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cristyb2cad532015-05-16 13:02:45 +000058<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 href="command-line-options.html#cdl">‑cdl</a><a href="command-line-options.html#channel">‑channel</a><a href="command-line-options.html#charcoal">‑charcoal</a><a href="command-line-options.html#chop">‑chop</a><a href="command-line-options.html#clamp">‑clamp</a><a href="command-line-options.html#clip">‑clip</a><a href="command-line-options.html#clip-mask">‑clip‑mask</a><a href="command-line-options.html#clip-path">‑clip‑path</a><a href="command-line-options.html#clone">‑clone</a><a href="command-line-options.html#clut">‑clut</a><a href="command-line-options.html#coalesce">‑coalesce</a><a href="command-line-options.html#colorize">‑colorize</a><a href="command-line-options.html#colormap">‑colormap</a><a href="command-line-options.html#color-matrix">‑color‑matrix</a><a href="command-line-options.html#colors">‑colors</a><a href="command-line-options.html#colorspace">‑colorspace</a><a href="command-line-options.html#combine">‑combine</a><a href="command-line-options.html#comment">‑comment</a><a href="command-line-options.html#compare">‑compare</a><a href="command-line-options.html#complex">‑complex</a><a href="command-line-options.html#compose">‑compose</a><a href="command-line-options.html#composite">‑composite</a><a href="command-line-options.html#compress">‑compress</a><a href="command-line-options.html#connected-components">‑connected‑components</a><a href="command-line-options.html#contrast">‑contrast</a><a href="command-line-options.html#contrast-stretch">‑contrast‑stretch</a><a href="command-line-options.html#convolve">‑convolve</a><a href="command-line-options.html#crop">‑crop</a><a href="command-line-options.html#cycle">‑cycle</a><a href="command-line-options.html#debug">‑debug</a><a href="command-line-options.html#decipher">‑decipher</a><a href="command-line-options.html#deconstruct">‑deconstruct</a><a href="command-line-options.html#define">‑define</a><a href="command-line-options.html#delay">‑delay</a><a href="command-line-options.html#delete">‑delete</a><a href="command-line-options.html#density">‑density</a><a href="command-line-options.html#depth">‑depth</a><a href="command-line-options.html#descend">‑descend</a><a href="command-line-options.html#deskew">‑deskew</a><a href="command-line-options.html#despeckle">‑despeckle</a><a href="command-line-options.html#direction">‑direction</a><a href="command-line-options.html#displace">‑displace</a><a href="command-line-options.html#display">‑display</a><a href="command-line-options.html#dispose">‑dispose</a><a href="command-line-options.html#dissimilarity-threshold">‑dissimilarity‑threshold</a><a href="command-line-options.html#dissolve">‑dissolve</a><a href="command-line-options.html#distort">‑distort</a><a href="command-line-options.html#distribute-cache">‑distribute‑cache</a><a href="command-line-options.html#dither">‑dither</a><a href="command-line-options.html#draw">‑draw</a><a href="command-line-options.html#duplicate">‑duplicate</a><a href="command-line-options.html#edge">‑edge</a><a href="command-line-options.html#emboss">‑emboss</a><a href="command-line-options.html#encipher">‑encipher</a><a href="command-line-options.html#encoding">‑encoding</a><a href="command-line-options.html#endian">‑endian</a><a href="command-line-options.html#enhance">‑enhance</a><a href="command-line-options.html#equalize">‑equalize</a><a href="command-line-options.html#evaluate">‑evaluate</a><a href="command-line-options.html#evaluate-sequence">‑evaluate‑sequence</a><a href="command-line-options.html#extent">‑extent</a><a href="command-line-options.html#extract">‑extract</a><a href="command-line-options.html#family">‑family</a><a href="command-line-options.html#features">‑features</a><a href="command-line-options.html#fft">‑fft</a><a href="command-line-options.html#fill">‑fill</a><a href="command-line-options.html#filter">‑filter</a><a 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#selective-blur">‑selective‑blur</a><a href="command-line-options.html#separate">‑separate</a><a href="command-line-options.html#sepia-tone">‑sepia‑tone</a><a href="command-line-options.html#set">‑set</a><a href="command-line-options.html#shade">‑shade</a><a href="command-line-options.html#shadow">‑shadow</a><a href="command-line-options.html#shared-memory">‑shared‑memory</a><a href="command-line-options.html#sharpen">‑sharpen</a><a href="command-line-options.html#shave">‑shave</a><a href="command-line-options.html#shear">‑shear</a><a href="command-line-options.html#sigmoidal-contrast">‑sigmoidal‑contrast</a><a href="command-line-options.html#silent">‑silent</a><a href="command-line-options.html#similarity-threshold">‑similarity‑threshold</a><a href="command-line-options.html#size">‑size</a><a href="command-line-options.html#sketch">‑sketch</a><a href="command-line-options.html#smush">‑smush</a><a href="command-line-options.html#snaps">‑snaps</a><a 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 +000059
cristyd2432012015-05-04 23:15:15 +000060<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>
61
62<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +000063 <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 +000064</div>
65
cristyd2432012015-05-04 23:15:15 +000066<p class="magick-description">Adaptively blur pixels, with decreasing effect near edges.</p>
cristy8ee7f242013-06-20 16:08:44 +000067
cristyd2432012015-05-04 23:15:15 +000068<p>A Gaussian operator of the given radius and standard deviation (<var>sigma</var>) is used. If <var>sigma</var> is not given it
69defaults to 1.</p>
70
71<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +000072 <h3 class="magick-header"><a id="adaptive-resize"></a>-adaptive-resize <var>geometry</var></h3>
cristy149d58c2013-08-07 19:44:54 +000073</div>
cristyd2432012015-05-04 23:15:15 +000074
75<p class="magick-description">Resize the image using data-dependent triangulation.</p>
76
77<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 +000078option defaults to data-dependent triangulation. Use the <a href="command-line-options.html#filter">-filter</a> to choose a different resampling algorithm.
79Offsets, 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 +000080
81<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +000082 <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 +000083</div>
cristyd2432012015-05-04 23:15:15 +000084
85<p class="magick-description">Adaptively sharpen pixels, with increasing effect near edges.</p>
86
87<p>A Gaussian operator of the given radius and standard deviation
88(<var>sigma</var>) is used. If <var>sigma</var> is not given it
89defaults to 1.</p>
90
91<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +000092 <h3 class="magick-header"><a id="adjoin"></a>-adjoin</h3>
cristyd2432012015-05-04 23:15:15 +000093</div>
94
95<p class="magick-description">Join images into a single multi-image file.</p>
96
97<p>This option is enabled by default. An attempt is made to save all images of
98an image sequence into the given output file. However, some formats, such as
99JPEG and PNG, do not support more than one image per file, and in that case
100ImageMagick is forced to write each image as a separate file. As such, if
101more than one image needs to be written, the filename given is modified by
102adding a <a href="command-line-options.html#scene">-scene</a> number before the suffix, in order to
103make distinct names for each image. </p>
104
105<p>Use <a href="command-line-options.html#adjoin">+adjoin</a> to force each image to be written to
106separate files, whether or not the file format allows multiple images per file
107(for example, GIF, MIFF, and TIFF). </p>
108
109<p>Including a C-style integer format string in the output filename will
110automagically enable <a href="command-line-options.html#adjoin">+adjoin</a> and are used to specify
111where the <a href="command-line-options.html#scene">-scene</a> number is placed in the filenames. These
112strings, such as '<code>%d</code>' or '<code>%03d</code>', are familiar to those
113who have used the standard <code>printf()</code>' C-library function. As an
114example, the command</p>
115
116<pre>
117convert logo: rose: -morph 15 my%02dmorph.jpg
118</pre>
119
120<p>will create a sequence of 17 images (the two given plus 15 more created by
121<a href="command-line-options.html#morph">-morph</a>), named: my00morph.jpg, my01morph.jpg,
122my02morph.jpg, ..., my16morph.jpg. </p>
123
124<p>In summary, ImageMagick tries to write all images to one file, but will
125save to multiple files, if any of the following conditions exist...</p>
126<ol>
127<li>the output image's file format does not allow multi-image files,</li>
128<li>the <a href="command-line-options.html#adjoin">+adjoin</a> option is given, or</li>
129<li>a printf() integer format string (eg: "%d") is present in the output
130 filename.</li>
131</ol>
132
133
134<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000135 <h3 class="magick-header"><a id="affine"></a>-affine
136 <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 +0000137</div>
138
139<p class="magick-description">Set the drawing transformation matrix for combined rotating and scaling.</p>
140
cristy82a2ff22015-05-12 16:41:32 +0000141<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 +0000142
143<p>The matrix entries are entered as comma-separated numeric values either in
144quotes or without spaces. </p>
145
146<p>Internally, the transformation matrix has 3x3 elements, but three of them
147are omitted from the input because they are constant. The new (transformed)
148coordinates (<var>x'</var>, <var>y'</var>) of a pixel at
149position (<var>x</var>, <var>y</var>) in the original
150image are calculated using the following matrix equation.</p>
151
cristyb2cad532015-05-16 13:02:45 +0000152<p class="text-center"><img class="img-thumbnail" alt="affine transformation" src="../images/affine.png"> </p>
cristyd2432012015-05-04 23:15:15 +0000153
154<p> The size of the resulting image is that of the smallest rectangle that
155contains the transformed source image. The parameters
156<var>t<sub>x</sub></var> and <var>t<sub>y</sub></var>
157subsequently shift the image pixels so that those that are moved out of the
158image area are cut off.</p>
159
160<p>The transformation matrix complies with the left-handed pixel coordinate
161system: positive <var>x</var> and <var>y</var> directions
162are rightward and downward, resp.; positive rotation is clockwise.</p>
163
164<p> If the translation coefficients <var>t<sub>x</sub></var> and
165<var>t<sub>y</sub></var> are omitted they default to 0,0. Therefore,
166four parameters suffice for rotation and scaling without translation.</p>
167
168<p>Scaling by the factors <var>s<sub>x</sub></var> and
169<var>s<sub>y</sub></var> in the <var>x</var> and <var>y</var> directions,
170respectively, is accomplished with the following.</p>
171
cristy82a2ff22015-05-12 16:41:32 +0000172<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 +0000173information </p>
174
175
176<pre>
177-affine <var>s<sub>x</sub></var>,0,0,<var>s<sub>y</sub></var>
178</pre>
179
180<p>Translation by a displacement (<var>t<sub>x</sub></var>, <var>t<sub>y</sub></var>) is accomplished like so:</p>
181
182<pre>
183-affine 1,0,0,1,<var>t<sub>x</sub></var>,<var>t<sub>y</sub></var>
184</pre>
185
186<p>Rotate clockwise about the origin (the upper left-hand corner) by an angle
187<var>a</var> by letting <var>c</var> = cos(<var>a</var>), <var>s</var>
188= sin(<var>a</var>), and using the following.</p>
189
190<pre>
191-affine <var>c</var>,<var>s</var>,-<var>s</var>,<var>c</var>
192</pre>
193
cristy82a2ff22015-05-12 16:41:32 +0000194<p>The cumulative effect of a sequence of <a href="command-line-options.html#affine">-affine</a>
195transformations 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 +0000196of the individual transformations.</p>
197
198<p>An attempt is made to detect near-singular transformation matrices. If the
199matrix determinant has a sufficiently small absolute value it is rejected.</p>
200
201<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000202 <h3 class="magick-header"><a id="alpha"></a>-alpha <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +0000203</div>
204
205<p class="magick-description">Gives control of the alpha/matte channel of an image.</p>
206
207<p>Used to set a flag on an image indicating whether or not to use existing alpha
208channel 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>
209
cristyb2cad532015-05-16 13:02:45 +0000210<dl class="dl-horizontal">
211 <dt>Activate</dt>
212 <dd>
213 Enable the image's transparency channel. Note normally Set
cristyd2432012015-05-04 23:15:15 +0000214 should be used instead of this, unless you specifically need to
cristyb2cad532015-05-16 13:02:45 +0000215 preserve existing (but specifically turned Off) transparency
216 channel. </dd>
cristyd2432012015-05-04 23:15:15 +0000217
cristyb2cad532015-05-16 13:02:45 +0000218 <dt>Associate</dt>
219 <dd>
220 associate the alpha channel with the image.</dd>
cristyd2432012015-05-04 23:15:15 +0000221
cristyb2cad532015-05-16 13:02:45 +0000222 <dt>Deactivate</dt>
223 <dd>
cristyd2432012015-05-04 23:15:15 +0000224 Disables the image's transparency channel. Does not delete or change the
cristyb2cad532015-05-16 13:02:45 +0000225 existing data, just turns off the use of that data.</dd>
cristyd2432012015-05-04 23:15:15 +0000226
cristyb2cad532015-05-16 13:02:45 +0000227 <dt>Disassociate</dt>
228 <dd>
229 disassociate the alpha channel from the image.</dd>
cristyd2432012015-05-04 23:15:15 +0000230
cristyb2cad532015-05-16 13:02:45 +0000231 <dt>Set</dt>
232 <dd>
cristyd2432012015-05-04 23:15:15 +0000233 Activates the alpha/matte channel. If it was previously turned off
234 then it also resets the channel to opaque. If the image already had
cristyb2cad532015-05-16 13:02:45 +0000235 the alpha channel turned on, it will have no effect.</dd>
cristyd2432012015-05-04 23:15:15 +0000236
cristyb2cad532015-05-16 13:02:45 +0000237 <dt>Opaque</dt>
238 <dd>
cristyd2432012015-05-04 23:15:15 +0000239 Enables the alpha/matte channel and forces it to be fully opaque.
cristyb2cad532015-05-16 13:02:45 +0000240 </dd>
cristyd2432012015-05-04 23:15:15 +0000241
cristyb2cad532015-05-16 13:02:45 +0000242 <dt>Transparent</dt>
243 <dd>
cristyd2432012015-05-04 23:15:15 +0000244 Activates the alpha/matte channel and forces it to be fully
245 transparent. This effectively creates a fully transparent image the
246 same size as the original and with all its original RGB data still
cristyb2cad532015-05-16 13:02:45 +0000247 intact, but fully transparent. </dd>
cristyd2432012015-05-04 23:15:15 +0000248
cristyb2cad532015-05-16 13:02:45 +0000249 <dt>Extract</dt>
250 <dd>
cristyd2432012015-05-04 23:15:15 +0000251 Copies the alpha channel values into all the color channels and turns
cristyb2cad532015-05-16 13:02:45 +0000252 'Off' the the image's transparency, so as to generate
cristyd2432012015-05-04 23:15:15 +0000253 a gray-scale mask of the image's shape. The alpha channel data is left
cristyb2cad532015-05-16 13:02:45 +0000254 intact just deactivated. This is the inverse of 'Copy'.
255 </dd>
cristyd2432012015-05-04 23:15:15 +0000256
cristyb2cad532015-05-16 13:02:45 +0000257 <dt>Copy</dt>
258 <dd>
259 Turns 'On' the alpha/matte channel, then copies the
cristyd2432012015-05-04 23:15:15 +0000260 gray-scale intensity of the image, into the alpha channel, converting
261 a gray-scale mask into a transparent shaped mask ready to be colored
cristyb2cad532015-05-16 13:02:45 +0000262 appropriately. The color channels are not modified. </dd>
cristyd2432012015-05-04 23:15:15 +0000263
cristyb2cad532015-05-16 13:02:45 +0000264 <dt>Shape</dt>
265 <dd>
266 As per 'Copy' but also colors the resulting shape mask with
cristyd2432012015-05-04 23:15:15 +0000267 the current background color. That is the RGB color channels is
268 replaced, with appropriate alpha shape.
cristyb2cad532015-05-16 13:02:45 +0000269 </dd>
cristyd2432012015-05-04 23:15:15 +0000270
cristyb2cad532015-05-16 13:02:45 +0000271 <dt>Remove</dt>
272 <dd>
cristyd2432012015-05-04 23:15:15 +0000273 Composite the image over the background color.
cristyb2cad532015-05-16 13:02:45 +0000274 </dd>
cristyd2432012015-05-04 23:15:15 +0000275
cristyb2cad532015-05-16 13:02:45 +0000276 <dt>Background</dt>
277 <dd>
cristyd2432012015-05-04 23:15:15 +0000278 Set any fully-transparent pixel to the background color, while leaving
279 it fully-transparent. This can make some image file formats, such as
280 PNG, smaller as the RGB values of transparent pixels are more uniform,
281 and thus can compress better.
cristyb2cad532015-05-16 13:02:45 +0000282 </dd>
283</dl>
cristyd2432012015-05-04 23:15:15 +0000284
285<p>Note that while the obsolete <code>+matte</code> operation was the
cristy82a2ff22015-05-12 16:41:32 +0000286same as "<code><a href="command-line-options.html#alpha">-alpha</a> Off</code>", the <code>
287&gt;-matte</code> operation was the same as "<code><a href="command-line-options.html#alpha">-alpha</a>
288Set</code>" and not "<code><a href="command-line-options.html#alpha">-alpha</a> On</code>". </p>
cristyd2432012015-05-04 23:15:15 +0000289
290
291<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000292 <h3 class="magick-header"><a id="annotate"></a>
cristy82a2ff22015-05-12 16:41:32 +0000293 -annotate <var>degrees</var> <var>text</var><br>
294 -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 +0000295</div>
296
297<p class="magick-description">Annotate an image with text</p>
298
299<p>This is a convenience for annotating an image with text. For more precise
300control over text annotations, use <a href="command-line-options.html#draw">-draw</a>.</p>
301
302
303<p>The values <var>Xdegrees</var> and <var>Ydegrees</var>
cristy82a2ff22015-05-12 16:41:32 +0000304control 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 +0000305
306<p>Using <a href="command-line-options.html#annotate">-annotate</a> <var>degrees</var>
307or <a href="command-line-options.html#annotate">-annotate</a> <var>degrees</var>x<var>degrees</var> produces an unsheared rotation of the text. The
308direction of the rotation is positive, which means a clockwise rotation if <var>degrees</var> is positive. (This conforms to the usual mathematical
309convention once it is realized that the positive <var>y</var>–direction is
310conventionally considered to be <var>downward</var> for images.)</p>
311
312<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 +0000313equation.</p>
314
315<p class="text-center"><img class="img-thumbnail" alt="annotate transformation" src="../images/annotate.png"></p>
cristyd2432012015-05-04 23:15:15 +0000316
317<p>If <var>t<sub>x</sub></var> and <var>t<sub>y</sub></var> are omitted, they default to 0. This makes the
318bottom-left of the text becomes the upper-left corner of the image, which is
cristy82a2ff22015-05-12 16:41:32 +0000319probably undesirable. Adding a <a href="command-line-options.html#gravity">-gravity</a> option in this
cristyd2432012015-05-04 23:15:15 +0000320case leads to nice results.</p>
321
322<p>Text is any UTF-8 encoded character sequence. If <var>text</var>
323is of the form '@mytext.txt', the text is read from the file
324<code>mytext.txt</code>. Text in a file is taken literally; no embedded
325formatting characters are recognized.</p>
326
327<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000328 <h3 class="magick-header"><a id="antialias"></a>-antialias</h3>
cristyd2432012015-05-04 23:15:15 +0000329</div>
330
331<p class="magick-description">Enable/Disable of the rendering of anti-aliasing pixels when drawing fonts and lines.</p>
332
333<p>By default, objects (e.g. text, lines, polygons, etc.) are antialiased when
334drawn. Use <a href="command-line-options.html#antialias">+antialias</a> to disable the addition of
335antialiasing edge pixels. This will then reduce the number of colors added to
336an image to just the colors being directly drawn. That is, no mixed colors
337are added when drawing such objects. </p>
338
339<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000340 <h3 class="magick-header"><a id="append"></a>-append</h3>
cristyd2432012015-05-04 23:15:15 +0000341</div>
342
343<p class="magick-description">Join current images vertically or horizontally.</p>
344
345<p>This option creates a single longer image, by joining all the current
346images in sequence top-to-bottom. Use <a href="command-line-options.html#append">+append</a> to
347stack images left-to-right. </p>
348
349<p>If they are not of the same width, narrower images are padded with the
350current <a href="command-line-options.html#background">-background</a> color setting, and their
cristy82a2ff22015-05-12 16:41:32 +0000351position 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 +0000352
353
354<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000355 <h3 class="magick-header"><a id="attenuate"></a>-attenuate <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +0000356</div>
357
358<p class="magick-description">Lessen (or intensify) when adding noise to an image.</p>
359
360<p>If unset the value is equivalent to 1.0, or a maximum noise addition</p>
361
362<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000363 <h3 class="magick-header"><a id="authenticate"></a>-authenticate <var>password</var></h3>
cristyd2432012015-05-04 23:15:15 +0000364</div>
365
366<p class="magick-description">Decrypt a PDF with a password.</p>
367
368<p>Use this option to supply a <var>password</var> for decrypting
369a PDF that has been encrypted using Microsoft Crypto API (MSC API). The
370encrypting using the MSC API is not supported.</p>
371
372<p>For a different encryption method, see <a href="command-line-options.html#encipher">-encipher</a>
373and <a href="command-line-options.html#decipher">-decipher</a>. </p>
374
375
376<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000377 <h3 class="magick-header"><a id="auto-gamma"></a>-auto-gamma</h3>
cristyd2432012015-05-04 23:15:15 +0000378</div>
379
380<p class="magick-description">Automagically adjust gamma level of image.</p>
381
cristy82a2ff22015-05-12 16:41:32 +0000382<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 +0000383image it will get a have a value of 50%. </p>
384
385<p>This means that any solid 'gray' image becomes 50% gray. </p>
386
387<p>This works well for real-life images with little or no extreme dark and
388light areas, but tend to fail for images with large amounts of bright sky or
389dark shadows. It also does not work well for diagrams or cartoon like images.
