2432012015-05-04 23:15:15 +00003462
3463<p>The magnitude and phase component images must be specified using image
3464formats that do not limit the color or compress the image. Thus, MIFF, TIF,
3465PFM, EXR and PNG are the recommended image formats to use. All of these
3466formats, except PNG support multi-frame images. So for example,</p>
3467
3468<pre>
3469convert image.png -fft fft_image.miff
3470</pre>
3471
3472<p>generates a magnitude image as <code>fft_image.miff[0]</code> and a phase
3473image as <code>fft_image.miff[1]</code>. Similarly,</p>
3474
3475<pre>
3476convert image.png -fft fft_image.png
3477</pre>
3478
3479<p>generates a magnitude image as <code>fft_image-0.png</code> and a phase image
3480as <code>fft_image-1.png</code>. If you prefer this representation, then you can
cristy82a2ff22015-05-12 16:41:32 +00003481force any of the other formats to produce two output images by including <a href="command-line-options.html#adjoin">+adjoin</a> following -fft in the command line.</p>
cristyd2432012015-05-04 23:15:15 +00003482
3483<p>The input image can be any size, but if not square and even-dimensioned, it
3484is padded automagically to the larger of the width or height of the input
3485image and to an even number of pixels. The padding will occur at the bottom
3486and/or right sides of the input image. The resulting output magnitude and
cristy82a2ff22015-05-12 16:41:32 +00003487phase images is square at this size. The kind of padding relies on the <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting.</p>
cristyd2432012015-05-04 23:15:15 +00003488
3489<p>Both output components will have dynamic ranges that fit within
3490[0, <var>QuantumRange</var>], so that HDRI need not be enabled.
3491Phase values nominally range from 0 to 2*π, but is scaled to span the full
3492dynamic range. (The first few releases had non-HDRI scaled but HDRI not
3493scaled). The magnitude image is not scaled and thus generally will contain
3494very small values. As such, the image normally will appear totally black. In
3495order to view any detail, the magnitude image typically is enhanced with a log
3496function into what is usually called the spectrum. A log function is used to
3497enhance the darker values more in comparison to the lighter values. This can
3498be done, for example, as follows:</p>
3499
3500<pre>
3501convert fft_image.miff[0] -contrast-stretch 0 \
3502 -evaluate log 1000 fft_image_spectrum.png"
3503</pre>
3504
cristy82a2ff22015-05-12 16:41:32 +00003505<p>where either <a href="command-line-options.html#contrast-stretch">-contrast-stretch</a> 0 or <a href="command-line-options.html#auto-level">-auto-level</a> is used to scale the image to full dynamic
cristyd2432012015-05-04 23:15:15 +00003506range, first. The argument to the <a href="command-line-options.html#evaluate">-evaluate</a> log
3507typically is specified between 100 and 10,000, depending upon the amount of
3508detail that one wants to bring out in the spectrum. Larger values produce more
3509visible detail. Too much detail, however, may hide the important features.</p>
3510
3511<p>The <a href="http://www.fftw.org/">FFTW</a> delegate library is required to
3512use <a href="command-line-options.html#fft">-fft</a>.</p>
3513
3514<p>Use <a href="command-line-options.html#fft">+fft</a> to produce two output images that are the real
3515and imaginary components of the complex valued Fourier transform.</p>
3516
3517<p>However, as the real and imaginary components can contain negative values,
3518this requires that IM be configured with HDRI enabled. In this case, you must
3519use either MIFF, TIF, PFM or MPC formats for the real and imaginary component
3520results, since they are formats that preserve both negative and fractional
3521values without clipping them or truncating the fractional part. With either
3522MIFF or TIF, one should add -define quantum:format=32, to allow those image
3523types to work properly in HDRI mode without clipping.</p>
3524
cristy82a2ff22015-05-12 16:41:32 +00003525<p>The real and imaginary component images resulting from <a href="command-line-options.html#fft">+fft</a> are also square, even dimensioned images due to the same
cristyd2432012015-05-04 23:15:15 +00003526padding that was discussed above for the magnitude and phase component
3527images.</p>
3528
cristy82a2ff22015-05-12 16:41:32 +00003529<p>See the discussion on HDRI implementations of ImageMagick on the page <a href="high-dynamic-range.html">High Dynamic-Range Images</a>. For more
3530about HDRI go the ImageMagick <a href="http://www.imagemagick.org/Usage/basics/#hdri">Usage</a> pages, <a href="http://www.fmwconcepts.com/imagemagick/fourier_transforms/fourier.html">Fred's Fourier Processing With ImageMagick page</a> or this <a href="http://en.wikipedia.org/wiki/High_dynamic_range_imaging">Wikipedia</a>
cristyd2432012015-05-04 23:15:15 +00003531 entry. </p>
3532
cristy82a2ff22015-05-12 16:41:32 +00003533<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 explicityly normalize the FFT and unnormalize the IFT.</p>
cristyd2432012015-05-04 23:15:15 +00003534
3535
3536<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003537 <h3 class="magick-header"><a id="fill"></a>-fill <var>color</var></h3>
cristyd2432012015-05-04 23:15:15 +00003538</div>
3539
3540<p class="magick-description">color to use when filling a graphic primitive.</p>
3541
3542<p>This option accepts a color name, a hex color, or a numerical RGB, RGBA,
cristy82a2ff22015-05-12 16:41:32 +00003543HSL, HSLA, CMYK, or CMYKA specification. See <a href="color.html">Color Names</a> for
cristyd2432012015-05-04 23:15:15 +00003544a description of how to properly specify the color argument.</p>
3545
3546<p>Enclose the color specification in quotation marks to prevent the "#" or
3547the parentheses from being interpreted by your shell.</p>
3548
3549<p>For example,</p>
3550
cristy29dc8652015-05-12 16:26:21 +00003551<pre>
3552-fill blue
3553-fill "#ddddff"
3554-fill "rgb(255,255,255)"
3555</pre>
cristyd2432012015-05-04 23:15:15 +00003556
3557<p>See <a href="command-line-options.html#draw">-draw</a> for further details.</p>
3558
3559<p>To print a complete list of color names, use the <a href="command-line-options.html#list">-list color</a> option.</p>
3560
3561<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003562 <h3 class="magick-header"><a id="filter"></a>-filter <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00003563</div>
3564
3565<p class="magick-description">Use this <var>type</var> of filter when resizing or distorting an image.</p>
3566
3567<p>Use this option to affect the resizing operation of an image during
cristy82a2ff22015-05-12 16:41:32 +00003568operations such as <a href="command-line-options.html#resize">-resize</a> and <a href="command-line-options.html#distort">-distort</a>. For example you can use a simple resize filter such as:</p>
cristyd2432012015-05-04 23:15:15 +00003569
3570<pre>
cristy29dc8652015-05-12 16:26:21 +00003571Point Hermite Cubic
3572Box Gaussian Catrom
3573Triangle Quadratic Mitchell
cristyd2432012015-05-04 23:15:15 +00003574</pre>
3575
3576<p>The <code>Bessel</code> and <code>Sinc</code> filter is also provided (as well
3577as a faster <code>SincFast</code> equivalent form). However these filters are
3578generally useless on their own as they are infinite filters that are being
3579clipped to the filters support size. Their direct use is not recommended
3580except via expert settings (see below). </p>
3581
3582<p>Instead these special filter functions are typically windowed by a windowing
cristy82a2ff22015-05-12 16:41:32 +00003583function that the <a href="command-line-options.html#filter">-filter</a> setting defines. That is
cristyd2432012015-05-04 23:15:15 +00003584using these functions will define a 'Windowed' filter, appropriate to the
3585operator involved. Windowed filters include: </p>
3586
3587<pre>
cristy29dc8652015-05-12 16:26:21 +00003588Lanczos Hamming Parzen
3589Blackman Kaiser Welsh
3590Hanning Bartlett Bohman
cristyd2432012015-05-04 23:15:15 +00003591</pre>
3592
3593<p>Also one special self-windowing filter is also provided
3594<code>Lagrange</code>, which will automagically re-adjust its function depending
3595on the current 'support' or 'lobes' expert settings (see below).</p>
3596
3597<p>If you do not select a filter with this option, the filter defaults to
3598<code>Mitchell</code> for a colormapped image, an image with a matte channel, or
3599if the image is enlarged. Otherwise the filter default to
3600<code>Lanczos</code>.</p>
3601
3602<p>To print a complete list of resize filters, use the <a href="command-line-options.html#list">-list
3603filter</a> option.</p>
3604
3605<p>You can modify how the filter behaves as it scales your image through the
cristy82a2ff22015-05-12 16:41:32 +00003606use of these expert settings (see also <a href="command-line-options.html#define">-define</a> and <a href="command-line-options.html#set">-set</a>):-</p>
cristyd2432012015-05-04 23:15:15 +00003607
cristy29dc8652015-05-12 16:26:21 +00003608<table class="table table-condensed table-striped">
3609 <tr>
3610 <td>-define filter:blur=<var>factor</var></td>
3611 <td>Scale the X axis of the filter (and its window). Use &gt; 1.0 for
cristyd2432012015-05-04 23:15:15 +00003612 blurry or &lt; 1.0 for sharp. This should only be used with Gaussian and
3613 Gaussian-like filters simple filters, or you may not get the expected
cristy29dc8652015-05-12 16:26:21 +00003614 results. </td>
3615 </tr>
cristyd2432012015-05-04 23:15:15 +00003616
cristy29dc8652015-05-12 16:26:21 +00003617 <tr>
3618 <td>-define filter:support=<var>radius</var></td>
3619 <td>Set the filter support radius. Defines how large the filter should be and
cristyd2432012015-05-04 23:15:15 +00003620 thus directly defines how slow the filtered resampling process is. All
3621 filters have a default 'prefered' support size. Some filters like
3622 <code>Lagrange</code> and windowed filters adjust themselves depending on
3623 this value. With simple filters this value either does nothing (but slow
3624 the resampling), or will clip the filter function in a detrimental way.
cristy29dc8652015-05-12 16:26:21 +00003625 </td>
3626 </tr>
cristyd2432012015-05-04 23:15:15 +00003627
cristy29dc8652015-05-12 16:26:21 +00003628 <tr>
3629 <td>-define filter:lobes=<var>count</var></td>
3630 <td>Set the number of lobes to use for the Sinc/Bessel filter. This an
cristyd2432012015-05-04 23:15:15 +00003631 alternative way of specifying the 'support' range of the filter, that is
3632 designed to be more suited to windowed filters, especially when used for
cristy29dc8652015-05-12 16:26:21 +00003633 image distorts.</td>
3634 </tr>
cristyd2432012015-05-04 23:15:15 +00003635
cristy29dc8652015-05-12 16:26:21 +00003636 <tr>
3637 <td>-define filter:sigma=<var>value</var></td>
3638 <td>The 'sigma' value used to define the <code>Gaussian</code> filter. Default
cristyd2432012015-05-04 23:15:15 +00003639 sigma value is '<code>0.5</code>'. It only effects <code>Gaussian</code> but
3640 does not shrink (but may enlarge) the filter's 'support'. It can be used
3641 to generate very small blurs but without the filter 'missing' pixels due
3642 to using a small support setting. A larger value of '<code>0.707</code>'
cristy29dc8652015-05-12 16:26:21 +00003643 (a value of '1/sqrt(2)') is another common setting. </td>
3644 </tr>
cristyd2432012015-05-04 23:15:15 +00003645
cristy29dc8652015-05-12 16:26:21 +00003646 <tr>
3647 <td>-define filter:b=<var>b-spline_factor</var></td>
cristy82a2ff22015-05-12 16:41:32 +00003648 </tr><tr>
cristy29dc8652015-05-12 16:26:21 +00003649 <td>-define filter:c=<var>keys_alpha_factor</var></td>
3650 <td>Redefine the values used for cubic filters such as <code>Cubic</code>,
cristyd2432012015-05-04 23:15:15 +00003651 <code>Catrom</code>, <code>Mitchel</code>, and <code>Hermite</code>, as well as
3652 the <code>Parzen</code> cubic windowing function. If only one of the values
3653 are defined, the other is set so as to generate a 'Cubic-Keys' filter.
3654 The values meaning was defined by a research paper by
cristy29dc8652015-05-12 16:26:21 +00003655 Mitchell-Netravali.</td>
3656 </tr>
cristyd2432012015-05-04 23:15:15 +00003657
cristy29dc8652015-05-12 16:26:21 +00003658 <tr>
3659 <td>-define filter:kaiser-beta=<var>value</var></td>
3660 <td>The 'alpha' value used to as part of the Kaiser Windowing function.
cristyd2432012015-05-04 23:15:15 +00003661 Default value is '6.5'. It only effects Kaiser windowing function, and
cristy29dc8652015-05-12 16:26:21 +00003662 does not effect any other attributes.
3663 Before ImageMagick v6.7.6-10, this option was known as "filter:alpha", (an
cristyd2432012015-05-04 23:15:15 +00003664 inheritance from the very old "zoom" program). It was changed to bring the
3665 function in line with more modern academic research usage, and better
cristy29dc8652015-05-12 16:26:21 +00003666 assign it be more definitive. </td>
3667 </tr>
cristyd2432012015-05-04 23:15:15 +00003668
cristy29dc8652015-05-12 16:26:21 +00003669 <tr>
3670 <td>-define filter:kaiser-alpha=<var>value</var></td>
3671 <td>This value when multiplied by 'PI' is equivalent to "kaiser-beta", and
cristyd2432012015-05-04 23:15:15 +00003672 will override that setting. It only effects Kaiser windowing function,
cristy29dc8652015-05-12 16:26:21 +00003673 and does not effect any other attributes. </td>
3674 </tr>
cristyd2432012015-05-04 23:15:15 +00003675
cristy29dc8652015-05-12 16:26:21 +00003676 <tr>
3677 <td>-define filter:filter=<var>filter_function</var></td>
3678 <td>Use this function directly as the weighting filter. This will allow
cristyd2432012015-05-04 23:15:15 +00003679 you to directly use a windowing function such as <code>Blackman</code>,
3680 as a resampling filter, rather than as its normal usage as a windowing
cristy29dc8652015-05-12 16:26:21 +00003681 function. If defined, no windowing function also defined, the window function is set
cristyd2432012015-05-04 23:15:15 +00003682 to <code>Box</code>). Directly specifying <code>Sinc</code> or <code>Jinc</code>
cristy29dc8652015-05-12 16:26:21 +00003683 as a filter will also do this. </td>
3684 </tr>
cristyd2432012015-05-04 23:15:15 +00003685
cristy29dc8652015-05-12 16:26:21 +00003686 <tr>
3687 <td>-define filter:window=<var>filter_function</var></td>
3688 <td>The IIR (infinite impulse response) filters <code>Sinc</code> and
cristyd2432012015-05-04 23:15:15 +00003689 <code>Jinc</code> are windowed (brought down to zero over the defined
3690 support range) with the given filter. This allows you to specify a filter
cristy29dc8652015-05-12 16:26:21 +00003691 function to be used as a windowing function for these IIR filters.
3692 Many of the defined filters are actually windowing functions for these IIR
cristyd2432012015-05-04 23:15:15 +00003693 filters. A typical choices is <code>Box</code>, (which effectively turns
cristy29dc8652015-05-12 16:26:21 +00003694 off the windowing function). </td>
3695 </tr>
cristyd2432012015-05-04 23:15:15 +00003696
cristy29dc8652015-05-12 16:26:21 +00003697 <tr>
3698 <td>-define filter:win-support=<var>radius</var></td>
3699 <td>Scale windowing function to this size instead. This causes the windowing
cristyd2432012015-05-04 23:15:15 +00003700 (or self-windowing Lagrange filter) to act is if the support window is
3701 larger than what is actually supplied to the calling operator. The filter
3702 however is still clipped to the real support size given. If unset this
cristy29dc8652015-05-12 16:26:21 +00003703 will equal the normal filter support size. </td>
3704 </tr>
cristyd2432012015-05-04 23:15:15 +00003705
cristy29dc8652015-05-12 16:26:21 +00003706 <tr>
3707 <td>-define filter:verbose=<var>1</var></td>
3708 <td>This causes IM to print information on the final internal filter
cristyd2432012015-05-04 23:15:15 +00003709 selection to standard output. This includes a commented header on the
3710 filter settings being used, and data allowing the filter weights to be
cristy29dc8652015-05-12 16:26:21 +00003711 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
cristyd2432012015-05-04 23:15:15 +00003712 a <code>SincFast</code> windowed <code>SincFast</code> filter, while
3713 <code>Mitchell</code> is defined as a general <code>Cubic</code> family filter
cristy29dc8652015-05-12 16:26:21 +00003714 with specific 'B' and 'C' settings. </td>
3715 </tr>
cristyd2432012015-05-04 23:15:15 +00003716
cristy29dc8652015-05-12 16:26:21 +00003717</table>
cristyd2432012015-05-04 23:15:15 +00003718
3719<p>For example, to get a 8 lobe jinc windowed sinc filter (Genseng filter?):</p>
3720
3721<pre>
3722convert image.png \
3723 -filter sinc \
3724 -set filter:window=jinc \
3725 -set filter:lobes=8 \
3726 -resize 150% image.jpg"
3727</pre>
3728
3729<p>Or a raw un-windowed Sinc filter with 4 lobes:</p>
3730
3731<pre>
3732convert image.png \
3733 -set filter:filter=sinc \
3734 -set filter:lobes=4 \
3735 -resize 150% image.jpg"
3736</pre>
3737
3738<p>To extract the data for a raw windowing function, combine it with
3739a '<code>Box</code>' filter. For example the '<code>Welch</code> parabolic
3740windowing function. </p>
3741
3742<pre>
3743convert null: -define filter:filter=Box \
3744 -define filter:window=Welch \
3745 -define filter:support=1.0 \
3746 -define filter:verbose=1 \
cristy82a2ff22015-05-12 16:41:32 +00003747 -resize 2 null: &gt; window_welch.dat
cristyd2432012015-05-04 23:15:15 +00003748gnuplot
3749 set grid
3750 plot \"window_welch.dat\" with lines
3751</pre>
3752
3753<p>Note that the use of expert options is provided for image processing experts
3754who have studied and understand how resize filters work. Without this
3755knowledge, and an understanding of the definition of the actual filters
3756involved, using expert settings are more likely to be detrimental to your image
3757resizing.</p>
3758
3759
3760<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003761 <h3 class="magick-header"><a id="flatten"></a>-flatten</h3>
cristyd2432012015-05-04 23:15:15 +00003762</div>
3763
cristy82a2ff22015-05-12 16:41:32 +00003764<p class="magick-description">This is a simple alias for the <a href="command-line-options.html#layers">-layers</a> method "flatten".</p>
cristyd2432012015-05-04 23:15:15 +00003765
3766
3767<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003768 <h3 class="magick-header"><a id="flip"></a>-flip</h3>
cristyd2432012015-05-04 23:15:15 +00003769</div>
3770
3771<p class="magick-description">create a <var>mirror image</var></p>
3772
3773<p>reflect the scanlines in the vertical direction. The image will be mirrored
3774upside-down. </p>
3775
3776
3777<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003778 <h3 class="magick-header"><a id="floodfill"></a>-floodfill {<var>+-</var>}<var>x</var>{<var>+-</var>}<var>y</var> <var>color</var></h3>
cristyd2432012015-05-04 23:15:15 +00003779</div>
3780
3781<p class="magick-description">floodfill the image with color at the specified offset.</p>
3782
3783<p>Flood fill starts from the given 'seed point' which is not gravity effected.
cristy82a2ff22015-05-12 16:41:32 +00003784Any color that matches within <a href="command-line-options.html#fuzz">-fuzz</a> color distance of the
cristyd2432012015-05-04 23:15:15 +00003785given <var>color</var> argument, connected to that 'seed point'
cristy82a2ff22015-05-12 16:41:32 +00003786will be replaced with the current <a href="command-line-options.html#fill">-fill</a> color. </p>
cristyd2432012015-05-04 23:15:15 +00003787
3788<p>Note that if the pixel at the 'seed point' does not itself match the given
cristy82a2ff22015-05-12 16:41:32 +00003789<var>color</var> (according to <a href="command-line-options.html#fuzz">-fuzz</a>), then no
cristyd2432012015-05-04 23:15:15 +00003790action will be taken. </p>
3791
cristy82a2ff22015-05-12 16:41:32 +00003792<p>This operator works more like the <a href="command-line-options.html#opaque">-opaque</a> option, than
cristyd2432012015-05-04 23:15:15 +00003793a more general flood fill that reads the matching color directly at the 'seed
cristy82a2ff22015-05-12 16:41:32 +00003794point'. For this form of flood fill, look at <a href="command-line-options.html#draw">-draw</a> and
cristyd2432012015-05-04 23:15:15 +00003795its 'color floodfill' drawing method. </p>
3796
3797
3798<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003799 <h3 class="magick-header"><a id="flop"></a>-flop</h3>
cristyd2432012015-05-04 23:15:15 +00003800</div>
3801
3802<p class="magick-description">create a <var>mirror image</var>.</p>
3803
3804<p>Reflect the scanlines in the horizontal direction, just like the image in
3805a vertical mirror. </p>
3806
3807
3808<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003809 <h3 class="magick-header"><a id="font"></a>-font <var>name</var></h3>
cristyd2432012015-05-04 23:15:15 +00003810</div>
3811
3812<p class="magick-description">set the font to use when annotating images with text, or creating labels.</p>
3813
3814<p>To print a complete list of fonts, use the <a href="command-line-options.html#list">-list font</a>
3815option (for versions prior to 6.3.6, use 'type' instead of 'font').</p>
3816
3817<p>In addition to the fonts specified by the above pre-defined list, you can
3818also specify a font from a specific source. For example <code>Arial.ttf</code>
3819is a TrueType font file, <code>ps:helvetica</code> is PostScript font, and
3820<code>x:fixed</code> is X11 font.</p>
3821
cristy82a2ff22015-05-12 16:41:32 +00003822<p>For other settings that affect fonts, see the options <a href="command-line-options.html#family">-family</a>, <a href="command-line-options.html#stretch">-stretch</a>, <a href="command-line-options.html#style">-style</a>, and <a href="command-line-options.html#weight">-weight</a>. </p>
cristyd2432012015-05-04 23:15:15 +00003823
3824
3825<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003826 <h3 class="magick-header"><a id="foreground"></a>-foreground <var>color</var></h3>
cristyd2432012015-05-04 23:15:15 +00003827</div>
3828
3829<p class="magick-description">Define the foreground color for menus.", "display</p>
3830
cristy82a2ff22015-05-12 16:41:32 +00003831<p>The color is specified using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p>
cristyd2432012015-05-04 23:15:15 +00003832
3833<p>The default foreground color is black.</p>
3834
3835<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003836 <h3 class="magick-header"><a id="format"></a>-format <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00003837</div>
3838
3839<p class="magick-description">the image format type.</p>
3840
3841<p>When used with the <code>mogrify</code> utility, this option converts any
3842image to the image <a href="formats.html">format</a> you specify.
cristy82a2ff22015-05-12 16:41:32 +00003843For a list of image format types supported by ImageMagick, use <a href="command-line-options.html#list">-list format</a>.</p>
cristyd2432012015-05-04 23:15:15 +00003844
3845<p>By default the file is written to its original name. However, if the
3846filename extension matches a supported format, the extension is replaced with
3847the image format type specified with <a href="command-line-options.html#format">-format</a>. For
3848example, if you specify <var>tiff</var> as the format type and the
3849input image filename is <var>image.gif</var>, the output image
3850filename becomes <var>image.tiff</var>.</p>
3851
3852<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003853 <h3 class="magick-header"><a id="format_identify_"></a>-format <var>string</var></h3>
cristyd2432012015-05-04 23:15:15 +00003854</div>
3855
3856<p class="magick-description">output formatted image characteristics.</p>
3857
3858<p>See <a href="escape.html">Format and Print Image
3859Properties</a> for an explanation on how to specify the argument to this
3860option.</p>
3861
3862<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003863 <h3 class="magick-header"><a id="frame"></a>-frame <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00003864</div>
3865
3866<p class="magick-description">Surround the image with a border or beveled frame.</p>
3867
cristy82a2ff22015-05-12 16:41:32 +00003868<p>The color of the border is specified with the <a href="command-line-options.html#mattecolor">-mattecolor</a> command line option. </p>
cristyd2432012015-05-04 23:15:15 +00003869
3870<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
3871height that is added to the dimensions of the image. If no offsets are given
3872in the <var>geometry</var> argument, then the border added is
3873a solid color. Offsets <var>x</var> and <var>y</var>, if present, specify that
3874the width and height of the border is partitioned to form an outer bevel of
3875thickness <var>x</var> pixels and an inner bevel of thickness
3876<var>y</var> pixels. Negative offsets make no sense as frame arguments.
3877</p>
3878
cristy82a2ff22015-05-12 16:41:32 +00003879<p>The <a href="command-line-options.html#frame">-frame</a> option is affected by the current <a href="command-line-options.html#compose">-compose</a> setting and assumes that this is using the default
cristyd2432012015-05-04 23:15:15 +00003880'<code>Over</code>' composition method. It generates an image of the appropriate
3881size with the current <a href="command-line-options.html#bordercolor">-bordercolor</a> setting, and then
cristy82a2ff22015-05-12 16:41:32 +00003882draws the frame of four distinct colors close to the current <a href="command-line-options.html#mattecolor">-mattecolor</a>. The original image is then overlaid onto
cristyd2432012015-05-04 23:15:15 +00003883center of this image. This means that with the default compose method of
cristy82a2ff22015-05-12 16:41:32 +00003884'<code>Over</code>' any transparent parts may be replaced by the current <a href="command-line-options.html#bordercolor">-bordercolor</a> setting.</p>
cristyd2432012015-05-04 23:15:15 +00003885
3886<p>The image composition is not
3887affected by the <a href="command-line-options.html#gravity">-gravity</a> option.</p>
3888
3889
3890<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003891 <h3 class="magick-header"><a id="frame_import_"></a>-frame</h3>
cristyd2432012015-05-04 23:15:15 +00003892</div>
3893
3894<p class="magick-description">include the X window frame in the imported image. </p>
3895<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003896 <h3 class="magick-header"><a id="function"></a>-function <var>function</var> <var>parameters</var></h3>
cristyd2432012015-05-04 23:15:15 +00003897</div>
3898
3899<p class="magick-description">Apply a function to channel values.</p>
3900
3901<p>This operator performs calculations based on the given arguments to modify
cristy82a2ff22015-05-12 16:41:32 +00003902each of the color values for each previously set <a href="command-line-options.html#channel">-channel</a> in the image. See <a href="command-line-options.html#evaluate">-evaluate</a> for details concerning how the results of the
cristyd2432012015-05-04 23:15:15 +00003903calculations are handled.</p>
3904
cristy82a2ff22015-05-12 16:41:32 +00003905<p>This is can be considered a multi-argument version of the <a href="command-line-options.html#evaluate">-evaluate</a> operator. (Added in
cristyd2432012015-05-04 23:15:15 +00003906ImageMagick 6.4.8−8.)</p>
3907
3908<p>Here, <var>parameters</var> is a comma-separated list of
3909numerical values. The number of values varies depending on which <var>function</var> is selected. Choose the <var>function</var> from:</p>
3910
3911<pre>
cristy29dc8652015-05-12 16:26:21 +00003912Polynomial
3913Sinusoid
3914Arcsin
3915Arctan
cristyd2432012015-05-04 23:15:15 +00003916</pre>
3917
3918<p>To print a complete list of <a href="command-line-options.html#function">-function</a> operators,
3919use <a href="command-line-options.html#list">-list function</a>. Descriptions follow.</p>
3920
cristy29dc8652015-05-12 16:26:21 +00003921<dl class="dl-horizontal">
3922 <dt>Polynomial</dt>
3923 <dd><p>The <code>Polynomial</code> function takes an arbitrary number of parameters,
cristyd2432012015-05-04 23:15:15 +00003924these being the coefficients of a polynomial, in decreasing order of degree.
3925That is, entering</p>
3926
cristy29dc8652015-05-12 16:26:21 +00003927<pre>
3928-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>
3929</pre>
cristyd2432012015-05-04 23:15:15 +00003930
3931<p>will invoke a polynomial function given by</p>
3932
cristy29dc8652015-05-12 16:26:21 +00003933<pre>
3934<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>,
3935</pre>
cristyd2432012015-05-04 23:15:15 +00003936
3937<p>where <b><var>u</var></b> is pixel's original normalized channel value.</p>
3938
3939<p>The <code>Polynomial</code> function can be used in place of <code>Set</code>
3940(the <var>constant</var> polynomial) and <code>Add</code>, <code>Divide</code>,
3941<code>Multiply</code>, and <code>Subtract</code> (some <var>linear</var>
cristy82a2ff22015-05-12 16:41:32 +00003942polynomials) of the <a href="command-line-options.html#evaluate">-evaluate</a> operator. The <a href="command-line-options.html#level">-level</a> operator also affects channels linearly. Some
cristyd2432012015-05-04 23:15:15 +00003943correspondences follow.</p>
3944
3945<table class="table table-condensed table-striped">
cristyd2432012015-05-04 23:15:15 +00003946 <tr>
3947 <td>-evaluate Set <var>value</var> </td>
3948 <td>-function Polynomial <var>value</var></td>
3949 <td>(Constant functions; set <var>value</var>×100% gray when channels are RGB.)</td>
3950 </tr>
3951 <tr>
3952 <td>-evaluate Add <var>value</var> </td>
3953 <td>-function Polynomial 1,<var>value</var></td>
3954 </tr>
3955 <tr>
3956 <td>-evaluate Subtract <var>value</var> </td>
3957 <td>-function Polynomial 1,−<var>value</var></td>
3958 </tr>
3959 <tr>
3960 <td>-evaluate Multiply <var>value</var> </td>
3961 <td>-function Polynomial <var>value</var>,0</td>
3962 </tr>
3963 <tr>
3964 <td>+level black% x white%</td>
3965 <td>-function Polynomial A,B</td>
3966 <td>(Reduce contrast. Here, A=(white-black)/100 and B=black/100.)</td>
3967 </tr>
3968</table>
3969
3970<p>The <code>Polynomial</code> function gives great versatility, since
3971polynomials can be used to fit any continuous curve to any degree of accuracy
3972desired.</p>
3973
3974</dd>
cristy29dc8652015-05-12 16:26:21 +00003975<dt>Sinusoid</dt>
cristyd2432012015-05-04 23:15:15 +00003976<dd>
3977<p>The <code>Sinusoid</code> function can be used to vary the channel values
3978sinusoidally by setting frequency, phase shift, amplitude, and a bias. These
3979values are given as one to four parameters, as follows,</p>
3980
cristy29dc8652015-05-12 16:26:21 +00003981<pre>
3982-function <code>Sinusoid</code> <var>freq</var>,[<var>phase</var>,[<var>amp</var>,[<var>bias</var>]]]
3983</pre>
cristyd2432012015-05-04 23:15:15 +00003984
3985<p>where <var>phase</var> is in degrees. (The domain [0,1] of the function
3986corresponds to 0 through <var>freq</var>×360 degrees.)
3987The result is that if a pixel's normalized channel value is originally
3988<b><var>u</var></b>, its resulting normalized value is given by </p>
3989
cristy29dc8652015-05-12 16:26:21 +00003990<pre>
cristyd2432012015-05-04 23:15:15 +00003991<var>amp</var> * sin(2*π* (<var>freq</var> * <b><var>u</var></b> + <var>phase</var> / 360)) + <var>bias</var>
cristy29dc8652015-05-12 16:26:21 +00003992</pre>
cristyd2432012015-05-04 23:15:15 +00003993
3994<p> For example, the following generates a curve that starts and ends at 0.9
3995(when <b><var>u</var></b>=0 and 1, resp.), oscillating three times between
3996.7−.2=.5 and .7+.2=.9. </p>
3997
cristy29dc8652015-05-12 16:26:21 +00003998<pre>
3999-function Sinusoid 3,-90,.2,.7
4000</pre>
cristyd2432012015-05-04 23:15:15 +00004001
4002<p>The default values of <var>amp</var> and <var>bias</var> are both .5. The default for <var>phase</var>
4003is 0.</p>
4004
4005<p>The <code>Sinusoid</code> function generalizes <code>Sin</code> and
4006<code>Cos</code> of the <a href="command-line-options.html#evaluate">-evaluate</a> operator by allowing
4007varying amplitude, phase and bias. The correspondence is as follows.</p>
4008
4009<table class="table table-condensed table-striped">
4010 <tr>
4011 <td>-evaluate Sin <var>freq</var> </td>
4012 <td>-function Sinusoid <var>freq</var>,0 </td>
4013 </tr>
4014 <tr>
4015 <td>-evaluate Cos <var>freq</var> </td>
4016 <td>-function Sinusoid <var>freq</var>,90 </td>
4017 </tr>
4018</table>
cristy29dc8652015-05-12 16:26:21 +00004019 </dd>
4020<dt>ArcSin</dt>
cristyd2432012015-05-04 23:15:15 +00004021<dd>
4022<p>The <code>ArcSin</code> function generates the inverse curve of a Sinusoid,
4023and can be used to generate cylindrical distortion and displacement maps.
4024The curve can be adjusted relative to both the input values and output range
4025of values.</p>
4026
cristy29dc8652015-05-12 16:26:21 +00004027<pre>
4028-function <code>ArcSin</code> <var>width</var>,[<var>center</var>,[<var>range</var>,[<var>bias</var>]]]
4029</pre>
cristyd2432012015-05-04 23:15:15 +00004030
4031<p>with all values given in terms of normalized color values (0.0 for black,
40321.0 for white). Defaulting to values covering the full range from 0.0 to 1.0
4033for bout input (<var>width</var>), and output (<var>width</var>) values. '<code>1.0,0.5,1.0,0.5</code>' </p>
4034
cristy29dc8652015-05-12 16:26:21 +00004035<pre>
cristyd2432012015-05-04 23:15:15 +00004036<var>range</var>/π * asin( 2/<var>width</var> * ( <b><var>u</var></b> - <var>center</var> ) ) + <var>bias</var>
cristy29dc8652015-05-12 16:26:21 +00004037</pre>
cristyd2432012015-05-04 23:15:15 +00004038
4039</dd>
cristy29dc8652015-05-12 16:26:21 +00004040<dt>ArcTan</dt>
cristyd2432012015-05-04 23:15:15 +00004041<dd>
4042<p>The <code>ArcTan</code> function generates a curve that smooth crosses from
4043limit values at infinities, though a center using the given slope value.
4044All these values can be adjusted via the arguments.</p>
4045
cristy29dc8652015-05-12 16:26:21 +00004046<pre>
4047-function <code>ArcTan</code> <var>slope</var>,[<var>center</var>,[<var>range</var>,[<var>bias</var>]]]
4048</pre>
cristyd2432012015-05-04 23:15:15 +00004049
4050<p>Defaulting to '<code>1.0,0.5,1.0,0.5</code>'.
4051</p>
4052
cristy29dc8652015-05-12 16:26:21 +00004053<pre>
cristyd2432012015-05-04 23:15:15 +00004054<var>range</var>/π * atan( <var>slope</var>*π * ( <b><var>u</var></b> - <var>center</var> ) ) + <var>bias</var>
cristy29dc8652015-05-12 16:26:21 +00004055</pre>
4056 </dd>
cristy82a2ff22015-05-12 16:41:32 +00004057
cristyd2432012015-05-04 23:15:15 +00004058</dl>
4059
4060
cristy29dc8652015-05-12 16:26:21 +00004061
cristyd2432012015-05-04 23:15:15 +00004062<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004063 <h3 class="magick-header"><a id="fuzz"></a>-fuzz <var>distance</var>{<var>%</var>}</h3>
cristyd2432012015-05-04 23:15:15 +00004064</div>
4065
4066<p class="magick-description">Colors within this <var>distance</var> are considered equal.</p>
4067
4068<p>A number of algorithms search for a target color. By default the color must
4069be exact. Use this option to match colors that are close to the target color
4070in RGB space. For example, if you want to automagically trim the edges of an
4071image with <a href="command-line-options.html#trim">-trim</a> but the image was scanned and the target
4072background color may differ by a small amount. This option can account for
4073these differences.</p>
4074
4075<p>The <var>distance</var> can be in absolute intensity units or, by
4076appending <code>%</code> as a percentage of the maximum possible intensity (255,
407765535, or 4294967295).</p>
4078
cristy82a2ff22015-05-12 16:41:32 +00004079<p>Use <a href="command-line-options.html#fuzz">+fuzz</a> to reset the fuzz value to 0.</p>
cristyd2432012015-05-04 23:15:15 +00004080
4081
4082<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004083 <h3 class="magick-header"><a id="fx"></a>-fx <var>expression</var></h3>
cristyd2432012015-05-04 23:15:15 +00004084</div>
4085
4086<p class="magick-description">apply a mathematical expression to an image or image channels.</p>
4087
4088<p>If the first character of <var>expression</var> is <code>@</code>,
4089the expression is read from a file titled by the remaining characters in the
4090string.</p>
4091
4092<p>See <a href="fx.html">FX,
4093The Special Effects Image Operator</a> for a detailed discussion of this
4094option.</p>
4095
4096
4097<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004098 <h3 class="magick-header"><a id="gamma"></a>-gamma <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00004099</div>
4100
4101<p class="magick-description">level of gamma correction.</p>
4102
4103<p>The same color image displayed on two different workstations may look
4104different due to differences in the display monitor. Use gamma correction to
4105adjust for this color difference. Reasonable values extend from
4106<code>0.8</code> to <code>2.3</code>. Gamma less than 1.0 darkens the image and
4107gamma greater than 1.0 lightens it. Large adjustments to image gamma may
4108result in the loss of some image information if the pixel quantum size is only
4109eight bits (quantum range 0 to 255).</p>
4110
4111<p>Gamma adjusts the image's channel values pixel-by-pixel according to
4112a power law, namely, pow(pixel,1/gamma) or pixel^(1/gamma), where pixel is the
4113normalized or 0 to 1 color value. For example, using a value of gamma=2 is the
4114same as taking the square root of the image.</p>
4115
4116<p>You can apply separate gamma values to the red, green, and blue channels of
4117the image with a gamma value list delimited with commas (e.g.,
4118<code>1.7,2.3,1.2</code>).</p>
4119
4120<p>Use <a href="command-line-options.html#gamma">+gamma <var>value</var></a> to set the
4121image gamma level without actually adjusting the image pixels. This option
4122is useful if the image is of a known gamma but not set as an image attribute
4123(e.g. PNG images). Write the "file gamma" which is the reciprocal of the
4124display gamma; e.g., if your image is sRGB and you want to write a PNG gAMA
4125chunk, use</p>
4126
4127<pre>
4128convert input.png +gamma .45455 output.png
4129</pre>
4130
4131<p>(0.45455 is 1/2.2)</p>
4132
4133<p>Note that gamma adjustments are also available via the <a href="command-line-options.html#level">-level</a> operator.</p>
4134
4135<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00004136 <h3 class="magick-header"><a id="gaussian-blur"></a>-gaussian-blur <var>radius</var><br>-gaussian-blur <var>radius</var>x<var>sigma</var></h3>
cristyd2432012015-05-04 23:15:15 +00004137</div>
4138
4139<p class="magick-description">Blur the image with a Gaussian operator.</p>
4140
4141<p>Convolve the image with a Gaussian or normal distribution using the given
cristy82a2ff22015-05-12 16:41:32 +00004142<var>Sigma</var> value. The formula is:</p>
cristyd2432012015-05-04 23:15:15 +00004143
cristyb2cad532015-05-16 13:02:45 +00004144<p class="text-center"><img class="img-thumbnail" alt="gaussian distribution" width="243px" height="42px" src="../images/gaussian-blur.png"> </p>
cristyd2432012015-05-04 23:15:15 +00004145
cristy82a2ff22015-05-12 16:41:32 +00004146<p>The <var>Sigma</var> value is the important argument, and
cristyd2432012015-05-04 23:15:15 +00004147determines the actual amount of blurring that will take place. </p>
4148
cristy82a2ff22015-05-12 16:41:32 +00004149<p>The <var>Radius</var> is only used to determine the size of the
cristyd2432012015-05-04 23:15:15 +00004150array which will hold the calculated Gaussian distribution. It should be an
4151integer. If not given, or set to zero, IM will calculate the largest possible
4152radius that will provide meaningful results for the Gaussian distribution.
4153</p>
4154
cristy82a2ff22015-05-12 16:41:32 +00004155<p>The larger the <var>Radius</var> the radius the slower the
4156operation is. However too small a <var>Radius</var>, and sever
4157aliasing effects may result. As a guideline, <var>Radius</var>
4158should be at least twice the <var>Sigma</var> value, though three
cristyd2432012015-05-04 23:15:15 +00004159times will produce a more accurate result. </p>
4160
4161<p>This differs from the faster <a href="command-line-options.html#blur">-blur</a> operator in that a
4162full 2-dimensional convolution is used to generate the weighted average of the
4163neighboring pixels. </p>
4164
4165<p>The <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting will determine how
4166pixels which are outside the image proper are blurred into the final result.
4167</p>
4168
4169
4170<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004171 <h3 class="magick-header"><a id="geometry"></a>-geometry <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00004172</div>
4173
4174<p class="magick-description">Set the preferred size and location of the image.</p>
4175
4176<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
4177
4178<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004179 <h3 class="magick-header"><a id="gravity"></a>-gravity <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00004180</div>
4181
4182<p class="magick-description">Sets the current gravity suggestion for various other settings and options.</p>
4183
4184<p>Choices include: <code>NorthWest</code>, <code>North</code>,
4185<code>NorthEast</code>, <code>West</code>, <code>Center</code>, <code>East</code>,
cristy82a2ff22015-05-12 16:41:32 +00004186<code>SouthWest</code>, <code>South</code>, <code>SouthEast</code>. Use <a href="command-line-options.html#list">-list gravity</a> to get a complete list of <a href="command-line-options.html#gravity">-gravity</a> settings available in your ImageMagick
cristyd2432012015-05-04 23:15:15 +00004187installation.</p>
4188
4189<p>The direction you choose specifies where to position text or subimages. For
4190example, a gravity of <code>Center</code> forces the text to be centered within
cristy82a2ff22015-05-12 16:41:32 +00004191the image. By default, the image gravity is <code>NorthWest</code>. See <a href="command-line-options.html#draw">-draw</a> for more details about graphic primitives. Only the
4192text primitive of <a href="command-line-options.html#draw">-draw</a> is affected by the <a href="command-line-options.html#gravity">-gravity</a> option.</p>
cristyd2432012015-05-04 23:15:15 +00004193
4194<p>The <a href="command-line-options.html#gravity">-gravity</a> option is also used in concert with the
4195<a href="command-line-options.html#geometry">-geometry</a> setting and other settings or options that
cristy82a2ff22015-05-12 16:41:32 +00004196take <var>geometry</var> as an argument, such as the <a href="command-line-options.html#crop">-crop</a> option. </p>
cristyd2432012015-05-04 23:15:15 +00004197
4198<p>If a <a href="command-line-options.html#gravity">-gravity</a> setting occurs before another option
4199or setting having a <var>geometry</var> argument that specifies an
4200offset, the offset is usually applied to the point within the image suggested
4201by the <a href="command-line-options.html#gravity">-gravity</a> argument. Thus, in the following
4202command, for example, suppose the file <code>image.png</code> has dimensions
4203200x100. The offset specified by the argument to <a href="command-line-options.html#region">-region</a>
4204is (−40,+20). The argument to <a href="command-line-options.html#gravity">-gravity</a> is
4205<code>Center</code>, which suggests the midpoint of the image, at the point
4206(100,50). The offset (−40,20) is applied to that point, giving
4207(100−40,50+20)=(60,70), so the specified 10x10 region is located at
4208that point. (In addition, the <a href="command-line-options.html#gravity">-gravity</a> affects the
4209region itself, which is <var>centered</var> at the pixel
4210coordinate (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>
4211
4212<pre>
4213convert image.png -gravity Center -region 10x10-40+20 \
4214 -negate output.png
4215</pre>
4216
cristy82a2ff22015-05-12 16:41:32 +00004217<p>When used as an option to <a href="composite.html">composite</a>, <a href="command-line-options.html#gravity">-gravity</a> gives the direction that the image gravitates
cristyd2432012015-05-04 23:15:15 +00004218within the composite.</p>
4219
cristy82a2ff22015-05-12 16:41:32 +00004220<p>When used as an option to <a href="montage.html">montage</a>, <a href="command-line-options.html#gravity">-gravity</a> gives the direction that an image gravitates
cristyd2432012015-05-04 23:15:15 +00004221within a tile. The default gravity is <code>Center</code> for this purpose.</p>
4222
4223
4224<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004225 <h3 class="magick-header"><a id="grayscale"></a>-grayscale <var>method</var></h3>
cristyd2432012015-05-04 23:15:15 +00004226</div>
4227
4228<p class="magick-description">convert image to grayscale.</p>
4229
cristy82a2ff22015-05-12 16:41:32 +00004230<p>This will use one of the <a href="command-line-options.html#intensity">-intensity</a> methods to
cristyd2432012015-05-04 23:15:15 +00004231convert the given image into a linear-grayscale image. </p>
4232
4233<p>For example, to convert an image to (linear) Rec709Luminance grayscale, type:</p>
4234
4235<pre>
4236convert in.png -grayscale Rec709Luminance out.png
4237</pre>
4238
4239<p>which is equivalent to:</p>
4240
4241<pre>
4242convert in.png -colorspace gray out.png
4243</pre>
4244
4245<p>Similarly, to convert an image to (non-linear) Rec709Luma grayscale, type:</p>
4246
4247<pre>
4248convert in.png -grayscale Rec709Luma out.png
4249</pre>
4250
4251<p>which is equivalent to:</p>
4252
4253<pre>
4254convert in.png -set colorspace RGB -colorspace gray out.png
4255</pre>
4256
4257<p>Note that a 'colorspace' intensity method will produce the same result
4258regardless of the current colorpsace of the image. But a 'mathematical'
4259intensity method will depend on the current colorspace the image is currently
4260using. </p>
4261
cristy82a2ff22015-05-12 16:41:32 +00004262<p>While this operation uses an <a href="command-line-options.html#intensity">-intensity</a> method,
4263it does not use or set the <a href="command-line-options.html#intensity">-intensity</a> setting, so
cristyd2432012015-05-04 23:15:15 +00004264will not effect other operations that may use that setting.</p>
4265
4266
4267<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004268 <h3 class="magick-header"><a id="green-primary"></a>-green-primary <var>x,y</var></h3>
cristyd2432012015-05-04 23:15:15 +00004269</div>
4270
4271<p class="magick-description">green chromaticity primary point.</p>
4272
4273
4274<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004275 <h3 class="magick-header"><a id="hald-clut"></a>-hald-clut</h3>
cristyd2432012015-05-04 23:15:15 +00004276</div>
4277
4278<p class="magick-description">apply a Hald color lookup table to the image.</p>
4279
4280<p>A Hald color lookup table is a 3-dimensional color cube mapped to 2
4281dimensions. Create it with the <code>HALD:</code> prefix (e.g. HALD:8). You
4282can apply any color transformation to the Hald image and then use this option
4283to apply the transform to the image. </p>
4284
4285<pre>
4286convert image.png hald.png -hald-clut transform.png
4287</pre>
4288
4289<p>This option provides a convenient method for you to use Gimp or Photoshop
4290to make color corrections to the Hald CLUT image and subsequently apply them
4291to multiple images using an ImageMagick script. </p>
4292
4293<p>Note that the representation is only of the normal RGB color space and that
4294the whole color value triplet is used for the interpolated lookup of the
cristy82a2ff22015-05-12 16:41:32 +00004295represented Hald color cube image. Because of this the operation is not <a href="command-line-options.html#channel">-channel</a> setting effected, nor can it adjust or modify an
cristyd2432012015-05-04 23:15:15 +00004296images transparency or alpha/matte channel.</p>
4297
cristy82a2ff22015-05-12 16:41:32 +00004298<p>See also <a href="command-line-options.html#clut">-clut</a> which provides color value replacement
cristyd2432012015-05-04 23:15:15 +00004299of the individual color channels, usually involving a simpler gray-scale
4300image. E.g: gray-scale to color replacement, or modification by a histogram
4301mapping. </p>
4302
4303
4304<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004305 <h3 class="magick-header"><a id="help"></a>-help</h3>
cristyd2432012015-05-04 23:15:15 +00004306</div>
4307
4308<p class="magick-description">print usage instructions.</p>
4309
4310<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004311 <h3 class="magick-header"><a id="highlight-color"></a>-highlight-color <var>color</var></h3>
cristyd2432012015-05-04 23:15:15 +00004312</div>
4313
4314<p class="magick-description">when comparing images, emphasize pixel differences with this color.</p>
4315
4316<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004317 <h3 class="magick-header"><a id="hough-lines"></a>-hough-lines <var>width</var>x<var>height</var>{<var>+threshold</var>}</h3>
cristyd2432012015-05-04 23:15:15 +00004318</div>
4319
4320<p class="magick-description">identify straight lines in the image (e.g. -hough-lines 9x9+195).</p>
4321
4322<p>Use the Hough line detector with any binary edge extracted image to locate and draw any straight lines that it finds.</p>
4323
4324<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>.
4325
4326<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>
4327
cristy82a2ff22015-05-12 16:41:32 +00004328<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>
cristyd2432012015-05-04 23:15:15 +00004329
cristy82a2ff22015-05-12 16:41:32 +00004330<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>
cristyd2432012015-05-04 23:15:15 +00004331
cristy82a2ff22015-05-12 16:41:32 +00004332<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>
cristyd2432012015-05-04 23:15:15 +00004333
4334<p>A text file listing the endpoints and counts may be created by using the suffix, .mvg, for the output image.</p>
4335
cristy82a2ff22015-05-12 16:41:32 +00004336<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>
cristyd2432012015-05-04 23:15:15 +00004337
4338<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004339 <h3 class="magick-header"><a id="iconGeometry"></a>-iconGeometry <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00004340</div>
4341
4342<p class="magick-description">specify the icon geometry.</p>
4343
4344<p>Offsets, if present in the geometry specification, are handled in the same
4345manner as the <a href="command-line-options.html#geometry">-geometry</a> option, using X11 style to
4346handle negative offsets.</p>
4347
4348<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
4349
4350<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004351 <h3 class="magick-header"><a id="iconic"></a>-iconic</h3>
cristyd2432012015-05-04 23:15:15 +00004352</div>
4353
4354<p class="magick-description">start in icon mode in X Windows", 'animate', 'display</p>
4355
4356<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004357 <h3 class="magick-header"><a id="identify"></a>-identify</h3>
cristyd2432012015-05-04 23:15:15 +00004358</div>
4359
4360<p class="magick-description">identify the format and characteristics of the image.</p>
4361
4362<p>This information is printed: image scene number; image name; image size;
4363the image class (<var>DirectClass</var> or <var>PseudoClass</var>); the total number of unique colors; and the
4364number of seconds to read and transform the image. Refer to <a href="miff.html">MIFF</a> for
4365a description of the image class.</p>
4366
4367<p>If <a href="command-line-options.html#colors">-colors</a> is also specified, the total unique colors
cristy82a2ff22015-05-12 16:41:32 +00004368in the image and color reduction error values are printed. Refer to <a href="quantize.html">color
cristyd2432012015-05-04 23:15:15 +00004369reduction algorithm</a> for a description of these values.</p>
4370
4371<p>If <a href="command-line-options.html#verbose">-verbose</a> precedes this option, copious
4372amounts of image properties are displayed including image statistics, profiles,
4373image histogram, and others.</p>
4374
4375<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004376 <h3 class="magick-header"><a id="ift"></a>-ift</h3>
cristyd2432012015-05-04 23:15:15 +00004377</div>
4378
4379<p class="magick-description">implements the inverse discrete Fourier transform (DFT).</p>
4380
4381<p>This option is new as of ImageMagick 6.5.4-3 (and now working for Windows
4382users in ImageMagick 6.6.0-9). It transforms a pair of magnitude and phase
4383images from the frequency domain to a single image in the normal or spatial
cristy82a2ff22015-05-12 16:41:32 +00004384domain. See for example, <a href="http://en.wikipedia.org/wiki/Fourier_transform">Fourier Transform</a>,
cristyd2432012015-05-04 23:15:15 +00004385<a href="http://en.wikipedia.org/wiki/DFT">Discrete Fourier Transform</a> and
4386<a href="http://en.wikipedia.org/wiki/FFT">Fast Fourier Transform</a>.</p>
4387
4388<p>For example, depending upon the image format used to store the result of
4389the <a href="command-line-options.html#fft">-fft</a>, one would use either</p>
4390
4391<pre>
4392convert fft_image.miff -ift fft_image_ift.png
4393</pre>
4394
4395<p>or</p>
4396
4397<pre>
4398convert fft_image-0.png fft_image-1.png -ift fft_image_ift.png
4399</pre>
4400
4401<p>The resulting image may need to be cropped due to padding introduced when
cristy82a2ff22015-05-12 16:41:32 +00004402the original image, prior to the <a href="command-line-options.html#fft">-fft</a> or <a href="command-line-options.html#fft">+fft</a>, was not square or even dimensioned. Any padding is at
cristyd2432012015-05-04 23:15:15 +00004403the right and/or bottom sides of the image.</p>
4404
4405<p>The <a href="http://www.fftw.org/">FFTW</a> delegate library is required to
4406use <a href="command-line-options.html#ift">-ift</a>.</p>
4407
4408<p>Use <a href="command-line-options.html#ift">+ift</a> (with HDRI enabled) to transform a pair of real
4409and imaginary images from the frequency domain to a single image in the normal
4410(spatial) domain.</p>
4411
cristy82a2ff22015-05-12 16:41:32 +00004412<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 explictly normalize the IFT and unnormalize the FFT.</p>
cristyd2432012015-05-04 23:15:15 +00004413
4414<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004415 <h3 class="magick-header"><a id="immutable"></a>-immutable</h3>
cristyd2432012015-05-04 23:15:15 +00004416</div>
4417
4418<p class="magick-description">make image immutable.</p>
4419
4420<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004421 <h3 class="magick-header"><a id="implode"></a>-implode <var>factor</var></h3>
cristyd2432012015-05-04 23:15:15 +00004422</div>
4423
4424<p class="magick-description">implode image pixels about the center.</p>
4425
4426<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004427 <h3 class="magick-header"><a id="insert"></a>-insert <var>index</var></h3>
cristyd2432012015-05-04 23:15:15 +00004428</div>
4429
4430<p class="magick-description">insert the last image into the image sequence.</p>
4431
4432<p>This option takes last image in the current image sequence and inserts it
4433at the given index. If a negative index is used, the insert position is
4434calculated before the last image is removed from the sequence. As such
4435<code>-insert -1</code> will result in no change to the image sequence.</p>
4436
4437<p>The <code>+insert</code> option is equivalent to <code>-insert -1</code>. In
4438other words, insert the last image, at the end of the current image sequence.