390</p>
391
cristy82a2ff22015-05-12 16:41:32 +0000392<p>It uses the <a href="command-line-options.html#channel">-channel</a> setting, (including the
cristyd2432012015-05-04 23:15:15 +0000393'<var>sync</var>' flag for channel synchronization), to determine which color
cristy82a2ff22015-05-12 16:41:32 +0000394values 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 +0000395together by the same gamma value, preserving colors. </p>
396
397
398
399<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000400 <h3 class="magick-header"><a id="auto-level"></a>-auto-level</h3>
cristyd2432012015-05-04 23:15:15 +0000401</div>
402
403<p class="magick-description">Automagically adjust color levels of image.</p>
404
405<p>This is a 'perfect' image normalization operator. It finds the exact
cristy82a2ff22015-05-12 16:41:32 +0000406minimum 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 +0000407values. </p>
408
409<p>The operator is not typically used for real-life images, image scans, or
410JPEG format images, as a single 'out-rider' pixel can set a bad min/max values
cristy82a2ff22015-05-12 16:41:32 +0000411for the <a href="command-line-options.html#level">-level</a> operation. On the other hand it is the
cristyd2432012015-05-04 23:15:15 +0000412right operator to use for color stretching gradient images being used to
413generate Color lookup tables, distortion maps, or other 'mathematically'
414defined images. </p>
415
cristy82a2ff22015-05-12 16:41:32 +0000416<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'
417problems 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 +0000418
cristy82a2ff22015-05-12 16:41:32 +0000419<p>It uses the <a href="command-line-options.html#channel">-channel</a> setting, (including the
cristyd2432012015-05-04 23:15:15 +0000420special '<var>sync</var>' flag for channel synchronization), to determine
cristy82a2ff22015-05-12 16:41:32 +0000421which 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 +0000422'<var>sync</var>' ensures that the color channels will are modified
423together by the same gamma value, preserving colors, and ignoring
424transparency. </p>
425
426
427<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000428 <h3 class="magick-header"><a id="auto-orient"></a>-auto-orient</h3>
cristyd2432012015-05-04 23:15:15 +0000429</div>
430
431<p class="magick-description">adjusts an image so that its orientation is suitable for viewing (i.e. top-left orientation).</p>
432
433<p>This operator reads and resets the EXIF image profile setting 'Orientation'
434and then performs the appropriate 90 degree rotation on the image to orient
435the image, for correct viewing. </p>
436
437<p>This EXIF profile setting is usually set using a gravity sensor in digital
438camera, however photos taken directly downward or upward may not have an
439appropriate value. Also images that have been orientation 'corrected' without
440reseting this setting, may be 'corrected' again resulting in a incorrect
cristy82a2ff22015-05-12 16:41:32 +0000441result. 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 +0000442
443
444<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000445 <h3 class="magick-header"><a id="average"></a>-average</h3>
cristyd2432012015-05-04 23:15:15 +0000446</div>
447
448<p class="magick-description">Average a set of images.</p>
449
450<p>An error results if the images are not identically sized.</p>
451
452
453<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000454 <h3 class="magick-header"><a id="backdrop"></a>-backdrop</h3>
cristyd2432012015-05-04 23:15:15 +0000455</div>
456
457<p class="magick-description">Display the image centered on a backdrop.</p>
458
459<p>This backdrop covers the entire workstation screen and is useful for hiding
460other X window activity while viewing the image. The color of the backdrop is
461specified as the background color. The color is specified using the format
462described under the <a href="command-line-options.html#fill">-fill</a> option.</p>
463
464<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000465 <h3 class="magick-header"><a id="background"></a>-background <var>color</var></h3>
cristyd2432012015-05-04 23:15:15 +0000466</div>
467
468<p class="magick-description">Set the background color.</p>
469
cristy82a2ff22015-05-12 16:41:32 +0000470<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 +0000471specified or found in the image) is white.</p>
472
473<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000474 <h3 class="magick-header"><a id="bench"></a>-bench <var>iterations</var></h3>
cristyd2432012015-05-04 23:15:15 +0000475</div>
476
477<p class="magick-description">Measure performance.</p>
478
479<p>Repeat the entire command for the given number of <var>iterations</var> and report the user-time and elapsed time. For instance,
480consider the following command and its output. Modify the benchmark with the
481-duration to run the benchmark for a fixed number of seconds and -concurrent
482to run the benchmark in parallel (requires the OpenMP feature).</p>
483
484<pre>
cristyb2cad532015-05-16 13:02:45 +0000485-&gt; convert logo: -resize 1000% -bench 5 logo.png
cristyd2432012015-05-04 23:15:15 +0000486Performance[4]: 5i 0.875657ips 6.880u 0:05.710
487</pre>
488
489<p>In this example, 5 iterations were completed at 0.875657 iterations per
490second, using 4 threads and 6.88 seconds of the user's allotted time, for
491a total elapsed time of 5.71 seconds.</p>
492
493<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000494 <h3 class="magick-header"><a id="bias"></a>-bias <var>value</var>{<var>%</var>}</h3>
cristyd2432012015-05-04 23:15:15 +0000495</div>
496
497<p class="magick-description">Add bias when convolving an image.</p>
498
cristy82a2ff22015-05-12 16:41:32 +0000499<p>This option shifts the output of <a href="command-line-options.html#convolve">‑convolve</a> so that
cristyd2432012015-05-04 23:15:15 +0000500positive and negative results are relative to the specified bias value. </p>
501
502<p>This is important for non-HDRI compilations of ImageMagick when dealing
503with convolutions that contain negative as well as positive values. This is
504especially the case with convolutions involving high pass filters or edge
505detection. Without an output bias, the negative values are clipped at
506zero.</p>
507
cristy82a2ff22015-05-12 16:41:32 +0000508<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 +0000509negative results without clipping to the color value range
510(0..QuantumRange).</p>
511
cristy82a2ff22015-05-12 16:41:32 +0000512<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
513about HDRI go the ImageMagick <a href="http://www.imagemagick.org/Usage/basics/#hdri">Usage</a> pages or this
514<a href="http://en.wikipedia.org/wiki/High_dynamic_range_imaging">Wikipedia</a>
cristyd2432012015-05-04 23:15:15 +0000515entry. </p>
516
517<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000518 <h3 class="magick-header"><a id="black-point-compensation"></a>-black-point-compensation</h3>
cristyd2432012015-05-04 23:15:15 +0000519</div>
520
521<p class="magick-description">Use black point compensation.</p>
522
523<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000524 <h3 class="magick-header"><a id="black-threshold"></a>-black-threshold <var>value</var>{<var>%</var>}</h3>
cristyd2432012015-05-04 23:15:15 +0000525</div>
526
527<p class="magick-description">Force to black all pixels below the threshold while leaving all pixels at or above the threshold unchanged.</p>
528
529<p> The threshold value can be given as a percentage or as an absolute integer
530value within [0, <var>QuantumRange</var>] corresponding to the
cristy82a2ff22015-05-12 16:41:32 +0000531desired <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 +0000532
533
534<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000535 <h3 class="magick-header"><a id="blend"></a>-blend <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +0000536</div>
537
538<p class="magick-description">blend an image into another by the given absolute value or percent.</p>
539
540<p>Blend will average the images together ('plus') according to the
541percentages given and each pixels transparency. If only a single percentage
542value is given it sets the weight of the composite or 'source' image, while
543the background image is weighted by the exact opposite amount. That is a
544<code>-blend 30%</code> merges 30% of the 'source' image with 70% of the
545'destination' image. Thus it is equivalent to <code>-blend 30x70%</code>.</p>
546
547
548<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000549 <h3 class="magick-header"><a id="blue-primary"></a>-blue-primary <var>x</var>,<var>y</var></h3>
cristyd2432012015-05-04 23:15:15 +0000550</div>
551
552<p class="magick-description">Set the blue chromaticity primary point.</p>
553
554<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000555 <h3 class="magick-header"><a id="blue-shift"></a>-blue-shift <var>factor</var></h3>
cristyd2432012015-05-04 23:15:15 +0000556</div>
557
558<p class="magick-description">simulate a scene at nighttime in the moonlight. Start with a factor of 1.5</p>
559
560<div style="margin: auto;">
561
562<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +0000563 <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 +0000564</div>
565
566<p class="magick-description">Reduce image noise and reduce detail levels.</p>
567
568<p>Convolve the image with a Gaussian or normal distribution using the given
cristy82a2ff22015-05-12 16:41:32 +0000569<var>Sigma</var> value. The formula is:</p>
cristyd2432012015-05-04 23:15:15 +0000570
cristyb2cad532015-05-16 13:02:45 +0000571<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 +0000572
cristy82a2ff22015-05-12 16:41:32 +0000573<p>The <var>Sigma</var> value is the important argument, and
cristyd2432012015-05-04 23:15:15 +0000574determines the actual amount of blurring that will take place. </p>
575
cristy82a2ff22015-05-12 16:41:32 +0000576<p>The <var>Radius</var> is only used to determine the size of the
cristyd2432012015-05-04 23:15:15 +0000577array which will hold the calculated Gaussian distribution. It should be an
578integer. If not given, or set to zero, IM will calculate the largest possible
579radius that will provide meaningful results for the Gaussian distribution.
580</p>
581
cristy82a2ff22015-05-12 16:41:32 +0000582<p>The larger the <var>Radius</var> the slower the
583operation is. However too small a <var>Radius</var>, and sever
584aliasing effects may result. As a guideline, <var>Radius</var>
585should be at least twice the <var>Sigma</var> value, though three
cristyd2432012015-05-04 23:15:15 +0000586times will produce a more accurate result. </p>
587
588<p>This option differs from <a href="command-line-options.html#gaussian-blur">-gaussian-blur</a> simply
589by taking advantage of the separability properties of the distribution. Here
590we apply a single-dimensional Gaussian matrix in the horizontal direction,
591then repeat the process in the vertical direction.</p>
592
593<p>The <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting will determine how
594pixels which are outside the image proper are blurred into the final result.
595</p>
596
597
598<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000599 <h3 class="magick-header">-blur <var>Width</var>[x<var>Height</var>[+<var>Angle</var>]]</h3>
cristyd2432012015-05-04 23:15:15 +0000600</div>
601
602<p class="magick-description">Variably blur an image according to the overlay mapping.</p>
603
604<p>Each pixel in the overlaid region is replaced with an Elliptical Weighted
605Average (EWA) of the source image, scaled according to the grayscale
606mapping. </p>
607
cristy82a2ff22015-05-12 16:41:32 +0000608<p>The ellipse is weighted with sigma set to the given <var>Width</var> and <var>Height</var>. The <var>Height</var>
609defaults to the <var>Width</var> for a normal circular Gaussian
610weighting. The <var>Angle</var> will rotate the ellipse from
cristyd2432012015-05-04 23:15:15 +0000611horizontal clock-wise. </p>
612
613<p>The <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting will determine how
614pixels which are outside the image proper are blurred into the final result.
615</p>
616
617
618<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000619 <h3 class="magick-header"><a id="border"></a>-border <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +0000620</div>
621
622<p class="magick-description">Surround the image with a border of color. </p>
623
624<p>Set the width and height using the <var>size</var> portion of the
625<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
626ignored. </p>
627
628<p>As of IM 6.7.8-8, the <var>geometry</var> arguments behave as follows:</p>
629
cristyb2cad532015-05-16 13:02:45 +0000630<dl class="dl-horizontal">
631<dt><var>value</var></dt>
632<dd>value is added to both left/right and top/bottom</dd>
633<dt><var>value-x</var><kbd>x</kbd></dt>
634<dd>value-x is added only to left/right and top/bottom are unchanged</dd>
635<dt><kbd>x</kbd><var>value-y</var></dt>
636<dd>value-y is added only to top/bottom and left/right are unchanged</dd>
637<dt><var>value-x</var><kbd>x</kbd><var>value-y</var></dt>
638<dd>value-x is added to left/right and value-y added to top/bottom</dd>
639<dt><var>value-x</var><kbd>x</kbd>0</dt>
640<dd>value-x is added only to left/right and top/bottom are unchanged</dd>
641<dt>0<kbd>x</kbd><var>value-y</var></dt>
642<dd>value-y is added only to top/bottom and left/right are unchanged</dd>
643<dt><var>value</var>%</dt>
644<dd>value % of width is added to left/right and value % of height is added to top/bottom</dd>
645<dt><var>value-x</var><kbd>x</kbd>%</dt>
646<dd>value-x % of width is added to left/right and to top/bottom</dd>
647<dt>x<var>value-y</var>%</dt>
648<dd>value-y % of height is added to top/bottom and to left/right</dd>
649<dt><var>value-x</var>%<kbd>x</kbd><var>value-y</var>%</dt>
650<dd>value-x % of width is added to left/right and value-y % of height is added to top/bottom</dd>
651<dt><var>value-x</var>%<kbd>x</kbd>0%</dt>
652<dd>value-x % of width is added to left/right and top/bottom are unchanged</dd>
653<dt>0%<kbd>x</kbd><var>value-y</var>%</dt>
654<dd>value-y % of height is added to top/bottom and left/right are unchanged</dd>
655</dl>
cristyd2432012015-05-04 23:15:15 +0000656
cristy82a2ff22015-05-12 16:41:32 +0000657<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 +0000658
cristy82a2ff22015-05-12 16:41:32 +0000659<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 +0000660'<code>Over</code>' composition method. It generates an image of the appropriate
661size colors by the current <a href="command-line-options.html#bordercolor">-bordercolor</a> before
662overlaying the original image in the center of this net image. This means that
663with the default compose method of '<code>Over</code>' any transparent parts may
664be replaced by the current <a href="command-line-options.html#bordercolor">-bordercolor</a> setting.</p>
665<p>See also the <a href="command-line-options.html#frame">-frame</a> option, which has more
666functionality.</p>
667
668<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000669 <h3 class="magick-header"><a id="bordercolor"></a>-bordercolor <var>color</var></h3>
cristyd2432012015-05-04 23:15:15 +0000670</div>
671
672<p class="magick-description">Set the border color.</p>
673
674<p>The color is specified using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p>
675
676<p>The default border color is <code>#DFDFDF</code>, <span style="background-color: #dfdfdf;">this shade of gray</span>.</p>
677
678<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000679 <h3 class="magick-header"><a id="borderwidth"></a>-borderwidth <var>geometry</var> </h3>
cristyd2432012015-05-04 23:15:15 +0000680</div>
681
682<p class="magick-description">Set the border width.</p>
683
684<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +0000685 <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 +0000686</div>
687
688<p class="magick-description">Adjust the brightness and/or contrast of the image.</p>
689
690<p>Brightness and Contrast values apply changes to the input image. They are
691not absolute settings. A brightness or contrast value of zero means no change.
692The range of values is -100 to +100 on each. Positive values increase the
693brightness or contrast and negative values decrease the brightness or contrast.
694To control only contrast, set the brightness=0. To control only brightness,
695set contrast=0 or just leave it off.</p>
696
697<p>You may also use <a href="command-line-options.html#fill">-channel</a> to control which channels to
698apply the brightness and/or contrast change. The default is to apply the same
699transformation to all channels.</p>
700
701<p>Brightness and Contrast arguments are converted to offset and slope of a
702linear transform and applied
703using <a href="command-line-options.html#fill">-function polynomial "slope,offset"</a>.</p>
704
705<p>The slope varies from 0 at contrast=-100 to almost vertical at
706contrast=+100. For brightness=0 and contrast=-100, the result are totally
707midgray. For brightness=0 and contrast=+100, the result will approach but
708not quite reach a threshold at midgray; that is the linear transformation
709is a very steep vertical line at mid gray.</p>
710
711<p>Negative slopes, i.e. negating the image, are not possible with this
712function. All achievable slopes are zero or positive.</p>
713
714<p>The offset varies from -0.5 at brightness=-100 to 0 at brightness=0 to +0.5
715at brightness=+100. Thus, when contrast=0 and brightness=100, the result is
716totally white. Similarly, when contrast=0 and brightness=-100, the result is
717totally black.</p>
718
719<p>As the range of values for the arguments are -100 to +100, adding the '%'
720symbol is no different than leaving it off.</p>
721
722<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000723 <h3 class="magick-header"><a id="cache"></a>-cache <var>threshold</var></h3>
cristyd2432012015-05-04 23:15:15 +0000724</div>
725
cristy82a2ff22015-05-12 16:41:32 +0000726<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 +0000727
728<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +0000729 <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 +0000730</div>
731
732<p class="magick-description">Canny edge detector uses a multi-stage algorithm to detect a wide range of edges in the image.</p>
733
734<p>The thresholds range from 0 to 100% (e.g. -canny 0x1+10%+30%) with {<var>+lower-percent</var>} &lt; {<var>+upper-percent</var>}. If {<var>+upper-percent</var>} is increased but {<var>+lower-percent</var>} remains the same, lesser edge components will be detected, but their lengths will be the same. If {<var>+lower-percent</var>} is increased but {<var>+upper-percent</var>} is the same, the same number of edge components will be detected but their lengths will be shorter. The default thresholds are shown. The <var>radius</var>x<var>sigma</var> controls a gaussian blur applied to the input image to reduce noise and smooth the edges.</p>
735
736<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000737 <h3 class="magick-header"><a id="caption"></a>-caption <var>string</var></h3>
cristyd2432012015-05-04 23:15:15 +0000738</div>
739
740<p class="magick-description">Assign a caption to an image.</p>
741
742<p>This option sets the caption meta-data of an image read in after this
743option has been given. To modify a caption of images already in memory use
744"<code><a href="command-line-options.html#set">-set</a> caption</code>". </p>
745
cristy82a2ff22015-05-12 16:41:32 +0000746<p>The caption can contain special format characters listed in the <a href="escape.html">Format and
cristyd2432012015-05-04 23:15:15 +0000747Print Image Properties</a>. These attributes are expanded when the caption
748is finally assigned to the individual images. </p>
749
750<p>If the first character of <var>string</var> is <var>@</var>, the image caption is read from a file titled by the
751remaining characters in the string. Comments read in from a file are literal;
752no embedded formatting characters are recognized.</p>
753
754<p>Caption meta-data is not visible on the image itself. To do that use the
755<a href="command-line-options.html#annotate">-annotate</a> or <a href="command-line-options.html#draw">-draw</a> options
756instead.</p>
757
758<p>For example,</p>
759
cristy29dc8652015-05-12 16:26:21 +0000760<pre>
761-caption "%m:%f %wx%h" bird.miff
762</pre>
cristyd2432012015-05-04 23:15:15 +0000763
764<p>produces an image caption of <code>MIFF:bird.miff 512x480</code> (assuming
765that the image <code>bird.miff</code> has a width of 512 and a height of
766480.</p>
767
768
769<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000770 <h3 class="magick-header"><a id="cdl"></a>-cdl <var>filename</var></h3>
cristyd2432012015-05-04 23:15:15 +0000771</div>
772
773<p class="magick-description">color correct with a color decision list.</p>
774
775<p>Here is an example color correction collection:</p>
776
777<pre>
778&lt;?xml version="1.0" encoding="UTF-8"?&gt;
779&lt;ColorCorrectionCollection xmlns="urn:ASC:CDL:v1.2"&gt;
780 &lt;ColorCorrection id="cc06668"&gt;
781 &lt;SOPNode&gt;
782 &lt;Slope&gt; 0.9 1.2 0.5 &lt;/Slope&gt;
783 &lt;Offset&gt; 0.4 -0.5 0.6 &lt;/Offset&gt;
784 &lt;Power&gt; 1.0 0.8 1.5 &lt;/Power&gt;
785 &lt;/SOPNode&gt;
786 &lt;SATNode&gt;
787 &lt;Saturation&gt; 0.85 &lt;/Saturation&gt;
788 &lt;/SATNode&gt;
789 &lt;/ColorCorrection&gt;
790&lt;/ColorCorrectionCollection&gt;
791</pre>
792
793<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000794 <h3 class="magick-header"><a id="channel"></a>-channel <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +0000795</div>
796
797<p class="magick-description">Specify those image color channels to which subsequent operators are limited.</p>
798
799<p>Choose from: <code>Red</code>, <code>Green</code>, <code>Blue</code>,
800<code>Alpha</code>, <code>Gray</code>, <code>Cyan</code>, <code>Magenta</code>,
801<code>Yellow</code>, <code>Black</code>, <code>Opacity</code>,
802<code>Index</code>, <code>RGB</code>, <code>RGBA</code>, <code>CMYK</code>, or
803<code>CMYKA</code>.</p>
804
805<p>The channels above can also be specified as a comma-separated list or can be
806abbreviated as a concatenation of the letters '<code>R</code>', '<code>G</code>',
807'<code>B</code>', '<code>A</code>', '<code>O</code>', '<code>C</code>',
808'<code>M</code>', '<code>Y</code>', '<code>K</code>'.
809
810For example, to only select the <code>Red</code> and <code>Blue</code> channels
811you can either use </p>
cristy29dc8652015-05-12 16:26:21 +0000812<pre>
813-channel Red,Blue
814</pre>
cristyd2432012015-05-04 23:15:15 +0000815<p>or you can use the short hand form</p>
cristy29dc8652015-05-12 16:26:21 +0000816<pre>
817-channel RB
818</pre>
cristyd2432012015-05-04 23:15:15 +0000819
820<p>All the channels that are present in an image can be specified using the
821special channel type <code>All</code>. Not all operators are 'channel capable',
822but generally any operators that are generally 'grey-scale' image operators,
823will understand this setting. See individual operator documentation. </p>
824
cristy82a2ff22015-05-12 16:41:32 +0000825<br>
cristyd2432012015-05-04 23:15:15 +0000826
827<p>On top of the normal channel selection an extra flag can be specified,
828'<code>Sync</code>'. This is turned on by default and if set means that
829operators that understand this flag should perform: cross-channel
830synchronization of the channels. If not specified, then most grey-scale
831operators will apply their image processing operations to each individual
832channel (as specified by the rest of the <a href="command-line-options.html#channel">-channel</a>
833setting) completely independently from each other. </p>
834
835<p>For example for operators such as <a href="command-line-options.html#auto-level">-auto-level</a> and
836<a href="command-line-options.html#auto-gamma">-auto-gamma</a> the color channels are modified
837together in exactly the same way so that colors will remain in-sync. Without
838it being set, then each channel is modified separately and
839independently, which may produce color distortion. </p>
840
841<p>The <a href="command-line-options.html#morphology">-morphology</a> '<code>Convolve</code>' method
842and the <a href="command-line-options.html#compose">-compose</a> mathematical methods, also understands
843the '<code>Sync</code>' flag to modify the behaviour of pixel colors according
844to the alpha channel (if present). That is to say it will modify the image
845processing with the understanding that fully-transparent colors should not
846contribute to the final result. </p>
847
848<p>Basically, by default, operators work with color channels in synchronous, and
849treats transparency as special, unless the <a href="command-line-options.html#channel">-channel</a>
850setting is modified so as to remove the effect of the '<code>Sync</code>' flag.
851How each operator does this depends on that operators current implementation.
852Not all operators understands this flag at this time, but that is changing.
853</p>
854
855<p>To print a complete list of channel types, use <a href="command-line-options.html#list">-list
856channel</a>.</p>
857
cristyd2432012015-05-04 23:15:15 +0000858<p>By default, ImageMagick sets <a href="command-line-options.html#channel">-channel</a> to the value
859'<code>RGBK,sync</code>', which specifies that operators act on all color
860channels except the transparency channel, and that all the color channels are
861to be modified in exactly the same way, with an understanding of transparency
cristy82a2ff22015-05-12 16:41:32 +0000862(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 +0000863
cristy82a2ff22015-05-12 16:41:32 +0000864<p>Options that are affected by the <a href="command-line-options.html#channel">-channel</a> setting
cristyd2432012015-05-04 23:15:15 +0000865include the following.