4439Consequently this has no effect on the image sequence order.</p>
4440
4441<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004442 <h3 class="magick-header"><a id="intensity"></a>-intensity <var>method</var></h3>
cristyd2432012015-05-04 23:15:15 +00004443</div>
4444
4445<p class="magick-description">method to generate intensity value from pixel.</p>
4446
4447<p>ImageMagick provides a number of methods used in situations where an
4448operatory needs to determine a single grayscale value for some purpose, from
4449an image with red, green, and blue pixel components. Typically the linear
4450<code>Rec709Luminance</code> formula is used, which is the same formula used when
4451converting images to <code>-colorspace gray</code>. </p>
4452
4453<p>The following formulas are currently provided, and will first convert
4454the pixel values to linear-RGB or non-linear sRGB colorspace before
4455being applied to calulate the final greyscale value. </p>
4456
cristyb2cad532015-05-16 13:02:45 +00004457<dl class="dl-horizontal">
4458<dt>Rec601Luma</dt><dd> 0.298839R' + 0.586811G'+ 0.114350B'</dd>
4459<dt>Rec601Luminance</dt><dd> 0.298839R + 0.586811G + 0.114350B</dd>
4460<dt>Rec709Luma</dt><dd> 0.212656R' + 0.715158G' + 0.072186B'</dd>
4461<dt>Rec709Luminance</dt><dd> 0.212656R + 0.715158G + 0.072186B</dd>
4462<dt>Brightness</dt><dd> max(R', G', B')</dd>
4463<dt>Lightness</dt><dd> (min(R', G', B') + max(R', G', B')) / 2.0</dd>
4464</dl>
4465
cristyd2432012015-05-04 23:15:15 +00004466<p>Note that the above R,G,B values is the image's linear-RGB values, while
4467R',G',B' are sRGB non-linear values. </p>
4468
4469<p>These intensity methods are mathematical in nature and will use the
4470current value in the images respective R,G,B channel regardless of
4471what that is, or what colorspace the image is currently using.</p>
4472
cristyb2cad532015-05-16 13:02:45 +00004473<dl class="dl-horizontal">
4474<dt>Average</dt><dd>(R + G + B) / 3.0</dd>
4475<dt>MS</dt><dd>(R^2 + G^2 + B^2) / 3.0</dd>
4476<dt>RMS</dt><dd>sqrt( (R^2 + G^2 + B^2) / 3.0 )</dd>
4477</dl>
cristyd2432012015-05-04 23:15:15 +00004478
4479<p>These methods are often used for other purposes, such as generating a
cristy82a2ff22015-05-12 16:41:32 +00004480grayscale difference image between two color images (using <a href="command-line-options.html#compose">-compose</a> '<code>Difference</code>' composition. </p>
cristyd2432012015-05-04 23:15:15 +00004481
4482<p> For example The 'MS' (Mean Squared) setting is good for minimizing color
4483error comparisions. While... The method 'RMS' (Root Mean Squared) for
4484example is appropriate for calculating color vector distance, from a color
cristy82a2ff22015-05-12 16:41:32 +00004485difference image. This is equivalent to the color only component of the <a href="command-line-options.html#fuzz">-fuzz</a> factor color compare setting. </p>
cristyd2432012015-05-04 23:15:15 +00004486
cristy82a2ff22015-05-12 16:41:32 +00004487<p>See also <a href="command-line-options.html#grayscale">-grayscale</a> which applies one of the above
4488grayscaling formula directly to an image without setting the <a href="command-line-options.html#intensity">-intensity</a> setting.</p>
cristyd2432012015-05-04 23:15:15 +00004489
cristy82a2ff22015-05-12 16:41:32 +00004490<p>The <a href="command-line-options.html#colorspace">-colorspace gray</a> image conversion also uses
cristyd2432012015-05-04 23:15:15 +00004491the current intensity setting, but will always convert the image to the
4492appropriate sRGB or linear-RGB colorspace before appling the above
4493function.</p>
4494
4495<p>To print a complete list of posible pixel intensity setting methods, use <a href="command-line-options.html#list">-list intensity</a>.</p>
4496
cristy82a2ff22015-05-12 16:41:32 +00004497<p>Operators affected by the <a href="command-line-options.html#intensity">-intensity</a> setting include:</p>
cristyd2432012015-05-04 23:15:15 +00004498
4499<pre>
4500-adaptive-blur
4501-adaptive-sharpen
4502-black-threshold
4503-clut (when mapping greyscale CLUT image to alpha channel if set by -channels)
4504-colors for gray colorspace
4505-compose {LightenIntensity, DarkenIntensity, CopyOpacity, CopyBlack}
4506-contrast-stretch
4507-distort {ErodeIntensity, DilateIntensity}
4508-normalize
4509-random-threshold
4510-selective-blur
4511-shade
4512-threshold
4513-tint
4514-white-threshold
4515</pre>
4516
4517<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004518 <h3 class="magick-header"><a id="intent"></a>-intent <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00004519</div>
4520
4521<p class="magick-description">use this type of rendering intent when managing the image color.</p>
4522
4523<p>Use this option to affect the color management operation of an image (see
4524<a href="command-line-options.html#profile">-profile</a>). Choose from these intents: <code>Absolute,
4525Perceptual, Relative, Saturation</code>.</p>
4526
4527<p>The default intent is Perceptual for the sRGB colorspace and undefined for the RGB and gray colorspaces.</p>
4528
4529<p>To print a complete list of rendering intents, use <a href="command-line-options.html#list">-list intent</a>.</p>
4530
4531<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004532 <h3 class="magick-header"><a id="interlace"></a>-interlace <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00004533</div>
4534
4535<p class="magick-description">the type of interlacing scheme.</p>
4536
4537<p>Choose from:</p>
4538
4539<pre>
cristyb2cad532015-05-16 13:02:45 +00004540none
4541line
4542plane
4543partition
4544JPEG
4545GIF
4546PNG
cristyd2432012015-05-04 23:15:15 +00004547</pre>
4548
4549<p>This option is used to specify the type of interlacing scheme for raw image
4550formats such as <code>RGB</code> or <code>YUV</code>.</p>
4551
4552<p><code>None</code> means do not interlace (RGBRGBRGBRGBRGBRGB...),</p>
4553
4554<p><code>Line</code> uses scanline interlacing (RRR...GGG...BBB...RRR...GGG...BBB...), and.</p>
4555
4556<p><code>Plane</code> uses plane interlacing (RRRRRR...GGGGGG...BBBBBB...).</p>
4557
4558<p><code>Partition</code> is like plane except the different planes are saved to
4559individual files (e.g. image.R, image.G, and image.B).</p>
4560
4561<p>Use <code>Line</code> or <code>Plane</code> to create an <code>interlaced
4562PNG</code> or <code>GIF</code> or <code>progressive JPEG</code> image.</p>
4563
4564<p>To print a complete list of interlacing schemes, use <a href="command-line-options.html#list">-list
4565interlace</a>.</p>
4566
4567<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004568 <h3 class="magick-header"><a id="interpolate"></a>-interpolate <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00004569</div>
4570
4571<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>
4572
4573<p>When looking up the color of a pixel using a non-integer floating point
4574value, you typically fall in between the pixel colors defined by the source
4575image. This setting determines how the color is determined from the colors of
4576the pixels surrounding that point. That is how to determine the color of a
4577point that falls between two, or even four different colored pixels. </p>
4578
cristy29dc8652015-05-12 16:26:21 +00004579<dl class="dl-horizontal">
4580 <dt>integer</dt>
4581 <dd>The color of the top-left pixel (floor function)</dd>
4582 <dt>nearest-neighbor</dt>
4583 <dd>The nearest pixel to the lookup point (rounded function)</dd>
4584 <dt>average</dt>
4585 <dd>The average color of the surrounding four pixels</dd>
4586 <dt>bilinear</dt>
4587 <dd>A double linear interpolation of pixels (the default)</dd>
4588 <dt>mesh</dt>
4589 <dd>Divide area into two flat triangular interpolations</dd>
4590 <dt>bicubic</dt>
4591 <dd>Fitted bicubic-spines of surrounding 16 pixels</dd>
4592 <dt>spline</dt>
4593 <dd>Direct spline curves (colors are blurred)</dd>
4594 <dt>filter</dt>
4595 <dd>Use resize <a href="command-line-options.html#filter">-filter</a> settings</dd>
4596</dl>
cristyd2432012015-05-04 23:15:15 +00004597
cristy82a2ff22015-05-12 16:41:32 +00004598<p>This most important for distortion operators such as <a href="command-line-options.html#distort">-distort</a>, <a href="command-line-options.html#implode">-implode</a>, <a href="command-line-options.html#transform">-transform</a> and <a href="command-line-options.html#fx">-fx</a>. </p>
cristyd2432012015-05-04 23:15:15 +00004599
4600<p>To print a complete list of interpolation methods, use <a href="command-line-options.html#list">-list interpolate</a>.</p>
4601
cristy82a2ff22015-05-12 16:41:32 +00004602<p>See also <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a>, for control of the
cristyd2432012015-05-04 23:15:15 +00004603lookup for positions outside the boundaries of the image. </p>
4604
4605
4606<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004607 <h3 class="magick-header"><a id="interline-spacing"></a>-interline-spacing <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00004608</div>
4609
4610<p class="magick-description">the space between two text lines.</p>
4611
4612<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004613 <h3 class="magick-header"><a id="interword-spacing"></a>-interword-spacing <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00004614</div>
4615
4616<p class="magick-description">the space between two words.</p>
4617
4618<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004619 <h3 class="magick-header"><a id="kerning"></a>-kerning <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00004620</div>
4621
4622<p class="magick-description">the space between two letters.</p>
4623
4624<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00004625 <h3 class="magick-header"><a id="kuwahara"></a>-kuwahara <var>radius</var><br>-kuwahara <var>radius</var>x<var>sigma</var></h3>
cristyd2432012015-05-04 23:15:15 +00004626</div>
4627
4628<p class="magick-description">edge preserving noise reduction filter.</p>
4629
cristy82a2ff22015-05-12 16:41:32 +00004630<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>
cristyd2432012015-05-04 23:15:15 +00004631
4632
4633<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004634 <h3 class="magick-header"><a id="label"></a>-label <var>name</var></h3>
cristyd2432012015-05-04 23:15:15 +00004635</div>
4636
4637<p class="magick-description">assign a label to an image.</p>
4638
4639<p>Use this option to assign a specific label to the image, as it is read in
cristy82a2ff22015-05-12 16:41:32 +00004640or created. You can use the <a href="command-line-options.html#set">-set</a> operation to re-assign
cristyd2432012015-05-04 23:15:15 +00004641a the labels of images already read in. Image formats such as TIFF, PNG,
4642MIFF, supports saving the label information with the image.</p>
4643
4644<p>When saving an image to a <var>PostScript</var> file, any label
4645assigned to an image is used as a header string to print above the postscript
4646image. </p>
4647
4648<p>You can include the image filename, type, width, height, or other image
4649attribute by embedding special format character. See <a href="escape.html">Format and Print Image
4650Properties</a> for details of the percent escape codes.</p>
4651
4652<p>For example,</p>
4653
cristy29dc8652015-05-12 16:26:21 +00004654<pre>
4655-label "%m:%f %wx%h" bird.miff
4656</pre>
cristyd2432012015-05-04 23:15:15 +00004657
4658<p>assigns an image label of <code>MIFF:bird.miff 512x480</code> to the
4659"<code>bird.miff</code>" image and whose width is 512 and height is 480, as it
4660is read in. If a <a href="command-line-options.html#label">+label</a> option was used instead, any
4661existing label present in the image would be used. You can remove all labels
4662from an image by assigning the empty string. </p>
4663
4664<p>A label is not drawn on the image, but is embedded in the image datastream
4665via <var>Label</var> tag or similar mechanism. If you want the label to be
4666visible on the image itself, use the <a href="command-line-options.html#draw">-draw</a> option, or
4667during the final processing in the creation of an image montage.</p>
4668
4669<p>If the first character of <var>string</var> is <var>@</var>, the image label is read from a file titled by the
4670remaining characters in the string. Labels in a file are literal, no embedded
4671formatting characters are recognized.</p>
4672
4673
4674<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00004675 <h3 class="magick-header"><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>
cristyd2432012015-05-04 23:15:15 +00004676</div>
4677
4678<p class="magick-description">perform local adaptive threshold.</p>
4679
4680<p>Adaptively threshold each pixel based on the value of pixels in a
4681surrounding window. If the current pixel is lighter than this average plus
4682the optional <code>offset</code>, then it is made white, otherwise it is made
4683black. Small variations in pixel values such as found in scanned documents
4684can be ignored if offset is positive. A negative offset will make it more
4685sensitive to those small variations. </p>
4686
4687<p>This is commonly used to threshold images with an uneven background. It is
4688based on the assumption that average color of the small window is the
4689the local background color, from which to separate the foreground color. </p>
4690
4691
4692<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004693 <h3 class="magick-header"><a id="layers"></a>-layers <var>method</var></h3>
cristyd2432012015-05-04 23:15:15 +00004694</div>
4695
4696<p class="magick-description">handle multiple images forming a set of image layers or animation frames.</p>
4697
4698<p>Perform various image operation methods to a ordered sequence of images
4699which may represent either a set of overlaid 'image layers', a GIF disposal
4700animation, or a fully-'coalesced' animation sequence. </p>
4701
4702<table class="table table-condensed table-striped">
4703 <tbody>
4704 <tr>
4705 <th style="width: 8%">Method</th>
4706 <th>Description</th>
4707 </tr>
4708
4709 <tr>
4710 <td>compare-any</td>
4711 <td>Crop the second and later frames to the smallest rectangle
cristy82a2ff22015-05-12 16:41:32 +00004712 that contains all the differences between the two images. No GIF <a href="command-line-options.html#dispose">-dispose</a> methods are taken into account. </td>
cristyd2432012015-05-04 23:15:15 +00004713 </tr>
4714
cristy82a2ff22015-05-12 16:41:32 +00004715 <tr><td></td><td>This exactly the same as the <a href="command-line-options.html#deconstruct">-deconstruct</a> operator, and does not preserve animations normal
cristyd2432012015-05-04 23:15:15 +00004716 working, especially when animation used layer disposal methods such as
4717 '<code>Previous</code>' or '<code>Background</code>'. </td>
4718 </tr>
4719
4720 <tr>
4721 <td>compare-clear</td>
4722 <td>As '<code>compare-any</code>' but crop to the bounds of any
4723 opaque pixels which become transparent in the second frame. That is the
4724 smallest image needed to mask or erase pixels for the next frame. </td>
4725 </tr>
4726
4727 <tr>
4728 <td>compare-overlay</td>
4729 <td>As '<code>compare-any</code>' but crop to pixels that add
4730 extra color to the next image, as a result of overlaying color pixels.
4731 That is the smallest single overlaid image to add or change colors. </td>
4732 </tr>
4733
cristy82a2ff22015-05-12 16:41:32 +00004734 <tr><td></td><td>This can be used with the <a href="command-line-options.html#compose">-compose</a> alpha
cristyd2432012015-05-04 23:15:15 +00004735 composition method '<code>change-mask</code>', to reduce the image to
4736 just the pixels that need to be overlaid. </td>
4737 </tr>
4738
4739 <tr>
4740 <td>coalesce</td>
cristy82a2ff22015-05-12 16:41:32 +00004741 <td>Equivalent to a call to the <a href="command-line-options.html#coalesce">-coalesce</a> operator. Apply the layer disposal methods set in the
cristyd2432012015-05-04 23:15:15 +00004742 current image sequence to form a fully defined animation sequence, as
4743 it should be displayed. Effectively converting a GIF animation into a
4744 'film strip'-like animation. </td>
4745 </tr>
4746
4747 <tr>
4748 <td>composite</td>
4749 <td>Alpha Composition of two image lists, separated by a
4750 "<code>null:</code>" image, with the destination image list first, and
4751 the source images last. An image from each list are composited
4752 together until one list is finished. The separator image and source
4753 image lists are removed. </td>
4754 </tr>
4755
4756
4757 <tr><td></td>
cristy82a2ff22015-05-12 16:41:32 +00004758 <td>The <a href="command-line-options.html#geometry">-geometry</a> offset is adjusted according
4759 to <a href="command-line-options.html#gravity">-gravity</a> in accordance of the virtual
4760 canvas size of the first image in each list. Unlike a normal <a href="command-line-options.html#composite">-composite</a> operation, the canvas offset is also
cristyd2432012015-05-04 23:15:15 +00004761 added to the final composite positioning of each image. </td> </tr>
4762
4763 <tr><td></td>
4764 <td>If one of the image lists only contains one image, that image is
4765 applied to all the images in the other image list, regardless of which
4766 list it is. In this case it is the image meta-data of the list which
4767 preserved. </td>
4768 </tr>
4769
4770
4771 <tr>
4772 <td>dispose</td>
4773 <td>This like '<code>coalesce</code>' but shows the look of
4774 the animation after the layer disposal method has been applied, before
4775 the next sub-frame image is overlaid. That is the 'dispose' image that
cristy82a2ff22015-05-12 16:41:32 +00004776 results from the application of the GIF <a href="command-line-options.html#dispose">-dispose</a> method. This allows you to check what
cristyd2432012015-05-04 23:15:15 +00004777 is going wrong with a particular animation you may be developing.
4778 </td>
4779 </tr>
4780
4781 <tr>
4782 <td>flatten</td>
4783 <td>Create a canvas the size of the first images virtual
cristy82a2ff22015-05-12 16:41:32 +00004784 canvas using the current <a href="command-line-options.html#background">-background</a> color,
4785 and <a href="command-line-options.html#compose">-compose</a> each image in turn onto that
cristyd2432012015-05-04 23:15:15 +00004786 canvas. Images falling outside that canvas is clipped. Final
4787 image will have a zero virtual canvas offset. </td>
4788 </tr>
4789
4790 <tr><td></td>
4791 <td>This usually used as one of the final 'image layering' operations
4792 overlaying all the prepared image layers into a final image. </td>
4793 </tr>
4794
4795 <tr><td></td>
4796 <td>For a single image this method can also be used to fillout a virtual
4797 canvas with real pixels, or to underlay an opaque color to remove
4798 transparency from an image.</td>
4799 </tr>
4800
4801
4802 <tr>
4803 <td>merge</td>
4804 <td>As 'flatten' method but merging all the given image
4805 layers to create a new layer image just large enough to hold all the
4806 image without clipping or extra space. The new images virtual offset
4807 will preserve the position of the new layer, even if this offset is
4808 negative. The virtual canvas size of the first image is preserved.
4809 </td>
4810 </tr>
4811
4812 <tr><td></td><td>Caution is advised when handling image layers with
4813 negative offsets as few image file formats handle them correctly.
cristy82a2ff22015-05-12 16:41:32 +00004814 Following this operation method with <a href="command-line-options.html#repage">+repage</a>
cristyd2432012015-05-04 23:15:15 +00004815 will remove the layer offset, and create an image in which all the
4816 overlaid image positions relative to each other is preserved, though
4817 not necessarily exactly where you specified them.
4818 </td>
4819 </tr>
4820
4821 <tr><td></td><td>See also 'trim-bounds' below which is closely related but
4822 without doing the'flatten' to merge the images together. </td>
4823 </tr>
4824
4825 <tr>
4826 <td>mosaic</td>
4827 <td>As 'flatten' method but expanding the initial canvas size
4828 of the first image in a positive direction only so as to hold all the
4829 image layers. However as a virtual canvas is 'locked' to the origin,
4830 by its own definition, image layers with a negative offsets will still
4831 become clipped by the top and left edges. See 'merge' or 'trim-bounds'
4832 if this could be a problem. </td>
4833
4834 </tr>
4835
4836 <tr><td></td><td>This method is commonly used to layout individual image
4837 using various offset but without knowing the final canvas size. The
4838 resulting image will, like 'flatten' not have any virtual offset, so
4839 can be saved to any image file format. </td>
4840 </tr>
4841
4842
4843 <tr>
4844 <td>optimize</td>
4845 <td>Optimize a coalesced animation, into GIF animation using
4846 a number of general techniques. This currently a short cut to
4847 apply both the '<code>optimize-frame</code>', and
4848 '<code>optimize-transparency</code>' methods but may be expanded to
4849 include other optimization methods as they are developed. </td>
4850 </tr>
4851
4852 <tr>
4853 <td>optimize-frame</td>
4854 <td>Optimize a coalesced animation, into GIF animation by
4855 reducing the number of pixels per frame as much as possible by
4856 attempting to pick the best layer disposal method to use, while ensuring
4857 the result will continue to animate properly. </td>
4858 </tr>
4859
4860 <tr><td></td><td> There is no guarantee that the best optimization is found.
4861 But then no reasonably fast GIF optimization algorithm can do this.
4862 However this does seem to do better than most other GIF frame
4863 optimizers seen. </td>
4864 </tr>
4865
4866 <tr>
4867 <td>optimize-plus</td>
4868 <td>As '<code>optimize-frame</code>' but attempt to improve the
4869 overall optimization by adding extra frames to the animation, without
4870 changing the final look or timing of the animation. The frames are
4871 added to attempt to separate the clearing of pixels from the
4872 overlaying of new additional pixels from one animation frame to the
4873 next. If this does not improve the optimization (for the next frame
4874 only), it will fall back to the results of the previous normal
4875 '<code>optimize-frame</code>' technique. </td>
4876 </tr>
4877
4878 <tr><td></td><td>There is the possibility that the change in the disposal
4879 style will result in a worsening in the optimization of later frames,
4880 though this is unlikely. In other words there no guarantee that it is
4881 better than the normal '<code>optimize-frame</code>' technique. For some
4882 animations however you can get a vast improvement in the final
4883 animation size. </td>
4884 </tr>
4885
4886 <tr>
4887 <td>optimize-transparency</td>
4888 <td>Given a GIF animation, replace any pixel in the sub-frame
4889 overlay images with transparency, if it does not change the resulting
cristy82a2ff22015-05-12 16:41:32 +00004890 animation by more than the current <a href="command-line-options.html#fuzz">-fuzz</a> factor.
cristyd2432012015-05-04 23:15:15 +00004891 </td>
4892 </tr>
4893
4894 <tr><td></td><td>This should allow a existing frame optimized GIF animation
4895 to compress into a smaller file size due to larger areas of one
4896 (transparent) color rather than a pattern of multiple colors repeating
4897 the current disposed image of the last frame. </td>
4898 </tr>
4899
4900 <tr>
4901 <td>remove-dups</td>
4902 <td>Remove (and merge time delays) of duplicate consecutive
4903 images, so as to simplify layer overlays of coalesced animations.
4904 </td>
4905 </tr>
4906
4907 <tr><td></td><td>Usually this a result of using a constant time delay
4908 across the whole animation, or after a larger animation was split into
4909 smaller sub-animations. The duplicate frames could also have been
4910 used as part of some frame optimization methods. </td>
4911 </tr>
4912
4913 <tr>
4914 <td>remove-zero</td>
4915 <td>Remove any image with a zero time delay, unless ALL the
4916 images have a zero time delay (and is not a proper timed animation, a
4917 warning is then issued). </td>
4918 </tr>
4919
4920 <tr><td></td><td>In a GIF animation, such images are usually frames which
4921 provide partial intermediary updates between the frames that are
4922 actually displayed to users. These frames are usually added for
4923 improved frame optimization in GIF animations. </td>
4924 </tr>
4925
4926 <tr>
4927 <td>trim-bounds</td>
4928 <td>Find the bounds of all the images in the current
4929 image sequence, then adjust the offsets so all images are contained on
4930 a minimal positive canvas. None of the image data is modified or
4931 merged, only the individual image virtual canvas size and offset.