866
867<a href="command-line-options.html#auto-gamma">-auto-gamma</a>,
868<a href="command-line-options.html#auto-level">-auto-level</a>,
869<a href="command-line-options.html#black-threshold">-black-threshold</a>,
870<a href="command-line-options.html#blur">-blur</a>,
871<a href="command-line-options.html#clamp">-clamp</a>,
872<a href="command-line-options.html#clut">-clut</a>,
873<a href="command-line-options.html#combine">-combine</a>,
874<a href="command-line-options.html#composite">-composite</a> (Mathematical compose methods only),
875<a href="command-line-options.html#convolve">-convolve</a>,
876<a href="command-line-options.html#contrast-stretch">-contrast-stretch</a>,
877<a href="command-line-options.html#evaluate">-evaluate</a>,
878<a href="command-line-options.html#function">-function</a>,
879<a href="command-line-options.html#fx">-fx</a>,
880<a href="command-line-options.html#gaussian-blur">-gaussian-blur</a>,
881<a href="command-line-options.html#hald-clut">-hald-clut</a>,
882<a href="command-line-options.html#motion-blur">-motion-blur</a>,
883<a href="command-line-options.html#morphology">-morphology</a>,
884<a href="command-line-options.html#negate">-negate</a>,
885<a href="command-line-options.html#normalize">-normalize</a>,
886<a href="command-line-options.html#ordered-dither">-ordered-dither</a>,
887<a href="command-line-options.html#radial-blur">-radial-blur</a>,
888<a href="command-line-options.html#random-threshold">-random-threshold</a>,
889<a href="command-line-options.html#separate">-separate</a>,
890<a href="command-line-options.html#threshold">-threshold</a>, and
891<a href="command-line-options.html#white-threshold">-white-threshold</a>.
892</p>
893
cristy82a2ff22015-05-12 16:41:32 +0000894<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 +0000895default). These operators have yet to be made to understand the newer 'Sync'
896flag. </p>
897
898<p>For example <a href="command-line-options.html#threshold">-threshold</a> will by default gray-scale
cristy82a2ff22015-05-12 16:41:32 +0000899the image before thresholding, if no <a href="command-line-options.html#channel">-channel</a> setting
cristyd2432012015-05-04 23:15:15 +0000900has been defined. This is not 'Sync flag controlled, yet. </p>
901
cristy82a2ff22015-05-12 16:41:32 +0000902<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
903color 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 +0000904fully-transparent colors are treated as being fully-transparent, and thus any
905underlying 'hidden' color has no effect on the final results. Typically
906resulting in 'halo' effects. The newer <a href="command-line-options.html#morphology">-morphology</a>
907convolution equivalents however does have a understanding of the 'Sync' flag
908and will thus handle transparency correctly by default. </p>
909
910<p>As a alpha channel is optional within images, some operators will read the
911color channels of an image as a greyscale alpha mask, when the image has no
cristy82a2ff22015-05-12 16:41:32 +0000912alpha channel present, and the <a href="command-line-options.html#channel">-channel</a> setting tells
913the 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 +0000914
915
916
917<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000918 <h3 class="magick-header"><a id="charcoal"></a>-charcoal <var>factor</var></h3>
cristyd2432012015-05-04 23:15:15 +0000919</div>
920
921<p class="magick-description">Simulate a charcoal drawing.</p>
922
923<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000924 <h3 class="magick-header"><a id="chop"></a>-chop <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +0000925</div>
926
927<p class="magick-description">Remove pixels from the interior of an image.</p>
928
929<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>
930and <var>height</var> given in the of the <var>size</var>
931portion of the <var>geometry</var> argument give the number of
932columns and rows to remove. The <var>offset</var> portion of
933the <var>geometry</var> argument is influenced by
934a <a href="command-line-options.html#gravity">-gravity</a> setting, if present.</p>
935
936<p>The <a href="command-line-options.html#chop">-chop</a> option removes entire rows and columns,
937and moves the remaining corner blocks leftward and upward to close the gaps.</p>
938
939<p>While it can remove internal rows and columns of pixels, it is more
940typically used with as <a href="command-line-options.html#gravity">-gravity</a> setting and zero
cristy82a2ff22015-05-12 16:41:32 +0000941offsets 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 +0000942sides of the image. </p>
943
cristy82a2ff22015-05-12 16:41:32 +0000944<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 +0000945
946<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000947 <h3 class="magick-header"><a id="clamp"></a>-clamp</h3>
cristyd2432012015-05-04 23:15:15 +0000948</div>
949
950<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>
951
952<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000953 <h3 class="magick-header"><a id="clip"></a>-clip</h3>
cristyd2432012015-05-04 23:15:15 +0000954</div>
955
956<p class="magick-description">Apply the clipping path if one is present.</p>
957
958<p>If a clipping path is present, it is applied to subsequent operations.</p>
959
960<p>For example, in the command</p>
961
962<pre>
963convert cockatoo.tif -clip -negate negated.tif
964</pre>
965
966<p>only the pixels within the clipping path are negated.</p>
967
968<p>The <a href="command-line-options.html#clip">-clip</a> feature requires SVG support. If the SVG
969delegate library is not present, the option is ignored.</p>
970
971<p>Use <a href="command-line-options.html#clip">+clip</a> to disable clipping for subsequent operations.</p>
972
973<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000974 <h3 class="magick-header"><a id="clip-mask"></a>-clip-mask</h3>
cristyd2432012015-05-04 23:15:15 +0000975</div>
976
977<p class="magick-description">Clip the image as defined by this mask.</p>
978
979<p>Use the alpha channel of the current image as a mask. Any areas that is
980white is not modified by any of the 'image processing operators' that follow,
981until the mask is removed. Pixels in the black areas of the clip mask are
982modified per the requirements of the operator. </p>
983
984<p>In some ways this is similar to (though not the same) as defining
cristy82a2ff22015-05-12 16:41:32 +0000985a rectangular <a href="command-line-options.html#region">-region</a>, or using the negative of the
986mask (third) image in a three image <a href="command-line-options.html#composite">-composite</a>,
cristyd2432012015-05-04 23:15:15 +0000987operation. </p>
988
989<p>Use <a href="command-line-options.html#clip-mask">+clip-mask</a> to disable clipping for subsequent operations.</p>
990
991<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +0000992 <h3 class="magick-header"><a id="clip-path"></a>-clip-path <var>id</var></h3>
cristyd2432012015-05-04 23:15:15 +0000993</div>
994
995<p class="magick-description">Clip along a named path from the 8BIM profile.</p>
996
997<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>
998
999<p>Use <a href="command-line-options.html#clip-path">+clip-path</a> to disable clipping for subsequent operations.</p>
1000
1001<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001002 <h3 class="magick-header"><a id="clone"></a>-clone <var>index(s)</var></h3>
cristyd2432012015-05-04 23:15:15 +00001003</div>
1004
1005<p class="magick-description">make a clone of an image (or images).</p>
1006
1007<p>Inside parenthesis (where the operator is normally used) it will make a
1008clone of the images from the last 'pushed' image sequence, and adds them to
1009the end of the current image sequence. Outside parenthesis
1010(not recommended) it clones the images from the current image sequence. </p>
1011
1012<p>Specify the image by its index in the sequence. The first image is index
10130. Negative indexes are relative to the end of the sequence; for
1014example, <code>−1</code>
1015represents the last image of the sequence. Specify a range of images with a
1016dash (e.g. <code>0−4</code>). Separate multiple indexes with commas but no
1017spaces (e.g. <code>0,2,5</code>). A value of '<code>0−−1</code> will
1018effectively clone all the images. </p>
1019
1020<p>The <a href="command-line-options.html#clone">+clone</a> will simply make a copy of the last image
1021in the image sequence, and is thus equivalent to using a argument of
1022'<code>−1</code>'. </p>
1023
1024<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001025 <h3 class="magick-header"><a id="clut"></a>-clut</h3>
cristyd2432012015-05-04 23:15:15 +00001026</div>
1027
1028<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>
1029
1030<p>The second (LUT) image is ordinarily a gradient image containing the
1031histogram mapping of how each channel should be modified. Typically it is a
1032either a single row or column image of replacement color values. If larger
1033than a single row or column, values are taken from a diagonal line from
1034top-left to bottom-right corners.</p>
1035
cristy82a2ff22015-05-12 16:41:32 +00001036<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 +00001037LUT which is not the full length needed by the ImageMagick installed Quality
1038(Q) level. Good settings for this are the '<code>bilinear</code>' and
1039'<code>bicubic</code>' interpolation settings, which give smooth color
1040gradients, and the '<code>integer</code>' setting for a direct, unsmoothed
1041lookup of color values. </p>
1042
1043<p>This operator is especially suited to replacing a grayscale image with a
1044specific color gradient from the CLUT image. </p>
1045
1046<p>Only the channel values defined by the <a href="command-line-options.html#channel">-channel</a>
cristy82a2ff22015-05-12 16:41:32 +00001047setting 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
1048transparency (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
1049set, 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 +00001050as the other channels, implying that alpha/matte values are replaced using the
1051alpha/matte values of the original image. </p>
1052
1053<p>If either the image being modified, or the lookup image, contains no
cristy82a2ff22015-05-12 16:41:32 +00001054transparency (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 +00001055assumed that image represents a gray-scale gradient which is used for the
1056replacement alpha values. That is you can use a gray-scale CLUT image to
1057adjust a existing images alpha channel, or you can color a gray-scale image
1058using colors form CLUT containing the desired colors, including transparency.
1059</p>
1060
cristy82a2ff22015-05-12 16:41:32 +00001061<p>See also <a href="command-line-options.html#hald-clut">-hald-clut</a> which replaces colors
cristyd2432012015-05-04 23:15:15 +00001062according to the lookup of the full color RGB value from a 2D representation
1063of a 3D color cube. </p>
1064
1065
1066<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001067 <h3 class="magick-header"><a id="coalesce"></a>-coalesce</h3>
cristyd2432012015-05-04 23:15:15 +00001068</div>
1069
1070<p class="magick-description">Fully define the look of each frame of an GIF animation sequence, to form a 'film strip' animation.</p>
1071
1072<p>Overlay each image in an image sequence according to
1073its <a href="command-line-options.html#dispose">-dispose</a> meta-data, to reproduce the look of
1074an animation at each point in the animation sequence. All images should be
1075the same size, and are assigned appropriate GIF disposal settings for the
1076animation to continue working as expected as a GIF animation. Such frames
1077are more easily viewed and processed than the highly optimized GIF overlay
1078images. </p>
1079
1080<p>The animation can be re-optimized after processing using
1081the <a href="command-line-options.html#layers">-layers</a> method '<code>optimize</code>', although
1082there is no guarantee that the restored GIF animation optimization is
1083better than the original. </p>
1084
1085
1086<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001087 <h3 class="magick-header"><a id="colorize"></a>-colorize <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00001088</div>
1089
cristy82a2ff22015-05-12 16:41:32 +00001090<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 +00001091
1092<p>Specify the amount of colorization as a percentage. Separate colorization
1093values can be applied to the red, green, and blue channels of the image with
1094a comma-delimited list of colorization
1095values (e.g., <code>-colorize 0,0,50</code>).</p>
1096
1097<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001098 <h3 class="magick-header"><a id="colormap"></a>-colormap <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00001099</div>
1100
1101<p class="magick-description">Define the colormap type.</p>
1102
1103<p>The <var>type</var> can be <code>shared</code> or <code>private</code>.</p>
1104
1105<p>This option only applies when the default X server visual
1106is <code>PseudoColor</code> or <code>GrayScale</code>. Refer
1107to <a href="command-line-options.html#visual">-visual</a> for more details. By default,
1108a shared colormap is allocated. The image shares colors with
1109other X clients. Some image colors could be approximated,
1110therefore your image may look very different than intended.
1111If <code>private</code> is chosen, the image colors appear exactly
1112as they are defined. However, other clients may go <var>technicolor</var>
1113when the image colormap is installed.</p>
1114
1115<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001116 <h3 class="magick-header"><a id="colors"></a>-colors <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00001117</div>
1118
1119<p class="magick-description">Set the preferred number of colors in the image.</p>
1120
1121<p>The actual number of colors in the image may be less than your request,
1122but never more. Note that this a color reduction option. Images with fewer
1123unique colors than specified by <var>value</var> will have any
1124duplicate or unused colors removed. The ordering of an existing color
1125palette may be altered. When converting an image from color to grayscale,
1126it is more efficient to convert the image to the gray colorspace before
1127reducing the number of colors. Refer to
1128the <a href="quantize.html">
1129color reduction algorithm</a> for more details.</p>
1130
1131<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001132 <h3 class="magick-header"><a id="color-matrix"></a>-color-matrix <var>matrix</var></h3>
cristyd2432012015-05-04 23:15:15 +00001133</div>
1134
1135<p class="magick-description">apply color correction to the image.</p>
1136
1137<p>This option permits saturation changes, hue rotation, luminance to alpha,
1138and various other effects. Although variable-sized transformation matrices
1139can be used, typically one uses a 5x5 matrix for an RGBA image and a 6x6
1140for CMYKA (or RGBA with offsets). The matrix is similar to those used by
1141Adobe Flash except offsets are in column 6 rather than 5 (in support of
1142CMYKA images) and offsets are normalized (divide Flash offset by 255).</p>
1143
1144<p>As an example, to add contrast to an image with offsets, try this command:</p>
1145
1146<pre>
cristy29dc8652015-05-12 16:26:21 +00001147convert kittens.jpg -color-matrix \
1148 " 1.5 0.0 0.0 0.0, 0.0, -0.157 \
1149 0.0 1.5 0.0 0.0, 0.0, -0.157 \
1150 0.0 0.0 1.5 0.0, 0.0, -0.157 \
1151 0.0 0.0 0.0 1.0, 0.0, 0.0 \
1152 0.0 0.0 0.0 0.0, 1.0, 0.0 \
1153 0.0 0.0 0.0 0.0, 0.0, 1.0" kittens.png
cristyd2432012015-05-04 23:15:15 +00001154</pre>
1155<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001156 <h3 class="magick-header"><a id="colorspace"></a>-colorspace <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00001157</div>
1158
1159<p class="magick-description">Set the image colorspace.</p>
1160
1161<p>Choices are:</p>
1162
1163<pre>
cristy29dc8652015-05-12 16:26:21 +00001164CMY CMYK Gray HCL
1165HCLp HSB HSI HSL
1166HSV HWB Lab LCHab
1167LCHuv LMS Log Luv
1168OHTA Rec601YCbCr Rec709YCbCr RGB
1169scRGB sRGB Transparent xyY
1170XYZ YCbCr YCC YDbDr
1171YIQ YPbPr YUV
cristyd2432012015-05-04 23:15:15 +00001172</pre>
1173
1174<p>To print a complete list of colorspaces, use <a href="command-line-options.html#list">-list colorspace</a>.</p>
1175
1176<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>
1177
1178<table class="table table-condensed table-striped">
1179 <caption>Conversion of RGB to Other Color Spaces</caption>
1180 <tr><th valign="middle">CMY</th></tr>
1181 <tr><td valign="middle">C=<var>QuantumRange</var>−R</td></tr>
1182 <tr><td valign="middle">M=<var>QuantumRange</var>−G</td></tr>
1183 <tr><td valign="middle">Y=<var>QuantumRange</var>−B</td></tr>
1184 <tr><th valign="middle">CMYK — starts with CMY from above</th></tr>
1185 <tr><td valign="middle">K=min(C,Y,M)</td></tr>
1186 <tr><td valign="middle">C=<var>QuantumRange</var>*(C−K)/(<var>QuantumRange</var>−K)</td></tr>
1187 <tr><td valign="middle">M=<var>QuantumRange</var>*(M−K)/(<var>QuantumRange</var>−K)</td></tr>
1188 <tr><td valign="middle">Y=<var>QuantumRange</var>*(Y−K)/(<var>QuantumRange</var>−K)</td></tr>
1189
1190 <tr><th valign="middle">Gray</th></tr>
1191 <tr><td valign="middle">Gray = 0.298839*R+0.586811*G+0.114350*B</td></tr>
1192
1193 <tr><th valign="middle">HSB — Hue, Saturation, Brightness; like a cone peak downward</th></tr>
1194 <tr><td valign="middle">H=angle around perimeter (0 to 360 deg); H=0 is red; increasing angles toward green</td></tr>
1195 <tr><td valign="middle">S=distance from axis outward</td></tr>
1196 <tr><td valign="middle">B=distance along axis from bottom upward; B=max(R,G,B); <var>intensity-like</var></td></tr>
1197
1198 <tr><th valign="middle">HSL — Hue, Saturation, Lightness; like a double cone end-to-end with peaks at very top and bottom</th></tr>
1199 <tr><td valign="middle">H=angle around perimeter (0 to 360 deg); H=0 is red; increasing angles toward green</td></tr>
1200 <tr><td valign="middle">S=distance from axis outward</td></tr>
1201 <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>
1202
1203 <tr><th valign="middle">HWB — Hue, Whiteness, Blackness</th></tr>
1204 <tr><td valign="middle">Hue (complicated equation)</td></tr>
1205 <tr><td valign="middle">Whiteness (complicated equation)</td></tr>
1206 <tr><td valign="middle">Blackness (complicated equation)</td></tr>
1207
1208 <tr><th valign="middle">LAB</th></tr>
1209 <tr><td valign="middle">L (complicated equation relating X,Y,Z)</td></tr>
1210 <tr><td valign="middle">A (complicated equation relating X,Y,Z)</td></tr>
1211 <tr><td valign="middle">B (complicated equation relating X,Y,Z)</td></tr>
1212
1213 <tr><th valign="middle">LOG</th></tr>
1214 <tr><td valign="middle">I1 (complicated equation involving logarithm of R)</td></tr>
1215 <tr><td valign="middle">I2 (complicated equation involving logarithm of G)</td></tr>
1216 <tr><td valign="middle">I3 (complicated equation involving logarithm of B)</td></tr>
1217
1218 <tr><th valign="middle">OHTA — approximates principal components transformation</th></tr>
1219 <tr><td valign="middle">I1=0.33333*R+0.33334*G+0.33333*B; <var>intensity-like</var></td></tr>
1220 <tr><td valign="middle">I2=(0.50000*R+0.00000*G−0.50000*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1221 <tr><td valign="middle">I3=(−0.25000*R+0.50000*G−0.25000*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1222
1223 <tr><th valign="middle">Rec601Luma</th></tr>
1224 <tr><td valign="middle">Gray = 0.298839*R+0.586811*G+0.114350*B</td></tr>
1225
1226 <tr><th valign="middle">Rec601YCbCr</th></tr>
1227 <tr><td valign="middle">Y=0.2988390*R+0.5868110*G+0.1143500*B; <var>intensity-like</var></td></tr>
1228 <tr><td valign="middle">Cb=(−0.168736*R-0.331264*G+0.500000*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1229 <tr><td valign="middle">Cr=(0.500000*R−0.418688*G−0.081312*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1230
1231 <tr><th valign="middle">Rec709Luma</th></tr>
1232 <tr><td valign="middle">Gray=0.212656*R+0.715158*G+0.072186*B</td></tr>
1233
1234 <tr><th valign="middle">Rec709YCbCr</th></tr>
1235 <tr><td valign="middle">Y=0.212656*R+0.715158*G+0.072186*B; <var>intensity-like</var></td></tr>
1236 <tr><td valign="middle">Cb=(−0.114572*R−0.385428*G+0.500000*B)+(<var>QuantumRange</var>+1)/2</td></tr>
1237 <tr><td valign="middle">Cr=(0.500000*R−0.454153*G−0.045847*B)+(<var>QuantumRange</var>+1)/2</td></tr>
1238
1239 <tr><th valign="middle">sRGB</th></tr>
1240 <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>
1241 <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>
1242 <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>
1243
1244 <tr><th valign="middle">XYZ</th></tr>
1245 <tr><td valign="middle">X=0.4124564*R+0.3575761*G+0.1804375*B</td></tr>
1246 <tr><td valign="middle">Y=0.2126729*R+0.7151522*G+0.0721750*B</td></tr>
1247 <tr><td valign="middle">Z=0.0193339*R+0.1191920*G+0.9503041*B</td></tr>
1248
1249 <tr><th valign="middle">YCC</th></tr>
1250 <tr><td valign="middle">Y=(0.298839*R+0.586811*G+0.114350*B) (with complicated scaling); <var>intensity-like</var></td></tr>
1251 <tr><td valign="middle">C1=(−0.298839*R−0.586811*G+0.88600*B) (with complicated scaling)</td></tr>
1252 <tr><td valign="middle">C2=(0.70100*R−0.586811*G−0.114350*B) (with complicated scaling)</td></tr>
1253
1254 <tr><th valign="middle">YCbCr</th></tr>
1255 <tr><td valign="middle">Y=0.2988390*R+0.5868110*G+0.1143500*B; <var>intensity-like</var></td></tr>
1256 <tr><td valign="middle">Cb=(−0.168736*R−0.331264*G+0.500000*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1257 <tr><td valign="middle">Cr=(0.500000*R−0.418688*G−0.081312*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1258
1259 <tr><th valign="middle">YIQ</th></tr>
1260 <tr><td valign="middle">Y=0.298839*R+0.586811*G+0.114350*B; <var>intensity-like</var></td></tr>
1261 <tr><td valign="middle">I=(0.59600*R−0.27400*G−0.32200*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1262 <tr><td valign="middle">Q=(0.21100*R−0.52300*G+0.31200*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1263
1264 <tr><th valign="middle">YPbPr</th></tr>
1265 <tr><td valign="middle">Y=0.2988390*R+0.5868110*G+0.1143500*B; <var>intensity-like</var></td></tr>
1266 <tr><td valign="middle">Pb=(−0.168736*R−0.331264*G+0.500000*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1267 <tr><td valign="middle">Pr=(0.500000*R−0.418688*G−0.081312*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1268
1269 <tr><th valign="middle">YUV</th></tr>
1270 <tr><td valign="middle">Y=0.298839*R+0.586811*G+0.114350*B; <var>intensity-like</var></td></tr>
1271 <tr><td valign="middle">U=(−0.14740*R−0.28950*G+0.43690*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1272 <tr><td valign="middle">V=(0.61500*R−0.51500*G−0.10000*B)*(<var>QuantumRange</var>+1)/2</td></tr>
1273</table>
1274
1275<p>Note the scRGB colorspace requires HDRI support otherwise it behaves just like linear RGB.</p>
1276
1277<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001278 <h3 class="magick-header"><a id="combine"></a>-combine</h3>
cristyd2432012015-05-04 23:15:15 +00001279</div>
1280
1281<p class="magick-description">Combine one or more images into a single image.</p>
1282
1283<p>The channels (previously set by <a href="command-line-options.html#channel">-channel</a>) of the
1284combined image are taken from the grayscale values of each image in the
1285sequence, in order. For the default -channel setting of <code>RGB</code>, this
1286means the first image is assigned to the <code>Red</code> channel, the second
1287to the <code>Green</code> channel, the third to the <code>Blue</code>.</p>
1288
cristy82a2ff22015-05-12 16:41:32 +00001289<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 +00001290Thus, in the following example, the final image should be a copy of the
1291original. </p>
1292
1293<pre>
1294convert original.png -channel RGB -separate sepimage.png
1295convert sepimage-0.png sepimage-1.png sepimage-2.png -channel RGB \
1296 -combine imagecopy.png
1297</pre>
1298
1299<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001300 <h3 class="magick-header"><a id="comment"></a>-comment <var>string</var></h3>
cristyd2432012015-05-04 23:15:15 +00001301</div>
1302
1303<p class="magick-description">Embed a comment in an image.</p>
1304
1305<p>This option sets the comment meta-data of an image read in after this
1306option has been given. To modify a comment of images already in memory use
1307"<code><a href="command-line-options.html#set">-set</a> comment</code>". </p>
1308
cristy82a2ff22015-05-12 16:41:32 +00001309<p>The comment can contain special format characters listed in the <a href="escape.html">Format and
cristyd2432012015-05-04 23:15:15 +00001310Print Image Properties</a>. These attributes are expanded when the comment
1311is finally assigned to the individual images. </p>
1312
1313<p>If the first character of <var>string</var> is <var>@</var>, the image comment is read from a file titled by the
1314remaining characters in the string. Comments read in from a file are literal;
1315no embedded formatting characters are recognized.</p>
1316
1317<p>Comment meta-data are not visible on the image itself. To do that use the
1318<a href="command-line-options.html#annotate">-annotate</a> or <a href="command-line-options.html#draw">-draw</a> options
1319instead.</p>
1320
1321<p>For example,</p>
1322
cristy29dc8652015-05-12 16:26:21 +00001323<pre>
1324-comment "%m:%f %wx%h" bird.miff
1325</pre>
cristyd2432012015-05-04 23:15:15 +00001326
1327<p>produces an image comment of <code>MIFF:bird.miff 512x480</code> (assuming
1328that the image <code>bird.miff</code> has a width of 512 and a height of
1329480.</p>
1330
1331<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001332 <h3 class="magick-header"><a id="compare"></a>-compare</h3>
cristyd2432012015-05-04 23:15:15 +00001333</div>
1334
1335<p class="magick-description">mathematically and visually annotate the difference between an image and its reconstruction</p>
1336
1337<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>
1338
1339<pre>
cristy82a2ff22015-05-12 16:41:32 +00001340convert image.png reference.png -metric RMSE -compare \ <br> difference.png
cristyd2432012015-05-04 23:15:15 +00001341</pre>
1342
1343<p>To get the metric value use the string format "%[distortion]".</p>
1344
1345<pre>
1346convert image.png reference.png -metric RMSE -compare -format \
1347 "%[distortion]" info:
1348</pre>
1349
1350<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001351 <h3 class="magick-header"><a id="complex"></a>-complex <var>operator</var></h3>
cristyd2432012015-05-04 23:15:15 +00001352</div>
1353
1354<p class="magick-description">perform complex mathematics on an image sequence</p>
1355
1356Choose from these operators:
1357
1358<pre>
cristy29dc8652015-05-12 16:26:21 +00001359add
1360conjugate
1361divide
1362magnuitude-phase
1363multiply
1364real-imaginary
1365subtract
cristyd2432012015-05-04 23:15:15 +00001366</pre>
1367
1368<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>
1369
1370<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001371 <h3 class="magick-header"><a id="compose"></a>-compose <var>operator</var></h3>
cristyd2432012015-05-04 23:15:15 +00001372</div>
1373
1374<p class="magick-description">Set the type of image composition.</p>
1375
1376<p>See <a href="compose.html">Alpha Compositing</a> for
1377a detailed discussion of alpha compositing.</p>
1378
1379<p>This setting effects image processing operators that merge two (or more)
1380images together in some way. This includes the operators,
1381<a href="command-line-options.html#composite">-compare</a>,
1382<a href="command-line-options.html#composite">-composite</a>,
1383<a href="command-line-options.html#layers">-layers</a> composite,
1384<a href="command-line-options.html#flatten">-flatten</a>,
1385<a href="command-line-options.html#mosaic">-mosaic</a>,
1386<a href="command-line-options.html#layers">-layers</a> merge,
1387<a href="command-line-options.html#border">-border</a>,
1388<a href="command-line-options.html#frame">-frame</a>,
1389and <a href="command-line-options.html#extent">-extent</a>. </p>
1390
1391<p>It is also one of the primary options for the "<code>composite</code>"
1392command. </p>
1393
1394
1395<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001396 <h3 class="magick-header"><a id="composite"></a>-composite</h3>
cristyd2432012015-05-04 23:15:15 +00001397</div>
1398
1399<p class="magick-description">Perform alpha composition on two images and an optional mask</p>
1400
1401<p>Take the first image 'destination' and overlay the second 'source' image
1402according to the current <a href="command-line-options.html#compose">-compose</a> setting. The location
cristy82a2ff22015-05-12 16:41:32 +00001403of 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 +00001404settings. </p>
1405
1406<p>If a third image is given this is treated as a gray-scale blending 'mask' image
1407relative to the first 'destination' image. This mask is blended with the
1408source image. However for the '<code>displace</code>' compose method, the
1409mask is used to provide a separate Y-displacement image instead. </p>
1410
1411<p>If a <a href="command-line-options.html#compose">-compose</a> method requires extra numerical
cristy82a2ff22015-05-12 16:41:32 +00001412arguments 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 +00001413appropriately for the compose method. </p>
1414
1415<p>Some <a href="command-line-options.html#compose">-compose</a> methods can modify the 'destination'
cristy82a2ff22015-05-12 16:41:32 +00001416image 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 +00001417to '<code>false</code>'. </p>
1418
1419<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>
1420
1421
1422<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001423 <h3 class="magick-header"><a id="compress"></a>-compress <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00001424</div>
1425
1426<p class="magick-description">Use pixel compression specified by <var>type</var> when writing the image.</p>
1427
cristy82a2ff22015-05-12 16:41:32 +00001428<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 +00001429
1430<p>To print a complete list of compression types, use <a href="command-line-options.html#list">-list
1431compress</a>.</p>
1432
1433<p>Specify <a href="command-line-options.html#compress">+compress</a> to store the binary image in an
1434uncompressed format. The default is the compression type of the specified
1435image file.</p>
1436
1437<p>If <code>LZW</code> compression is specified but LZW compression has not been
1438enabled, the image data is written in an uncompressed LZW format that can be
1439read by LZW decoders. This may result in larger-than-expected GIF files.</p>
1440
1441<p><code>Lossless</code> refers to lossless JPEG, which is only available if the
1442JPEG library has been patched to support it. Use of lossless JPEG is generally
1443not recommended.</p>
1444
1445<p>
1446When writing an ICO file, you may request that the images be encoded in
1447PNG format, by specifying <code>Zip</code> compression.</p>
1448
1449<p>
1450When writing a JNG file, specify <code>Zip</code> compression to request that
1451the alpha channel be encoded in PNG "IDAT" format, or <code>JPEG</code>
1452to request that it be encoded in JPG "JDAA" format.</p>
1453
1454<p>Use the <a href="command-line-options.html#quality">-quality</a> option to set the compression level
1455to be used by JPEG, PNG, MIFF, and MPEG encoders.
1456Use the <a href="command-line-options.html#sampling-factor">-sampling-factor</a> option to set the
1457sampling factor to be used by JPEG, MPEG, and YUV encoders for down-sampling
1458the chroma channels.</p>
1459
1460<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001461 <h3 class="magick-header"><a id="connected-components"></a>-connected-components <var>connectivity</var></h3>
cristyd2432012015-05-04 23:15:15 +00001462</div>
1463
1464<p class="magick-description">connected-components uniquely labeled, choose from 4 or 8 way connectivity.</p>
1465
cristy82a2ff22015-05-12 16:41:32 +00001466<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 +00001467
1468<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001469 <h3 class="magick-header"><a id="contrast"></a>-contrast</h3>
cristyd2432012015-05-04 23:15:15 +00001470</div>
1471
1472<p class="magick-description">Enhance or reduce the image contrast.</p>
1473
1474<p>This option enhances the intensity differences between the lighter and
1475darker elements of the image. Use <a href="command-line-options.html#contrast">-contrast</a> to enhance
1476the image or <a href="command-line-options.html#contrast">+contrast</a> to reduce the image
1477contrast.</p>
1478
1479<p>For a more pronounced effect you can repeat the option:</p>
1480
1481<pre>
1482convert rose: -contrast -contrast rose_c2.png
1483</pre>
1484
1485<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00001486 <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 +00001487</div>
1488
1489<p class="magick-description">Increase the contrast in an image by <var>stretching</var> the range of intensity values.</p>
1490
1491<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 +00001492<var>black-point %</var> pixels and white-out at most <var>white-point %</var> pixels.</p>
cristyd2432012015-05-04 23:15:15 +00001493
cristy82a2ff22015-05-12 16:41:32 +00001494<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 +00001495minus 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>
1496
1497<p>Note that <code>-contrast-stretch 0</code> will modify the image such that
1498the 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 +00001499clipping 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 +00001500prior to ImageMagick 6.4.7-0, <code>-contrast-stretch 2%x99%</code>).</p>
1501
1502<p>Internally operator works by creating a histogram bin, and then uses that
1503bin to modify the image. As such some colors may be merged together when they
1504originally fell into the same 'bin'. </p>
1505
1506<p>All the channels are normalized in concert by the came amount so as to
cristy82a2ff22015-05-12 16:41:32 +00001507preserve color integrity, when the default <a href="command-line-options.html#channel">+channel</a>
1508setting is in use. Specifying any other <a href="command-line-options.html#channel">-channel</a>
cristyd2432012015-05-04 23:15:15 +00001509setting will normalize the RGB channels independently.</p>
1510
cristy82a2ff22015-05-12 16:41:32 +00001511<p>See also <a href="command-line-options.html#auto-level">-auto-level</a> for a 'perfect'
cristyd2432012015-05-04 23:15:15 +00001512normalization of mathematical images. </p>
1513
1514<p>This operator is under review for re-development. </p>
1515
1516
1517<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001518 <h3 class="magick-header"><a id="convolve"></a>-convolve <var>kernel</var></h3>
cristyd2432012015-05-04 23:15:15 +00001519</div>
1520
1521<p class="magick-description">Convolve an image with a user-supplied convolution kernel.</p>
1522
1523<p>The <var>kernel</var> is a matrix specified as
1524a comma-separated list of integers (with no spaces), ordered left-to right,
1525starting with the top row. Presently, only odd-dimensioned kernels are
1526supported, and therefore the number of entries in the specified <var>kernel</var> must be 3<sup>2</sup>=9, 5<sup>2</sup>=25,
15277<sup>2</sup>=49, etc. </p>
1528
cristy82a2ff22015-05-12 16:41:32 +00001529<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 +00001530positive and negative results are relative to a user-specified bias value.
1531This is important for non-HDRI compilations of ImageMagick when dealing with
1532convolutions that contain negative as well as positive values. This is
1533especially the case with convolutions involving high pass filters or edge
1534detection. Without an output bias, the negative values is clipped at zero.
1535</p>
1536
cristy82a2ff22015-05-12 16:41:32 +00001537<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 +00001538negative results without clipping to the color value range (0..QuantumRange).
cristy82a2ff22015-05-12 16:41:32 +00001539See the discussion on HDRI implementations of ImageMagick on the page <a href="high-dynamic-range.html">High
1540Dynamic-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 +00001541<a href="http://en.wikipedia.org/wiki/High_dynamic_range_imaging">Wikipedia</a>
1542entry. </p>
1543
1544
1545<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001546 <h3 class="magick-header"><a id="crop"></a>-crop <var>geometry</var>{<var>@</var>}{<var>!</var>}</h3>
cristyd2432012015-05-04 23:15:15 +00001547</div>
1548
1549<p class="magick-description">Cut out one or more rectangular regions of the image.</p>
1550
1551<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
1552
1553<p>The <var>width</var> and <var>height</var> of the <var>geometry</var> argument give the size of the image that remains
1554after cropping, and <var>x</var> and <var>y</var> in the
1555<var>offset</var> (if present) gives the location of the top left
1556corner of the cropped image with respect to the original image. To specify the
1557amount to be removed, use <a href="command-line-options.html#shave">-shave</a> instead.</p>
1558
1559<p>If the <var>x</var> and <var>y</var> offsets are
1560present, a single image is generated, consisting of the pixels from the
1561cropping region. The offsets specify the location of the upper left corner of
1562the cropping region measured downward and rightward with respect to the upper
1563left corner of the image. If the <a href="command-line-options.html#gravity">-gravity</a> option is
1564present with <code>NorthEast</code>, <code>East</code>, or <code>SouthEast</code>
1565gravity, it gives the distance leftward from the right edge of the image to
cristy82a2ff22015-05-12 16:41:32 +00001566the 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 +00001567<code>South</code>, or <code>SouthEast</code> gravity, the distance is measured
1568upward between the bottom edges.</p>
1569
1570<p>If the <var>x</var> and <var>y</var> offsets are
1571omitted, a set of tiles of the specified geometry, covering the entire input
1572image, is generated. The rightmost tiles and the bottom tiles are smaller if
1573the specified geometry extends beyond the dimensions of the input image.</p>
1574
1575<p>You can add the <var>@</var> to the geometry argument to equally divide the image into the number of tiles generated.</p>
1576
1577<p>By adding a exclamation character flag to the geometry argument, the
1578cropped images virtual canvas page size and offset is set as if the
1579geometry argument was a viewport or window. This means the canvas page size
1580is set to exactly the same size you specified, the image offset set
1581relative top left corner of the region cropped. </p>
1582
1583<p>If the cropped image 'missed' the actual image on its virtual canvas, a
1584special single pixel transparent 'missed' image is returned, and a 'crop
1585missed' warning given. </p>
1586
cristy82a2ff22015-05-12 16:41:32 +00001587<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 +00001588cropping the image to ensure the crop coordinate frame is relocated to the
1589upper-left corner of the visible image.
1590
cristy82a2ff22015-05-12 16:41:32 +00001591Similarly you may want to use <a href="command-line-options.html#repage">+repage</a> after cropping to
cristyd2432012015-05-04 23:15:15 +00001592remove the page offset that will be left behind. This is especially true when
1593you are going to write to an image format such as PNG that supports an image
1594offset.</p>
1595
1596<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001597 <h3 class="magick-header"><a id="cycle"></a>-cycle <var>amount</var></h3>
cristyd2432012015-05-04 23:15:15 +00001598</div>
1599
1600<p class="magick-description">displace image colormap by amount.</p>
1601
1602<p><var>Amount</var> defines the number of positions each
1603colormap entry is shifted.</p>
1604
1605
1606<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001607 <h3 class="magick-header"><a id="debug"></a>-debug <var>events</var></h3>
cristyd2432012015-05-04 23:15:15 +00001608</div>
1609
1610<p class="magick-description">enable debug printout.</p>
1611
1612<p>The <code>events</code> parameter specifies which events are to be logged. It
1613can be either <code>None</code>, <code>All</code>, <code>Trace</code>, or
1614a comma-separated list consisting of one or more of the following domains:
1615<code>Accelerate</code>, <code>Annotate</code>, <code>Blob</code>, <code>Cache</code>,
1616<code>Coder</code>, <code>Configure</code>, <code>Deprecate</code>,
1617<code>Exception</code>, <code>Locale</code>, <code>Render</code>,
1618<code>Resource</code>, <code>Security</code>, <code>TemporaryFile</code>,
1619<code>Transform</code>, <code>X11</code>, or <code>User</code>. </p>
1620
1621
1622<p>For example, to log cache and blob events, use.</p>
1623
1624<pre>
1625convert -debug "Cache,Blob" rose: rose.png
1626</pre>
1627
1628<p>The <code>User</code> domain is normally empty, but developers can log user
1629events in their private copy of ImageMagick.</p>
1630
1631<p>To print the complete list of debug methods, use <a href="command-line-options.html#list">-list
1632debug</a>.</p>
1633
1634<p>Use the <a href="command-line-options.html#log">-log</a> option to specify the format for debugging
1635output.</p>
1636
1637<p>Use <a href="command-line-options.html#debug">+debug</a> to turn off all logging.</p>
1638
cristy82a2ff22015-05-12 16:41:32 +00001639<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 +00001640environment variable are the same as for the <a href="command-line-options.html#debug">-debug</a>
1641option.</p>
1642
1643
1644<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001645 <h3 class="magick-header"><a id="decipher"></a>-decipher <var>filename</var></h3>
cristyd2432012015-05-04 23:15:15 +00001646</div>
1647
1648<p class="magick-description">Decipher and restore pixels that were previously transformed by <a href="command-line-options.html#encipher">-encipher</a>.</p>
1649
1650<p>Get the passphrase from the file specified by <var>filename</var>.</p>
1651
cristy82a2ff22015-05-12 16:41:32 +00001652<p>For more information, see the webpage, <a href="http://www.imagemagick.org/www/cipher.html">ImageMagick: Encipher or
cristyd2432012015-05-04 23:15:15 +00001653Decipher an Image</a>.</p>
1654
1655
1656<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001657 <h3 class="magick-header"><a id="deconstruct"></a>-deconstruct</h3>
cristyd2432012015-05-04 23:15:15 +00001658</div>
1659
1660<p class="magick-description">find areas that has changed between images </p>
1661
cristy82a2ff22015-05-12 16:41:32 +00001662<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 +00001663a smaller image of just the area that changed relative to the previous image.
1664</p>
1665
1666<p>The resulting sequence of images can be used to optimize an animation
1667sequence, though will not work correctly for GIF animations when parts of the
1668animation can go from opaque to transparent. </p>
1669
1670<p>This option is actually equivalent to the <a href="command-line-options.html#layers">-layers</a>
1671method '<code>compare-any</code>'. </p>
1672
1673
1674<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00001675 <h3 class="magick-header"><a id="define"></a>-define <var>key</var>{<var>=value</var>}<var>...</var></h3>
cristyd2432012015-05-04 23:15:15 +00001676</div>
1677
1678<p class="magick-description">add specific global settings generally used to control coders and image processing operations.</p>
1679
1680<p>This option creates one or more definitions for coders and decoders to use
1681while reading and writing image data. Definitions are generally used to
1682control image file format coder modules, and image processing operations,
cristy82a2ff22015-05-12 16:41:32 +00001683beyond 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 +00001684as "Artifacts". </p>
1685
1686<p>If <var>value</var> is missing for a definition, an empty-valued
1687definition of a flag is created with that name. This used to control on/off
1688options. Use <a href="command-line-options.html#define">+define key</a> to remove definitions
1689previously created. Use <a href="command-line-options.html#define">+define "*"</a> to remove all
1690existing definitions.</p>
1691
cristy82a2ff22015-05-12 16:41:32 +00001692<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 +00001693Properties</a> in the defined value. </p>
1694
1695<p>The <var>option</var> and <var>key</var> are case-independent (they are
1696converted to lowercase for use within the decoders) while the <var>value</var>
1697is case-dependent.</p>
1698
1699<p>Such settings are global in scope, and affect all images and operations. </p>
1700
1701<p>The following definitions are just some of the artifacts that are
1702available:</p>
1703
cristy29dc8652015-05-12 16:26:21 +00001704<table class="table table-condensed table-striped">
1705 <tr>
1706 <td>bmp:format=<var>value</var></td>
1707 <td> valid values are <var>bmp2</var>, <var>bmp3</var>,
cristyd2432012015-05-04 23:15:15 +00001708 and <var>bmp4</var>. This option can be useful when the
1709 method of prepending "BMP2:" to the output filename is inconvenient or
cristy29dc8652015-05-12 16:26:21 +00001710 is not available, such as when using the <a href="mogrify.html">mogrify</a> utility.</td>
1711 </tr>
cristyd2432012015-05-04 23:15:15 +00001712
cristy29dc8652015-05-12 16:26:21 +00001713 <tr>
1714 <td>complex:snr=<var>value</var></td>
cristy82a2ff22015-05-12 16:41:32 +00001715 <td>Set the divide SNR constant<a href="command-line-options.html#complex">-complex</a></td>
cristy29dc8652015-05-12 16:26:21 +00001716 </tr>
cristyd2432012015-05-04 23:15:15 +00001717
cristy29dc8652015-05-12 16:26:21 +00001718 <tr>
1719 <td>compose:args=<var>arguments</var></td>
1720 <td>Sets certain compose argument values when using convert ... -compose ...
cristy82a2ff22015-05-12 16:41:32 +00001721 -composite. See <a href="compose.html">Image Composition</a></td>
cristy29dc8652015-05-12 16:26:21 +00001722 </tr>
cristyd2432012015-05-04 23:15:15 +00001723
cristy29dc8652015-05-12 16:26:21 +00001724 <tr>
1725 <td>convolve:scale=<var>{kernel_scale}[!^] [,{origin_addition}] [%]</var></td>
1726 <td>Defines the kernel scaling. The special flag ! automatically scales to
cristyd2432012015-05-04 23:15:15 +00001727 full dynamic range. The ! flag can be used in combination with a factor or
1728 percent. The factor or percent is then applied after the automatic scaling.
1729 An example is 50%!. This produces a result 50% darker than full dynamic
1730 range scaling. The ^ flag assures the kernel is 'zero-summing', for
1731 example when some values are positive and some are negative as in edge
1732 detection kernels. The origin addition adds that value to the center
1733 pixel of the kernel. This produces and effect that is like adding the image
1734 that many times to the result of the filtered image. The typical value
1735 is 1 so that the original image is added to the result of the convolution.
cristy29dc8652015-05-12 16:26:21 +00001736 The default is 0.</td>
1737 </tr>
cristyd2432012015-05-04 23:15:15 +00001738
cristy29dc8652015-05-12 16:26:21 +00001739 <tr>
1740 <td>convolve:showkernel=<var>1</var></td>
cristy82a2ff22015-05-12 16:41:32 +00001741 <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 +00001742 </tr>
cristyd2432012015-05-04 23:15:15 +00001743
cristy29dc8652015-05-12 16:26:21 +00001744 <tr>
1745 <td>dcm:display-range=<var>reset</var></td>
1746 <td>Sets the display range to the minimum and maximum pixel values for the
1747 DCM image format.</td>
1748 </tr>
cristyd2432012015-05-04 23:15:15 +00001749
cristy29dc8652015-05-12 16:26:21 +00001750 <tr>
1751 <td>dds:cluster-fit=<var>true|false</var></td>
1752 <td>Enables the dds cluster-fit.</td>
1753 </tr>
cristyd2432012015-05-04 23:15:15 +00001754
cristy29dc8652015-05-12 16:26:21 +00001755 <tr>
1756 <td>dds:compression=<var>dxt1|dxt5|none</var></td>
1757 <td>Sets the dds compression.</td>
1758 </tr>
cristyd2432012015-05-04 23:15:15 +00001759
cristy29dc8652015-05-12 16:26:21 +00001760 <tr>
1761 <td>dds:mipmaps=<var>value</var></td>
1762 <td>Sets the dds number of mipmaps.</td>
1763 </tr>
cristyd2432012015-05-04 23:15:15 +00001764
cristy29dc8652015-05-12 16:26:21 +00001765 <tr>
1766 <td>dds:weight-by-alpha=<var>true|false</var></td>
1767 <td>Enables the dds alpha weighting.</td>
1768 </tr>
cristyd2432012015-05-04 23:15:15 +00001769
cristy29dc8652015-05-12 16:26:21 +00001770 <tr>
1771 <td>delegate:bimodal=<var>true</var></td>
1772 <td>Specifies direct conversion from Postscript to PDF.</td>
1773 </tr>
cristyd2432012015-05-04 23:15:15 +00001774
cristy29dc8652015-05-12 16:26:21 +00001775 <tr>
1776 <td>distort:scale=<var>value</var></td>
cristy82a2ff22015-05-12 16:41:32 +00001777 <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 +00001778 </tr>
cristyd2432012015-05-04 23:15:15 +00001779
cristy29dc8652015-05-12 16:26:21 +00001780 <tr>
1781 <td>distort:viewport=<var>WxH+X+Y</var></td>
1782 <td>Sets the viewport for use with <a href="command-line-options.html#distort">-distort</a></td>
1783 </tr>
cristyd2432012015-05-04 23:15:15 +00001784
cristy29dc8652015-05-12 16:26:21 +00001785 <tr>
1786 <td>dot:layout-engine=<var>value</var></td>
1787 <td>Specifies the layout engine for the DOT image format (e.g.