4932 All the images is given the same canvas size, and and will have
4933 a positive offset, but will remain in the same position relative to
4934 each other. As a result of the minimal canvas size at least one image
4935 will touch every edge of that canvas. The image data touching those
4936 edges however may be transparent. </td>
4937 </tr>
4938
4939 <tr><td></td><td>The result is much like if you used 'merge' followed by a
cristy82a2ff22015-05-12 16:41:32 +00004940 <a href="command-line-options.html#repage">+repage</a> option, except that all the images
cristyd2432012015-05-04 23:15:15 +00004941 have been kept separate. If 'flatten' is used after using
4942 'trim-bounds' you will get the same result. </td>
4943 </tr>
4944
4945 </tbody>
4946</table>
4947
4948<p>To print a complete list of layer types, use <a href="command-line-options.html#list">-list layers</a>.</p>
4949
cristy82a2ff22015-05-12 16:41:32 +00004950<p>The operators <a href="command-line-options.html#coalesce">-coalesce</a>, <a href="command-line-options.html#deconstruct">-deconstruct</a>, <a href="command-line-options.html#flatten">-flatten</a>, and <a href="command-line-options.html#mosaic">-mosaic</a> are only aliases for the above methods and may be depreciated in
4951the future. Also see <a href="command-line-options.html#page">-page</a>, <a href="command-line-options.html#repage">-repage</a> operators, the <a href="command-line-options.html#compose">-compose</a> setting, and the
4952GIF <a href="command-line-options.html#dispose">-dispose</a> and <a href="command-line-options.html#delay">-delay</a>
cristyd2432012015-05-04 23:15:15 +00004953settings. </p>
4954
4955
4956<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004957 <h3 class="magick-header"><a id="level"></a>-level <var>black_point</var>{,<var>white_point</var>}{<var>%</var>}{,<var>gamma</var>}</h3>
cristyd2432012015-05-04 23:15:15 +00004958</div>
4959
4960<p class="magick-description">adjust the level of image channels.</p>
4961
4962<p>Given one, two or three values delimited with commas: black-point,
4963white-point, gamma (for example: 10,250,1.0 or 2%,98%,0.5). The black and
4964white points range from 0 to <var>QuantumRange</var>, or from 0 to
4965100%; if the white point is omitted it is set to (<var>QuantumRange</var> - black_point), so as to center contrast changes.
4966If a <code>%</code> sign is present anywhere in the string, both black and white
cristy82a2ff22015-05-12 16:41:32 +00004967points are percentages of the full color range. Gamma will do a <a href="command-line-options.html#gamma">-gamma</a> adjustment of the values. If it is omitted, the
cristyd2432012015-05-04 23:15:15 +00004968default of 1.0 (no gamma correction) is assumed.</p>
4969
4970<p>In normal usage (<code>-level</code>) the image values are stretched so that
4971the given '<code>black_point</code>' value in the original image is set to zero
4972(or black), while the given '<code>white_point</code>' value is set to <var>QuantumRange</var> (or white). This provides you with direct
4973contrast adjustments to the image. The '<code>gamma</code>' of the resulting
4974image will then be adjusted. </p>
4975
4976<p>From ImageMagick v6.4.1-9 using the plus form of the operator
4977(<code>+level</code>) or adding the special '!' flag anywhere in the argument
4978list, will cause the operator to do the reverse of the level adjustment. That
4979is a zero, or <var>QuantumRange</var> value (black, and white, resp.)
4980in the original image, is adjusted to the given level values, allowing you to
4981de-contrast, or compress the channel values within the image. The
4982'<code>gamma</code>' is adjusted before the level adjustment to de-contrast the
4983image is made. </p>
4984
4985<p>Only the channels defined by the current <a href="command-line-options.html#channel">-channel</a>
4986setting are adjusted (defaults to RGB color channels only), allowing you to
4987limit the effect of this operator. </p>
4988
4989<p>Please note that the transparency channel is treated as 'matte'
4990values (0 is opaque) and not as 'alpha' values (0 is transparent).</p>
4991
4992
4993<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004994 <h3 class="magick-header"><a id="level-colors"></a>-level-colors {<var>black_color</var>}{,}{<var>white_color</var>}</h3>
cristyd2432012015-05-04 23:15:15 +00004995</div>
4996
4997<p class="magick-description">adjust the level of an image using the provided dash separated colors.</p>
4998
4999<p>This function is exactly like <a href="command-line-options.html#level">-level</a>, except that the
5000value value for each color channel is determined by the
5001'<code>black_color</code>' and '<code>white_color</code>' colors given (as
5002described under the <a href="command-line-options.html#fill">-fill</a> option). </p>
5003
5004<p>This effectually means the colors provided to <code>-level-colors</code>
5005is mapped to become 'black' and 'white' respectively, with all the other
5006colors linearly adjusted (or clipped) to match that change. Each channel is
5007adjusted separately using the channel values of the colors specified. </p>
5008
5009<p>On the other hand the plus form of the operator (<code>+level-colors</code>)
5010will map the image color 'black' and 'white' to the given colors
5011respectively, resulting in a gradient (de-contrasting) tint of the image to
5012those colors. This can also be used to convert a plain gray-scale image into a
5013one using the gradient of colors specified. </p>
5014
5015<p>By supplying a single color with a comma separator either before or after
5016that color, will just replace the respective 'black' or 'white' point
5017respectively. But if no comma separator is provided, the given color is
5018used for both the black and white color points, making the operator either
5019threshold the images around that color (- form) or set all colors to that
5020color (+ form). </p>
5021
5022
5023<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005024 <h3 class="magick-header"><a id="limit"></a>-limit <var>type value</var></h3>
cristyd2432012015-05-04 23:15:15 +00005025</div>
5026
5027<p class="magick-description">Set the pixel cache resource limit.</p>
5028
5029<p>Choose from: <code>area</code>, <code>disk</code>, <code>file</code>,
5030<code>map</code>, <code>memory</code>, <code>thread</code>, or <code>time</code>.</p>
5031
5032<p>The value for <code>file</code> is in number of files. The other limits are
5033in bytes. Define arguments for the memory, map, area, and disk resource limits
5034with SI prefixes (.e.g 100MB).</p>
5035
5036<p>By default the limits are 768 files, 3GB of image area, 1.5GiB memory, 3GiB
5037memory map, and 18.45EB of disk. These limits are adjusted relative to the
5038available resources on your computer if this information is available. When
5039any limit is reached, ImageMagick fails in some fashion but attempts to take
5040compensating actions, if possible. For example, the following limits
5041memory:</p>
5042
cristy29dc8652015-05-12 16:26:21 +00005043<pre>
5044-limit memory 32MiB -limit map 64MiB
5045</pre>
cristyd2432012015-05-04 23:15:15 +00005046
5047<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>
5048
5049<pre>
cristy82a2ff22015-05-12 16:41:32 +00005050-&gt; identify -list resource
cristyd2432012015-05-04 23:15:15 +00005051Resource limits:
5052 Width: 100MP
5053 Height: 100MP
5054 Area: 25.181GB
5055 Memory: 11.726GiB
5056 Map: 23.452GiB
5057 Disk: unlimited
5058 File: 768
5059 Thread: 12
5060 Throttle: 0
5061 Time: unlimited
5062</pre>
5063
5064<p>Requests for pixel storage to keep intermediate images are satisfied by one
5065of three resource categories: in-memory pool, memory-mapped files pool, and
cristy82a2ff22015-05-12 16:41:32 +00005066disk pool (in that order) depending on the <a href="command-line-options.html#limit">‑limit</a> settings
cristyd2432012015-05-04 23:15:15 +00005067and whether the system honors a resource request. If the total size of
5068allocated pixel storage in the given pool reaches the corresponding limit, the
5069request is passed to the next pool. Additionally, requests that exceed the
5070<code>area</code> limit automagically are allocated on disk.</p>
5071
5072<p>To illustrate how ImageMagick utilizes resource limits, consider a typical
5073image resource request. First, ImageMagick tries to allocate the pixels in
5074memory. The request might be denied if the resource request exceeds the
5075<code>memory</code> limit or if the system does not honor the request. If
5076a memory request is not honored, the pixels are allocated to disk and the file
5077is memory-mapped. However, if the allocation request exceeds the
5078<code>map</code> limit, the resource allocation goes to disk. In all cases, if
5079the resource request exceeds the <code>area</code> limit, the pixels are
5080automagically cached to disk. If the disk has a hard limit, the program
5081fails.</p>
5082
5083<p>In most cases you simply do not need to concern yourself with resource
5084limits. ImageMagick chooses reasonable defaults and most images do not tax
5085your computer resources. Where limits do come in handy is when you process
5086images that are large or on shared systems where ImageMagick can consume all
5087or most of the available memory. In this case, the ImageMagick workflow slows
5088other processes or, in extreme cases, brings the system to a halt. Under
5089these circumstances, setting limits give some assurances that the ImageMagick
5090workflow will not interfere with other concurrent uses of the computer. For
5091example, assume you have a web interface that processes images uploaded from
5092the Internet. To assure ImageMagick does not exceed 10MiB of memory you can
5093simply set the area limit to 10MiB:</p>
5094
cristy29dc8652015-05-12 16:26:21 +00005095<pre>
cristyd2432012015-05-04 23:15:15 +00005096-limit area 10MB
cristy29dc8652015-05-12 16:26:21 +00005097</pre>
cristyd2432012015-05-04 23:15:15 +00005098
5099<p>Now whenever a large image is processed, the pixels are automagically
5100cached to disk instead of memory. This of course implies that large images
5101typically process very slowly, simply because pixel processing in memory can
5102be an order of magnitude faster than on disk. Because your web site users
5103might inadvertently upload a huge image to process, you should set a disk
5104limit as well:</p>
5105
cristy29dc8652015-05-12 16:26:21 +00005106<pre>
cristyd2432012015-05-04 23:15:15 +00005107-limit area 10MB -limit disk 500MB
cristy29dc8652015-05-12 16:26:21 +00005108</pre>
cristyd2432012015-05-04 23:15:15 +00005109
5110<p>Here ImageMagick stops processing if an image requires more than 500MB of disk storage.</p>
5111
5112<p>In addition to command-line resource limit option, resources can be set
cristy82a2ff22015-05-12 16:41:32 +00005113with <a href="resources.html#environment">environment variables</a>. Set the
cristyd2432012015-05-04 23:15:15 +00005114environment variables <code>MAGICK_AREA_LIMIT</code>,
5115<code>MAGICK_DISK_LIMIT</code>, <code>MAGICK_FILE_LIMIT</code>,
5116<code>MAGICK_MEMORY_LIMIT</code>, <code>MAGICK_MAP_LIMIT</code>,
5117<code>MAGICK_THREAD_LIMIT</code>, <code>MAGICK_TIME_LIMIT</code> for limits of
5118image area, disk space, open files, heap memory, memory map, number of threads
5119of execution, and maximum elapsed time in seconds respectively.</p>
5120
5121<p> Inquisitive users can try adding <a href="command-line-options.html#debug">-debug cache</a> to
5122their commands and then scouring the generated output for references to the
5123pixel cache, in order to determine how the pixel cache was allocated and how
5124resources were consumed. Advanced Unix/Linux users can pipe that output
5125through <code>grep memory|open|destroy|disk</code> for more readable sifting.
5126</p>
5127
5128<p>For more about ImageMagick's use of resources, see the section <b>Cache
cristy82a2ff22015-05-12 16:41:32 +00005129Storage and Resource Requirements</b> on the <a href="architecture.html#cache%0A">Architecture</a> page. </p>
cristyd2432012015-05-04 23:15:15 +00005130
5131<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00005132 <h3 class="magick-header"><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>
cristyd2432012015-05-04 23:15:15 +00005133</div>
5134
5135<p class="magick-description">Linear with saturation stretch.</p>
5136
cristy82a2ff22015-05-12 16:41:32 +00005137<p>This is very similar to <a href="command-line-options.html#contrast-stretch">-contrast-stretch</a>,
cristyd2432012015-05-04 23:15:15 +00005138and uses a 'histogram bin' to determine the range of color values that needs to
cristy82a2ff22015-05-12 16:41:32 +00005139be stretched. However it then stretches those colors using the <a href="command-line-options.html#level">-level</a> operator.</p>
cristyd2432012015-05-04 23:15:15 +00005140
5141<p>As such while the initial determination may have 'binning' round off
5142effects, the image colors are stretched mathematically, rather than using the
5143histogram bins. This makes the operator more accurate. </p>
5144
cristy82a2ff22015-05-12 16:41:32 +00005145<p>note however that a <a href="command-line-options.html#linear-stretch">-linear-stretch</a> of
cristyd2432012015-05-04 23:15:15 +00005146'<code>0</code>' does nothing, while a value of '<code>1</code>' does a near
5147perfect stretch of the color range. </p>
5148
cristy82a2ff22015-05-12 16:41:32 +00005149<p>See also <a href="command-line-options.html#auto-level">-auto-level</a> for a 'perfect'
cristyd2432012015-05-04 23:15:15 +00005150normalization of mathematical images. </p>
5151
5152<p>This operator is under review for re-development. </p>
5153
5154
5155<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005156 <h3 class="magick-header"><a id="linewidth"></a>-linewidth</h3>
cristyd2432012015-05-04 23:15:15 +00005157</div>
5158
5159<p class="magick-description">the line width for subsequent draw operations.</p>
5160
5161<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005162 <h3 class="magick-header"><a id="liquid-rescale"></a>-liquid-rescale <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00005163</div>
5164
5165<p class="magick-description">rescale image with seam-carving.</p>
5166
5167<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
5168
5169<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005170 <h3 class="magick-header"><a id="list"></a>-list <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00005171</div>
5172
5173<p class="magick-description">Print a list of supported arguments for various options or settings. Choose from these list types:</p>
5174
cristyb2cad532015-05-16 13:02:45 +00005175<pre class="pre-scrollable">
5176Align
5177Alpha
5178Boolean
5179Cache
5180Channel
5181Class
5182ClipPath
5183Coder
5184Color
5185Colorspace
5186Command
5187Complex
5188Compose
5189Compress
5190Configure
5191DataType
5192Debug
5193Decoration
5194Delegate
5195Direction
5196Dispose
5197Distort
5198Dither
5199Endian
5200Evaluate
5201FillRule
5202Filter
5203Font
5204Format
5205Function
5206Gravity
5207Intensity
5208Intent
5209Interlace
5210Interpolate
5211Kernel
5212Layers
5213LineCap
5214LineJoin
5215List
5216Locale
5217LogEvent
5218Log
5219Magic
5220Method
5221Metric
5222Mime
5223Mode
5224Morphology
5225Module
5226Noise
5227Orientation
5228PixelIntensity
5229Policy
5230PolicyDomain
5231PolicyRights
5232Preview
5233Primitive
5234QuantumFormat
5235Resource
5236SparseColor
5237Statistic
5238Storage
5239Stretch
5240Style
5241Threshold
5242Type
5243Units
5244Validate
5245VirtualPixel
cristyd2432012015-05-04 23:15:15 +00005246</pre>
5247
5248<p>These lists vary depending on your version of ImageMagick. Use "<code>-list
5249list</code>" to get a complete listing of all the "<code>-list</code>" arguments
5250available:</p>
5251
5252<pre>
5253identify -list list
5254</pre>
5255
5256<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005257 <h3 class="magick-header"><a id="log"></a>-log <var>string</var></h3>
cristyd2432012015-05-04 23:15:15 +00005258</div>
5259
5260<p class="magick-description">Specify format for debug log.</p>
5261
cristy82a2ff22015-05-12 16:41:32 +00005262<p>This option specifies the format for the log printed when the <a href="command-line-options.html#debug">-debug</a> option is active.</p>
cristyd2432012015-05-04 23:15:15 +00005263
5264<p>You can display the following components by embedding special format
5265characters:</p>
5266
cristyb2cad532015-05-16 13:02:45 +00005267<dl class="dl-horizontal">
5268<dt>%d</dt><dd>domain</dd>
5269<dt>%e</dt><dd>event</dd>
5270<dt>%f</dt><dd>function</dd>
5271<dt>%l</dt><dd>line</dd>
5272<dt>%m</dt><dd>module</dd>
5273<dt>%p</dt><dd>process ID</dd>
5274<dt>%r</dt><dd>real CPU time</dd>
5275<dt>%t</dt><dd>wall clock time</dd>
5276<dt>%u</dt><dd>user CPU time</dd>
5277<dt>%%</dt><dd>percent sign</dd>
5278<dt>\n</dt><dd>newline</dd>
5279<dt>\r</dt><dd>carriage return</dd>
5280</dl>
cristyd2432012015-05-04 23:15:15 +00005281
5282<p>For example:</p>
5283
5284<pre>
5285convert -debug coders -log "%u %m:%l %e" in.gif out.png
5286</pre>
5287
5288<p>The default behavior is to print all of the components.</p>
5289
5290<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005291 <h3 class="magick-header"><a id="loop"></a>-loop <var>iterations</var></h3>
cristyd2432012015-05-04 23:15:15 +00005292</div>
5293
5294<p class="magick-description">add Netscape loop extension to your GIF animation.</p>
5295
5296<p>Set iterations to zero to repeat the animation an infinite number of times,
5297otherwise the animation repeats itself up to <var>iterations</var>
5298times.</p>
5299
5300<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005301 <h3 class="magick-header"><a id="lowlight-color"></a>-lowlight-color <var>color</var></h3>
cristyd2432012015-05-04 23:15:15 +00005302</div>
5303
5304<p class="magick-description">when comparing images, de-emphasize pixel differences with this color.</p>
5305
5306<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005307 <h3 class="magick-header"><a id="magnify"></a>-magnify</h3>
cristyd2432012015-05-04 23:15:15 +00005308</div>
5309
5310<p class="magick-description">double the size of the image with pixel art scaling.</p>
5311
5312
5313<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005314 <h3 class="magick-header"><a id="map"></a>-map <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00005315</div>
5316
5317<p class="magick-description">Display image using this <var>type</var>.</p>
5318
5319<p>Choose from these <var>Standard Colormap</var> types:</p>
5320
5321<pre>
cristy29dc8652015-05-12 16:26:21 +00005322best
5323default
5324gray
5325red
5326green
5327blue
cristyd2432012015-05-04 23:15:15 +00005328</pre>
5329
5330<p>The <var>X server</var> must support the <var>Standard
5331Colormap</var> you choose, otherwise an error occurs. Use <code>list</code> as
5332the type and <code>display</code> searches the list of colormap types in
5333<code>top-to-bottom</code> order until one is located. See <var>xstdcmap(1)</var> for one way of creating Standard Colormaps.</p>
5334
5335
5336<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005337 <h3 class="magick-header"><a id="map_stream_"></a>-map <var>components</var></h3>
cristyd2432012015-05-04 23:15:15 +00005338</div>
5339
5340<p class="magick-description">pixel map.</p>
5341
5342<p>Here are the valid components of a map:</p>
5343
cristyb2cad532015-05-16 13:02:45 +00005344<dl class="dl-horizontal">
5345<dt>r</dt><dd> red pixel component</dd>
5346<dt>g</dt><dd> green pixel component</dd>
5347<dt>b</dt><dd> blue pixel component</dd>
5348<dt>a</dt><dd> alpha pixel component (0 is transparent)</dd>
5349<dt>o</dt><dd> opacity pixel component (0 is opaque)</dd>
5350<dt>i</dt><dd> grayscale intensity pixel component</dd>
5351<dt>c</dt><dd> cyan pixel component</dd>
5352<dt>m</dt><dd> magenta pixel component</dd>
5353<dt>y</dt><dd> yellow pixel component</dd>
5354<dt>k</dt><dd> black pixel component</dd>
5355<dt>p</dt><dd> pad component (always 0)</dd>
5356</dl>
cristyd2432012015-05-04 23:15:15 +00005357
5358<p>You can specify as many of these components as needed in any order (e.g.
5359bgr). The components can repeat as well (e.g. rgbr).</p>
5360
5361
5362<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005363 <h3 class="magick-header"><a id="mask"></a>-mask
5364<var>filename</var></h3>
cristyd2432012015-05-04 23:15:15 +00005365</div>
5366
5367<p class="magick-description">Prevent updates to image pixels specified by the mask.</p>
5368
5369<p>This the same as using a mask used for composite masking operations, with
5370grayscale values causing blended updates of the image the mask is attached to.
5371</p>
5372
5373<p>Use <a href="command-line-options.html#mask">+mask</a> to remove the mask from images.</p>
5374
5375<p>Also see <a href="command-line-options.html#clip-mask">-clip-mask</a> which work in the same way,
5376but with strict boolean masking. </p>
5377
5378<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005379 <h3 class="magick-header"><a id="mattecolor"></a>-mattecolor <var>color</var></h3>
cristyd2432012015-05-04 23:15:15 +00005380</div>
5381
5382<p class="magick-description">Specify the color to be used with the <a href="command-line-options.html#frame">-frame</a> option.</p>
5383
5384<p>The color is specified using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p>
5385
cristy82a2ff22015-05-12 16:41:32 +00005386<p>The default matte color is <code>#BDBDBD</code>, <span style="background-color: #bdbdbd;">this shade of gray</span>.</p>
cristyd2432012015-05-04 23:15:15 +00005387
5388<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005389 <h3 class="magick-header"><a id="maximum"></a>-maximum</h3>
cristyd2432012015-05-04 23:15:15 +00005390</div>
5391
5392<p class="magick-description">return the maximum intensity of an image sequence.</p>
5393
5394<p>Select the 'maximum' value from all the surrounding pixels. </p>
5395
cristy82a2ff22015-05-12 16:41:32 +00005396<p>This is legacy option from the <a href="command-line-options.html#statistic">method</a> of the same
cristyd2432012015-05-04 23:15:15 +00005397name. </p>
5398
5399<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005400 <h3 class="magick-header"><a id="median"></a>-median <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00005401</div>
5402
5403<p class="magick-description">apply a median filter to the image.</p>
5404
5405<p>Select the 'middle' value from all the surrounding pixels. </p>
5406
cristy82a2ff22015-05-12 16:41:32 +00005407<p>This is legacy option from the <a href="command-line-options.html#statistic">method</a> of the same
cristyd2432012015-05-04 23:15:15 +00005408name. </p>
5409
5410<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005411 <h3 class="magick-header"><a id="mean-shift"></a>-mean-shift <var>width</var>x<var>height</var>{<var>+distance</var>{%}}</h3>
cristyd2432012015-05-04 23:15:15 +00005412</div>
5413
5414<p class="magick-description">image noise removal and color reduction/segmentation (e.g. -mean-shift 7x7+10%).</p>
5415
5416<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>
5417
cristyb2cad532015-05-16 13:02:45 +00005418<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>
cristyd2432012015-05-04 23:15:15 +00005419
5420<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005421 <h3 class="magick-header"><a id="metric"></a>-metric <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00005422</div>
5423
5424<p class="magick-description">Output to STDERR a measure of the differences between images according to the <var>type</var> given metric.</p>
5425
5426<p>Choose from:</p>
5427
cristy29dc8652015-05-12 16:26:21 +00005428<dl class="dl-horizontal">
5429<dt>AE</dt><dd> absolute error count, number of different pixels (-fuzz effected)</dd>
5430<dt>FUZZ</dt><dd> mean color distance</dd>
5431<dt>MAE</dt><dd> mean absolute error (normalized), average channel error distance</dd>
5432<dt>MEPP</dt><dd> mean error per pixel (normalized mean error, normalized peak error)</dd>
5433<dt>MSE</dt><dd> mean error squared, average of the channel error squared</dd>
5434<dt>NCC</dt><dd> normalized cross correlation</dd>
5435<dt>PAE</dt><dd> peak absolute (normalized peak absolute)</dd>
5436<dt>PHASH</dt><dd> perceptual hash</dd>
5437<dt>PSNR</dt><dd> peak signal to noise ratio</dd>
5438<dt>RMSE</dt><dd> root mean squared (normalized root mean squared)</dd>
5439</dl>
cristyd2432012015-05-04 23:15:15 +00005440
5441<p>Control the '<code>AE</code>', or absolute count of pixels that are different,
cristy82a2ff22015-05-12 16:41:32 +00005442with the <a href="command-line-options.html#fuzz">-fuzz</a> factor (ignore pixels which
cristyd2432012015-05-04 23:15:15 +00005443only changed by a small amount). Use '<code>PAE</code>' to find the
cristy82a2ff22015-05-12 16:41:32 +00005444size of the <a href="command-line-options.html#fuzz">-fuzz</a> factor needed to make all pixels
cristyd2432012015-05-04 23:15:15 +00005445'similar', while '<code>MAE</code>' determines the factor needed
5446for about half the pixels to be similar. </p>
5447
5448<p>The '<code>MEPP</code>' metric returns three different metrics
5449('<code>MAE</code>', '<code>MAE</code>' normalized, and '<code>PAE</code>'
5450normalized) from a single comparison run. </p>
5451
5452<p>To print a complete list of metrics, use the <a href="command-line-options.html#list">-list
5453metric</a> option.</p>
5454
5455
5456<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005457 <h3 class="magick-header"><a id="minimum"></a>-minimum</h3>
cristyd2432012015-05-04 23:15:15 +00005458</div>
5459
5460<p class="magick-description">return the minimum intensity of an image sequence.</p>
5461
5462<p>Select the 'minimal' value from all the surrounding pixels. </p>
5463
cristy82a2ff22015-05-12 16:41:32 +00005464<p>This is legacy option from the <a href="command-line-options.html#statistic">method</a> of the same
cristyd2432012015-05-04 23:15:15 +00005465name. </p>
5466
5467
5468
5469<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005470 <h3 class="magick-header"><a id="mode"></a>-mode <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00005471</div>
5472
5473<p class="magick-description">make each pixel the \'predominant color\' of the neighborhood.'</p>
5474
5475<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005476 <h3 class="magick-header">-mode <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00005477</div>
5478
5479<p class="magick-description">Mode of operation.</p>
5480
5481<p>Choose the <var>value</var> from these styles: <code>Frame,
5482Unframe, or Concatenate</code></p>
5483
cristy82a2ff22015-05-12 16:41:32 +00005484<p>Use the <a href="command-line-options.html#list">-list</a> option with a '<code>Mode</code>' argument
5485for a list of <a href="command-line-options.html#mode">-mode</a> arguments available in your
cristyd2432012015-05-04 23:15:15 +00005486ImageMagick installation.</p>
5487
5488
5489<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005490 <h3 class="magick-header"><a id="modulate"></a>-modulate <var>brightness</var>[,<var>saturation</var>,<var>hue</var>]</h3>
cristyd2432012015-05-04 23:15:15 +00005491</div>
5492
5493<p class="magick-description">Vary the <var>brightness</var>, <var>saturation</var>, and <var>hue</var> of an image.</p>
5494
5495<p>The arguments are given as a percentages of variation. A value of 100 means
5496no change, and any missing values are taken to mean 100.</p>
5497
5498<p>The <var>brightness</var> is a multiplier of the overall
5499brightness of the image, so 0 means pure black, 50 is half as bright, 200 is
5500twice as bright. To invert its meaning <a href="command-line-options.html#negate">-negate</a> the image
5501before and after. </p>
5502
5503<p>The <var>saturation</var> controls the amount of color in an
5504image. For example, 0 produce a grayscale image, while a large value such as
5505200 produce a very colorful, 'cartoonish' color.</p>
5506
5507<p>The <var>hue</var> argument causes a "rotation" of the colors
5508within the image by the amount specified. For example, 50 results in
5509a counter-clockwise rotation of 90, mapping red shades to purple, and so on.