1788 <code>neato</code>).</td>
1789 </tr>
cristyd2432012015-05-04 23:15:15 +00001790
cristy29dc8652015-05-12 16:26:21 +00001791 <tr>
1792 <td>filter:option=<var>value</var></td>
1793 <td>Set a filter option for use with <a href="command-line-options.html#resize">-resize</a>.
1794 See <a href="command-line-options.html#filter">-filter</a> for details.</td>
1795 </tr>
cristyd2432012015-05-04 23:15:15 +00001796
cristy29dc8652015-05-12 16:26:21 +00001797 <tr>
1798 <td>fourier:normalize=<var>inverse</var></td>
1799 <td>Sets the location for the FFT/IFT normalization as use by
cristyd2432012015-05-04 23:15:15 +00001800 <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 +00001801 forward.</td>
1802 </tr>
cristyd2432012015-05-04 23:15:15 +00001803
cristy29dc8652015-05-12 16:26:21 +00001804 <tr>
1805 <td>icon:auto-resize</td>
1806 <td>Automatically stores multiple sizes when writing an ico image
1807 (requires a 256x256 input image).</td>
1808 </tr>
cristyd2432012015-05-04 23:15:15 +00001809
cristy29dc8652015-05-12 16:26:21 +00001810 <tr>
1811 <td>jp2:layer-number=<var>value</var></td>
1812 <td>Sets the maximum number of quality layers to decode. Same for JPT, JC2,
1813 and J2K</td>
1814 </tr>
cristyd2432012015-05-04 23:15:15 +00001815
cristy29dc8652015-05-12 16:26:21 +00001816 <tr>
1817 <td>jp2:number-resolutions=<var>value</var></td>
1818 <td>Sets the number of resolutions to encode.Same for JPT, JC2, and J2K</td>
1819 </tr>
cristyd2432012015-05-04 23:15:15 +00001820
cristy29dc8652015-05-12 16:26:21 +00001821 <tr>
1822 <td>jp2:progression-order=<var>value</var></td>
1823 <td>choose from LRCP, RLCP, RPCL, PCRL or CPRL. Same for JPT, JC2, and
1824 J2K</td>
1825 </tr>
cristyd2432012015-05-04 23:15:15 +00001826
cristy29dc8652015-05-12 16:26:21 +00001827 <tr>
1828 <td>jp2:quality=<var>value,value...</var></td>
1829 <td>Sets the quality layer PSNR, given in dB. The order is from left to
cristyd2432012015-05-04 23:15:15 +00001830 right in ascending order. The default is a single lossless quality layer.
cristy29dc8652015-05-12 16:26:21 +00001831 Same for JPT, JC2, and J2K</td>
1832 </tr>
cristyd2432012015-05-04 23:15:15 +00001833
cristy29dc8652015-05-12 16:26:21 +00001834 <tr>
1835 <td>jp2:rate=<var>value</var></td>
1836 <td>Specify the compression factor to use while writing JPEG-2000 files. The
cristyd2432012015-05-04 23:15:15 +00001837 compression factor is the reciprocal of the compression ratio. The valid
1838 range is 0.0 to 1.0, with 1.0 indicating lossless compression. If defined,
1839 this value overrides the -quality setting. A quality setting of 75
cristy29dc8652015-05-12 16:26:21 +00001840 results in a rate value of 0.06641. Same for JPT, JC2, and J2K</td>
1841 </tr>
cristyd2432012015-05-04 23:15:15 +00001842
cristy29dc8652015-05-12 16:26:21 +00001843 <tr>
1844 <td>jp2:reduce-factor=<var>value</var></td>
1845 <td>Sets the number of highest resolution levels to be discarded.Same for
1846 JPT, JC2, and J2K</td>
1847 </tr>
cristyd2432012015-05-04 23:15:15 +00001848
cristy29dc8652015-05-12 16:26:21 +00001849 <tr>
1850 <td>jpeg:block-smoothing=<var>on|off</var></td>
cristyb2cad532015-05-16 13:02:45 +00001851 <td>&amp;nbsp</td>
1852 </tr>
cristyd2432012015-05-04 23:15:15 +00001853
cristyb2cad532015-05-16 13:02:45 +00001854 <tr>
cristy29dc8652015-05-12 16:26:21 +00001855 <td>jpeg:colors=<var>value</var></td>
1856 <td>Set the desired number of colors and let the JPEG encoder do the
1857 quantizing.</td>
1858 </tr>
cristyd2432012015-05-04 23:15:15 +00001859
cristy29dc8652015-05-12 16:26:21 +00001860 <tr>
1861 <td>jpeg:dct-method=<var>value</var></td>
1862 <td>Choose from <code>default</code>, <code>fastest</code>,
1863 <code>float</code>, <code>ifast</code>, and <code>islow</code>.</td>
1864 </tr>
cristyd2432012015-05-04 23:15:15 +00001865
cristy29dc8652015-05-12 16:26:21 +00001866 <tr>
1867 <td>jpeg:extent=<var>value</var></td>
1868 <td>Restrict the maximum JPEG file size, for example <code>-define
cristyd2432012015-05-04 23:15:15 +00001869 jpeg:extent=400KB</code>. The JPEG encoder will search for the highest
1870 compression quality level that results in an output file that does not
1871 exceed the value. The <code>-quality</code> option is ignored if it
cristy29dc8652015-05-12 16:26:21 +00001872 is also present.</td>
1873 </tr>
cristyd2432012015-05-04 23:15:15 +00001874
cristy29dc8652015-05-12 16:26:21 +00001875 <tr>
1876 <td>jpeg:fancy-upsampling=<var>on|off</var></td>
cristyb2cad532015-05-16 13:02:45 +00001877 <td>&amp;nbsp</td>
1878 </tr>
cristyd2432012015-05-04 23:15:15 +00001879
cristyb2cad532015-05-16 13:02:45 +00001880 <tr>
cristy29dc8652015-05-12 16:26:21 +00001881 <td>jpeg:optimize-coding=<var>on|off</var></td>
cristyb2cad532015-05-16 13:02:45 +00001882 <td>&amp;nbsp</td>
1883 </tr>
cristyd2432012015-05-04 23:15:15 +00001884
cristyb2cad532015-05-16 13:02:45 +00001885 <tr>
cristy29dc8652015-05-12 16:26:21 +00001886 <td>jpeg:q-table=<var>table</var></td>
cristyb2cad532015-05-16 13:02:45 +00001887 <td>&amp;nbsp</td>
1888 </tr>
cristyd2432012015-05-04 23:15:15 +00001889
cristyb2cad532015-05-16 13:02:45 +00001890 <tr>
cristy29dc8652015-05-12 16:26:21 +00001891 <td>jpeg:sampling-factor=<var>sampling-factor-string</var></td>
cristyb2cad532015-05-16 13:02:45 +00001892 <td>&amp;nbsp</td>
1893 </tr>
cristyd2432012015-05-04 23:15:15 +00001894
cristyb2cad532015-05-16 13:02:45 +00001895 <tr>
cristy29dc8652015-05-12 16:26:21 +00001896 <td>jpeg:size=<var>geometry</var></td>
1897 <td>Set the size hint of a JPEG image, for
cristyd2432012015-05-04 23:15:15 +00001898 example, <code>-define jpeg:size=128x128</code>.
1899 It is most useful for increasing performance and reducing the memory
cristy29dc8652015-05-12 16:26:21 +00001900 requirements when reducing the size of a large JPEG image.</td>
1901 </tr>
cristyd2432012015-05-04 23:15:15 +00001902
cristy29dc8652015-05-12 16:26:21 +00001903 <tr>
1904 <td>json:features</td>
1905 <td>includes features in verbose information</td>
1906 </tr>
cristyd2432012015-05-04 23:15:15 +00001907
cristy29dc8652015-05-12 16:26:21 +00001908 <tr>
1909 <td>json:limit</td>
cristyb2cad532015-05-16 13:02:45 +00001910 <td>&amp;nbsp</td>
1911 </tr>
cristyd2432012015-05-04 23:15:15 +00001912
cristyb2cad532015-05-16 13:02:45 +00001913 <tr>
cristy29dc8652015-05-12 16:26:21 +00001914 <td>json:locate</td>
cristyb2cad532015-05-16 13:02:45 +00001915 <td>&amp;nbsp</td>
1916 </tr>
cristyd2432012015-05-04 23:15:15 +00001917
cristyb2cad532015-05-16 13:02:45 +00001918 <tr>
cristy29dc8652015-05-12 16:26:21 +00001919 <td>json:moments</td>
1920 <td>includes image moments in verbose information</td>
1921 </tr>
cristyd2432012015-05-04 23:15:15 +00001922
cristy29dc8652015-05-12 16:26:21 +00001923 <tr>
1924 <td>mng:need-cacheoff</td>
1925 <td>turn playback caching off for streaming MNG.</td>
1926 </tr>
cristyd2432012015-05-04 23:15:15 +00001927
cristy29dc8652015-05-12 16:26:21 +00001928 <tr>
1929 <td>morphology:compose=<var>compose-method</var></td>
cristy82a2ff22015-05-12 16:41:32 +00001930 <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 +00001931 typical value is 'lighten' as used, for example, with the sobel edge
cristy29dc8652015-05-12 16:26:21 +00001932 kernels. </td>
1933 </tr>
cristyd2432012015-05-04 23:15:15 +00001934
cristy29dc8652015-05-12 16:26:21 +00001935 <tr>
1936 <td>morphology:showkernel=<var>1</var></td>
cristy82a2ff22015-05-12 16:41:32 +00001937 <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 +00001938 </tr>
cristyd2432012015-05-04 23:15:15 +00001939
cristy29dc8652015-05-12 16:26:21 +00001940 <tr>
1941 <td>pcl:fit-to-page=<var>true</var></td>
cristyd2432012015-05-04 23:15:15 +00001942
cristy82a2ff22015-05-12 16:41:32 +00001943 </tr><tr>
cristy29dc8652015-05-12 16:26:21 +00001944 <td>pdf:fit-page=<var>geometry</var></td>
1945 <td> geometry specifies the scaling dimensions for resizing when the PDF is
cristyd2432012015-05-04 23:15:15 +00001946 being read. The geometry is either WxH{%} or page size. No offsets are
cristy29dc8652015-05-12 16:26:21 +00001947 allowed. (introduced in IM 6.8.8-8)</td>
1948 </tr>
cristyd2432012015-05-04 23:15:15 +00001949
cristy29dc8652015-05-12 16:26:21 +00001950 <tr>
1951 <td>pdf:fit-to-page=<var>true</var></td>
cristyb2cad532015-05-16 13:02:45 +00001952 <td>&amp;nbsp</td>
1953 </tr>
cristyd2432012015-05-04 23:15:15 +00001954
cristyb2cad532015-05-16 13:02:45 +00001955 <tr>
cristy29dc8652015-05-12 16:26:21 +00001956 <td>pdf:use-cropbox=<var>true</var></td>
cristyb2cad532015-05-16 13:02:45 +00001957 <td>&amp;nbsp</td>
1958 </tr>
cristyd2432012015-05-04 23:15:15 +00001959
cristyb2cad532015-05-16 13:02:45 +00001960 <tr>
cristy29dc8652015-05-12 16:26:21 +00001961 <td>pdf:use-trimbox=<var>true</var></td>
cristyb2cad532015-05-16 13:02:45 +00001962 <td>&amp;nbsp</td>
1963 </tr>
cristyd2432012015-05-04 23:15:15 +00001964
cristyb2cad532015-05-16 13:02:45 +00001965 <tr>
cristy29dc8652015-05-12 16:26:21 +00001966 <td>png:bit-depth=<var>value</var></td>
cristyb2cad532015-05-16 13:02:45 +00001967 <td>&amp;nbsp</td>
1968 </tr>
1969 <tr>
cristy29dc8652015-05-12 16:26:21 +00001970 <td>png:color-type=<var>value</var></td>
1971 <td>desired bit-depth and color-type for PNG output. You can force the PNG
cristyd2432012015-05-04 23:15:15 +00001972 encoder to use a different bit-depth and color-type than it would have
1973 normally selected, but only if this does not cause any loss of image
1974 quality. Any attempt to reduce image quality is treated as an error and no
1975 PNG file is written. E.g., if you have a 1-bit black-and-white image, you
1976 can use these "defines" to cause it to be written as an 8-bit grayscale,
1977 indexed, or even a 64-bit RGBA. But if you have a 16-million color image,
1978 you cannot force it to be written as a grayscale or indexed PNG. If you
1979 wish to do this, you must use the appropriate <a href="command-line-options.html#depth">-depth</a>,
1980 <a href="command-line-options.html#colors">-colors</a>, or <a href="command-line-options.html#type">-type</a> directives to
1981 reduce the image quality prior to using the PNG encoder. Note that in
1982 indexed PNG files, "bit-depth" refers to the number of bits per index,
1983 which can be 1, 2, 4, or 8. In such files, the color samples always have
cristy29dc8652015-05-12 16:26:21 +00001984 8-bit depth.</td>
1985 </tr>
cristyd2432012015-05-04 23:15:15 +00001986
cristy29dc8652015-05-12 16:26:21 +00001987 <tr>
1988 <td>png:compression-filter=<var>value</var></td>
1989 <td> valid values are 0 through 9. 0-4 are the corresponding PNG filters,
cristyd2432012015-05-04 23:15:15 +00001990 5 means adaptive filtering except for images with a colormap, 6 means
1991 adaptive filtering for all images, 7 means MNG "loco" compression, 8 means
1992 Z_RLE strategy with adaptive filtering, and 9 means Z_RLE strategy with no
cristy29dc8652015-05-12 16:26:21 +00001993 filtering.</td>
1994 </tr>
cristyd2432012015-05-04 23:15:15 +00001995
cristy29dc8652015-05-12 16:26:21 +00001996 <tr>
1997 <td>png:compression-level=<var>value</var></td>
1998 <td> valid values are 0 through 9, with 0 providing the least but fastest
1999 compression and 9 usually providing the best and always the slowest.</td>
2000 </tr>
cristyd2432012015-05-04 23:15:15 +00002001
cristy29dc8652015-05-12 16:26:21 +00002002 <tr>
2003 <td>png:compression-strategy=<var>value</var></td>
2004 <td> valid values are 0 through 4, meaning default, filtered, huffman_only,
cristyd2432012015-05-04 23:15:15 +00002005 rle, and fixed ZLIB compression strategy. If you are using an old zlib
2006 that does not support Z_RLE (before 1.2.0) or Z_FIXED (before 1.2.2.2),
2007 values 3 and 4, respectively, will use the zlib default strategy
cristy29dc8652015-05-12 16:26:21 +00002008 instead.</td>
2009 </tr>
cristyd2432012015-05-04 23:15:15 +00002010
cristy29dc8652015-05-12 16:26:21 +00002011 <tr>
2012 <td>png:format=<var>value</var></td>
2013 <td> valid values are <var>png8</var>, <var>png24</var>,
cristyd2432012015-05-04 23:15:15 +00002014 <var>png32</var>, <var>png48</var>,
2015 <var>png64</var>, and <var>png00</var>.
2016 This property can be useful for specifying
2017 the specific PNG format to be used, when the usual method of prepending the
2018 format name to the output filename is inconvenient, such as when writing
2019 a PNG-encoded ICO file or when using <a href="mogrify.html">mogrify</a>.
2020 Value = <var>png8</var> reduces the number of colors to 256,
2021 only one of which may be fully transparent, if necessary. The other
2022 values do not force any reduction of quality; it is an error to request
2023 a format that cannot represent the image data without loss (except that
2024 it is allowed to reduce the bit-depth from 16 to 8 for all formats).
2025 Value = <var>png24</var> and <var>png48</var>
2026 allow transparency, only if a single color is fully transparent and that
2027 color does not also appear in an opaque pixel; such transparency is
2028 written in a PNG <code>tRNS</code> chunk.
2029 Value = <var>png00</var> causes the image to inherit its
2030 color-type and bit-depth from the input image, if the input was also
cristy29dc8652015-05-12 16:26:21 +00002031 a PNG.</td>
2032 </tr>
cristyd2432012015-05-04 23:15:15 +00002033
cristy29dc8652015-05-12 16:26:21 +00002034 <tr>
2035 <td>png:exclude-chunk=<var>value</var></td>
cristyd2432012015-05-04 23:15:15 +00002036
cristy82a2ff22015-05-12 16:41:32 +00002037 </tr><tr>
cristy29dc8652015-05-12 16:26:21 +00002038 <td>png:include-chunk=<var>value</var></td>
2039 <td>ancillary chunks to be excluded from or included in PNG output.
cristyd2432012015-05-04 23:15:15 +00002040
2041 <p>The <var>value</var> can be the name of a PNG chunk-type such
2042 as <var>bKGD</var>, a comma-separated list of chunk-names
2043 (which can include the word <var>date</var>, the word
2044 <var>all</var>, or the word <var>none</var>).
2045 Although PNG chunk-names are case-dependent, you can use all lowercase
2046 names if you prefer.</p>
2047
2048 <p>The "include-chunk" and "exclude-chunk" lists only affect the behavior
2049 of the PNG encoder and have no effect on the PNG decoder.</p>
2050
2051 <p>As a special case, if the <code>sRGB</code> chunk is excluded and
2052 the <code>gAMA</code> chunk is included, the <code>gAMA</code> chunk will
2053 only be written if gamma is not 1/2.2, since most decoders assume
2054 sRGB and gamma=1/2.2 when no colorspace information is included in
2055 the PNG file. Because the list is processed from left to right, you
2056 can achieve this with a single define:</p>
2057
2058<pre>
cristy29dc8652015-05-12 16:26:21 +00002059-define png:include-chunk=none,gAMA
cristyd2432012015-05-04 23:15:15 +00002060</pre>
2061
2062 <p>As a special case, if the <code>sRGB</code> chunk is not excluded and
2063 the PNG encoder recognizes that the image contains the sRGB ICC profile,
2064 the PNG encoder will write the <code>sRGB</code> chunk instead of the
2065 entire ICC profile. To force the PNG encoder to write the sRGB
2066 profile as an <code>iCCP</code> chunk in the output PNG instead of the
2067 <code>sRGB</code> chunk, exclude the <code>sRGB</code> chunk.</p>
2068
2069 <p>The critical PNG chunks <code>IHDR</code>, <code>PLTE</code>,
2070 <code>IDAT</code>, and <code>IEND</code> cannot be excluded. Any such
2071 entries appearing in the list will be ignored.</p>
2072
2073 <p>If the ancillary PNG <code>tRNS</code> chunk is excluded and the
2074 image has transparency, the PNG colortype is forced to be 4 or 6
2075 (GRAY_ALPHA or RGBA). If the image is not transparent, then the
2076 <code>tRNS</code> chunk isn't written anyhow, and there is no effect
2077 on the PNG colortype of the output image.</p>
2078
2079 <p>The <a href="command-line-options.html#strip">-strip</a> option does the equivalent of the
2080 following for PNG output:</p>
2081
2082<pre>
cristy29dc8652015-05-12 16:26:21 +00002083-define png:exclude-chunk=EXIF,iCCP,iTXt,sRGB,tEXt,zCCP,zTXt,date
cristyd2432012015-05-04 23:15:15 +00002084</pre>
2085
2086 <p>The default behavior is to include all known PNG ancillary chunks
2087 plus ImageMagick's private <code>vpAg</code> ("virtual page") chunk,
2088 and to exclude all PNG chunks that are unknown to ImageMagick,
2089 regardless of their PNG "copy-safe" status as described in the
2090 PNG specification.</p>
2091
2092 <p>Any chunk names that are not known to ImageMagick are ignored
2093 if they appear in either the "include-chunk" or "exclude-chunk" list.
2094 The ancillary chunks currently known to ImageMagick are
2095 <code>bKGD</code>, <code>cHRM</code>, <code>gAMA</code>, <code>iCCP</code>,
2096 <code>oFFs</code>, <code>pHYs</code>, <code>sRGB</code>, <code>tEXt</code>,
2097 <code>tRNS</code>, <code>vpAg</code>, and <code>zTXt</code>.</p>
2098
2099 <p>You can also put <code>date</code> in the list to include or exclude
2100 the "Date:create" and "Date:modify" text chunks that ImageMagick normally
cristy29dc8652015-05-12 16:26:21 +00002101 inserts in the output PNG.</p></td>
2102 </tr>
cristyd2432012015-05-04 23:15:15 +00002103
cristy29dc8652015-05-12 16:26:21 +00002104 <tr>
2105 <td>png:preserve-colormap[=<var>true</var>]</td>
cristy82a2ff22015-05-12 16:41:32 +00002106 <td>Use the existing image-&gt;colormap. Normally the PNG encoder will
cristyd2432012015-05-04 23:15:15 +00002107 try to optimize the palette, eliminating unused entries and putting
2108 the transparent colors first. If this flag is set, that behavior
cristy29dc8652015-05-12 16:26:21 +00002109 is suppressed.</td>
2110 </tr>
cristyd2432012015-05-04 23:15:15 +00002111
cristy29dc8652015-05-12 16:26:21 +00002112 <tr>
2113 <td>png:preserve-iCCP[=<var>true</var>]</td>
2114 <td>By default, the PNG decoder and encoder examine any ICC profile
cristyd2432012015-05-04 23:15:15 +00002115 that is present, either from an <code>iCCP</code> chunk in the PNG
2116 input or supplied via an option, and if the profile is recognized
2117 to be the sRGB profile, converts it to the <code>sRGB</code> chunk.
2118 You can use <code>-define png:preserve-iCCP</code> to prevent
2119 this from happening; in such cases the <code>iCCP</code> chunk
2120 will be read or written and no <code>sRGB</code> chunk will be
2121 written. There are some ICC profiles that claim to be sRGB but
2122 have various errors that cause them to be rejected by libpng16; such
2123 profiles are recognized anyhow and converted to the <code>sRGB</code>
2124 chunk, but are rejected if the <code>-define png:preserve-iCCP</code>
2125 is present. Note that not all "sRGB" ICC profiles are recognized
cristy29dc8652015-05-12 16:26:21 +00002126 yet; we will add them to the list as we encounter them.</td>
2127 </tr>
cristyd2432012015-05-04 23:15:15 +00002128
cristy29dc8652015-05-12 16:26:21 +00002129 <tr>
2130 <td>png:swap-bytes[=<var>true</var>]</td>
2131 <td>The PNG specification requires that any multi-byte integers be stored in
cristyd2432012015-05-04 23:15:15 +00002132 network byte order (MSB-LSB endian). This option allows you to
2133 fix any invalid PNG files that have 16-bit samples stored incorrectly
2134 in little-endian order (LSB-MSB). The "-define png:swap-bytes" option
2135 must appear before the input filename on the commandline. The swapping
cristy29dc8652015-05-12 16:26:21 +00002136 is done during the libpng decoding operation.</td>
2137 </tr>
cristyd2432012015-05-04 23:15:15 +00002138
cristy29dc8652015-05-12 16:26:21 +00002139 <tr>
2140 <td>profile:skip=<var>name1,name2,...</var></td>
2141 <td>Skip the named profile[s] when reading the image. Use skip="*" to
cristyd2432012015-05-04 23:15:15 +00002142 skip all named profiles in the image. Many named profiles exist,
cristy29dc8652015-05-12 16:26:21 +00002143 including ICC, EXIF, APP1, IPTC, XMP, and others.</td>
2144 </tr>
cristyd2432012015-05-04 23:15:15 +00002145
cristy29dc8652015-05-12 16:26:21 +00002146 <tr>
2147 <td>ps:imagemask</td>
2148 <td>If the ps:imagemask flag is defined, the PS3 and EPS3 coders will create
cristyd2432012015-05-04 23:15:15 +00002149 Postscript files that render bilevel images with the Postscript imagemask
cristy29dc8652015-05-12 16:26:21 +00002150 operator instead of the image operator.</td>
2151 </tr>
cristyd2432012015-05-04 23:15:15 +00002152
cristy29dc8652015-05-12 16:26:21 +00002153 <tr>
2154 <td>quantum:format=<var>type</var></td>
2155 <td>Set the type to <code>floating-point</code> to specify a floating-point
cristyd2432012015-05-04 23:15:15 +00002156 format for raw files (e.g. GRAY:) or for MIFF and TIFF images in HDRI mode
2157 to preserve negative values. If <a href="command-line-options.html#depth">-depth</a> 16 is
2158 included, the result is a single precision floating point format.
2159 If <a href="command-line-options.html#depth">-depth</a> 32 is included, the result is
cristy29dc8652015-05-12 16:26:21 +00002160 double precision floating point format.</td>
2161 </tr>
cristyd2432012015-05-04 23:15:15 +00002162
cristy29dc8652015-05-12 16:26:21 +00002163 <tr>
2164 <td>quantum:polarity=<var>photometric-interpretation</var></td>
2165 <td>Set the photometric-interpretation of an image (typically for TIFF image
cristyd2432012015-05-04 23:15:15 +00002166 file format) to either <code>min-is-black</code> (default) or
cristy29dc8652015-05-12 16:26:21 +00002167 <code>min-is-white</code>.</td>
2168 </tr>
cristyd2432012015-05-04 23:15:15 +00002169
cristy29dc8652015-05-12 16:26:21 +00002170 <tr>
2171 <td>sample:offset=<var>geometry</var></td>
2172 <td>Location of the sampling point within the sub-region being sampled,
cristy82a2ff22015-05-12 16:41:32 +00002173 expressed as percentages (see <a href="command-line-options.html#sample">-sample</a>).</td>
cristy29dc8652015-05-12 16:26:21 +00002174 </tr>
cristyd2432012015-05-04 23:15:15 +00002175
cristy29dc8652015-05-12 16:26:21 +00002176 <tr>
2177 <td>showkernel=<var>1</var></td>
cristy82a2ff22015-05-12 16:41:32 +00002178 <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 +00002179 </tr>
cristyd2432012015-05-04 23:15:15 +00002180
cristy29dc8652015-05-12 16:26:21 +00002181 <tr>
2182 <td>stream:buffer-size=<var>value</var></td>
2183 <td>Set the stream buffer size. Select 0 for unbuffered I/O.</td>
2184 </tr>
cristyd2432012015-05-04 23:15:15 +00002185
cristy29dc8652015-05-12 16:26:21 +00002186 <tr>
2187 <td>tiff:alpha=<var>associated|unassociated|unspecified</var></td>
2188 <td>Specify the alpha extra samples as associated, unassociated or unspecified </td>
2189 </tr>
cristyd2432012015-05-04 23:15:15 +00002190
cristy29dc8652015-05-12 16:26:21 +00002191 <tr>
2192 <td>tiff:endian=<var>msb|lsb</var></td>
cristyb2cad532015-05-16 13:02:45 +00002193 <td>&amp;nbsp</td>
2194 </tr>
cristyd2432012015-05-04 23:15:15 +00002195
cristyb2cad532015-05-16 13:02:45 +00002196 <tr>
cristy29dc8652015-05-12 16:26:21 +00002197 <td>tiff:exif-properties=<var>false</var></td>
2198 <td>Skips reading the EXIF properties.</td>
2199 </tr>
cristyd2432012015-05-04 23:15:15 +00002200
cristy29dc8652015-05-12 16:26:21 +00002201 <tr>
2202 <td>tiff:fill-order=<var>msb|lsb</var></td>
cristyb2cad532015-05-16 13:02:45 +00002203 <td>&amp;nbsp</td>
2204 </tr>
cristyd2432012015-05-04 23:15:15 +00002205
cristyb2cad532015-05-16 13:02:45 +00002206 <tr>
cristy29dc8652015-05-12 16:26:21 +00002207 <td>tiff:ignore-tags=<var>comma-separate-list-of-tag-IDs</var></td>
2208 <td>Allows one or more tag ID values to be ignored.</td>
2209 </tr>
cristyd2432012015-05-04 23:15:15 +00002210
cristy29dc8652015-05-12 16:26:21 +00002211 <tr>
2212 <td>tiff:rows-per-strip=<var>value</var></td>
2213 <td>Sets the number of rows per strip</td>
2214 </tr>
cristyd2432012015-05-04 23:15:15 +00002215
cristy29dc8652015-05-12 16:26:21 +00002216 <tr>
2217 <td>tiff:tile-geometry=<var>WxH</var></td>
2218 <td>Sets the tile size for pyramid tiffs. Requires the suffix
2219 PTIF: before the outputname</td>
2220 </tr>
2221</table>
cristyd2432012015-05-04 23:15:15 +00002222
2223<p>For example, to create a postscript file that will render only the black
2224pixels of a bilevel image, use:</p>
2225
2226<pre>
2227convert bilevel.tif -define ps:imagemask eps3:stencil.ps
2228</pre>
2229
2230<p>Set attributes of the image registry by prefixing the value with
2231<code>registry:</code>. For example, to set a temporary path to put work files,
2232use:</p>
2233
cristy29dc8652015-05-12 16:26:21 +00002234<pre>
cristyd2432012015-05-04 23:15:15 +00002235-define registry:temporary-path=/data/tmp
cristy29dc8652015-05-12 16:26:21 +00002236</pre>
cristyd2432012015-05-04 23:15:15 +00002237
2238<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00002239 <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 +00002240</div>
2241
2242<p class="magick-description">display the next image after pausing.</p>
2243
2244<p>This option is useful for regulating the animation of image sequences
2245<var>ticks/ticks-per-second</var> seconds must expire before the display of the
2246next image. The default is no delay between each showing of the image
2247sequence. The default ticks-per-second is 100.</p>
2248
2249<p>Use <code>&gt;</code> to change the image delay <var>only</var> if its current
2250value exceeds the given delay. <code>&lt;</code> changes the image delay
2251<var>only</var> if current value is less than the given delay. For example, if
2252you specify <code>30&gt;</code> and the image delay is 20, the image delay does
2253not change. However, if the image delay is 40 or 50, the delay it is changed
2254to 30. Enclose the given delay in quotation marks to prevent the
2255<code>&lt;</code> or <code>&gt;</code> from being interpreted by your shell as
2256a file redirection.</p>
2257
2258
2259<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002260 <h3 class="magick-header"><a id="delete"></a>-delete <var>indexes</var></h3>
cristyd2432012015-05-04 23:15:15 +00002261</div>
2262
2263<p class="magick-description">delete the images specified by index, from the image sequence.</p>
2264
2265<p>Specify the image by its index in the sequence. The first image is index
22660. Negative indexes are relative to the end of the sequence, for example, -1
2267represents the last image of the sequence. Specify a range of images with
2268a dash (e.g. 0-4). Separate indexes with a comma (e.g. 0,2). Use
2269<code>+delete</code> to delete the last image in the current image sequence.</p>
2270
2271
2272<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00002273 <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 +00002274</div>
2275
2276<p class="magick-description">Set the horizontal and vertical resolution of an image for rendering to devices.</p>
2277
2278<p>This option specifies the image resolution to store while encoding a raster
2279image or the canvas resolution while rendering (reading) vector formats such
2280as Postscript, PDF, WMF, and SVG into a raster image. Image resolution
2281provides the unit of measure to apply when rendering to an output device or
cristy82a2ff22015-05-12 16:41:32 +00002282raster 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 +00002283instead.</p>
2284
2285<p>The default resolution is 72 dots per inch, which is equivalent to one
2286point per pixel (Macintosh and Postscript standard). Computer screens are
2287normally 72 or 96 dots per inch, while printers typically support 150, 300,
2288600, or 1200 dots per inch. To determine the resolution of your display, use
2289a ruler to measure the width of your screen in inches, and divide by the
2290number of horizontal pixels (1024 on a 1024x768 display).</p>
2291
2292<p>If the file format supports it, this option may be used to update the
2293stored image resolution. Note that Photoshop stores and obtains image
2294resolution from a proprietary embedded profile. If this profile is not
2295stripped from the image, then Photoshop will continue to treat the image using
2296its former resolution, ignoring the image resolution specified in the standard
2297file header.</p>
2298
2299<p>The <a href="command-line-options.html#density">-density</a> option sets an <var>attribute</var> and
2300does not alter the underlying raster image. It may be used to adjust the
2301rendered size for desktop publishing purposes by adjusting the scale applied
2302to the pixels. To resize the image so that it is the same size at a different
2303resolution, use the <a href="command-line-options.html#resample">-resample</a> option.</p>
2304
2305<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002306 <h3 class="magick-header"><a id="depth"></a>-depth <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00002307</div>
2308
2309<p class="magick-description">depth of the image.</p>
2310
2311<p>This the number of bits in a color sample within a pixel. Use this option
2312to specify the depth of raw images whose depth is unknown such as GRAY, RGB,
2313or CMYK, or to change the depth of any image after it has been read.</p>
2314
2315<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002316 <h3 class="magick-header"><a id="descend"></a>-descend</h3>
cristyd2432012015-05-04 23:15:15 +00002317</div>
2318
2319<p class="magick-description">obtain image by descending window hierarchy.</p>
2320
2321<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002322 <h3 class="magick-header"><a id="deskew"></a>-deskew <var>threshold</var></h3>
cristyd2432012015-05-04 23:15:15 +00002323</div>
2324
2325<p class="magick-description">straighten an image. A threshold of 40% works for most images.</p>
2326
2327<p>Use <a href="command-line-options.html#set">-set</a> <code>option:deskew:auto-crop
2328<var>width</var></code> to auto crop the image. The set argument is the pixel
2329width of the image background (e.g 40).</p>
2330
2331<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002332 <h3 class="magick-header"><a id="despeckle"></a>-despeckle</h3>
cristyd2432012015-05-04 23:15:15 +00002333</div>
2334
2335<p class="magick-description">reduce the speckles within an image.</p>
2336
2337<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002338 <h3 class="magick-header"><a id="direction"></a>-direction <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00002339</div>
2340
2341<p class="magick-description">render text right-to-left or left-to-right.</p>
2342
2343<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00002344 <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 +00002345</div>
2346
2347<p class="magick-description">shift image pixels as defined by a displacement map.</p>
2348
2349<p>With this option, the 'overlay' image, and optionally the 'mask' image,
2350is used as a displacement map, which is used to displace the lookup of
2351what part of the 'background' image is seen at each point of the overlaid
2352area. Much like the displacement map is a 'lens' that redirects light shining
2353through it so as to present a distorted view the original 'background' image
2354behind it. </p>
2355
2356<p>Any perfect grey areas of the displacement map produce a zero
2357displacement of the image. Black areas produce the given maximum negative
2358displacement of the lookup point, while white produce a maximum positive
2359displacement of the lookup. </p>
2360
2361<p>Note that it is the lookup of the 'background' that is displaced, not a
2362displacement of the image itself. As such an area of the displacement map
2363containing 'white' will have the lookup point 'shifted' by a positive amount,
2364and thus generating a copy of the destination image to the right/downward from
2365the correct position. That is the image will look like it may have been
2366'shifted' in a negative left/upward direction. Understanding this is a very
2367important in understanding how displacement maps work. </p>
2368
2369<p>The given arguments define the maximum amount of displacement in pixels
2370that a particular map can produce. If the displacement scale is large enough
2371it is also possible to lookup parts of the 'background' image that lie well
2372outside the bounds of the displacement map itself. That is you could very
2373easily copy a section of the original image from outside the overlay area
2374into the overlay area. </p>
2375
2376<p>The '%' flag makes the displacement scale relative to the size of the
2377overlay image (100% = half width/height of image). Using '!' switches
2378percentage arguments to refer to the destination image size instead.
2379these flags were added as of IM v6.5.3-5.</p>
2380
2381<p>Normally a single grayscale displacement map is provided, which with the
2382given scaling values will determine a single direction (vector) in which
2383displacements can occur (positively or negatively). However, if you also
2384specify a third image which is normally used as a <var>mask</var>,
2385the <var>composite image</var> is used for horizontal X
2386displacement, while the <var>mask image</var> is used for vertical Y
2387displacement. This allows you to define completely different displacement
2388values for the X and Y directions, and allowing you to lookup any point within
2389the <var>scale</var> bounds. In other words each pixel can lookup
2390any other nearby pixel, producing complex 2 dimensional displacements, rather
2391than a simple 1 dimensional vector displacements. </p>
2392
2393<p>Alternatively rather than supplying two separate images, as of IM v6.4.4-0,
2394you can use the 'red' channel of the overlay image to specify the horizontal
2395or X displacement, and the 'green' channel for the vertical or Y displacement.
2396</p>
2397
2398<p>As of IM v6.5.3-5 any alpha channel in the overlay image is used as a
2399mask the transparency of the destination image. However areas outside the
2400overlaid areas will not be effected. </p>
2401
2402
2403<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002404 <h3 class="magick-header"><a id="display"></a>-display <var>host:display[.screen]</var></h3>
cristyd2432012015-05-04 23:15:15 +00002405</div>
2406
2407<p class="magick-description">Specifies the X server to contact.</p>
2408
2409<p>This option is used with convert for obtaining image or font from this
2410X server. See <var>X(1)</var>.</p>
2411
2412<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002413 <h3 class="magick-header"><a id="dispose"></a>-dispose <var>method</var></h3>
cristyd2432012015-05-04 23:15:15 +00002414</div>
2415
2416<p class="magick-description">define the GIF disposal image setting for images that are being created or read in. </p>
2417
2418<p>The layer disposal method defines the way each the displayed image is to be
2419modified after the current 'frame' of an animation has finished being
2420displayed (after its 'delay' period), but before the next frame on an
2421animation is to be overlaid onto the display. </p>
2422
2423<p>Here are the valid methods:</p>
2424
cristy29dc8652015-05-12 16:26:21 +00002425<dl class="dl-horizontal">
2426<dt>Undefined</dt><dd>0: No disposal specified (equivalent to '<code>none</code>').</dd>
2427<dt>None</dt><dd>1: Do not dispose, just overlay next frame image.</dd>
2428<dt>Background</dt><dd>2: Clear the frame area with the background color.</dd>
2429<dt>Previous</dt><dd>3: Clear to the image prior to this frames overlay.</dd>
2430</dl>
cristyd2432012015-05-04 23:15:15 +00002431
2432<p>You can also use the numbers given above, which is what the GIF format
2433uses internally to represent the above settings. </p>
2434
2435<p>To print a complete list of dispose methods, use <a href="command-line-options.html#list">-list dispose</a>.</p>
2436
cristy82a2ff22015-05-12 16:41:32 +00002437<p>Use <a href="command-line-options.html#dispose">+dispose</a>, turn off the setting and prevent
cristyd2432012015-05-04 23:15:15 +00002438resetting the layer disposal methods of images being read in. </p>
2439
2440<p>Use <a href="command-line-options.html#set">-set</a> '<code>dispose</code>' method to set the image
2441disposal method for images already in memory.</p>
2442
2443<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002444 <h3 class="magick-header"><a id="dissimilarity-threshold"></a>-dissimilarity-threshold <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00002445</div>
2446
2447<p class="magick-description">maximum RMSE for subimage match (default 0.2).</p>
2448
2449
2450<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002451 <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 +00002452</div>
2453
2454<p class="magick-description">dissolve an image into another by the given percent.</p>
2455
2456<p>The opacity of the composite image is multiplied by the given percent, then
2457it is composited 'over' the main image. If <var>src_percent</var>
2458is greater than 100, start dissolving the main image so it becomes
2459transparent at a value of '<code>200</code>'. If both percentages
2460are given, each image are dissolved to the percentages given. </p>
2461
2462<p>Note that dissolve percentages do not add, two opaque images dissolved
2463'50,50', produce a 75% transparency. For a 50% + 50% blending of the two
2464images, you would need to use dissolve values of '50,100'. </p>
2465
2466<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002467 <h3 class="magick-header"><a id="distort"></a>-distort <var>method arguments</var></h3>
cristyd2432012015-05-04 23:15:15 +00002468</div>
2469
2470<p class="magick-description">distort an image, using the given <var>method</var> and its required <var>arguments</var>.</p>
2471
2472<p>The <var>arguments</var> is a single string containing a list
2473of floating point numbers separated by commas or spaces. The number of
2474and meaning of the floating point values depends on the distortion <var>method</var> being used. </p>
2475
2476<p>Choose from these distortion types:</p>
2477
2478<table class="table table-condensed table-striped">
2479 <tr>
2480 <th style="width: 8%">Method</th>
2481 <th>Description</th>
2482 </tr>
2483
2484 <tr>
cristyb2cad532015-05-16 13:02:45 +00002485 <td>ScaleRotateTranslate <br> SRT</td>
cristyd2432012015-05-04 23:15:15 +00002486 <td>
2487 Distort image by first scaling and rotating about a given 'center',
2488 before translating that 'center' to the new location, in that order. It
cristyb2cad532015-05-16 13:02:45 +00002489 is an alternative method of specifying a 'Affine' type of
cristyd2432012015-05-04 23:15:15 +00002490 distortion, but without shearing effects. It also provides a good way
2491 of rotating and displacing a smaller image for tiling onto a larger
cristy82a2ff22015-05-12 16:41:32 +00002492 background (IE 2-dimensional animations). <br>
cristyd2432012015-05-04 23:15:15 +00002493
2494 The number of arguments determine the specific meaning of each
cristy82a2ff22015-05-12 16:41:32 +00002495 argument for the scales, rotation, and translation operations. <br>
cristyd2432012015-05-04 23:15:15 +00002496
cristyb2cad532015-05-16 13:02:45 +00002497 <dl class="dl-horizontal">
2498 <dt>2:</dt><dd><var>Scale Angle</var></dd>
2499 <dt>3:</dt><dd><var>X,Y Angle</var></dd>
2500 <dt>4:</dt><dd><var>X,Y Scale Angle</var></dd>
2501 <dt>5:</dt> <dd><var>X,Y ScaleX,ScaleY Angle</var></dd>
2502 <dt>6:</dt> <dd><var>X,Y Scale Angle NewX,NewY</var></dd>
2503 <dt>7:</dt> <dd><var>X,Y ScaleX,ScaleY Angle NewX,NewY</var></dd>
2504 </dl>
cristyd2432012015-05-04 23:15:15 +00002505
2506 This is actually an alternative way of specifying a 2 dimensional linear
cristyb2cad532015-05-16 13:02:45 +00002507 'Affine' or 'AffineProjection' distortion. </td> </tr>
cristyd2432012015-05-04 23:15:15 +00002508
2509 <tr>
cristyb2cad532015-05-16 13:02:45 +00002510 <td>Affine</td>
cristyd2432012015-05-04 23:15:15 +00002511 <td>
2512 Distort the image linearly by moving a list of at least 3 or more sets
2513 of control points (as defined below). Ideally 3 sets or 12 floating
2514 point values are given allowing the image to be linearly scaled,
2515 rotated, sheared, and translated, according to those three points. See
cristyb2cad532015-05-16 13:02:45 +00002516 also the related 'AffineProjection' and 'SRT'
cristy82a2ff22015-05-12 16:41:32 +00002517 distortions. <br>
cristyd2432012015-05-04 23:15:15 +00002518
2519 More than 3 sets given control point pairs (12 numbers) is least
2520 squares fitted to best match a linear affine distortion. If only 2
2521 control point pairs (8 numbers) are given a two point image translation
2522 rotation and scaling is performed, without any possible shearing,
2523 flipping or changes in aspect ratio to the resulting image. If only one
2524 control point pair is provides the image is only translated, (which may
cristy82a2ff22015-05-12 16:41:32 +00002525 be a floating point non-integer translation). <br>
cristyd2432012015-05-04 23:15:15 +00002526
2527 This distortion does not include any form of perspective distortion.
2528 </td>
2529
2530 </tr>
2531
2532 <tr>
cristyb2cad532015-05-16 13:02:45 +00002533 <td>AffineProjection</td>
cristyd2432012015-05-04 23:15:15 +00002534 <td>
2535 Linearly distort an image using the given Affine Matrix of 6
2536 pre-calculated coefficients forming a set of Affine Equations to map
2537 the source image to the destination image.