5510A value of either 0 or 200 results in a complete 180 degree rotation of the
5511image. Using a value of 300 is a 360 degree rotation resulting in no change to
5512the original image. </p>
5513
5514<p>For example, to increase the color brightness by 20% and decrease the color
cristy82a2ff22015-05-12 16:41:32 +00005515saturation by 10% and leave the hue unchanged, use <a href="command-line-options.html#modulate">-modulate 120,90</a>.</p>
cristyd2432012015-05-04 23:15:15 +00005516
cristy82a2ff22015-05-12 16:41:32 +00005517<p>Use <a href="command-line-options.html#set">-set</a> attribute of '<code>option:modulate:colorspace</code>' to specify which colorspace to
cristyd2432012015-05-04 23:15:15 +00005518modulate. 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>
5519
5520<pre>
5521convert image.png -set option:modulate:colorspace hsb -modulate 120,90 modulate.png
5522</pre>
5523
5524<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005525 <h3 class="magick-header"><a id="moments"></a>-moments</h3>
cristyd2432012015-05-04 23:15:15 +00005526</div>
5527
5528<p class="magick-description">report image moments and perceptual hash.</p>
5529
5530
5531<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005532 <h3 class="magick-header"><a id="monitor"></a>-monitor</h3>
cristyd2432012015-05-04 23:15:15 +00005533</div>
5534
5535<p class="magick-description">monitor progress.</p>
5536
5537
5538<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005539 <h3 class="magick-header"><a id="monochrome"></a>-monochrome</h3>
cristyd2432012015-05-04 23:15:15 +00005540</div>
5541
5542<p class="magick-description">transform the image to black and white.</p>
5543
5544<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005545 <h3 class="magick-header"><a id="morph"></a>-morph <var>frames</var></h3>
cristyd2432012015-05-04 23:15:15 +00005546</div>
5547
5548<p class="magick-description">morphs an image sequence.</p>
5549
5550<p>Both the image pixels and size are linearly interpolated to give the
5551appearance of a metamorphosis from one image to the next, over all the images
cristy82a2ff22015-05-12 16:41:32 +00005552in the current image list. The added images are the equivalent of a <a href="command-line-options.html#blend">-blend</a> composition. The <var>frames</var>
cristyd2432012015-05-04 23:15:15 +00005553argument determine how many images to interpolate between each image. </p>
5554
5555
5556<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005557 <h3 class="magick-header"><a id="morphology"></a>-morphology</h3>
5558 <h3 class="magick-header">-morphology <var>method</var> <var>kernel</var></h3>
cristyd2432012015-05-04 23:15:15 +00005559</div>
5560
5561<p class="magick-description">apply a morphology method to the image.</p>
5562
cristy82a2ff22015-05-12 16:41:32 +00005563<p>Until I get around to writing an option summary for this, see <a href="http://www.imagemagick.org/Usage/morphology/">IM Usage Examples,
cristyd2432012015-05-04 23:15:15 +00005564Morphology</a>. </p>
5565
5566
5567<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005568 <h3 class="magick-header"><a id="mosaic"></a>-mosaic</h3>
cristyd2432012015-05-04 23:15:15 +00005569</div>
5570
cristy82a2ff22015-05-12 16:41:32 +00005571<p class="magick-description">an simple alias for the <a href="command-line-options.html#layers">-layers</a> method "mosaic"</p>
cristyd2432012015-05-04 23:15:15 +00005572
5573
5574<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00005575 <h3 class="magick-header"><a id="motion-blur"></a>-motion-blur <var>radius</var><br>-motion-blur <var>radius</var>x<var>sigma</var>+<var>angle</var></h3>
cristyd2432012015-05-04 23:15:15 +00005576</div>
5577
5578<p class="magick-description">simulate motion blur.</p>
5579
5580<p>Blur with the given radius, standard deviation (sigma), and angle. The
5581angle given is the angle toward which the image is blurred. That is the
5582direction people would consider the object is coming from. </p>
5583
5584<p>Note that the blur is not uniform distribution, giving the motion a
5585definite sense of direction of movement. </p>
5586
5587<p>The <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting will determine how
5588pixels which are outside the image proper are blurred into the final result.
5589</p>
5590
5591<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005592 <h3 class="magick-header"><a id="name"></a>-name</h3>
cristyd2432012015-05-04 23:15:15 +00005593</div>
5594
5595<p class="magick-description">name an image.</p>
5596<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005597 <h3 class="magick-header"><a id="negate"></a>-negate</h3>
cristyd2432012015-05-04 23:15:15 +00005598</div>
5599
5600<p class="magick-description">replace each pixel with its complementary color.</p>
5601
5602<p>The red, green, and blue intensities of an image are negated. White becomes
5603black, yellow becomes blue, etc. Use <a href="command-line-options.html#negate">+negate</a> to only
5604negate the grayscale pixels of the image.</p>
5605
5606<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00005607 <h3 class="magick-header"><a id="noise"></a>-noise <var>geometry</var><br>
cristy29dc8652015-05-12 16:26:21 +00005608 +noise <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00005609</div>
5610
5611<p class="magick-description">Add or reduce noise in an image.</p>
5612
5613<p>The principal function of noise peak elimination filter is to smooth the
5614objects within an image without losing edge information and without creating
5615undesired structures. The central idea of the algorithm is to replace a pixel
5616with its next neighbor in value within a pixel window, if this pixel has been
5617found to be noise. A pixel is defined as noise if and only if this pixel is
5618a maximum or minimum within the pixel window.</p>
5619
5620<p>Use <code><a href="command-line-options.html#noise">-noise</a> <var>radius</var></code> to
5621specify the width of the neighborhood when reducing noise. This is equivalent
cristy82a2ff22015-05-12 16:41:32 +00005622to using a <code><a href="command-line-options.html#statistic">-statistic</a> NonPeak</code> operation,
cristyd2432012015-05-04 23:15:15 +00005623which should be used in preference.</p>
5624
5625<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
5626types:</p>
5627
5628<pre>
cristy29dc8652015-05-12 16:26:21 +00005629Gaussian
5630Impulse
5631Laplacian
5632Multiplicative
5633Poisson
5634Random
5635Uniform
cristyd2432012015-05-04 23:15:15 +00005636</pre>
5637
cristy82a2ff22015-05-12 16:41:32 +00005638<p>The amount of noise added can be controled by the <code><a href="command-line-options.html#attunuuate">-attenuate</a></code> setting. If unset the value is
cristyd2432012015-05-04 23:15:15 +00005639equivalent to 1.0, or a maximum noise addition.</p>
5640
5641<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>
5642
5643<p>To print a complete list of noises, use the <a href="command-line-options.html#list">-list noise</a> option.</p>
5644
5645<p>Also see the <a href="command-line-options.html#evaluate">-evaluate</a> noise functions that allows
5646the use of a controlling value to specify the amount of noise that should be
5647added to an image. </p>
5648
5649
5650<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005651 <h3 class="magick-header"><a id="normalize"></a>-normalize</h3>
cristyd2432012015-05-04 23:15:15 +00005652</div>
5653
5654<p class="magick-description">Increase the contrast in an image by <var>stretching</var> the range of intensity values.</p>
5655
5656<p>The intensity values are stretched to cover the entire range of possible
5657values. While doing so, black-out at most <var>2%</var> of the pixels and
5658white-out at most <var>1%</var> of the pixels.</p>
5659
cristy82a2ff22015-05-12 16:41:32 +00005660<p>Note that as of ImageMagick 6.4.7-0, <a href="command-line-options.html#normalize">-normalize</a>
5661is equivalent to <a href="command-line-options.html#contrast-stretch">-contrast-stretch 2%x1%</a>.
5662(Before this version, it was equivalent to <a href="command-line-options.html#contrast-stretch">-contrast-stretch 2%x99%</a>).</p>
cristyd2432012015-05-04 23:15:15 +00005663
5664<p>All the channels are normalized in concert by the came amount so as to
cristy82a2ff22015-05-12 16:41:32 +00005665preserve color integrity, when the default <a href="command-line-options.html#channel">+channel</a>
5666setting is in use. Specifying any other <a href="command-line-options.html#channel">-channel</a>
cristyd2432012015-05-04 23:15:15 +00005667setting will normalize the RGB channels independently.</p>
5668
cristy82a2ff22015-05-12 16:41:32 +00005669<p>See <a href="command-line-options.html#contrast-stretch">-contrast-stretch</a> for more details.
5670Also see <a href="command-line-options.html#auto-level">-auto-level</a> for a 'perfect' normalization
cristyd2432012015-05-04 23:15:15 +00005671that is better suited to mathematically generated images. </p>
5672
5673<p>This operator is under review for re-development. </p>
5674
5675
5676<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005677 <h3 class="magick-header"><a id="opaque"></a>-opaque <var>color</var></h3>
cristyd2432012015-05-04 23:15:15 +00005678</div>
5679
5680<p class="magick-description">change this color to the fill color within the image.</p>
5681
5682<p>The <var>color</var> argument is defined using the format
cristy82a2ff22015-05-12 16:41:32 +00005683described under the <a href="command-line-options.html#fill">-fill</a> option. The <a href="command-line-options.html#fuzz">-fuzz</a> setting can be used to match and replace colors similar to the one
cristyd2432012015-05-04 23:15:15 +00005684given.</p>
5685
5686<p>Use <a href="command-line-options.html#opaque">+opaque</a> to paint any pixel that does not match
5687the target color. </p>
5688
5689<p>The <a href="command-line-options.html#transparent">-transparent</a> operator is exactly the same
cristy82a2ff22015-05-12 16:41:32 +00005690as <a href="command-line-options.html#opaque">-opaque</a> but replaces the matching color with
cristyd2432012015-05-04 23:15:15 +00005691transparency rather than the current <a href="command-line-options.html#fill">-fill</a> color setting.
5692To ensure that it can do this it also ensures that the image has an alpha
cristy82a2ff22015-05-12 16:41:32 +00005693channel enabled, as per "<code><a href="command-line-options.html#alpha">-alpha</a> set</code>", for
5694the new transparent colors, and does not require you to modify the <a href="command-line-options.html#channel">-channel</a> to enable alpha channel handling. </p>
cristyd2432012015-05-04 23:15:15 +00005695
5696
5697<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005698 <h3 class="magick-header"><a id="ordered-dither"></a>-ordered-dither <var>threshold_map</var>{,<var>level</var>...}</h3>
cristyd2432012015-05-04 23:15:15 +00005699</div>
5700
5701<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
5702given number of <var>levels</var> per color channel.</p>
5703
5704<p>You can choose from these standard threshold maps:</p>
5705
cristyb2cad532015-05-16 13:02:45 +00005706<pre class="pre-scrollable">
cristy29dc8652015-05-12 16:26:21 +00005707threshold 1x1 Threshold 1x1 (non-dither)
5708checks 2x1 Checkerboard 2x1 (dither)
5709o2x2 2x2 Ordered 2x2 (dispersed)
5710o3x3 3x3 Ordered 3x3 (dispersed)
5711o4x4 4x4 Ordered 4x4 (dispersed)
5712o8x8 8x8 Ordered 8x8 (dispersed)
5713h3x4a 4x1 Halftone 4x4 (angled)
5714h6x6a 6x1 Halftone 6x6 (angled)
5715h8x8a 8x1 Halftone 8x8 (angled)
5716h3x4o Halftone 4x4 (orthogonal)
5717h6x6o Halftone 6x6 (orthogonal)
5718h8x8o Halftone 8x8 (orthogonal)
5719h36x16o Halftone 16x16 (orthogonal)
5720c5x5b c5x5 Circles 5x5 (black)
5721c5x5w Circles 5x5 (white)
5722c6x6b c6x6 Circles 6x6 (black)
5723c6x6w Circles 6x6 (white)
5724c7x7b c7x7 Circles 7x7 (black)
5725c7x7w Circles 7x7 (white)
cristyd2432012015-05-04 23:15:15 +00005726</pre>
5727
5728<p> The <code>threshold</code> generated a simple 50% threshold of the image.
cristy82a2ff22015-05-12 16:41:32 +00005729This could be used with <var>level</var> to do the equivalent of <a href="command-line-options.html#posterize">-posterize</a> to reduce an image to basic primary colors.
cristyd2432012015-05-04 23:15:15 +00005730</p>
5731
5732<p>The <code>checks</code> pattern produces a 3 level checkerboard dither
5733pattern. That is a grayscale will become a pattern of solid black, solid
5734white, and mid-tone colors into a checkerboard pattern of black and white.
5735</p>
5736
cristy82a2ff22015-05-12 16:41:32 +00005737<p>You can define your own <var>threshold map</var> for ordered
cristyd2432012015-05-04 23:15:15 +00005738dithering and halftoning your images, in either personal or system
cristy82a2ff22015-05-12 16:41:32 +00005739<code>thresholds.xml</code> XML file. See <a href="resources.html">Resources</a>
cristyd2432012015-05-04 23:15:15 +00005740for more details of configuration files. </p>
5741
5742<p>To print a complete list of the thresholds that have been defined, use the
cristy82a2ff22015-05-12 16:41:32 +00005743<a href="command-line-options.html#list">-list threshold</a> option.</p>
cristyd2432012015-05-04 23:15:15 +00005744
5745<p>Note that at this time the same threshold dithering map is used for all
5746color channels, no attempt is made to offset or rotate the map for different
5747channels is made, to create an offset printing effect. Also as the maps are
5748simple threshold levels, the halftone and circle maps will create incomplete
5749circles along the edges of a colored area. Also all the effects are purely
5750on/off boolean effects, without anti-aliasing to make the circles smooth
5751looking. Large dots can be made to look better with a small amount of blurring
5752after being created. </p>
5753
5754
5755<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005756 <h3 class="magick-header"><a id="orient"></a>-orient <var>image orientation</var></h3>
cristyd2432012015-05-04 23:15:15 +00005757</div>
5758
5759<p class="magick-description">specify orientation of a digital camera image.</p>
5760
5761<p>Choose from these orientations:</p>
5762
5763<pre>
cristyb2cad532015-05-16 13:02:45 +00005764bottom-left right-top
5765bottom-right top-left
5766left-bottom top-right
5767left-top undefined
cristy29dc8652015-05-12 16:26:21 +00005768right-bottom
cristyd2432012015-05-04 23:15:15 +00005769</pre>
5770
cristy82a2ff22015-05-12 16:41:32 +00005771<p>To print a complete list of orientations, use the <a href="command-line-options.html#list">-list
cristyd2432012015-05-04 23:15:15 +00005772orientation</a> option.</p>
5773
5774
5775<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00005776 <h3 class="magick-header"><a id="page"></a>-page <var>geometry</var><br>
5777 -page <var>media</var>[<var>offset</var>][{<var>^!&lt;&gt;</var>}]<br>
cristyd2432012015-05-04 23:15:15 +00005778 +page
cristy29dc8652015-05-12 16:26:21 +00005779 </h3>
cristyd2432012015-05-04 23:15:15 +00005780</div>
5781
5782<p class="magick-description">Set the size and location of an image on the larger virtual canvas.</p>
5783
5784<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
5785
5786<p>For convenience you can specify the page size using <var>media</var> (see below). Offsets can then be added as with other
cristy82a2ff22015-05-12 16:41:32 +00005787<var>geometry</var> arguments (e.g. <a href="command-line-options.html#page">-page</a> <code>Letter+43+43</code>).</p>
cristyd2432012015-05-04 23:15:15 +00005788
5789<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.
5790The choices for a PostScript page are:</p>
5791
cristyb2cad532015-05-16 13:02:45 +00005792<dl class="dl-horizontal">
5793<dt> 11x17 </dt> <dd> 792 x 1224</dd>
5794<dt> Ledger </dt> <dd> 1224 x 792</dd>
5795<dt> Legal </dt> <dd> 612 x 1008</dd>
5796<dt> Letter </dt> <dd> 612 x 792</dd>
5797<dt> LetterSmall</dt> <dd> 612 x 792</dd>
5798<dt> ArchE </dt> <dd> 2592 x 3456</dd>
5799<dt> ArchD </dt> <dd> 1728 x 2592</dd>
5800<dt> ArchC </dt> <dd> 1296 x 1728</dd>
5801<dt> ArchB </dt> <dd> 864 x 1296</dd>
5802<dt> ArchA </dt> <dd> 648 x 864</dd>
5803<dt> A0 </dt> <dd> 2380 x 3368</dd>
5804<dt> A1 </dt> <dd> 1684 x 2380</dd>
5805<dt> A2 </dt> <dd> 1190 x 1684</dd>
5806<dt> A3 </dt> <dd> 842 x 1190</dd>
5807<dt> A4 </dt> <dd> 595 x 842</dd>
5808<dt> A4Small </dt> <dd> 595 x 842</dd>
5809<dt> A5 </dt> <dd> 421 x 595</dd>
5810<dt> A6 </dt> <dd> 297 x 421</dd>
5811<dt> A7 </dt> <dd> 210 x 297</dd>
5812<dt> A8 </dt> <dd> 148 x 210</dd>
5813<dt> A9 </dt> <dd> 105 x 148</dd>
5814<dt> A10 </dt> <dd> 74 x 105</dd>
5815<dt> B0 </dt> <dd> 2836 x 4008</dd>
5816<dt> B1 </dt> <dd> 2004 x 2836</dd>
5817<dt> B2 </dt> <dd> 1418 x 2004</dd>
5818<dt> B3 </dt> <dd> 1002 x 1418</dd>
5819<dt> B4 </dt> <dd> 709 x 1002</dd>
5820<dt> B5 </dt> <dd> 501 x 709</dd>
5821<dt> C0 </dt> <dd> 2600 x 3677</dd>
5822<dt> C1 </dt> <dd> 1837 x 2600</dd>
5823<dt> C2 </dt> <dd> 1298 x 1837</dd>
5824<dt> C3 </dt> <dd> 918 x 1298</dd>
5825<dt> C4 </dt> <dd> 649 x 918</dd>
5826<dt> C5 </dt> <dd> 459 x 649</dd>
5827<dt> C6 </dt> <dd> 323 x 459</dd>
5828<dt> Flsa </dt> <dd> 612 x 936</dd>
5829<dt> Flse </dt> <dd> 612 x 936</dd>
5830<dt> HalfLetter </dt> <dd> 396 x 612</dd>
5831</dl>
cristyd2432012015-05-04 23:15:15 +00005832
5833<p>This option is also used to place subimages when writing to a multi-image
5834format that supports offsets, such as GIF89 and MNG. When used for this
5835purpose the offsets are always measured from the top left corner of the canvas
5836and are not affected by the <a href="command-line-options.html#gravity">-gravity</a> option. To
5837position 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
5838file, a <a href="command-line-options.html#page">-page</a> option appearing ahead of the first image in
5839the sequence with nonzero width and height defines the width and height values
5840that are written in the <code>MHDR</code> chunk. Otherwise, the MNG width and
5841height are computed from the bounding box that contains all images in the
5842sequence. When writing a GIF89 file, only the bounding box method is used to
5843determine its dimensions.</p>
5844
cristy82a2ff22015-05-12 16:41:32 +00005845<p>For a PostScript page, the image is sized as in <a href="command-line-options.html#geometry">-geometry</a> but positioned relative to the <var>lower
5846left-hand corner</var> of the page by {+-}<code>x</code><var>offset</var>{+-}<code>y</code> <var>offset</var>. Use <a href="command-line-options.html#page">-page 612x792</a>, for example, to center the image within the
cristyd2432012015-05-04 23:15:15 +00005847page. If the image size exceeds the PostScript page, it is reduced to fit the
5848page. 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
5849corner of the page, unless the <a href="command-line-options.html#gravity">-gravity</a> option is
5850present with a value other than <var>NorthWest</var>.</p>
5851
5852<p>The default page dimensions for a TEXT image is 612x792.</p>
5853
5854<p>This option is used in concert with <a href="command-line-options.html#density">-density</a>.</p>
5855
5856<p>Use <a href="command-line-options.html#page">+page</a> to remove the page settings for an image.</p>
5857
5858<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005859 <h3 class="magick-header"><a id="paint"></a>-paint <var>radius</var></h3>
cristyd2432012015-05-04 23:15:15 +00005860</div>
5861
5862<p class="magick-description">simulate an oil painting.</p>
5863
5864<p>Each pixel is replaced by the most frequent color in a circular
5865neighborhood whose width is specified with <var>radius</var>.</p>
5866
5867<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005868 <h3 class="magick-header"><a id="path"></a>-path <var>path</var></h3></div>
cristyd2432012015-05-04 23:15:15 +00005869
5870<p class="magick-description">write images to this path on disk.</p>
5871
5872<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005873 <h3 class="magick-header"><a id="pause_animate_"></a>-pause <var>seconds</var></h3>
cristyd2432012015-05-04 23:15:15 +00005874</div>
5875
5876<p class="magick-description">Pause between animation loops</p>
5877
5878<p>Pause for the specified number of seconds before repeating the animation.</p>
5879
5880<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005881 <h3 class="magick-header"><a id="pause_import_"></a>-pause <var>seconds</var></h3>
cristyd2432012015-05-04 23:15:15 +00005882</div>
5883
5884<p class="magick-description">Pause between snapshots.</p>
5885
5886<p>Pause for the specified number of seconds before taking the next snapshot.</p>
5887
5888<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005889 <h3 class="magick-header"><a id="perceptible"></a>-perceptible <var>epsilon</var></h3>
cristyd2432012015-05-04 23:15:15 +00005890</div>
5891
5892<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>
5893
5894<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005895 <h3 class="magick-header"><a id="ping"></a>-ping</h3>
cristyd2432012015-05-04 23:15:15 +00005896</div>
5897
5898<p class="magick-description">efficiently determine image characteristics.</p>
5899
5900<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005901 <h3 class="magick-header"><a id="pointsize"></a>-pointsize <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00005902</div>
5903
5904<p class="magick-description">pointsize of the PostScript, OPTION1, or TrueType font.</p>
5905
5906<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005907 <h3 class="magick-header"><a id="polaroid"></a>-polaroid <var>angle</var></h3>
cristyd2432012015-05-04 23:15:15 +00005908</div>
5909
5910<p class="magick-description">simulate a Polaroid picture.</p>
5911
5912<p>Use <code>+polaroid</code> to rotate the image at a random angle between -15 and +15 degrees.</p>
5913
5914<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005915 <h3 class="magick-header"><a id="poly"></a>-poly <var>"wt,exp ..."</var></h3>
cristyd2432012015-05-04 23:15:15 +00005916</div>
5917
5918<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>
5919
5920<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>
5921
5922<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>
5923
cristyb2cad532015-05-16 13:02:45 +00005924<p>The format is: <var>output = wt1*image1^exp1 + wt2*image2^exp2 </var>...</p>
cristyd2432012015-05-04 23:15:15 +00005925
5926<p>Some simple uses are:</p>
5927<ul>
5928<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>
5929<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>
5930</ul>
5931
5932<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>
5933
5934<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>
5935
5936
5937<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005938 <h3 class="magick-header"><a id="posterize"></a>-posterize <var>levels</var></h3>
cristyd2432012015-05-04 23:15:15 +00005939</div>
5940
5941<p class="magick-description">reduce the image to a limited number of color levels per channel.</p>
5942
5943<p>Very low values of <var>levels</var>, e.g., 2, 3, 4, have the most
5944visible effect.</p>
5945
5946<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005947 <h3 class="magick-header"><a id="precision"></a>-precision <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00005948</div>
5949
5950<p class="magick-description">set the maximum number of significant digits to be printed.</p>
5951
5952<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005953 <h3 class="magick-header"><a id="preview"></a>-preview <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00005954</div>
5955
5956<p class="magick-description">image preview type.</p>
5957
5958<p>Use this option to affect the preview operation of an image (e.g.
5959<code>convert file.png -preview Gamma Preview:gamma.png</code>). Choose from
5960these previews:</p>
5961
cristyb2cad532015-05-16 13:02:45 +00005962<pre class="pre-scrollable">
5963AddNoise
5964Blur
5965Brightness
5966Charcoal
5967Despeckle
5968Dull
5969EdgeDetect
5970Gamma
5971Grayscale
5972Hue
5973Implode
cristy29dc8652015-05-12 16:26:21 +00005974JPEG
cristyb2cad532015-05-16 13:02:45 +00005975OilPaint
5976Quantize
5977Raise
5978ReduceNoise
5979Roll
5980Rotate
5981Saturation
5982Segment
5983Shade
5984Sharpen
5985Shear
5986Solarize
5987Spiff
5988Spread
5989Swirl
5990Threshold
5991Wave
cristyd2432012015-05-04 23:15:15 +00005992</pre>
5993
5994<p>To print a complete list of previews, use the <a href="command-line-options.html#list">-list preview</a> option.</p>
5995
5996<p>The default preview is <code>JPEG</code>.</p>
5997
5998<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005999 <h3 class="magick-header"><a id="print"></a>-print <var>string</var></h3>
cristyd2432012015-05-04 23:15:15 +00006000</div>
6001
6002<p class="magick-description">interpret string and print to console.</p>
6003
6004<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006005 <h3 class="magick-header"><a id="process"></a>-process <var>command</var></h3>
cristyd2432012015-05-04 23:15:15 +00006006</div>
6007
6008<p class="magick-description">process the image with a custom image filter.</p>
6009
6010<p>The command arguments has the form <code>"module arg1 arg2 arg3 ...
6011argN"</code> where <code>module</code> is the name of the module to invoke (e.g.