2538
cristyb2cad532015-05-16 13:02:45 +00002539 <p class="text-center"><var>
cristyd2432012015-05-04 23:15:15 +00002540 s<sub>x</sub>, r<sub>x</sub>,
2541 r<sub>y</sub>, s<sub>y</sub>,
2542 t<sub>x</sub>, t<sub>y</sub>
cristyb2cad532015-05-16 13:02:45 +00002543 </var></p>
cristyd2432012015-05-04 23:15:15 +00002544
cristy82a2ff22015-05-12 16:41:32 +00002545 See <a href="command-line-options.html#affine">-affine</a> setting for more detail, and
2546 meanings of these coefficients. <br>
cristyd2432012015-05-04 23:15:15 +00002547
cristyb2cad532015-05-16 13:02:45 +00002548 The distortions 'Affine' and 'SRT' provide
cristyd2432012015-05-04 23:15:15 +00002549 alternative methods of defining this distortion, with ImageMagick doing
2550 the calculations needed to generate the required coefficients. You can
cristy82a2ff22015-05-12 16:41:32 +00002551 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 +00002552
2553 </tr>
2554
2555 <tr>
cristyb2cad532015-05-16 13:02:45 +00002556 <td>BilinearForward<br>
2557 BilinearReverse</td>
cristyd2432012015-05-04 23:15:15 +00002558 <td>
2559 Bilinear Distortion, given a minimum of 4 sets of coordinate pairs, or
2560 16 values (see below). Not that lines may not appear straight after
2561 distortion, though the distance between coordinates will remain
cristy82a2ff22015-05-12 16:41:32 +00002562 consistent. <br>
cristyd2432012015-05-04 23:15:15 +00002563
cristyb2cad532015-05-16 13:02:45 +00002564 The 'BilinearForward' is used to map rectangles to any
2565 quadrilateral, while the 'BilinearReverse' form maps any
cristyd2432012015-05-04 23:15:15 +00002566 quadrilateral to a rectangle, while preserving the straight line edges
cristy82a2ff22015-05-12 16:41:32 +00002567 in each case. <br>
cristyd2432012015-05-04 23:15:15 +00002568
cristyb2cad532015-05-16 13:02:45 +00002569 Note that 'BilinearForward' can generate invalid pixels
cristy82a2ff22015-05-12 16:41:32 +00002570 which will be colored using the <a href="command-line-options.html#mattecolor">-mattecolor</a>
cristyd2432012015-05-04 23:15:15 +00002571 color setting. Also if the quadrilateral becomes 'flipped' the image
cristy82a2ff22015-05-12 16:41:32 +00002572 may disappear. <br>
cristyd2432012015-05-04 23:15:15 +00002573
2574 There are future plans to produce a true Bilinear distortion that will
2575 attempt to map any quadrilateral to any other quadrilateral, while
2576 preserving edges (and edge distance ratios).
2577
2578 </td>
2579 </tr>
2580
2581 <tr>
cristyb2cad532015-05-16 13:02:45 +00002582 <td>Perspective</td>
cristyd2432012015-05-04 23:15:15 +00002583 <td>
2584 Perspective distort the images, using a list of 4 or more sets of
2585 control points (as defined below). More that 4 sets (16 numbers) of
2586 control points provide least squares fitting for more accurate
2587 distortions (for the purposes of image registration and panorama
cristyb2cad532015-05-16 13:02:45 +00002588 effects). Less than 4 sets will fall back to a 'Affine'
cristy82a2ff22015-05-12 16:41:32 +00002589 linear distortion. <br>
cristyd2432012015-05-04 23:15:15 +00002590
2591 Perspective Distorted images ensures that straight lines remain
2592 straight, but the scale of the distorted image will vary. The horizon
2593 is anti-aliased, and the 'sky' color may be set using the
cristy82a2ff22015-05-12 16:41:32 +00002594 <a href="command-line-options.html#mattecolor">-mattecolor</a> setting. </td>
cristyd2432012015-05-04 23:15:15 +00002595 </tr>
2596
2597 <tr>
cristyb2cad532015-05-16 13:02:45 +00002598 <td>PerspectiveProjection </td>
cristyd2432012015-05-04 23:15:15 +00002599 <td>
cristyb2cad532015-05-16 13:02:45 +00002600 Do a 'Perspective' distortion biased on a set of 8
cristyd2432012015-05-04 23:15:15 +00002601 pre-calculated coefficients. You can get these coefficients by looking
cristy82a2ff22015-05-12 16:41:32 +00002602 at the <a href="command-line-options.html#verbose">-verbose</a> output of a
cristyb2cad532015-05-16 13:02:45 +00002603 'Perspective' distortion, or by calculating them yourself.
cristyd2432012015-05-04 23:15:15 +00002604 If the last two perspective scaling coefficients are zero, the
2605 remaining 6 represents a transposed 'Affine Matrix'. </td>
2606
2607 </tr>
2608
2609 <tr>
cristyb2cad532015-05-16 13:02:45 +00002610 <td>Arc</td>
cristyd2432012015-05-04 23:15:15 +00002611 <td>
2612 Arc the image (variation of polar mapping) over the angle given around
cristyb2cad532015-05-16 13:02:45 +00002613 a circle.
2614
2615 <p></p><dl class="dl-horizontal">
2616 <dt>arc_angle</dt>
2617 <dd>The angle over which to arc the image side-to-side</dd>
2618 <dt>rotate_angle</dt>
2619 <dd>Angle to rotate resulting image from vertical center</dd>
2620 <dt>top_radius</dt>
2621 <dd>Set top edge of source image at this radius</dd>
2622 <dt>bottom_radius </dt>
2623 <dd>Set bottom edge to this radius (radial scaling)</dd>
2624 </dl>
cristyd2432012015-05-04 23:15:15 +00002625
2626 The resulting image is always resized to best fit the resulting image,
cristy82a2ff22015-05-12 16:41:32 +00002627 (as if using <a href="command-line-options.html#distort">+distort</a>) while attempting to
cristyd2432012015-05-04 23:15:15 +00002628 preserve scale and aspect ratio of the original image as much as
2629 possible with the arguments given by the user. All four arguments will
cristy82a2ff22015-05-12 16:41:32 +00002630 be needed to change the overall aspect ratio of an 'Arc'ed image. <br>
cristyd2432012015-05-04 23:15:15 +00002631
2632 This a variation of a polar distortion designed to try to preserve the
2633 aspect ratio of the image rather than direct Cartesian to Polar
2634 conversion. </td>
2635 </tr>
2636
2637 <tr>
cristyb2cad532015-05-16 13:02:45 +00002638 <td>Polar</td>
cristyd2432012015-05-04 23:15:15 +00002639 <td>
cristyb2cad532015-05-16 13:02:45 +00002640 Like 'Arc' but do a complete Cartesian to Polar mapping of
cristyd2432012015-05-04 23:15:15 +00002641 the image. that is the height of the input image is mapped to the
2642 radius limits, while the width is wrapped around between the
cristy82a2ff22015-05-12 16:41:32 +00002643 angle limits. <br>
cristyd2432012015-05-04 23:15:15 +00002644
cristy82a2ff22015-05-12 16:41:32 +00002645 Arguments: <var>Rmax,Rmin CenterX,CenterY, start,end_angle</var> <br>
cristyd2432012015-05-04 23:15:15 +00002646
2647 All arguments are optional. With <var>Rmin</var> defaulting to zero, the
2648 center to the center of the image, and the angles going from -180 (top)
2649 to +180 (top). If <var>Rmax</var> is given the special value of
cristyb2cad532015-05-16 13:02:45 +00002650 '0', the the distance from the center to the nearest edge
cristyd2432012015-05-04 23:15:15 +00002651 is used for the radius of the output image, which will ensure the whole
2652 image is visible (though scaled smaller). However a special value of
cristyb2cad532015-05-16 13:02:45 +00002653 '-1' will use the distance from the center to the furthest
cristyd2432012015-05-04 23:15:15 +00002654 corner, This may 'clip' the corners from the input rectangular image,
cristyb2cad532015-05-16 13:02:45 +00002655 but will generate the exact reverse of a 'DePolar' with
cristy82a2ff22015-05-12 16:41:32 +00002656 the same arguments. <br>
cristyd2432012015-05-04 23:15:15 +00002657
cristy82a2ff22015-05-12 16:41:32 +00002658 If the plus form of distort (<a href="command-line-options.html#distort">+distort</a>) is used
cristyb2cad532015-05-16 13:02:45 +00002659 output image center will default to 0,0 of the virtual
cristyd2432012015-05-04 23:15:15 +00002660 canvas, and the image size adjusted to ensure the whole input image is
2661 made visible in the output image on the virtual canvas. </td>
2662
2663 </tr>
2664
2665 <tr>
cristyb2cad532015-05-16 13:02:45 +00002666 <td>DePolar</td>
cristyd2432012015-05-04 23:15:15 +00002667 <td>
cristyb2cad532015-05-16 13:02:45 +00002668 Uses the same arguments and meanings as a 'Polar' distortion
cristy82a2ff22015-05-12 16:41:32 +00002669 but generates the reverse Polar to Cartesian distortion. <br>
cristyd2432012015-05-04 23:15:15 +00002670
cristyb2cad532015-05-16 13:02:45 +00002671 The special <var>Rmax</var> setting of '0' may however clip
cristyd2432012015-05-04 23:15:15 +00002672 the corners of the input image. However using the special
cristyb2cad532015-05-16 13:02:45 +00002673 <var>Rmax</var> setting of '-1' (maximum center to corner
cristyd2432012015-05-04 23:15:15 +00002674 distance) will ensure the whole distorted image is preserved in the
cristyb2cad532015-05-16 13:02:45 +00002675 generated result, so that the same argument to 'Polar' will
cristyd2432012015-05-04 23:15:15 +00002676 reverse the distortion re-producing the original.
2677
2678 Note that as this distortion requires the area resampling of a circular
2679 arc, which can not be handled by the builtin EWA resampling function.
2680 As such the normal EWA filters are turned off. It is recommended some
2681 form of 'super-sampling' image processing technique be used to produce
2682 a high quality result. </td>
2683
2684 </tr>
2685
2686 <tr>
cristyb2cad532015-05-16 13:02:45 +00002687 <td>Barrel</td>
cristyd2432012015-05-04 23:15:15 +00002688 <td>
cristy82a2ff22015-05-12 16:41:32 +00002689 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 +00002690 Dersch</a>, perform a barrel or pin-cushion distortion appropriate to
2691 correct radial lens distortions. That is in photographs, make straight
cristy82a2ff22015-05-12 16:41:32 +00002692 lines straight again. <br>
cristyd2432012015-05-04 23:15:15 +00002693
cristyb2cad532015-05-16 13:02:45 +00002694 <p class="text-center">Arguments: <var>A B C</var> [ <var>D</var> [
cristy82a2ff22015-05-12 16:41:32 +00002695 <var>X</var> , <var>Y</var> ] ] <br>
cristyd2432012015-05-04 23:15:15 +00002696 or <var>A<sub>x</sub> B<sub>x</sub> C<sub>x</sub> D<sub>x</sub>
2697 A<sub>y</sub> B<sub>y</sub> C<sub>y</sub> D<sub>y</sub></var>
cristyb2cad532015-05-16 13:02:45 +00002698 [ <var>X</var> , <var>Y</var> ] </p>
2699 So that it forms the function
2700 <p class="text-center">Rsrc = r * ( <var>A</var>*r<sup>3</sup> + <var>B</var>*r<sup>2</sup> +
2701 <var>C</var>*r + <var>D</var> )</p>
cristyd2432012015-05-04 23:15:15 +00002702
2703 Where <var>X</var>,<var>Y</var> is the optional center of the distortion
cristy82a2ff22015-05-12 16:41:32 +00002704 (defaulting to the center of the image). <br>
cristyd2432012015-05-04 23:15:15 +00002705 The second form is typically used to distort images, rather than
cristy82a2ff22015-05-12 16:41:32 +00002706 correct lens distortions. <br>
cristyd2432012015-05-04 23:15:15 +00002707 </td>
2708
2709 </tr>
2710
2711 <tr>
cristyb2cad532015-05-16 13:02:45 +00002712 <td>BarrelInverse</td>
cristyd2432012015-05-04 23:15:15 +00002713 <td>
cristyb2cad532015-05-16 13:02:45 +00002714 This is very similar to 'Barrel' with the same set of
cristyd2432012015-05-04 23:15:15 +00002715 arguments, and argument handling. However it uses the inverse
2716 of the radial polynomial,
cristyb2cad532015-05-16 13:02:45 +00002717 so that it forms the function
2718 <p class="text-center">Rsrc = r / ( <var>A</var>*r<sup>3</sup> + <var>B</var>*r<sup>2</sup> +
2719 <var>C</var>*r + <var>D</var> )</p>
2720 Note that this is not the reverse of the 'Barrel'
cristyd2432012015-05-04 23:15:15 +00002721 distortion, just a different barrel-like radial distortion method.
2722
2723 </td>
2724 </tr>
2725
2726 <tr>
cristyb2cad532015-05-16 13:02:45 +00002727 <td>Shepards</td>
cristyd2432012015-05-04 23:15:15 +00002728 <td>
2729 Distort the given list control points (any number) using an Inverse
cristy82a2ff22015-05-12 16:41:32 +00002730 Squared Distance Interpolation Method (<a href="http://en.wikipedia.org/wiki/Shepard%27s_method">Shepards
cristyd2432012015-05-04 23:15:15 +00002731 Method</a>). The control points in effect do 'localized' displacement
2732 of the image around the given control point (preserving the look and
2733 the rotation of the area near the control points. For best results
2734 extra control points should be added to 'lock' the positions of the
2735 corners, edges and other unchanging parts of the image, to prevent
cristy82a2ff22015-05-12 16:41:32 +00002736 their movement. <br>
cristyd2432012015-05-04 23:15:15 +00002737
2738 The distortion has been likened to 'taffy pulling' using nails, or
2739 pins' stuck in a block of 'jelly' which is then moved to the new
cristy82a2ff22015-05-12 16:41:32 +00002740 position, distorting the surface of the jelly. <br>
cristyd2432012015-05-04 23:15:15 +00002741
cristy82a2ff22015-05-12 16:41:32 +00002742 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
2743 the <a href="command-line-options.html#sparse-color">-sparse-color</a> method of the same name.
cristyd2432012015-05-04 23:15:15 +00002744
2745 </td>
2746 </tr>
2747
2748</table>
2749
2750<p>To print a complete list of distortion methods, use <a href="command-line-options.html#list">-list
2751distort</a>.</p>
2752
2753<p>Many of the above distortion methods such as '<code>Affine</code>',
2754'<code>Perspective</code>', and '<code>Shepards</code>' use a list control points
2755defining how these points in the given image should be distorted in the
2756destination image. Each set of four floating point values represent a source
2757image coordinate, followed immediately by the destination image coordinate.
2758This produces a list of values such as...</p>
cristyb2cad532015-05-16 13:02:45 +00002759<p class="text-center"><var>
cristyd2432012015-05-04 23:15:15 +00002760 U<sub>1</sub>,V<sub>1</sub> X<sub>1</sub>,Y<sub>1</sub>
2761 U<sub>2</sub>,V<sub>2</sub> X<sub>2</sub>,Y<sub>2</sub>
2762 U<sub>3</sub>,V<sub>3</sub> X<sub>3</sub>,Y<sub>3</sub>
2763 ...
2764 U<sub>n</sub>,V<sub>n</sub> X<sub>n</sub>,Y<sub>n</sub>
cristyb2cad532015-05-16 13:02:45 +00002765</var></p>
cristyd2432012015-05-04 23:15:15 +00002766<p>where <var>U,V</var> on the source image is mapped to <var>X,Y</var> on the
2767destination image. </p>
2768
2769<p>For example, to warp an image using '<code>perspective</code>' distortion,
2770needs a list of at least 4 sets of coordinates, or 16 numbers. Here is the
2771perspective distortion of the built-in "rose:" image. Note how spaces were
2772used to group the 4 sets of coordinate pairs, to make it easier to read and
2773understand.</p>
2774
2775<pre>
2776convert rose: -virtual-pixel black \
cristy29dc8652015-05-12 16:26:21 +00002777 -distort Perspective '0,0,0,0 0,45,0,45 69,0,60,10 69,45,60,35' \
2778 rose_3d_rotated.gif"
cristyd2432012015-05-04 23:15:15 +00002779</pre>
2780
2781<p>If more that the required number of coordinate pairs are given for
2782a distortion, the distortion method is 'least squares' fitted to produce the
2783best result for all the coordinate pairs given. If less than the ideal number
2784of points are given, the distort will generally fall back to a simpler form of
2785distortion that can handles the smaller number of coordinates (usually a linear
2786'<code>Affine</code>' distortion). </p>
2787
2788<p>By using more coordinates you can make use of image registration tool to
2789find matching coordinate pairs in overlapping images, so as to improve the
2790'fit' of the distortion. Of course a bad coordinate pair can also make the
2791'fit' worse. Caution is always advised. </p>
2792
2793<p>Colors are acquired from the source image according to a cylindrical
cristy82a2ff22015-05-12 16:41:32 +00002794resampling <a href="command-line-options.html#filter">-filter</a>, using a special technique known as
cristyd2432012015-05-04 23:15:15 +00002795EWA resampling. This produces very high quality results, especially when
2796images become smaller (minified) in the output, which is very common when
2797using '<code>perspective</code>' distortion. For example here we view
2798a infinitely tiled 'plane' all the way to the horizon. </p>
2799
2800<pre>
2801convert -size 90x90 pattern:checkerboard -normalize -virtual-pixel tile \
cristy29dc8652015-05-12 16:26:21 +00002802 -distort perspective '0,0,5,45 89,0,45,46 0,89,0,89 89,89,89,89' \
2803 checks_tiled.jpg
cristyd2432012015-05-04 23:15:15 +00002804</pre>
2805
2806<p>Note that a infinitely tiled perspective images involving the horizon can
2807be very slow, because of the number of pixels that are compressed to generate
2808each individual pixel close to the 'horizon'. You can turn off EWA
cristy82a2ff22015-05-12 16:41:32 +00002809resampling, by specifing the special <a href="command-line-options.html#filter">-filter</a> setting of
cristyd2432012015-05-04 23:15:15 +00002810'<code>point</code>' (recommended if you plan to use super-sampling instead).
2811</p>
2812
2813<p>If an image generates <i>invalid pixels</i>, such as the 'sky' in the last
cristy82a2ff22015-05-12 16:41:32 +00002814example, <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 +00002815what these pixels to be visible, set the color to match the rest of the
2816ground. </p>
2817
2818<p>The output image size will by default be the same as the input image. This
2819means that if the part of the distorted image falls outside the viewed area of
2820the 'distorted space', those parts is clipped and lost. However if you use
cristy82a2ff22015-05-12 16:41:32 +00002821the plus form of the operator (<a href="command-line-options.html#distort">+distort</a>) the operator
cristyd2432012015-05-04 23:15:15 +00002822will attempt (if possible) to show the whole of the distorted image, while
2823retaining a correct 'virtual canvas' offset, for image layering. This offset
cristy82a2ff22015-05-12 16:41:32 +00002824may need to be removed using <a href="command-line-options.html#repage">+repage</a>, to remove if it
cristyd2432012015-05-04 23:15:15 +00002825is unwanted. </p>
2826
cristy82a2ff22015-05-12 16:41:32 +00002827<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,
2828and the <a href="command-line-options.html#fx">-fx</a> equivalent to the distortion, for expert study,
cristyd2432012015-05-04 23:15:15 +00002829and debugging purposes. This many not be available for all distorts. </p>
2830
cristy82a2ff22015-05-12 16:41:32 +00002831<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 +00002832specify the size and the offset of the generated 'viewport' image of the
2833distorted image space.</p>
2834
cristy82a2ff22015-05-12 16:41:32 +00002835<p>Setting a "<code><a href="command-line-options.html#define">-define</a>
cristyd2432012015-05-04 23:15:15 +00002836distort:scale={scale_factor}</code>" will scale the output image (viewport or
2837otherwise) by that factor without changing the viewed contents of the
2838distorted image. This can be used either for 'super-sampling' the image for
2839a higher quality result, or for panning and zooming around the image (with
2840appropriate viewport changes, or post-distort cropping and resizing). </p>
2841
cristy82a2ff22015-05-12 16:41:32 +00002842<p>Setting "<code><a href="command-line-options.html#define">-define</a> resample:verbose=1</code>"
cristyd2432012015-05-04 23:15:15 +00002843will output the cylindrical filter lookup table created by the EWA (Elliptical
2844Weighted Average) resampling algorithm. Note this table uses a squared radius
2845lookup value. This is typically only used for debugging EWA resampling. </p>
2846
2847
2848<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002849 <h3 class="magick-header"><a id="distribute-cache"></a>-distribute-cache <var>port</var></h3>
cristyd2432012015-05-04 23:15:15 +00002850</div>
2851
2852<p class="magick-description">launch a distributed pixel cache server. </p>
2853
2854<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002855 <h3 class="magick-header"><a id="dither"></a>-dither <var>method</var></h3>
cristyd2432012015-05-04 23:15:15 +00002856</div>
2857
2858<p class="magick-description">Apply a Riemersma or Floyd-Steinberg error diffusion dither to
2859images when general color reduction is applied via an option, or automagically
2860when saving to specific formats. This enabled by default.</p>
2861
2862<p>Dithering places two or more colors in neighboring pixels so that to the
2863eye a closer approximation of the images original color is reproduced. This
2864reduces the number of colors needed to reproduce the image but at the cost of
2865a lower level pattern of colors. Error diffusion dithers can use any set of
2866colors (generated or user defined) to an image. </p>
2867
2868<p>Dithering is turned on by default, to turn it off use the plus form of the
2869setting, <a href="command-line-options.html#dither">+dither</a>. This will also also render PostScript
2870without text or graphic aliasing. Disabling dithering often (but not always)
2871leads to faster process, a smaller number of colors, but more cartoon like
2872image coloring. Generally resulting in 'color banding' effects in areas with
2873color gradients. </p>
2874
cristy82a2ff22015-05-12 16:41:32 +00002875<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 +00002876color set they created. These operators are also used as part of automatic
2877color reduction when saving images to formats with limited color support, such
2878as <code>GIF:</code>, <code>XBM:</code>, and others, so dithering may also be used
2879in these cases. </p>
2880
2881<p>Alternatively you can use <a href="command-line-options.html#random-threshold">-random-threshold</a>
cristy82a2ff22015-05-12 16:41:32 +00002882to 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 +00002883patterns, using uniform color maps, rather than specific color maps. </p>
2884
2885
2886<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00002887 <h3 class="magick-header"><a id="draw"></a>-draw <var>string</var></h3>
cristyd2432012015-05-04 23:15:15 +00002888</div>
2889
2890<p class="magick-description">Annotate an image with one or more graphic primitives.</p>
2891
2892<p>Use this option to annotate or decorate an image with one or more graphic
2893primitives. The primitives include shapes, text, transformations, and pixel
2894operations.</p>
2895
2896<p>The shape primitives:</p>
2897
cristyb2cad532015-05-16 13:02:45 +00002898<dl class="dl-horizontal">
2899<dt>point</dt><dd> x,y</dd>
2900<dt>line</dt><dd> x0,y0 x1,y1</dd>
2901<dt>rectangle</dt><dd> x0,y0 x1,y1</dd>
2902<dt>roundRectangle</dt><dd> x0,y0 x1,y1 wc,hc</dd>
2903<dt>arc</dt><dd> x0,y0 x1,y1 a0,a1</dd>
2904<dt>ellipse</dt><dd> x0,y0 rx,ry a0,a1</dd>
2905<dt>circle</dt><dd> x0,y0 x1,y1</dd>
2906<dt>polyline</dt><dd> x0,y0 ... xn,yn</dd>
2907<dt>polygon</dt><dd> x0,y0 ... xn,yn</dd>
2908<dt>bezier</dt><dd> x0,y0 ... xn,yn</dd>
2909<dt>path</dt><dd>specification </dd>
2910<dt>image</dt><dd> operator x0,y0 w,h filename</dd>
2911</dl>
cristyd2432012015-05-04 23:15:15 +00002912
2913<p>The text primitive:</p>
2914
cristyb2cad532015-05-16 13:02:45 +00002915<dl class="dl-horizontal">
2916<dt>text</dt><dd>x0,y0 string</dd>
2917</dl>
cristyd2432012015-05-04 23:15:15 +00002918<p>The text gravity primitive:</p>
2919
cristyb2cad532015-05-16 13:02:45 +00002920<dl class="dl-horizontal">
2921<dt>gravity</dt><dd>NorthWest, North, NorthEast, West, Center, East, SouthWest, South, or SouthEast</dd>
2922</dl>
cristyd2432012015-05-04 23:15:15 +00002923
2924<p>The text gravity primitive only affects the placement of text and does not
cristy82a2ff22015-05-12 16:41:32 +00002925interact 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 +00002926scope to the <a href="command-line-options.html#draw">-draw</a> option in which it appears.</p>
2927
2928<p>The transformation primitives:</p>
2929
cristyb2cad532015-05-16 13:02:45 +00002930<dl class="dl-horizontal">
2931<dt>rotate</dt><dd>degrees</dd>
2932<dt>translate</dt><dd>dx,dy</dd>
2933<dt>scale</dt><dd>sx,sy</dd>
2934<dt>skewX</dt><dd>degrees</dd>
2935<dt>skewY</dt><dd>degrees</dd>
2936</dl>
cristyd2432012015-05-04 23:15:15 +00002937
2938<p>The pixel operation primitives:</p>
2939
cristyb2cad532015-05-16 13:02:45 +00002940<dl class="dl-horizontal">
2941<dt>color</dt><dd>x0,y0 method</dd>
2942<dt>matte</dt><dd>x0,y0 method</dd>
2943</dl>
cristyd2432012015-05-04 23:15:15 +00002944
cristy82a2ff22015-05-12 16:41:32 +00002945<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
2946"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 +00002947
2948<p>A <code>point</code> primitive is specified by a single <var>point</var> in the
2949pixel plane, that is, by an ordered pair of integer coordinates,
2950<var>x</var>,<var>y</var>. (As it involves only a single pixel, a <code>point</code>
cristy82a2ff22015-05-12 16:41:32 +00002951primitive 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 +00002952
2953<p>A <code>line</code> primitive requires a start point and end point.</p>
2954
2955<p>A <code>rectangle</code> primitive is specified by the pair of points at the
2956upper left and lower right corners.</p>
2957
2958<p>A <code>roundRectangle</code> primitive takes the same corner points as
2959a <code>rectangle</code> followed by the width and height of the rounded corners
2960to be removed.</p>
2961
2962<p>The <code>circle</code> primitive makes a disk (filled) or circle (unfilled).