6012"Analyze") and arg1 arg2 arg3 ... argN are an arbitrary number of arguments to
6013pass to the process module.</p>
6014
6015<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00006016 <h3 class="magick-header"><a id="profile"></a>-profile <var>filename</var><br>
cristy29dc8652015-05-12 16:26:21 +00006017 +profile <var>profile_name</var></h3>
cristyd2432012015-05-04 23:15:15 +00006018</div>
6019
6020<p class="magick-description">Manage ICM, IPTC, or generic profiles in an image.</p>
6021
6022<p>Using <a href="command-line-options.html#profile">-profile</a> <var>filename</var> adds an
6023ICM (ICC color management), IPTC (newswire information), or a generic profile
6024to the image.</p>
6025
6026<p>Use <a href="command-line-options.html#profile">+profile <var>profile_name</var></a> to
6027remove the indicated profile. ImageMagick uses standard filename globbing, so
6028wildcard expressions may be used to remove more than one profile. Here we
6029remove all profiles from the image except for the XMP profile: <code>+profile
6030"!xmp,*"</code>. </p>
6031
6032<p>Use <code>identify -verbose</code> to find out which profiles are in the
6033image file. Use <a href="command-line-options.html#strip">-strip</a> to remove all profiles (and
6034comments).</p>
6035
6036<p>To extract a profile, the <a href="command-line-options.html#profile">-profile</a> option is not
6037used. Instead, simply write the file to an image format such as <var>APP1, 8BIM, ICM,</var> or <var>IPTC</var>.</p>
6038
6039<p>For example, to extract the Exif data (which is stored in JPEG files in the
6040<var>APP1</var> profile), use.</p>
6041
6042<pre>
6043convert cockatoo.jpg profile.exif
6044</pre>
6045
6046<p>It is important to note that results may depend on whether or not the
cristy82a2ff22015-05-12 16:41:32 +00006047original image already has an included profile. Also, keep in mind that <a href="command-line-options.html#profile">-profile</a> is an "operator" (as opposed to a "setting") and
cristyd2432012015-05-04 23:15:15 +00006048therefore a conversion is made each time it is encountered, in order, in the
6049command-line. For instance, in the following example, if the original image is
6050CMYK with profile, a CMYK-CMYK-RGB conversion results.</p>
6051
6052<pre>
6053convert CMYK.tif -profile "CMYK.icc" -profile "RGB.icc" RGB.tiff
6054</pre>
6055
6056<p>Furthermore, since ICC profiles are not necessarily symmetric, extra
6057conversion steps can yield unwanted results. CMYK profiles are often very
6058asymmetric since they involve 3−&gt;4 and 4−&gt;3 channel mapping.
6059</p>
6060
6061<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006062 <h3 class="magick-header"><a id="quality"></a>-quality <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00006063</div>
6064
6065<p class="magick-description">JPEG/MIFF/PNG compression level.</p>
6066
6067<p>For the JPEG and MPEG image formats, quality is 1 (lowest image quality and
6068highest compression) to 100 (best quality but least effective compression).
6069The default is to use the estimated quality of your input image if it can
6070be determined, otherwise 92. When the quality is greater than 90, then the
6071chroma channels are not downsampled.
6072Use the <a href="command-line-options.html#sampling-factor">-sampling-factor</a> option to specify the
6073factors for chroma downsampling.</p>
6074
6075<p>For the MIFF image format, quality/10 is the zlib compression level, which
6076is 0 (worst but fastest compression) to 9 (best but slowest). It has no effect
6077on the image appearance, since the compression is always lossless.</p>
6078
6079<p>For the JPEG-2000 image format, quality is mapped using a non-linear
6080equation to the compression ratio required by the Jasper library. This
6081non-linear equation is intended to loosely approximate the quality provided by
6082the JPEG v1 format. The default quality value 100, a request for non-lossy
6083compression. A quality of 75 results in a request for 16:1 compression.</p>
6084
6085<p>For the MNG and PNG image formats, the quality value sets the zlib
6086compression level (quality / 10) and filter-type (quality % 10). The default
6087PNG "quality" is 75, which means compression level 7 with adaptive PNG
6088filtering, unless the image has a color map, in which case it means
6089compression level 7 with no PNG filtering.</p>
6090
6091<p>For compression level 0 (quality value less than 10), the Huffman-only
6092strategy is used, which is fastest but not necessarily the worst
6093compression.</p>
6094
6095<p>If filter-type is 4 or less, the specified PNG filter-type is used for
6096all scanlines:</p>
6097
cristyb2cad532015-05-16 13:02:45 +00006098<dl class="dl-horizontal">
6099<dt>0</dt><dd>none</dd>
6100<dt>1</dt><dd>sub</dd>
6101<dt>2</dt><dd>up</dd>
6102<dt>3</dt><dd>average</dd>
6103<dt>4</dt><dd>Paeth</dd>
6104</dl>
cristyd2432012015-05-04 23:15:15 +00006105
6106<p>If filter-type is 5, adaptive filtering is used when quality is greater
6107than 50 and the image does not have a color map, otherwise no filtering is
6108used.</p>
6109
6110<p>If filter-type is 6, adaptive filtering
6111with <var>minimum-sum-of-absolute-values</var> is used.</p>
6112
6113<p>Only if the output is MNG, if filter-type is 7, the LOCO color
6114transformation (intrapixel differencing) and adaptive filtering
6115with <var>minimum-sum-of-absolute-values</var> are used.</p>
6116
6117<p>If the filter-type is 8 the zlib Z_RLE compression strategy (or the
6118Z_HUFFMAN_ONLY strategy, when compression level is 0) is used with
6119adaptive PNG filtering.</p>
6120
6121<p>If the filter-type is 9 the zlib Z_RLE compression strategy (or the
6122Z_HUFFMAN_ONLY strategy, when compression level is 0) is used with
6123no PNG filtering.</p>
6124
6125<p>The quality setting has no effect on the appearance or signature of PNG
6126and MNG images, since the compression is always lossless.</p>
6127
6128<p>Not all combinations of compression level, strategy, and PNG filter type
6129can be obtained using the -quality option. For more precise control,
6130you can use the PNG:compression-level=N, PNG:compression-strategy=N, and
6131PNG:compression-filter=N defines, respectively, instead.
6132See <a href="command-line-options.html#define">-define</a>. Values from the defines take precedence
6133over values from the -quality option.</p>
6134
6135<p>For further information, see
6136the <a href="http://www.w3.org/pub/WWW/TR">PNG</a> specification.</p>
6137
6138<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006139 <h3 class="magick-header"><a id="quantize"></a>-quantize <var>colorspace</var></h3>
cristyd2432012015-05-04 23:15:15 +00006140</div>
6141
6142<p class="magick-description">reduce colors using this colorspace.</p>
6143
6144<p>This setting defines the colorspace used to sort out and reduce the number
cristy82a2ff22015-05-12 16:41:32 +00006145of colors needed by an image (for later dithering) by operators such as <a href="command-line-options.html#colors">-colors</a>, Note that color reduction also happens
cristyd2432012015-05-04 23:15:15 +00006146automatically when saving images to color-limited image file formats, such as
6147GIF, and PNG8.</p>
6148
6149
6150<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006151 <h3 class="magick-header"><a id="quiet"></a>-quiet</h3>
cristyd2432012015-05-04 23:15:15 +00006152</div>
6153
6154<p class="magick-description">suppress all warning messages. Error messages are still reported.</p>
6155
6156<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006157 <h3 class="magick-header"><a id="radial-blur"></a>-radial-blur <var>angle</var></h3>
cristyd2432012015-05-04 23:15:15 +00006158</div>
6159
6160<p class="magick-description">Blur around the center of the image.</p>
6161
6162<p>Note that this is actually a rotational blur rather than a radial and as
6163such actually mis-named. </p>
6164
6165<p>The <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting will determine how
6166pixels which are outside the image proper are blurred into the final result.
6167</p>
6168
6169
6170<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006171 <h3 class="magick-header"><a id="raise"></a>-raise <var>thickness</var></h3>
cristyd2432012015-05-04 23:15:15 +00006172</div>
6173
6174<p class="magick-description">Lighten or darken image edges.</p>
6175
6176<p>This will create a 3-D effect. Use <a href="command-line-options.html#raise">-raise</a> to create
6177a raised effect, otherwise use <a href="command-line-options.html#raise">+raise</a>. </p>
6178
cristy82a2ff22015-05-12 16:41:32 +00006179<p>Unlike the similar <a href="command-line-options.html#frame">-frame</a> option, <a href="command-line-options.html#raise">-raise</a> does not alter the dimensions of the image.</p>
cristyd2432012015-05-04 23:15:15 +00006180
6181<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006182 <h3 class="magick-header"><a id="random-threshold"></a>-random-threshold <var>low</var>x<var>high</var></h3>
cristyd2432012015-05-04 23:15:15 +00006183</div>
6184
6185<p class="magick-description">Apply a random threshold to the image.</p>
6186
6187<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006188 <h3 class="magick-header"><a id="red-primary"></a>-red-primary <var>x,y</var></h3>
cristyd2432012015-05-04 23:15:15 +00006189</div>
6190
6191<p class="magick-description">Set the red chromaticity primary point.</p>
6192
6193<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006194 <h3 class="magick-header"><a id="regard-warnings"></a>-regard-warnings</h3>
cristyd2432012015-05-04 23:15:15 +00006195</div>
6196
6197<p class="magick-description">Pay attention to warning messages.</p>
6198
6199<p>This option causes some warnings in some image formats to be treated
6200as errors. </p>
6201
6202<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006203 <h3 class="magick-header"><a id="remap"></a>-remap <var>filename</var></h3>
cristyd2432012015-05-04 23:15:15 +00006204</div>
6205
6206<p class="magick-description">Reduce the number of colors in an image to the colors used by this image.</p>
6207
6208<p>If the <a href="command-line-options.html#dither">-dither</a> setting is enabled (the default) then
6209the given colors are dithered over the image as necessary, otherwise the closest
6210color (in RGB colorspace) is selected to replace that pixel in the image. </p>
6211
6212<p>As a side effect of applying a <a href="command-line-options.html#remap">-remap</a> of colors across all
6213images in the current image sequence, all the images will have the same color
6214table. That means that when saved to a file format such as GIF, it will use
6215that color table as a single common or global color table, for all the images,
6216without requiring extra local color tables. </p>
6217
6218<p>Use <a href="command-line-options.html#remap">+remap</a> to reduce all images in the current image
6219sequence to use a common color map over all the images. This equivalent to
6220appending all the images together (without extra background colors) and color
6221reducing those images using <a href="command-line-options.html#colors">-colors</a> with a 256 color
6222limit, then <a href="command-line-options.html#remap">-remap</a> those colors over the original list of
6223images. This ensures all the images follow a single color map. </p>
6224
cristy82a2ff22015-05-12 16:41:32 +00006225<p>If the number of colors over all the images is less than 256, then <a href="command-line-options.html#remap">+remap</a> should not perform any color reduction or dithering, as
cristyd2432012015-05-04 23:15:15 +00006226no color changes are needed. In that case, its only effect is to force the use
cristy82a2ff22015-05-12 16:41:32 +00006227of a global color table. This recommended after using either <a href="command-line-options.html#colors">-colors</a> or <a href="command-line-options.html#ordered-dither">-ordered-dither</a> to
cristyd2432012015-05-04 23:15:15 +00006228reduce the number of colors in an animated image sequence. </p>
6229
6230<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>
6231
6232<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006233 <h3 class="magick-header"><a id="region"></a>-region <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00006234</div>
6235
6236<p class="magick-description">Set a region in which subsequent operations apply.</p>
6237
6238<p>The <var>x</var> and <var>y</var> offsets are treated
6239in the same manner as in <a href="command-line-options.html#crop">-crop</a>.</p>
6240
6241<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
6242
6243<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006244 <h3 class="magick-header"><a id="remote"></a>-remote</h3>
cristyd2432012015-05-04 23:15:15 +00006245</div>
6246
6247<p class="magick-description">perform a remote operation.</p>
6248
6249<p>The only command recognized is the name of an image file to load.</p>
6250
6251<p>If you have more than one <a href="display.html">display</a> application
6252running simultaneously, use the <a href="command-line-options.html#window"> window</a> option to
6253specify which application to control.</p>
6254
6255<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006256 <h3 class="magick-header"><a id="render"></a>-render</h3>
cristyd2432012015-05-04 23:15:15 +00006257</div>
6258
6259<p class="magick-description">render vector operations.</p>
6260
6261<p>Use <a href="command-line-options.html#render">+render</a> to turn off rendering vector operations.
6262This useful when saving the result to vector formats such as MVG or SVG.</p>
6263
6264<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006265<h3 class="magick-header"><a id="repage"></a>-repage <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00006266</div>
6267
6268<p class="magick-description">Adjust the canvas and offset information of the image.</p>
6269
6270<p>This option is like <a href="command-line-options.html#page">-page</a> but acts as an image operator
6271rather than a setting. You can separately set the canvas size or the offset
6272of the image on that canvas by only providing those components. </p>
6273
6274<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
6275
6276<p>If a <code>!</code> flag is given the offset given is added to the existing
6277offset to move the image relative to its previous position. This useful for
6278animation sequences. </p>
6279
6280<p>A given a canvas size of zero such as '<code>0x0</code>' forces it to
6281recalculate the canvas size so the image (at its current offset) will appear
6282completely on that canvas (unless it has a negative offset).</p>
6283
6284<p>Use <a href="command-line-options.html#repage">+repage</a> to completely remove/reset the virtual
6285canvas meta-data from the images. </p>
6286
6287<p>The <a href="command-line-options.html#set">-set</a> '<code>page</code>' option can be used to
6288directly assign virtual canvas meta-data. </p>
6289
6290
6291<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006292 <h3 class="magick-header"><a id="resample"></a>-resample <var>horizontal</var>x<var>vertical</var></h3>
cristyd2432012015-05-04 23:15:15 +00006293</div>
6294
6295<p class="magick-description">Resample image to specified horizontal and vertical resolution.</p>
6296
6297<p>Resize the image so that its rendered size remains the same as the original
6298at the specified target resolution. For example, if a 300 DPI image renders at
62993 inches by 2 inches on a 300 DPI device, when the image has been resampled to
630072 DPI, it will render at 3 inches by 2 inches on a 72 DPI device. Note that
6301only a small number of image formats (e.g. JPEG, PNG, and TIFF) are capable of
6302storing the image resolution. For formats which do not support an image
cristy82a2ff22015-05-12 16:41:32 +00006303resolution, the original resolution of the image must be specified via <a href="command-line-options.html#density">-density</a> on the command line prior to specifying the
cristyd2432012015-05-04 23:15:15 +00006304resample resolution.</p>
6305
6306<p>Note that Photoshop stores and obtains image resolution from a proprietary
6307embedded profile. If this profile exists in the image, then Photoshop will
6308continue to treat the image using its former resolution, ignoring the image
6309resolution specified in the standard file header.</p>
6310
6311<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006312 <h3 class="magick-header"><a id="resize"></a>-resize <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00006313</div>
6314
6315<p class="magick-description">Resize an image.</p>
6316
6317<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
6318ignored, and the <a href="command-line-options.html#gravity">-gravity</a> option has no effect.</p>
6319
6320<p>If the <a href="command-line-options.html#filter">-filter</a> option
cristy82a2ff22015-05-12 16:41:32 +00006321or <code>-define filter:option=value</code> precedes the <a href="command-line-options.html#resize">-resize</a> option, the image is resized with the specified
cristyd2432012015-05-04 23:15:15 +00006322filter.</p>
6323
6324<p>Many image processing algorithms assume your image is in a linear-light
6325coding. If your image is gamma-corrected, you can remove the nonlinear gamma
6326correction, apply the transform, then restore it like this:</p>
6327
6328<pre>
cristy29dc8652015-05-12 16:26:21 +00006329convert portrait.jpg -gamma .45455 -resize 25% -gamma 2.2 \
6330 -quality 92 passport.jpg
cristyd2432012015-05-04 23:15:15 +00006331</pre>
6332
6333<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006334 <h3 class="magick-header"><a id="respect-parentheses"></a>-respect-parentheses</h3>
cristyd2432012015-05-04 23:15:15 +00006335</div>
6336
6337<p class="magick-description">settings remain in effect until parenthesis boundary.</p>
6338
6339<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006340 <h3 class="magick-header"><a id="reverse"></a>-reverse</h3>
cristyd2432012015-05-04 23:15:15 +00006341</div>
6342
6343<p class="magick-description">Reverse the order of images in the current image list.</p>
6344
6345
6346<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006347 <h3 class="magick-header"><a id="roll"></a>-roll {<var>+-</var>}<var>x</var>{<var>+-</var>}<var>y</var></h3>
cristyd2432012015-05-04 23:15:15 +00006348</div>
6349
6350<p class="magick-description">roll an image vertically or horizontally by the amount given.</p>
6351
6352<p>A negative <var>x</var> offset rolls the image right-to-left.
6353A negative <var>y</var> offset rolls the image bottom-to-top.</p>
6354
6355
6356<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006357 <h3 class="magick-header"><a id="rotate"></a>-rotate <var>degrees</var>{<var>&lt;</var>}{<var>&gt;</var>}</h3>
cristyd2432012015-05-04 23:15:15 +00006358</div>
6359
6360<p class="magick-description">Apply Paeth image rotation (using shear operations) to the image.</p>
6361
6362<p>Use <code>&gt;</code> to rotate the image only if its width exceeds the
6363height. <code>&lt;</code> rotates the image <var>only</var> if its width is less
6364than the height. For example, if you specify <code>-rotate "-90&gt;"</code> and
6365the image size is 480x640, the image is not rotated. However, if the image is
6366640x480, it is rotated by -90 degrees. If you use <code>&gt;</code> or
6367<code>&lt;</code>, enclose it in quotation marks to prevent it from being
6368misinterpreted as a file redirection.</p>
6369
6370<p>Empty triangles in the corners, left over from rotating the image, are
6371filled with the <code>background</code> color. </p>
6372
6373<p>See also the <a href="command-line-options.html#distort">-distort</a> operator and specifically the
6374'<code>ScaleRotateTranslate</code>' distort method. </p>
6375
6376
6377<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006378 <h3 class="magick-header"><a id="sample"></a>-sample <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00006379</div>
6380
6381<p class="magick-description">minify / magnify the image with pixel subsampling and pixel replication, respectively.</p>
6382
6383<p>Change the image size simply by directly sampling the pixels original
6384from the image. When magnifying, pixels are replicated in blocks. When
6385minifying, pixels are sub-sampled (i.e., some rows and columns are skipped
6386over). </p>
6387
6388<p>The results are thus equivalent to using <a href="command-line-options.html#resize">-resize</a> with
6389a <a href="command-line-options.html#filter">-filter</a> setting of <code>point</code> (nearest
6390neighbour), though <a href="command-line-options.html#sample">-sample</a> is a lot faster, as it
6391avoids all the filter processing of the image. As such it completely ignores
6392the current <a href="command-line-options.html#filter">-filter</a> setting. </p>
6393
6394<p>The key feature of the <a href="command-line-options.html#sample">-sample</a> is that no new colors
6395will be added to the resulting image, though some colors may disappear. </p>
6396
6397<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
6398ignored, unlike <a href="command-line-options.html#resize">-resize</a>. </p>
6399
6400
6401<p>The actual sampling point is the middle of the sub-region being sampled.
6402As such a single pixel sampling of an image will take the middle pixel, (or
cristy82a2ff22015-05-12 16:41:32 +00006403top-left-middle if image has even dimensions). However the <a href="command-line-options.html#define">-define</a> '<code>sample:offset</code>' can be set to modify
cristyd2432012015-05-04 23:15:15 +00006404this position some other location within each sub-region being sampled, as
6405a percentage offset.</p>
6406
6407<p>By default this value is '<code>50</code>' for the midpoint, but could be set
6408to '<code>0</code>' for top-left, '<code>100</code>' for bottom-right, or with
6409separate X and Y offsets such as '<code>0x50</code>' for left-middle edge of
6410sampling sub-region.</p>
6411
6412
6413<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006414 <h3 class="magick-header"><a id="sampling-factor"></a>-sampling-factor <var>horizontal-factor</var>x<var>vertical-factor</var></h3>
cristyd2432012015-05-04 23:15:15 +00006415</div>
6416
6417<p class="magick-description">sampling factors used by JPEG or MPEG-2 encoder and YUV decoder/encoder.</p>
6418
6419<p>This option specifies the sampling factors to be used by the JPEG encoder
6420for chroma downsampling. If this option is omitted, the JPEG library will use
6421its own default values. When reading or writing the YUV format and when
cristy82a2ff22015-05-12 16:41:32 +00006422writing the M2V (MPEG-2) format, use <a href="command-line-options.html#sampling-factor">-sampling-factor 2x1</a> or <a href="command-line-options.html#sampling-factor">-sampling-factor 4:2:2</a> to specify the 4:2:2
cristyd2432012015-05-04 23:15:15 +00006423downsampling method.</p>
6424
6425<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006426 <h3 class="magick-header"><a id="scale"></a>-scale <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00006427</div>
6428
6429<p class="magick-description">minify / magnify the image with pixel block averaging and pixel replication, respectively.</p>
6430
6431<p>Change the image size simply by replacing pixels by averaging pixels
6432together when minifying, or replacing pixels when magnifying. </p>
6433
6434<p>The results are thus equivalent to using <a href="command-line-options.html#resize">-resize</a> with
6435a <a href="command-line-options.html#filter">-filter</a> setting of <code>box</code>. Though it is a lot
6436faster, as it avoids all the filter processing of the image. As such it
6437completely ignores the current <a href="command-line-options.html#filter">-filter</a> setting. </p>
6438
6439<p>If when shrinking (minifying) images the original image is some integer
6440multiple of the new image size, the number of pixels averaged together to
6441produce the new pixel color is the same across the whole image. This is
6442a special case known as 'binning' and is often used as a method of reducing
6443noise in image such as those generated by digital cameras, especially in low
6444light conditions. </p>
6445
6446
6447<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006448 <h3 class="magick-header"><a id="scene"></a>-scene <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00006449</div>
6450
6451<p class="magick-description">set scene number.</p>
6452
6453<p>This option sets the scene number of an image or the first image in an image sequence.</p>
6454
6455<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006456 <h3 class="magick-header"><a id="screen"></a>-screen</h3>
cristyd2432012015-05-04 23:15:15 +00006457</div>
6458
6459<p class="magick-description">specify the screen to capture.</p>
6460
6461<p>This option indicates that the GetImage request used to obtain the image
6462should be done on the root window, rather than directly on the specified
6463window. In this way, you can obtain pieces of other windows that overlap the
6464specified window, and more importantly, you can capture menus or other popups
6465that are independent windows but appear over the specified window.</p>
6466
6467<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006468 <h3 class="magick-header"><a id="seed"></a>-seed</h3>
cristyd2432012015-05-04 23:15:15 +00006469</div>
6470
6471<p class="magick-description">seed a new sequence of pseudo-random numbers</p>
6472
6473<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006474 <h3 class="magick-header"><a id="segment"></a>-segment <var>cluster-threshold</var>x<var>smoothing-threshold</var></h3>
cristyd2432012015-05-04 23:15:15 +00006475</div>
6476
6477<p class="magick-description">segment the colors of an image.</p>
6478
6479<p>Segment an image by analyzing the histograms of the color components and
6480identifying units that are homogeneous with the fuzzy c-means technique. This
6481is part of the ImageMagick color quantization routines. </p>
6482
6483<p>Specify <var>cluster threshold</var> as the number of pixels in
6484each cluster that must exceed the cluster threshold to be considered valid.
6485<var>Smoothing threshold</var> eliminates noise in the second
6486derivative of the histogram. As the value is increased, you can expect
6487a smoother second derivative. The default is 1.5.</p>
6488
6489<p>If the <a href="command-line-options.html#verbose">-verbose</a> setting is defined, a detailed report
6490of the color clusters is returned.</p>
6491
6492
6493<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00006494 <h3 class="magick-header"><a id="selective-blur"></a>-selective-blur <var>radius</var><br>-selective-blur <var>radius</var>x<var>sigma</var>{<var>+threshold</var>}</h3>
cristyd2432012015-05-04 23:15:15 +00006495</div>
6496
6497<p class="magick-description">Selectively blur pixels within a contrast threshold.</p>
6498
6499<p>Blurs those pixels that are less than or equal to the threshold in
6500contrast. The threshold may be expressed as a fraction of <var>QuantumRange</var> or as a percentage.</p>
6501
6502<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006503 <h3 class="magick-header"><a id="separate"></a>-separate</h3>
cristyd2432012015-05-04 23:15:15 +00006504</div>
6505
6506<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>
6507
6508<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006509 <h3 class="magick-header"><a id="sepia-tone"></a>-sepia-tone <var>threshold</var></h3>
cristyd2432012015-05-04 23:15:15 +00006510</div>
6511
6512<p class="magick-description">simulate a sepia-toned photo.</p>
6513
6514<p>Specify <var>threshold</var> as the percent threshold of the intensity (0 - 99.9%).</p>
6515
6516<p>This option applies a special effect to the image, similar to the effect
6517achieved 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
6518toning. A threshold of 80% is a good starting point for a reasonable
6519tone.</p>
6520
6521
6522
6523<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006524 <h3 class="magick-header"><a id="set"></a>-set <var>key value</var></h3>
6525 <h3 class="magick-header">+set <var>key</var></h3>
cristyd2432012015-05-04 23:15:15 +00006526</div>
6527
6528<p class="magick-description">sets image attributes and properties for images in the current image sequence.</p>
6529
6530<p>This will assign (or modify) specific settings attached to all the images
6531in the current image sequence. Using the <a href="command-line-options.html#set">+set</a> form of the
6532option will either remove, or reset that setting to a default state, as
6533appropriate. </p>
6534
6535<p>For example, it will modify specific well known image meta-data
cristy82a2ff22015-05-12 16:41:32 +00006536'attributes' such as those normally overridden by: the options <a href="command-line-options.html#delay">-delay</a>, <a href="command-line-options.html#dispose">-dispose</a>, and <a href="command-line-options.html#page">-page</a>, <a href="command-line-options.html#colorspace">-colorspace</a>; generally
cristyd2432012015-05-04 23:15:15 +00006537assigned before the image is read in, by using a <var>key</var> of
6538the same name. </p>
6539
6540<p>If the given <var>key</var> does not match a specific known
6541'attribute ', such as shown above, the setting is stored as a a free form
cristy82a2ff22015-05-12 16:41:32 +00006542'property' string. Such settings are listed in <a href="command-line-options.html#verbose">-verbose</a> information ("<code>info:</code>" output format) as "Properties".
cristyd2432012015-05-04 23:15:15 +00006543</p>
6544
6545<p>This includes string 'properties' that are set by and assigned to images
cristy82a2ff22015-05-12 16:41:32 +00006546using the options <a href="command-line-options.html#comment">-comment</a>, <a href="command-line-options.html#label">-label</a>, <a href="command-line-options.html#caption">-caption</a>. These options actually assign
6547a global 'artifact' which are automatically assigned (and any <a href="escape.html">Format Percent
cristyd2432012015-05-04 23:15:15 +00006548Escapes</a> expanded) to images as they are read in. For example:</p>
6549
6550<pre>
cristyb2cad532015-05-16 13:02:45 +00006551-&gt; convert rose: -set comment 'Rose is a rose is a rose is a rose' rose.png
cristyd2432012015-05-04 23:15:15 +00006552identify -format %c rose.png
6553Rose is a rose is a rose is a rose
6554</pre>
6555
cristy82a2ff22015-05-12 16:41:32 +00006556<p>The set value can also make use of <a href="escape.html">Format and Print Image
cristyd2432012015-05-04 23:15:15 +00006557Properties</a> in the defined value. For example:</p>
6558
6559<pre>
cristyb2cad532015-05-16 13:02:45 +00006560-&gt; convert rose: -set origsize '%wx%h' -resize 50% \
cristyd2432012015-05-04 23:15:15 +00006561 -format 'Old size = %[origsize] New size = %wx%h' info:
6562Old size = 70x46 New size = 35x23
6563</pre>
6564
6565<p>Other well known 'properties' that are availible include:
6566'<code>date:create</code>' and '<code>date:modify</code>' and
6567'<code>signature</code>'. </p>
6568
6569<p>The <a href="command-line-options.html#repage">-repage</a> operator will also allow you to modify
6570the '<code>page</code>' attribute of an image for images already in memory (also
6571see <a href="command-line-options.html#repage">-page</a>). However it is designed to provide a finer
6572control of the sub-parts of this 'attribute'. The <a href="command-line-options.html#set">-set page</a>
6573option will only provide a direct, unmodified assignment of '<code>page</code>'
6574attribute. </p>
6575
6576<p>This option can also associate a colorspace or profile with your image.
6577For example,</p>
6578
6579<pre>
6580convert image.psd -set profile ISOcoated_v2_eci.icc image-icc.psd
6581</pre>
6582
6583<p>Some 'properties' must be defined in a specific way to be used. For
6584example only 'properties' prefixed with "<code>filename:</code>" can be used to
6585modify the output filename of an image. For example</p>
6586
6587<pre>
6588convert rose: -set filename:mysize '%wx%h' 'rose_%[filename:mysize].png'
6589</pre>
6590
6591<p>If the setting value is prefixed with "<code>option:</code>" the setting will
cristy82a2ff22015-05-12 16:41:32 +00006592be saved as a global "Artifact" exactly as if it was set using the <a href="command-line-options.html#define">-define</a> option. As such settings are global in scope, they
cristyd2432012015-05-04 23:15:15 +00006593can be used to pass 'attributes' and 'properties' of one specific image,
6594in a way that allows you to use them in a completely different image, even if
6595the original image has long since been modified or destroyed. For example: </p>
6596
6597<pre>
6598convert rose: -set option:rosesize '%wx%h' -delete 0 \
6599 label:'%[rosesize]' label_size_of_rose.gif"
6600</pre>
6601
cristy82a2ff22015-05-12 16:41:32 +00006602<p>Note that <a href="escape.html">Format Percent Escapes</a> will only match
cristyd2432012015-05-04 23:15:15 +00006603a 'artifact' if the given <var>key</var> does not match an existing
6604'attribute' or 'property'. </p>
6605
6606<p>You can set the attributes of the image registry by prefixing the value
6607with <code>registry:</code>.</p>
6608
6609<p>The <a href="command-line-options.html#set">-set profile</a> option can also be used to inject
6610previously-formatted ancillary chunks into the output PNG file, using
6611the commandline option as shown below or by setting the profile via a
6612programming interface:</p>
6613
6614<pre>
6615convert in.png -set profile PNG-chunk-x:&lt;filename&gt; out.png
6616</pre>
6617
6618<p>where <var>x</var> is a location flag and
6619<var>filename</var> is a file containing the chunk
6620name in the first 4 bytes, then a colon (":"), followed by the chunk data.
6621This encoder will compute the chunk length and CRC, so those must not
6622be included in the file.</p>
6623
6624<p>"x" can be "b" (before PLTE), "m" (middle, i.e., between PLTE and IDAT),
6625or "e" (end, i.e., after IDAT). If you want to write multiple chunks
6626of the same type, then add a short unique string after the "x" to prevent
6627subsequent profiles from overwriting the preceding ones, e.g.,</p>
6628
6629
6630<pre>
6631convert in.png -set profile PNG-chunk-b01:file01 \
6632 -profile PNG-chunk-b02:file02 out.png
6633</pre>
6634
6635<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006636 <h3 class="magick-header"><a id="shade"></a>-shade <var>azimuth</var>x<var>elevation</var></h3>
cristyd2432012015-05-04 23:15:15 +00006637</div>
6638
6639<p class="magick-description">shade the image using a distant light source.</p>
6640
6641<p>Specify <var>azimuth</var> and <var>elevation</var> as
6642the position of the light source. Use <a href="command-line-options.html#shade">+shade</a> to return
6643the shading results as a grayscale image.</p>
6644
6645<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006646 <h3 class="magick-header"><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>
cristyd2432012015-05-04 23:15:15 +00006647</div>
6648
6649<p class="magick-description">simulate an image shadow.</p>
6650
6651<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00006652 <h3 class="magick-header"><a id="shared-memory"></a>-shared-memory</h3>
cristyd2432012015-05-04 23:15:15 +00006653</div>
6654
6655<p class="magick-description">use shared memory.</p>
6656
6657<p>This option specifies whether the utility should attempt to use shared
6658memory for pixmaps. ImageMagick must be compiled with shared memory support,
6659and the display must support the <var>MIT-SHM</var> extension.
6660Otherwise, this option is ignored. The default is <code>True</code>.</p>
6661
6662<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00006663 <h3 class="magick-header"><a id="sharpen"></a>-sharpen <var>radius</var><br>-sharpen <var>radius</var>x<var>sigma</var></h3>
cristyd2432012015-05-04 23:15:15 +00006664</div>
6665
6666<p class="magick-description">sharpen the image.</p>
6667
6668<p>Use a Gaussian operator of the given radius and standard deviation (sigma).</p>
6669
6670<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006671 <h3 class="magick-header"><a id="shave"></a>-shave <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00006672</div>
6673
6674<p class="magick-description">Shave pixels from the image edges.</p>
6675
6676<p>The <var>size</var> portion of the <var>geometry</var>
6677argument specifies the width of the region to be removed from both sides of
6678the image and the height of the regions to be removed from top and bottom.
6679Offsets are ignored.</p>
6680
6681<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
6682
6683<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006684 <h3 class="magick-header"><a id="shear"></a>-shear <var>Xdegrees</var>[x<var>Ydegrees</var>]</h3>
cristyd2432012015-05-04 23:15:15 +00006685</div>
6686
6687<p class="magick-description">Shear the image along the x-axis and/or y-axis.</p>
6688
6689<p>The shear angles may be positive, negative, or zero. When <var>Ydegrees</var> is omitted it defaults to 0. When both angles are
6690given, the horizontal component of the shear is performed before the vertical
6691component.</p>
6692
6693<p>Shearing slides one edge of an image along the x-axis or y-axis (i.e.,
6694horizontally or vertically, respectively),creating a parallelogram. The amount
6695of each is controlled by the respective shear angle. For horizontal shears,
6696<var>Xdegrees</var> is measured clockwise relative to "up" (the
6697negative 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
6698positive 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>
6699
6700<p>Empty triangles left over from shearing the image are filled with the color
6701defined by the <a href="command-line-options.html#fill">-background</a> option. The color is specified
6702using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p>
6703
6704<p>The horizontal shear is performed before the vertical part. This is
6705important to note, since horizontal and vertical shears do not
6706<var>commute</var>, i.e., the order matters in a sequence of shears. For
6707example, the following two commands are not equivalent.</p>
6708
6709<pre>
6710convert logo: -shear 20x0 -shear 0x60 logo-sheared.png
6711convert logo: -shear 0x60 -shear 20x0 logo-sheared.png
6712</pre>
6713
6714<p>The first of the two commands above is equivalent to the following, except
6715for the amount of empty space created; the command that follows generates
6716a smaller image, and so is a better choice in terms of time and space.</p>
6717
6718<pre>
6719convert logo: -shear 20x60 logo-sheared.png
6720</pre>
6721
6722<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006723 <h3 class="magick-header"><a id="sigmoidal-contrast"></a>-sigmoidal-contrast <var>contrast</var>x<var>mid-point</var></h3>
cristyd2432012015-05-04 23:15:15 +00006724</div>
6725
6726<p class="magick-description">increase the contrast without saturating highlights or shadows.</p>
6727
6728<p>Increase the contrast of the image using a sigmoidal transfer function
6729without saturating highlights or shadows. <var>Contrast</var>
6730indicates how much to increase the contrast. For example, 0 is none, 3 is
6731typical and 20 is a lot.
6732</p>
6733
6734<p>The <var>mid-point</var> indicates where the maximum change
6735'slope' in contrast should fall in the resultant image (0 is white; 50% is
6736middle-gray; 100% is black). </p>
6737
6738<p>By default the image contrast is increased, use <var>+sigmoidal-contrast</var> to decrease the contrast.</p>
6739
6740<p>To achieve the equivalent of a sigmoidal brightness change (similar to
6741a gamma adjustment), you would use <var>-sigmoidal-contrast
6742{brightness}x0%</var> to increase brightness and <var>+sigmoidal-contrast {brightness}x0%</var> to decrease brightness.
6743Note the use of '0' fo rthe mid-point of the sigmoidal curve. </p>
6744
6745<p>Using a very high <var>contrast</var> will produce a sort of
6746'smoothed thresholding' of the image. Not as sharp (with high aliasing
6747effects) of a true threshold, but with tapered gray-levels around the threshold
6748<var>mid-point</var>. </p>
6749
6750<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006751 <h3 class="magick-header"><a id="silent"></a>-silent</h3>
cristyd2432012015-05-04 23:15:15 +00006752</div>
6753
6754<p class="magick-description">operate silently.</p>
6755
6756<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006757 <h3 class="magick-header"><a id="similarity-threshold"></a>-similarity-threshold <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00006758</div>
6759
6760<p class="magick-description">minimum RMSE for subimage match.</p>
6761
6762<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>
6763
6764<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006765 <h3 class="magick-header"><a id="size"></a>-size <var>width</var>[x<var>height</var>][<var>+offset</var>]</h3>
cristyd2432012015-05-04 23:15:15 +00006766</div>
6767
6768<p class="magick-description">set the width and height of the image.</p>
6769
6770<p>Use this option to specify the width and height of raw images whose
6771dimensions are unknown such as <code>GRAY</code>, <code>RGB</code>, or
cristy82a2ff22015-05-12 16:41:32 +00006772<code>CMYK</code>. In addition to width and height, use <a href="command-line-options.html#size">-size</a> with an offset to skip any header information in the
cristyd2432012015-05-04 23:15:15 +00006773image or tell the number of colors in a <code>MAP</code> image file, (e.g. -size
6774640x512+256).</p>
6775
6776<p>For Photo CD images, choose from these sizes:</p>
6777
6778<pre>
cristy29dc8652015-05-12 16:26:21 +00006779192x128
6780384x256
6781768x512
67821536x1024
67833072x2048
cristyd2432012015-05-04 23:15:15 +00006784</pre>
6785
6786<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00006787 <h3 class="magick-header"><a id="sketch"></a>-sketch <var>radius</var><br>-sketch <var>radius</var>x<var>sigma</var>+<var>angle</var></h3>
cristyd2432012015-05-04 23:15:15 +00006788</div>
6789
6790<p class="magick-description">simulate a pencil sketch.</p>
6791
6792<p>Sketch with the given radius, standard deviation (sigma), and angle. The
6793angle given is the angle toward which the image is sketched. That is the
6794direction people would consider the object is coming from. </p>
6795
6796<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006797 <h3 class="magick-header"><a id="smush"></a>-smush <var>offset</var></h3>
cristyd2432012015-05-04 23:15:15 +00006798</div>
6799
6800<p class="magick-description">smush an image sequence together.</p>
6801
6802<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006803 <h3 class="magick-header"><a id="snaps"></a>-snaps <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00006804</div>
6805
6806<p class="magick-description">Set the number of screen snapshots.</p>
6807
6808<p>Use this option to grab more than one image from the X server screen, to create an animation sequence.</p>
6809
6810<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006811 <h3 class="magick-header"><a id="solarize"></a>-solarize <var>threshold</var></h3>
cristyd2432012015-05-04 23:15:15 +00006812</div>
6813
6814<p class="magick-description">negate all pixels above the threshold level.</p>
6815
6816<p>Specify <var>factor</var> as the percent threshold of the intensity (0 - 99.9%).</p>
6817
6818<p>This option produces a <var>solarization</var> effect seen when
6819exposing a photographic film to light during the development process.</p>
6820
6821<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006822 <h3 class="magick-header"><a id="sparse-color"></a>-sparse-color <var>method</var> '<var>x</var>,<var>y</var> <var>color</var> ...'</h3>
cristyd2432012015-05-04 23:15:15 +00006823</div>
6824
6825<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>
6826
6827
cristyb2cad532015-05-16 13:02:45 +00006828<dl class="dl-horizontal">
6829 <dt>barycentric</dt>
6830 <dd>three point triangle of color given 3 points.
cristyd2432012015-05-04 23:15:15 +00006831 Giving only 2 points will form a linear gradient between those points.
6832 The gradient generated extends beyond the triangle created by those
cristyb2cad532015-05-16 13:02:45 +00006833 3 points. </dd>
6834 <dt>bilinear</dt>
6835 <dd>Like barycentric but for 4 points. Less than 4 points
6836 fall back to barycentric. </dd>
6837 <dt>voronoi</dt>
6838 <dd>Simply map each pixel to the to nearest color point
6839 given. The result are polygonal 'cells' of solid color. </dd>
6840 <dt>shepards</dt>
6841 <dd>Colors points biased on the ratio of inverse distance
cristyd2432012015-05-04 23:15:15 +00006842 squared. Generating spots of color in a sea of the average of
cristyb2cad532015-05-16 13:02:45 +00006843 colors. </dd>
6844 <dt>inverse</dt>
6845 <dd>Colors points biased on the ratio of inverse distance.
cristyd2432012015-05-04 23:15:15 +00006846 This generates sharper points of color rather than rounded spots of
6847 '<code>shepards</code>' Generating spots of color in a sea of the
cristyb2cad532015-05-16 13:02:45 +00006848 average of colors. </dd>
6849</dl>
cristyd2432012015-05-04 23:15:15 +00006850
6851<p>The points are placed according to the images location on the virtual
cristy82a2ff22015-05-12 16:41:32 +00006852canvas (<a href="command-line-options.html#page">-page</a> or <a href="command-line-options.html#repage">-repage</a>
cristyd2432012015-05-04 23:15:15 +00006853offset), and do not actually have to exist on the given image, but may be
6854some point beyond the edge of the image. All points are floating point values.
6855</p>
6856
cristy82a2ff22015-05-12 16:41:32 +00006857<p>Only the color channels defined by the <a href="command-line-options.html#channel">-channel</a> are
cristyd2432012015-05-04 23:15:15 +00006858modified, which means that by default matte/alpha transparency channel is not
6859effected. Typically transparency channel is turned off either before or after
6860the operation. </p>
6861
6862<p>Of course if some color points are transparent to generate a transparent
6863gradient, then the image also requires transparency enabled to store the
6864values. </p>
6865
6866<p>All the above methods when given a single point of color will replace all
6867the colors in the image with the color given, regardless of the point. This is
6868logical, and provides an alternative technique to recolor an image to some
6869default value. </p>
6870
6871
6872<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006873 <h3 class="magick-header"><a id="splice"></a>-splice <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00006874</div>
6875
6876<p class="magick-description">Splice the current background color into the image.</p>
6877
cristy82a2ff22015-05-12 16:41:32 +00006878<p>This will add rows and columns of the current <a href="command-line-options.html#background">-background</a> color into the given image according to the
cristyd2432012015-05-04 23:15:15 +00006879given <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
6880image into four quadrants, separating them by the inserted rows and columns.
6881</p>
6882
6883<p>If a dimension of geometry is zero no rows or columns will be added for that
cristy82a2ff22015-05-12 16:41:32 +00006884dimension. Similarly using a zero offset with the appropriate <a href="command-line-options.html#gravity">-gravity</a> setting will add rows and columns to the edges of
6885the image, padding the image only along that one edge. Edge padding is what <a href="command-line-options.html#splice">-splice</a> is most commonly used for. </p>
cristyd2432012015-05-04 23:15:15 +00006886
cristy82a2ff22015-05-12 16:41:32 +00006887<p>If the exact same <var>geometry</var> and <a href="command-line-options.html#gravity">-gravity</a> is later used with <a href="command-line-options.html#chop">-chop</a> the
cristyd2432012015-05-04 23:15:15 +00006888added added all splices removed. </p>
6889
6890<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006891 <h3 class="magick-header"><a id="spread"></a>-spread <var>amount</var></h3>
cristyd2432012015-05-04 23:15:15 +00006892</div>
6893
6894<p class="magick-description">displace image pixels by a random amount.</p>
6895
6896<p>The argument <var>amount</var> defines the size of the
6897neighborhood around each pixel from which to choose a candidate pixel to
6898swap.</p>
6899
6900<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006901 <h3 class="magick-header"><a id="statistic"></a>-statistic <var>type</var> <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00006902</div>
6903
6904<p class="magick-description">replace each pixel with corresponding statistic from the neighborhood.</p>
6905
6906<p>Choose from these statistic types:</p>
cristy29dc8652015-05-12 16:26:21 +00006907<dl class="dl-horizontal">
6908<dt>Gradient</dt><dd>maximum difference (max - min) value in neighborhood</dd>
6909<dt>Maximum</dt><dd>maximum value per channel in neighborhood</dd>
6910<dt>Minimum</dt><dd>minimum value per channel in neighborhood</dd>
6911<dt>Mean</dt><dd>average value per channel in neighborhood</dd>
6912<dt>Median</dt><dd>median value per channel in neighborhood</dd>
6913<dt>Mode</dt><dd>mode (most frequent) value per channel in neighborhood</dd>
6914<dt>Nonpeak</dt><dd>value just before or after the median value per channel in neighborhood</dd>
6915<dt>RMS</dt><dd>root mean square value per channel in neighborhood</dd>
6916<dt>StandardDeviation</dt><dd> standard deviation value per channel in neighborhood</dd>
6917</dl>
cristyd2432012015-05-04 23:15:15 +00006918
6919<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006920 <h3 class="magick-header"><a id="stegano"></a>-stegano <var>offset</var></h3>
cristyd2432012015-05-04 23:15:15 +00006921</div>
6922
6923<p class="magick-description">hide watermark within an image.</p>
6924
6925<p>Use an offset to start the image hiding some number of pixels from the
6926beginning of the image. Note this offset and the image size. You will need
6927this information to recover the steganographic image (e.g. display -size
6928320x256+35 stegano:image.png).</p>
6929
6930<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006931 <h3 class="magick-header"><a id="stereo"></a>-stereo <var>+x</var>{<var>+y</var>}</h3>
cristyd2432012015-05-04 23:15:15 +00006932</div>
6933
6934<p class="magick-description">composite two images to create a red / cyan stereo anaglyph.</p>
6935
6936<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>
6937
6938<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006939 <h3 class="magick-header"><a id="storage-type"></a>-storage-type <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00006940</div>
6941
6942<p class="magick-description">pixel storage type. Here are the valid types:</p>
6943
cristyb2cad532015-05-16 13:02:45 +00006944<dl class="dl-horizontal">
6945<dt>char</dt><dd>unsigned characters</dd>
6946<dt>double</dt><dd>doubles</dd>
6947<dt>float</dt><dd>floats</dd>
6948<dt>integer</dt><dd>integers</dd>
6949<dt>long</dt><dd>longs</dd>
6950<dt>quantum</dt><dd>pixels in the native depth of your ImageMagick distribution</dd>
6951<dt>short</dt><dd>unsigned shorts</dd>
6952</dl>
cristyd2432012015-05-04 23:15:15 +00006953
6954<p>Float and double types are normalized from 0.0 to 1.0 otherwise the pixels
6955values range from 0 to the maximum value the storage type can support.</p>
6956
6957<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006958 <h3 class="magick-header"><a id="stretch"></a>-stretch <var>fontStretch</var></h3>
cristyd2432012015-05-04 23:15:15 +00006959</div>
6960
6961<p class="magick-description">Set a type of stretch style for fonts.</p>
6962
6963<p>This setting suggests a type of stretch that ImageMagick should try to
6964apply to the currently selected font family. Select <var>fontStretch</var> from the following.</p>
6965
6966<pre>
cristy29dc8652015-05-12 16:26:21 +00006967Any
6968Condensed
6969Expanded
6970ExtraCondensed
6971ExtraExpanded
6972Normal
6973SemiCondensed
6974SemiExpanded
6975UltraCondensed
6976UltraExpanded
cristyd2432012015-05-04 23:15:15 +00006977</pre>
6978
6979<p>To print a complete list of stretch types, use <a href="command-line-options.html#list">-list
6980stretch</a>.</p>
6981
cristy82a2ff22015-05-12 16:41:32 +00006982<p>For other settings that affect fonts, see the options <a href="command-line-options.html#font">-font</a>, <a href="command-line-options.html#family">-family</a>, <a href="command-line-options.html#style">-style</a>, and <a href="command-line-options.html#weight">-weight</a>. </p>
cristyd2432012015-05-04 23:15:15 +00006983
6984<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006985 <h3 class="magick-header"><a id="strip"></a>-strip</h3>
cristyd2432012015-05-04 23:15:15 +00006986</div>
6987
6988<p class="magick-description">strip the image of any profiles or comments.</p>
6989
6990<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006991 <h3 class="magick-header"><a id="stroke"></a>-stroke <var>color</var></h3>
cristyd2432012015-05-04 23:15:15 +00006992</div>
6993
6994<p class="magick-description">color to use when stroking a graphic primitive.</p>
6995
6996<p>The color is specified using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p>
6997
6998<p>See <a href="command-line-options.html#draw">-draw</a> for further details.</p>
6999
7000<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007001 <h3 class="magick-header"><a id="strokewidth"></a>-strokewidth <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00007002</div>
7003
7004<p class="magick-description">set the stroke width.</p>
7005
7006<p>See <a href="command-line-options.html#draw">-draw</a> for further details.</p>
7007
7008<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007009 <h3 class="magick-header"><a id="style"></a>-style <var>fontStyle</var></h3>
cristyd2432012015-05-04 23:15:15 +00007010</div>
7011
7012<p class="magick-description">Set a font style for text.</p>
7013
7014<p>This setting suggests a font style that ImageMagick should try to apply to
7015the currently selected font family. Select <var>fontStyle</var> from
7016the following.</p>
7017
7018<pre>
cristy29dc8652015-05-12 16:26:21 +00007019Any
7020Italic
7021Normal
7022Oblique
cristyd2432012015-05-04 23:15:15 +00007023</pre>
7024
cristy82a2ff22015-05-12 16:41:32 +00007025<p>For other settings that affect fonts, see the options <a href="command-line-options.html#font">-font</a>, <a href="command-line-options.html#family">-family</a>, <a href="command-line-options.html#stretch">-stretch</a>, and <a href="command-line-options.html#weight">-weight</a>. </p>
cristyd2432012015-05-04 23:15:15 +00007026
7027<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007028 <h3 class="magick-header"><a id="subimage-search"></a>-subimage-search</h3>
cristyd2432012015-05-04 23:15:15 +00007029</div>
7030
7031<p class="magick-description">search for subimage.</p>
7032
7033<p>This option is required to have compare search for the best match location
7034of a small image within a larger image. This search will produce two images
7035(or two frames). The first is the "difference" image and the second will
7036be the "match score" image.</p>
7037
7038<p>The "match-score" image is smaller containing a pixel for ever possible
7039position of the top-left corner of the given sub-image. that is its size will
7040be the size of the larger_image - sub_image + 1. The brightest location in
7041this image is the location s the locate on the best match that is also
7042reported. Note that this may or may not be a perfect match, and the actual
7043brightness will reflect this. Other bright 'peaks' can be used to locate other
7044possible matching locations. </p>
7045
7046<p>Note that the search will try to compare the sub-image at every possible
7047location in the larger image, as such it can be very slow. The smaller the
7048sub-image the faster this search is. </p>
7049
7050
7051<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007052 <h3 class="magick-header"><a id="swap"></a>-swap <var>index,index</var></h3>
cristyd2432012015-05-04 23:15:15 +00007053</div>
7054
7055<p class="magick-description">Swap the positions of two images in the image sequence.</p>
7056
7057<p>For example, <a href="command-line-options.html#swap">-swap 0,2</a> swaps the first and the third
7058images in the current image sequence. Use <a href="command-line-options.html#swap">+swap</a> to switch
7059the last two images in the sequence.</p>
7060
7061<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007062 <h3 class="magick-header"><a id="swirl"></a>-swirl <var>degrees</var></h3>
cristyd2432012015-05-04 23:15:15 +00007063</div>
7064
7065<p class="magick-description">swirl image pixels about the center.</p>
7066
7067<p><var>Degrees</var> defines the tightness of the swirl.</p>
7068
7069<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007070 <h3 class="magick-header"><a id="synchronize"></a>-synchronize</h3>
cristyd2432012015-05-04 23:15:15 +00007071</div>
7072
7073<p class="magick-description">synchronize image to storage device.</p>
7074
7075<p>Set to "true" to ensure all image data is fully flushed and synchronized
7076to disk. There is a performance penalty, but the benefits include ensuring a
7077valid image file in the event of a system crash and early reporting if there
7078is not enough disk space for the image pixel cache.</p>
7079
7080<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007081 <h3 class="magick-header"><a id="taint"></a>-taint</h3>
cristyd2432012015-05-04 23:15:15 +00007082</div>
7083
7084<p class="magick-description">Mark the image as modified.</p>
7085
7086<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007087 <h3 class="magick-header"><a id="text-font"></a>-text-font <var>name</var></h3>
cristyd2432012015-05-04 23:15:15 +00007088</div>
7089
7090<p class="magick-description">font for writing fixed-width text.</p>
7091
7092<p>Specifies the name of the preferred font to use in fixed (typewriter style)
7093formatted text. The default is 14 point <var>Courier</var>.</p>
7094
7095<p>You can tag a font to specify whether it is a PostScript, TrueType, or
7096OPTION1 font. For example, <code>Courier.ttf</code> is a TrueType font and
7097<code>x:fixed</code> is OPTION1.</p>
7098
7099<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007100 <h3 class="magick-header"><a id="texture"></a>-texture <var>filename</var></h3>
cristyd2432012015-05-04 23:15:15 +00007101</div>
7102
7103<p class="magick-description">name of texture to tile onto the image background.</p>
7104
7105<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007106 <h3 class="magick-header"><a id="threshold"></a>-threshold <var>value</var>{<var>%</var>}</h3>
cristyd2432012015-05-04 23:15:15 +00007107</div>
7108
7109<!-- {<var>green,blue,opacity</var>}
7110<p>If the green or blue value is omitted, these channels use the same value as
7111the first one provided. If all three color values are the same, the result is
7112a bi-level image. If the opacity threshold is omitted, OpaqueOpacity is used
7113and any partially transparent pixel becomes fully transparent.</p>
7114-->
7115
7116<p class="magick-description">Apply simultaneous black/white threshold to the image.</p>
7117
cristy82a2ff22015-05-12 16:41:32 +00007118<p>Any pixel values (more specifically, those channels set using <a href="command-line-options.html#channel">‑channel</a>) that exceed the specified threshold are reassigned the
cristyd2432012015-05-04 23:15:15 +00007119maximum channel value, while all other values are assigned the minimum.</p>
7120
7121<p> The threshold value can be given as a percentage or as an absolute integer
7122value corresponding to the desired channel value. When given as an integer,
7123the minimum attainable value is 0 (corresponding to black when all channels
7124are affected), but the maximum value (corresponding to white) is that of the
7125<code>quantum depth</code> of the particular build of ImageMagick, and is
7126therefore dependent on the installation. For that reason, a reasonable
7127recommendation for most applications is to specify the threshold values as
7128a percentage. </p>
7129
7130<p> The following would force pixels with red values above 50% to have 100%
7131red values, while those at or below 50% red would be set to 0 in the red
7132channel. The green, blue, and alpha channels (if present) would be unchanged.
7133</p>
7134
7135<pre>
7136convert in.png -channel red -threshold 50% out.png
7137</pre>
7138
7139<p>As (possibly) impractical but instructive examples, the following would
7140generate an all-black and an all-white image with the same dimensions as the
7141input image.</p>
7142
7143
7144<pre>
7145convert in.png -threshold 100% black.png
7146convert in.png -threshold -1 white.png
7147</pre>
7148
7149<p>Note that the values of the transparency channel is treated as 'matte'
7150values (0 is opaque) and not as 'alpha' values (0 is transparent).</p>
7151
cristy82a2ff22015-05-12 16:41:32 +00007152<p> See also <a href="command-line-options.html#black-threshold">‑black‑threshold</a> and <a href="command-line-options.html#white-threshold">‑white‑threshold</a>.
cristyd2432012015-05-04 23:15:15 +00007153</p>
7154
7155<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007156 <h3 class="magick-header"><a id="thumbnail"></a>-thumbnail <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00007157</div>
7158
7159<p class="magick-description">Create a thumbnail of the image.</p>
7160
7161<p>This is similar to <a href="command-line-options.html#resize">-resize</a>, except it is optimized
7162for speed and any image profile, other than a color profile, is removed to
cristy82a2ff22015-05-12 16:41:32 +00007163reduce the thumbnail size. To strip the color profiles as well, add <a href="command-line-options.html#strip">-strip</a> just before of after this option.</p>
cristyd2432012015-05-04 23:15:15 +00007164
7165<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
7166
7167<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007168 <h3 class="magick-header"><a id="tile"></a>-tile <var>filename</var></h3>
cristyd2432012015-05-04 23:15:15 +00007169</div>
7170
7171<p class="magick-description">Set the tile image used for filling a subsequent graphic primitive.</p>
7172
7173<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007174 <h3 class="magick-header">-tile <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00007175</div>
7176
7177<p class="magick-description">Specify the layout of images.</p>
7178
7179<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
7180
7181<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007182 <h3 class="magick-header">-tile</h3>
cristyd2432012015-05-04 23:15:15 +00007183</div>
7184
7185<p class="magick-description">Specifies that a subsequent composite operation is repeated across and down image.</p>
7186
7187<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007188 <h3 class="magick-header"><a id="tile-offset"></a>-tile-offset {<var>+-</var>}<var>x</var>{<var>+-</var>}<var>y</var></h3>
cristyd2432012015-05-04 23:15:15 +00007189</div>
7190
7191<p class="magick-description">Specify the offset for tile images, relative to the background image it is tiled on.</p>
7192
cristy82a2ff22015-05-12 16:41:32 +00007193<p>This should be set before the tiling image is set by <a href="command-line-options.html#tile">-tile</a> or <a href="command-line-options.html#texture">-texture</a>, or directly applied for
cristyd2432012015-05-04 23:15:15 +00007194creating a tiled canvas using <code>TILE:</code> or <code>PATTERN:</code> input
7195formats. </p>
7196
cristy82a2ff22015-05-12 16:41:32 +00007197<p>Internally ImageMagick does a <a href="command-line-options.html#roll">-roll</a> of the tile image
cristyd2432012015-05-04 23:15:15 +00007198by the arguments given when the tile image is set. </p>
7199
7200<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007201 <h3 class="magick-header"><a id="tint"></a>-tint <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00007202</div>
7203
7204<p class="magick-description">Tint the image with the fill color.</p>
7205
7206<p>Tint the image with the fill color.</p>
7207
7208<p>Specify the amount of tinting as a percentage. Pure colors like black,
7209white red, yellow, will not be affected by -tint. Only mid-range colors such
7210as the various shades of grey.</p>
7211
7212<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007213 <h3 class="magick-header"><a id="title"></a>-title <var>string</var></h3>
cristyd2432012015-05-04 23:15:15 +00007214</div>
7215
7216<p class="magick-description">Assign a title to displayed image.", "animate", "display", "montage</p>
7217
7218<p>Use this option to assign a specific title to the image. This assigned to
7219the image window and is typically displayed in the window title bar.
7220Optionally you can include the image filename, type, width, height, Exif data,
7221or other image attribute by embedding special format characters described
7222under the <a href="command-line-options.html#format">-format</a> option.</p>
7223
7224<p>For example,</p>
7225
cristy29dc8652015-05-12 16:26:21 +00007226<pre>
7227-title "%m:%f %wx%h"
7228</pre>
cristyd2432012015-05-04 23:15:15 +00007229
7230<p>produces an image title of <code>MIFF:bird.miff 512x480</code> for an image
7231titled <code>bird.miff</code> and whose width is 512 and height is 480.</p>
7232
7233
7234<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007235 <h3 class="magick-header"><a id="transform"></a>-transform</h3>
cristyd2432012015-05-04 23:15:15 +00007236</div>
7237
7238<p class="magick-description">transform the image.</p>
7239
7240<p>This option applies the transformation matrix from a previous <a href="command-line-options.html#affine">-affine</a> option.</p>
7241
7242<pre>
7243convert -affine 2,2,-2,2,0,0 -transform bird.ppm bird.jpg
7244</pre>
7245
7246
cristy82a2ff22015-05-12 16:41:32 +00007247<p>This operator has been now been superseded by the <a href="command-line-options.html#distort">-distort</a> '<code>AffineProjection</code>' method. </p>
cristyd2432012015-05-04 23:15:15 +00007248
7249
7250<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007251 <h3 class="magick-header"><a id="transparent"></a>-transparent <var>color</var></h3>
cristyd2432012015-05-04 23:15:15 +00007252</div>
7253
7254<p class="magick-description">Make this color transparent within the image.</p>
7255
7256<p>The <var>color</var> argument is defined using the format
cristy82a2ff22015-05-12 16:41:32 +00007257described under the <a href="command-line-options.html#fill">-fill</a> option. The <a href="command-line-options.html#fuzz">-fuzz</a> setting can be used to match and replace colors similar to the one
cristyd2432012015-05-04 23:15:15 +00007258given. </p>
7259
cristy82a2ff22015-05-12 16:41:32 +00007260<p>Use <a href="command-line-options.html#transparent">+transparent</a> to invert the pixels matched.
cristyd2432012015-05-04 23:15:15 +00007261that is make all non-matching colors transparent. </p>
7262
cristy82a2ff22015-05-12 16:41:32 +00007263<p>The <a href="command-line-options.html#opaque">-opaque</a> operator is exactly the same as <a href="command-line-options.html#transparent">-transparent</a> but replaces the matching color with the
cristyd2432012015-05-04 23:15:15 +00007264current <a href="command-line-options.html#fill">-fill</a> color setting, rather than transparent.
cristy82a2ff22015-05-12 16:41:32 +00007265However the <a href="command-line-options.html#transparent">-transparent</a> operator also ensures
7266that the image has an alpha channel enabled, as per "<code><a href="command-line-options.html#alpha">-alpha</a> set</code>", and does not require you to modify the <a href="command-line-options.html#channel">-channel</a> to enable alpha channel handling. </p>
cristyd2432012015-05-04 23:15:15 +00007267
7268<p>Note that this does not define the color as being the 'transparency color'
cristy82a2ff22015-05-12 16:41:32 +00007269used for color-mapped image formats, such as GIF. For that use <a href="command-line-options.html#transparent-color">-transparent-color</a> </p>
cristyd2432012015-05-04 23:15:15 +00007270
7271
7272<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007273 <h3 class="magick-header"><a id="transparent-color"></a>-transparent-color <var>color</var></h3>
cristyd2432012015-05-04 23:15:15 +00007274</div>
7275
7276<p class="magick-description">Set the transparent color.</p>
7277
7278<p>Sometimes this is used for saving to image formats such as
7279GIF and PNG8 which uses this color to represent boolean transparency. This
7280does not make a color transparent, it only defines what color the transparent
cristy82a2ff22015-05-12 16:41:32 +00007281color is in the color palette of the saved image. Use <a href="command-line-options.html#transparent">-transparent</a> to make an opaque color transparent.</p>
cristyd2432012015-05-04 23:15:15 +00007282
7283<p>This option allows you to have both an opaque visible color, as well as a
7284transparent color of the same color value without conflict. That is, you can
7285use the same color for both the transparent and opaque color areas within an
7286image. This, in turn, frees to you to select a transparent color that is
7287appropriate when an image is displayed by an application that does not handle a
7288transparent color index, while allowing ImageMagick to correctly handle images of this
7289type. </p>
7290
7291<p>The default transparent color is <code>#00000000</code>, which is fully transparent black.</p>
7292
7293<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007294 <h3 class="magick-header"><a id="transpose"></a>-transpose</h3>
cristyd2432012015-05-04 23:15:15 +00007295</div>
7296
7297<p class="magick-description">Mirror the image along the top-left to bottom-right diagonal.</p>
7298
7299<p> This option mathematically transposes the pixel array. It is equivalent to the sequence <code>-flip -rotate 90</code>.
7300</p>
7301
7302<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007303 <h3 class="magick-header"><a id="transverse"></a>-transverse</h3>
cristyd2432012015-05-04 23:15:15 +00007304</div>
7305
7306<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>
7307
7308
7309<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007310 <h3 class="magick-header"><a id="treedepth"></a>-treedepth <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00007311</div>
7312
7313<p class="magick-description">tree depth for the color reduction algorithm.</p>
7314
7315<p>Normally, this integer value is zero or one. A value of zero or one causes
7316the use of an optimal tree depth for the color reduction algorithm.</p>
7317
7318<p>An optimal depth generally allows the best representation of the source
7319image with the fastest computational speed and the least amount of memory.
7320However, the default depth is inappropriate for some images. To assure the
7321best representation, try values between 2 and 8 for this parameter. Refer to
cristy82a2ff22015-05-12 16:41:32 +00007322the <a href="quantize.html">color reduction algorithm</a> for more details.</p>
cristyd2432012015-05-04 23:15:15 +00007323
7324<p>The <a href="command-line-options.html#colors">-colors</a> or <a href="command-line-options.html#monochrome">-monochrome</a>
7325option, or writing to an image format which requires color reduction, is
7326required for this option to take effect.</p>
7327
7328<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007329 <h3 class="magick-header"><a id="trim"></a>-trim</h3>
cristyd2432012015-05-04 23:15:15 +00007330</div>
7331
7332<p class="magick-description">trim an image.</p>
7333
7334<p>This option removes any edges that are exactly the same color as the corner
7335pixels. Use <a href="command-line-options.html#fuzz">-fuzz</a> to make <a href="command-line-options.html#trim">-trim</a> remove
7336edges that are nearly the same color as the corner pixels.</p>
7337
7338<p>The page or virtual canvas information of the image is preserved allowing
7339you to extract the result of the <a href="command-line-options.html#trim">-trim</a> operation from the
7340image. Use a <a href="command-line-options.html#repage">+repage</a> to remove the virtual canvas page
7341information if it is unwanted.</p>
7342
7343<p>If the trimmed image 'disappears' an warning is produced, and a special
7344single pixel transparent 'missed' image is returned, in the same way as when a
7345<a href="command-line-options.html#crop">-crop</a> operation 'misses' the image proper. </p>
7346
7347
7348<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007349 <h3 class="magick-header"><a id="type"></a>-type <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00007350</div>
7351
7352<p class="magick-description">the image type.</p> <p>Choose from: <code>Bilevel</code>,
7353<code>Grayscale</code>, <code>GrayscaleMatte</code>, <code>Palette</code>,
7354<code>PaletteMatte</code>, <code>TrueColor</code>, <code>TrueColorMatte</code>,
7355<code>ColorSeparation</code>, or <code>ColorSeparationMatte</code>.</p>
7356
7357<p>Normally, when a format supports different subformats such as grayscale and
cristy82a2ff22015-05-12 16:41:32 +00007358truecolor, the encoder will try to choose an efficient subformat. The <a href="command-line-options.html#type">-type</a> option can be used to override this behavior. For
cristyd2432012015-05-04 23:15:15 +00007359example, to prevent a JPEG from being written in grayscale format even though
7360only gray pixels are present, use.</p>
7361
7362<pre>
7363convert bird.png -type TrueColor bird.jpg
7364</pre>
7365
7366<p>Similarly, use <a href="command-line-options.html#type">-type TrueColorMatte</a> to force the
7367encoder to write an alpha channel even though the image is opaque, if the
7368output format supports transparency.</p>
7369
7370<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>
7371
7372<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007373 <h3 class="magick-header"><a id="undercolor"></a>-undercolor <var>color</var></h3>
cristyd2432012015-05-04 23:15:15 +00007374</div>
7375
7376<p class="magick-description">set the color of the annotation bounding box.</p>
7377
7378<p>The color is specified using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p>
7379
7380<p>See <a href="command-line-options.html#draw">-draw</a> for further details.</p>
7381
7382
7383<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007384 <h3 class="magick-header"><a id="update"></a>-update <var>seconds</var></h3>
cristyd2432012015-05-04 23:15:15 +00007385</div>
7386
7387<p class="magick-description">detect when image file is modified and redisplay.</p>
7388
7389<p>Suppose that while you are displaying an image the file that is currently
7390displayed is over-written. <code>display</code> will automagically detect that
7391the input file has been changed and update the displayed image
7392accordingly.</p>
7393
7394
7395<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007396 <h3 class="magick-header"><a id="unique-colors"></a>-unique-colors</h3>
cristyd2432012015-05-04 23:15:15 +00007397</div>
7398
7399<p class="magick-description">discard all but one of any pixel color.</p>
7400
7401
7402<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007403 <h3 class="magick-header"><a id="units"></a>-units <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00007404</div>
7405
7406<p class="magick-description">the units of image resolution.</p>
7407
7408<p>Choose from: <code>Undefined</code>, <code>PixelsPerInch</code>, or
7409<code>PixelsPerCentimeter</code>. This option is normally used in conjunction
7410with the <a href="command-line-options.html#density">-density</a> option.</p>
7411
7412
7413<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00007414 <h3 class="magick-header"><a id="unsharp"></a>-unsharp <var>radius</var><br>-unsharp <var>radius</var>x<var>sigma</var>{<var>+gain</var>}{<var>+threshold</var>}</h3>
cristyd2432012015-05-04 23:15:15 +00007415</div>
7416
7417<p class="magick-description">sharpen the image with an unsharp mask operator.</p>
7418
7419<p>The <a href="command-line-options.html#unsharp">-unsharp</a> option sharpens an image. The image is
7420convolved with a Gaussian operator of the given radius and standard deviation
7421(sigma). For reasonable results, radius should be larger than sigma. Use
7422a radius of 0 to have the method select a suitable radius.</p>
7423
7424<p>The parameters are:</p>
7425
cristyb2cad532015-05-16 13:02:45 +00007426<dl class="dl-horizontal">
7427<dt>radius</dt>
7428<dd>The radius of the Gaussian, in pixels, not counting the center pixel (default 0).</dd>
7429<dt>sigma</dt>
7430<dd>The standard deviation of the Gaussian, in pixels (default 1.0).</dd>
7431<dt>gain</dt>
7432<dd>The fraction of the difference between the original and the blur image that is added back into the original (default 1.0).</dd>
7433<dt>threshold</dt>
7434<dd>The threshold, as a fraction of <var>QuantumRange</var>, needed to apply the difference amount (default 0.05).</dd>
7435</dl>
cristyd2432012015-05-04 23:15:15 +00007436
7437<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007438 <h3 class="magick-header"><a id="verbose"></a>-verbose</h3>
cristyd2432012015-05-04 23:15:15 +00007439</div>
7440
7441<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>
7442
7443
7444<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007445 <h3 class="magick-header"><a id="version"></a>-version</h3>
cristyd2432012015-05-04 23:15:15 +00007446</div>
7447
7448<p class="magick-description">print ImageMagick version string and exit.</p>
7449
7450
7451<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007452 <h3 class="magick-header"><a id="view"></a>-view <var>string</var></h3>
cristyd2432012015-05-04 23:15:15 +00007453</div>
7454
7455<p class="magick-description">FlashPix viewing parameters.</p>
7456
7457
7458<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007459 <h3 class="magick-header"><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>
cristyd2432012015-05-04 23:15:15 +00007460</div>
7461
7462<p class="magick-description">soften the edges of the image in vignette style.</p>
7463
7464<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>
7465
7466<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007467 <h3 class="magick-header"><a id="virtual-pixel"></a>-virtual-pixel <var>method</var></h3>
cristyd2432012015-05-04 23:15:15 +00007468</div>
7469
7470<p class="magick-description">Specify contents of <var>virtual pixels</var>.</p>
7471
7472<p>This option defines what color source should be used if and when a color
7473lookup completely 'misses' the source image. The color(s) that appear to
7474surround the source image. Generally this color is derived from the source
7475image, but could also be set to a specify background color. </p>
7476
7477<p>Choose from these methods:</p>
7478
cristy29dc8652015-05-12 16:26:21 +00007479<dl class="dl-horizontal">
7480<dt>background</dt><dd>the area surrounding the image is the background color</dd>
7481<dt>black</dt><dd>the area surrounding the image is black</dd>
7482<dt>checker-tile</dt><dd>alternate squares with image and background color</dd>
7483<dt>dither</dt><dd>non-random 32x32 dithered pattern</dd>
7484<dt>edge</dt><dd>extend the edge pixel toward infinity</dd>
7485<dt>gray</dt><dd>the area surrounding the image is gray</dd>
7486<dt>horizontal-tile</dt><dd>horizontally tile the image, background color above/below</dd>
7487<dt>horizontal-tile-edge</dt><dd>horizontally tile the image and replicate the side edge pixels</dd>
7488<dt>mirror</dt><dd>mirror tile the image</dd>
7489<dt>random</dt><dd>choose a random pixel from the image</dd>
7490<dt>tile</dt><dd>tile the image (default)</dd>
7491<dt>transparent</dt><dd>the area surrounding the image is transparent blackness</dd>
7492<dt>vertical-tile</dt><dd>vertically tile the image, sides are background color</dd>
7493<dt>vertical-tile-edge</dt><dd>vertically tile the image and replicate the side edge pixels</dd>
7494<dt>white</dt><dd>the area surrounding the image is white</dd>
7495</dl>
cristyd2432012015-05-04 23:15:15 +00007496
7497<p>The default value is "edge".</p>
7498
cristy82a2ff22015-05-12 16:41:32 +00007499<p>This most important for distortion operators such as <a href="command-line-options.html#distort">-distort</a>, <a href="command-line-options.html#implode">-implode</a>, and <a href="command-line-options.html#fx">-fx</a>.
cristyd2432012015-05-04 23:15:15 +00007500However it also effects operations that may access pixels just outside the
cristy82a2ff22015-05-12 16:41:32 +00007501image proper, such as <a href="command-line-options.html#convolve">-convolve</a>, <a href="command-line-options.html#blur">-blur</a>, and <a href="command-line-options.html#sharpen">-sharpen</a>. </p>
cristyd2432012015-05-04 23:15:15 +00007502
cristy82a2ff22015-05-12 16:41:32 +00007503<p>To print a complete list of virtual pixel types, use the <a href="command-line-options.html#list">-list virtual-pixel</a> option.</p>
cristyd2432012015-05-04 23:15:15 +00007504
7505
7506<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007507 <h3 class="magick-header"><a id="visual"></a>-visual <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00007508</div>
7509
7510<p class="magick-description">Animate images using this X visual type.", 'animate', 'display'</p>
7511
7512<p>Choose from these visual classes:</p>
7513
7514<pre>
cristyb2cad532015-05-16 13:02:45 +00007515StaticGray TrueColor
7516GrayScale DirectColor
7517StaticColor default
7518PseudoColor visual id
cristyd2432012015-05-04 23:15:15 +00007519</pre>
7520
7521<p>The X server must support the visual you choose, otherwise an error occurs.
7522If a visual is not specified, the visual class that can display the most
7523simultaneous colors on the default screen is chosen.</p>
7524
7525
7526<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007527 <h3 class="magick-header"><a id="watermark"></a>-watermark <var>brightness</var>x<var>saturation</var></h3>
cristyd2432012015-05-04 23:15:15 +00007528</div>
7529
7530<p class="magick-description">Watermark an image using the given percentages of brightness and saturation.</p>
7531
7532<p>Take a grayscale image (with alpha mask) and modify the destination image's
7533brightness according to watermark image's grayscale value and the
7534<var>brightness</var> percentage. The destinations color saturation
7535attribute is just direct modified by the <var>saturation</var>
7536percentage, which defaults to 100 percent (no color change). </p>
7537
7538
7539<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00007540 <h3 class="magick-header"><a id="wave"></a>-wave <var>amplitude</var><br>-wave <var>amplitude</var>x<var>wavelength</var></h3>
cristyd2432012015-05-04 23:15:15 +00007541</div>
7542
7543<p class="magick-description">Shear the columns of an image into a sine wave.</p>
7544
7545<p>Specify <var>amplitude</var> and <var>wavelength</var>
7546of the wave.</p>
7547
7548<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007549 <h3 class="magick-header"><a id="weight"></a>-weight <var>fontWeight</var></h3>
cristyd2432012015-05-04 23:15:15 +00007550</div>
7551
7552<p class="magick-description">Set a font weight for text.</p>
7553
7554<p>This setting suggests a font weight that ImageMagick should try to apply to
7555the currently selected font family. Use a positive integer for
7556<var>fontWeight</var> or select from the following.</p>
7557
cristyb2cad532015-05-16 13:02:45 +00007558<dl class="dl-horizontal">
7559<dt>All </dt>
7560<dd>No effect. </dd>
7561<dt>Bold </dt>
7562<dd>Same as <var>fontWeight</var> = 700.</dd>
7563<dt>Bolder </dt>
7564<dd>Add 100 to font weight if currently ≤ 800.</dd>
7565<dt>Lighter </dt>
7566<dd>Subtract 100 to font weight if currently ≤ 100.</dd>
7567<dt>Normal </dt>
7568<dd>Same as <var>fontWeight</var> = 400.</dd>
cristyd2432012015-05-04 23:15:15 +00007569
cristyb2cad532015-05-16 13:02:45 +00007570<br>
7571
7572<p>To print a complete list of weight types, use <a href="command-line-options.html#list">-list weight</a>.</p>
cristyd2432012015-05-04 23:15:15 +00007573
cristy82a2ff22015-05-12 16:41:32 +00007574<p>For other settings that affect fonts, see the options <a href="command-line-options.html#font">-font</a>, <a href="command-line-options.html#family">-family</a>, <a href="command-line-options.html#stretch">-stretch</a>, and <a href="command-line-options.html#style">-style</a>. </p>
cristyd2432012015-05-04 23:15:15 +00007575
7576<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007577 <h3 class="magick-header"><a id="white-point"></a>-white-point <var>x,y</var></h3>
cristyd2432012015-05-04 23:15:15 +00007578</div>
7579
7580<p class="magick-description">chromaticity white point.</p>
7581
7582<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007583 <h3 class="magick-header"><a id="white-threshold"></a>-white-threshold <var>value</var>{<var>%</var>}</h3>
cristyd2432012015-05-04 23:15:15 +00007584</div>
7585
7586<p class="magick-description">Force to white all pixels above the threshold while leaving all pixels at or below the threshold unchanged.</p>
7587
7588<p> The threshold value can be given as a percentage or as an absolute integer
7589value within [0, <var>QuantumRange</var>] corresponding to the
cristy82a2ff22015-05-12 16:41:32 +00007590desired <a href="command-line-options.html#channel">‑channel</a> value. See <a href="command-line-options.html#threshold">‑threshold</a>for more details on thresholds and resulting values. </p>
cristyd2432012015-05-04 23:15:15 +00007591
7592<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007593 <h3 class="magick-header"><a id="window"></a>-window <var>id</var></h3>
cristyd2432012015-05-04 23:15:15 +00007594</div>
7595
7596<p class="magick-description">Make the image the background of a window.", 'animate', 'display'</p>
7597
7598<p><var>id</var> can be a window id or name. Specify <code>root</code>
7599to select X's root window as the target window.</p>
7600
7601<p>By default the image is tiled onto the background of the target window. If
7602<code>backdrop</code> or <a href="command-line-options.html#geometry">-resize</a> are specified, the
7603image is surrounded by the background color. Refer to <code>X RESOURCES</code>
7604for details.</p>
7605
7606<p>The image will not display on the root window if the image has more unique
cristy82a2ff22015-05-12 16:41:32 +00007607colors than the target window colormap allows. Use <a href="command-line-options.html#colors">-colors</a> to reduce the number of colors.</p>
cristyd2432012015-05-04 23:15:15 +00007608
7609<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007610 <h3 class="magick-header"><a id="window-group"></a>-window-group</h3>
cristyd2432012015-05-04 23:15:15 +00007611</div>
7612
7613<p class="magick-description">specify the window group.</p>
7614
7615<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007616 <h3 class="magick-header"><a id="write"></a>-write <var>filename</var></h3>
cristyd2432012015-05-04 23:15:15 +00007617</div>
7618
7619<p class="magick-description">write an image sequence.</p>
7620
7621<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>
7622
7623<p>Use <a href="command-line-options.html#compress">-compress</a> to specify the type of image compression.</p>
cristyb2cad532015-05-16 13:02:45 +00007624</dl></div>
cristyd2432012015-05-04 23:15:15 +00007625</div>
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7631 <a href="links.html">Related</a>
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7635 <p><a href="command-line-options.html#">Back to top</a>
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