2963Give the center and any point on the perimeter (boundary).</p>
2964
2965<p>The <code>arc</code> primitive is used to inscribe an elliptical segment in
2966to a given rectangle. An <code>arc</code> requires the two corners used for
2967<code>rectangle</code> (see above) followed by the start and end angles of the
2968arc of the segment segment (e.g. 130,30 200,100 45,90). The start and end
2969points produced are then joined with a line segment and the resulting segment
2970of an ellipse is filled.</p>
2971
2972<p>Use <code>ellipse</code> to draw a partial (or whole) ellipse. Give the
2973center point, the horizontal and vertical "radii" (the <var>semi-axes</var> of
2974the ellipse) and start and end angles in degrees (e.g. 100,100 100,150
29750,360).</p>
2976
2977<p>The <code>polyline</code> and <code>polygon</code> primitives require three or
2978more points to define their perimeters. A <code>polyline</code> is simply
2979a <code>polygon</code> in which the final point is not stroked to the start
cristy82a2ff22015-05-12 16:41:32 +00002980point. 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 +00002981a <code>polyline</code> is identical to a <code>polygon</code>. </p>
2982
2983<p>A <var>coordinate</var> is a pair of integers separated by a space or
2984optional comma. </p>
2985
2986<p>As an example, to define a circle centered at 100,100 that extends to
2987150,150 use:</p>
2988
cristy29dc8652015-05-12 16:26:21 +00002989<pre>
2990-draw 'circle 100,100 150,150'
2991</pre>
cristyd2432012015-05-04 23:15:15 +00002992
2993<p>The <code>Bezier</code> primitive creates a spline curve and requires three
2994or points to define its shape. The first and last points are the
2995<var>knots</var> and these points are attained by the curve, while any
2996intermediate coordinates are <var>control points</var>. If two control points
2997are specified, the line between each end knot and its sequentially respective
2998control point determines the tangent direction of the curve at that end. If
2999one control point is specified, the lines from the end knots to the one
3000control point determines the tangent directions of the curve at each end. If
3001more than two control points are specified, then the additional control points
3002act in combination to determine the intermediate shape of the curve. In order
3003to draw complex curves, it is highly recommended either to use the
3004<code>path</code> primitive or to draw multiple four-point bezier segments with
3005the start and end knots of each successive segment repeated. For example:</p>
3006
cristy29dc8652015-05-12 16:26:21 +00003007<pre>
3008-draw 'bezier 20,50 45,100 45,0 70,50'
3009-draw 'bezier 70,50 95,100 95,0 120,50'
3010</pre>
cristyd2432012015-05-04 23:15:15 +00003011
3012<p>A <code>path</code> represents an outline of an object, defined in terms of
3013moveto (set a new current point), lineto (draw a straight line), curveto (draw
3014a Bezier curve), arc (elliptical or circular arc) and closepath (close the
3015current shape by drawing a line to the last moveto) elements. Compound paths
3016(i.e., a path with subpaths, each consisting of a single moveto followed by
3017one or more line or curve operations) are possible to allow effects such as
cristy82a2ff22015-05-12 16:41:32 +00003018<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 +00003019
3020<p>Use <code>image</code> to composite an image with another image. Follow the
3021image keyword with the composite operator, image location, image size, and
3022filename:</p>
3023
cristy29dc8652015-05-12 16:26:21 +00003024<pre>
3025-draw 'image SrcOver 100,100 225,225 image.jpg'
3026</pre>
cristyd2432012015-05-04 23:15:15 +00003027
3028<p>You can use 0,0 for the image size, which means to use the actual
3029dimensions found in the image header. Otherwise, it is scaled to the given
3030dimensions. See <a href="compose.html">Alpha Compositing</a> for
3031a detailed discussion of alpha composition methods that are available. </p>
3032
3033<p>The "special augmented compose operators" such as "dissolve" that require
3034arguments cannot be used at present with the <code>-draw image</code> option.
3035 </p>
3036
3037<p>Use <code>text</code> to annotate an image with text. Follow the text
3038coordinates with a string. If the string has embedded spaces, enclose it in
3039single or double quotes.</p>
3040
3041<p>For example, the following annotates the image with <code>Works like
3042magick!</code> for an image titled <code>bird.miff</code>. </p>
3043
cristy29dc8652015-05-12 16:26:21 +00003044<pre>
3045-draw "text 100,100 'Works like magick!' "
3046</pre>
cristyd2432012015-05-04 23:15:15 +00003047
3048<p>See the <a href="command-line-options.html#annotate">-annotate</a> option for another convenient way
3049to annotate an image with text.</p>
3050
3051<p>The <code>rotate</code> primitive rotates subsequent shape primitives and
cristy82a2ff22015-05-12 16:41:32 +00003052text 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 +00003053option, the origin for transformations is the upper left corner of the
3054region.</p>
3055
3056<p>The <code>translate</code> primitive translates subsequent shape and text
3057primitives.</p>
3058
3059<p>The <code>scale</code> primitive scales them.</p>
3060
3061<p>The <code>skewX</code> and <code>skewY</code> primitives skew them with respect
3062to the origin of the main image or the region.</p>
3063
3064<p>The transformations modify the current affine matrix, which is initialized
3065from the initial affine matrix defined by the <a href="command-line-options.html#affine">-affine</a>
3066option. Transformations are cumulative within the <a href="command-line-options.html#draw">-draw</a>
3067option. The initial affine matrix is not affected; that matrix is only changed
3068by the appearance of another <a href="command-line-options.html#affine">-affine</a> option. If another
3069<a href="command-line-options.html#draw">-draw</a> option appears, the current affine matrix is
3070reinitialized from the initial affine matrix.</p>
3071
3072<p>Use the <code>color</code> primitive to change the color of a pixel to the
3073fill color (see <a href="command-line-options.html#fill">-fill</a>). Follow the pixel coordinate with
3074a method:</p>
3075
3076<pre>
cristy29dc8652015-05-12 16:26:21 +00003077point
3078replace
3079floodfill
3080filltoborder
3081reset
cristyd2432012015-05-04 23:15:15 +00003082</pre>
3083
3084<p>Consider the target pixel as that specified by your coordinate. The
3085<code>point</code> method recolors the target pixel. The <code>replace</code>
3086method recolors any pixel that matches the color of the target pixel.
3087<code>Floodfill</code> recolors any pixel that matches the color of the target
3088pixel and is a neighbor, whereas <code>filltoborder</code> recolors any neighbor
3089pixel that is not the border color. Finally, <code>reset</code> recolors all
3090pixels.</p>
3091
3092<p>Use <code>matte</code> to the change the pixel matte value to transparent.
3093Follow the pixel coordinate with a method (see the <code>color</code> primitive
3094for a description of methods). The <code>point</code> method changes the matte
3095value of the target pixel. The <code>replace</code> method changes the matte
3096value of any pixel that matches the color of the target pixel.
3097<code>Floodfill</code> changes the matte value of any pixel that matches the
3098color of the target pixel and is a neighbor, whereas <code>filltoborder</code>
cristy82a2ff22015-05-12 16:41:32 +00003099changes 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 +00003100matte value of all pixels.</p>
3101
cristy82a2ff22015-05-12 16:41:32 +00003102<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 +00003103respectively. Options are processed in command line order so be sure to use
3104these options <var>before</var> the <a href="command-line-options.html#draw">-draw</a> option.</p>
3105
3106<p>Strings that begin with a number must be quoted (e.g. use '1.png' rather
3107than 1.png).</p>
3108
cristy82a2ff22015-05-12 16:41:32 +00003109<p>Drawing primitives conform to the <a href="magick-vector-graphics.html">Magick
cristyd2432012015-05-04 23:15:15 +00003110Vector Graphics</a> format.</p>
3111
3112
3113<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003114 <h3 class="magick-header"><a id="duplicate"></a>-duplicate <var>count,indexes</var></h3>
cristyd2432012015-05-04 23:15:15 +00003115</div>
3116
3117<p class="magick-description">duplicate an image one or more times.</p>
3118
3119<p>Specify the count and the image to duplicate by its index in the sequence.
3120The first image is index 0. Negative indexes are relative to the end of the
3121sequence, for example, -1 represents the last image of the sequence. Specify
3122a range of images with a dash (e.g. 0-4). Separate indexes with a comma (e.g.
31230,2). Use <code>+duplicate</code> to duplicate the last image in the current
3124image sequence.</p>
3125
3126<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003127 <h3 class="magick-header"><a id="edge"></a>-edge <var>radius</var></h3>
cristyd2432012015-05-04 23:15:15 +00003128</div>
3129
3130<p class="magick-description">detect edges within an image.</p>
3131
3132<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003133 <h3 class="magick-header"><a id="emboss"></a>-emboss <var>radius</var></h3>
cristyd2432012015-05-04 23:15:15 +00003134</div>
3135
3136<p class="magick-description">emboss an image.</p>
3137
3138<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003139 <h3 class="magick-header"><a id="encipher"></a>-encipher <var>filename</var></h3>
cristyd2432012015-05-04 23:15:15 +00003140</div>
3141
3142<p class="magick-description">Encipher pixels for later deciphering by <a href="command-line-options.html#decipher">-decipher</a>.</p>
3143
3144<p>Get the passphrase from the file specified by <var>filename</var>.</p>
3145
cristy82a2ff22015-05-12 16:41:32 +00003146<p>For more information, see the webpage, <a href="http://www.imagemagick.org/www/cipher.html">ImageMagick: Encipher or
cristyd2432012015-05-04 23:15:15 +00003147Decipher an Image</a>.</p>
3148
3149
3150
3151<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003152 <h3 class="magick-header"><a id="encoding"></a>-encoding <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00003153</div>
3154
3155<p class="magick-description">specify the text encoding.</p>
3156
cristyb2cad532015-05-16 13:02:45 +00003157<p>Choose from</p>
3158
3159<pre>
3160AdobeCustom AdobeExpert
3161AdobeStandard AppleRoman
3162BIG5 GB2312
3163Latin 2 None
3164SJIScode Symbol
3165Unicode Wansung
3166</pre>
cristyd2432012015-05-04 23:15:15 +00003167
3168<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003169 <h3 class="magick-header"><a id="endian"></a>-endian <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00003170</div>
3171
3172<p class="magick-description">Specify endianness (<code>MSB</code> or <code>LSB</code>) of the image.</p>
3173
3174<p>To print a complete list of endian types, use the <a href="command-line-options.html#list">-list endian</a> option.</p>
3175
3176<p>Use <a href="command-line-options.html#endian">+endian</a> to revert to unspecified endianness.</p>
3177
3178
3179<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003180 <h3 class="magick-header"><a id="enhance"></a>-enhance</h3>
cristyd2432012015-05-04 23:15:15 +00003181</div>
3182
3183<p class="magick-description">Apply a digital filter to enhance a noisy image.</p>
3184
3185
3186<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003187 <h3 class="magick-header"><a id="equalize"></a>-equalize</h3>
cristyd2432012015-05-04 23:15:15 +00003188</div>
3189
3190<p class="magick-description">perform histogram equalization on the image channel-by-channel.</p>
3191
3192<p>To perform histogram equalization on all channels in concert, transform the
3193image into some other color space, such as HSL, OHTA, YIQ or YUV, then
3194equalize the appropriate intensity-like channel, then convert back to RGB.</p>
3195
3196<p>For example using HSL, we have: ... <code>-colorspace HSL -channel lightness
3197-equalize -colorspace RGB</code> ...</p>
3198
3199<p>For YIQ, YUV and OHTA use the red channel. For example, OHTA is a principal
3200components transformation that puts most of the information in the first
3201channel. Here we have ... <code>-colorspace OHTA -channel red -equalize
3202-colorspace RGB</code> ...</p>
3203
3204<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003205 <h3 class="magick-header"><a id="evaluate"></a>-evaluate <var>operator value</var></h3>
cristyd2432012015-05-04 23:15:15 +00003206</div>
3207
3208<p class="magick-description">Alter channel pixels by evaluating an arithmetic, relational, or logical expression.</p>
3209
cristy82a2ff22015-05-12 16:41:32 +00003210<p>(See the <a href="command-line-options.html#function">-function</a> operator for some
3211multi-parameter functions. See the <a href="command-line-options.html#fx">-fx</a> operator if more
cristyd2432012015-05-04 23:15:15 +00003212elaborate calculations are needed.)</p>
3213
3214<p>The behaviors of each <var>operator</var> are summarized in the
3215following list. For brevity, the numerical value of a "pixel" referred to
3216below is the value of the corresponding channel of that pixel, while
3217a "normalized pixel" is that number divided by the maximum
3218(installation-dependent) value <var>QuantumRange</var>. (If
3219normalized pixels are used, they are restored, following the other
3220calculations, to the full range by multiplying by <var>QuantumRange</var>.)</p>
3221
3222<table class="table table-condensed table-striped">
cristy82a2ff22015-05-12 16:41:32 +00003223 <col width="25%">
3224 <col width="75%">
cristyd2432012015-05-04 23:15:15 +00003225 <thead>
3226 <tr>
3227 <th><var>operator</var></th>
3228 <th>Summary (see further below for details)</th>
3229 </tr>
3230 </thead>
3231 <tbody>
3232
3233 <tr><td>Abs </td> <td>Add <var>value</var> to pixels and return absolute value. </td></tr>
3234 <tr><td>Add </td> <td>Add <var>value</var> to pixels. </td></tr>
3235 <tr><td>AddModulus </td> <td>Add <var>value</var> to pixels modulo <var>QuantumRange</var>.</td></tr>
3236 <tr><td>And </td> <td>Binary AND of pixels with <var>value</var>.</td></tr>
3237 <tr><td>Cos, Cosine </td> <td>Apply cosine to pixels with frequency <var>value</var> with 50% bias added.</td></tr>
3238 <tr><td>Divide </td> <td>Divide pixels by <var>value</var>.</td></tr>
3239 <tr><td>Exp </td> <td>base-e exponential function</td></tr>
3240 <tr><td>Exponential </td> <td>base-e exponential function</td></tr>
3241 <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>
3242 <tr><td>Log </td> <td>Apply scaled logarithm to normalized pixels.</td></tr>
3243 <tr><td>Max </td> <td>Clip pixels at lower bound <var>value</var>.</td></tr>
3244 <tr><td>Mean </td> <td>Add the <var>value</var> and divide by 2.</td></tr>
3245 <tr><td>Median </td> <td>Choose the median value from an image sequence.</td></tr>
3246 <tr><td>Min </td> <td>Clip pixels at upper bound <var>value</var>.</td></tr>
3247 <tr><td>Multiply </td> <td>Multiply pixels by <var>value</var>.</td></tr>
3248 <tr><td>Or </td> <td>Binary OR of pixels with <var>value</var>.</td></tr>
3249 <tr><td>Pow </td> <td>Raise normalized pixels to the power <var>value</var>.</td></tr>
3250 <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>
3251 <tr><td>RMS</td> <td>Square the pixel and add the <var>value</var>.</td></tr>
3252 <tr><td>RootMeanSquare</td> <td>Square the pixel and add the <var>value</var>.</td></tr>
3253 <tr><td>Set </td> <td>Set pixel equal to <var>value</var>.</td></tr>
3254 <tr><td>Sin, Sine </td> <td>Apply sine to pixels with frequency <var>value</var> with 50% bias added.</td></tr>
3255 <tr><td>Subtract </td> <td>Subtract <var>value</var> from pixels.</td></tr>
3256 <tr><td>Xor </td> <td>Binary XOR of pixels with <var>value.</var></td></tr>
3257
cristya1890f02015-05-15 23:32:44 +00003258 <tr><td> </td><td> </td></tr>
cristyd2432012015-05-04 23:15:15 +00003259
cristy29dc8652015-05-12 16:26:21 +00003260 <tr><td>Gaussian-noise</td><td> </td></tr>
3261 <tr><td>Impulse-noise</td><td> </td></tr>
3262 <tr><td>Laplacian-noise</td><td> </td></tr>
cristy82a2ff22015-05-12 16:41:32 +00003263 <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 +00003264 <tr><td>PoissonNoise</td><td> </td></tr>
3265 <tr><td>Uniform-noise</td><td> </td></tr>
cristyd2432012015-05-04 23:15:15 +00003266
cristya1890f02015-05-15 23:32:44 +00003267 <tr><td> </td><td> </td></tr>
cristyd2432012015-05-04 23:15:15 +00003268
3269 <tr><td>Threshold </td> <td>Threshold pixels larger than <var>value</var>.</td></tr>
3270 <tr><td>ThresholdBlack </td> <td>Threshold pixels to zero values equal to or below <var>value</var>.</td></tr>
3271 <tr><td>ThresholdWhite </td> <td>Threshold pixels to maximum values above <var>value</var>. </td></tr>
3272 </tbody>
3273 </table>
3274
cristy82a2ff22015-05-12 16:41:32 +00003275<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 +00003276calculations are truncated (clipped) to fit in the interval [0, <var>QuantumRange</var>]. The transparency channel of the image is
3277represented as a 'alpha' values (0 = fully transparent), so, for example, a
3278<code>Divide</code> by 2 of the alpha channel will make the image
3279semi-transparent. Append the percent symbol '<code>%</code>' to specify a value
3280as a percentage of the <var>QuantumRange</var>.</p>
3281
3282<p>To print a complete list of <a href="command-line-options.html#evaluate">-evaluate</a> operators, use
3283<a href="command-line-options.html#list">-list evaluate</a>.</p>
3284
3285<p>The results of the <code>Add</code>, <code>Subtract</code> and
cristy82a2ff22015-05-12 16:41:32 +00003286<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 +00003287appropriate argument, to linearly modify the overall range of color values.
cristy82a2ff22015-05-12 16:41:32 +00003288Please note, however, that <a href="command-line-options.html#level">-level</a> treats transparency as
3289'matte' values (0 = opaque), while <a href="command-line-options.html#level">-evaluate</a> works with
cristyd2432012015-05-04 23:15:15 +00003290'alpha' values.</p>
3291
3292<p><code>AddModulus</code> has been added as of ImageMagick 6.4.8-4 and provides
3293addition modulo the <var>QuantumRange</var>. It is therefore
3294equivalent to <code>Add</code> unless the resulting pixel value is outside the
3295interval [0, <var>QuantumRange</var>]. </p>
3296
3297<p><code>Exp or Exponential</code> has been added as of ImageMagick 6.6.5-1 and
3298works on normalized pixel values. The <var>value</var> used with
3299<code>Exp</code> should be negative so as to produce a decaying exponential
3300function. Non-negative values will always produce results larger unity and
3301thus outside the interval [0, <var>QuantumRange</var>]. The
3302formula is expressed below. </p>
3303
cristya1890f02015-05-15 23:32:44 +00003304<p class="text-center">
3305exp(<var>value</var> × <b><var>u</var></b>)
3306</p>
cristyd2432012015-05-04 23:15:15 +00003307
cristy82a2ff22015-05-12 16:41:32 +00003308<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 +00003309the result.</p>
3310
3311<p><code>Log</code> has been added as of ImageMagick 6.4.2-1 and works on
3312normalized pixel values. This a <var>scaled</var> log function. The <var>value</var> used with <code>Log</code> provides a <var>scaling
3313factor</var> that adjusts the curvature in the graph of the log function. The
3314formula applied to a normalized value <b><var>u</var></b> is below. </p>
3315
cristya1890f02015-05-15 23:32:44 +00003316<p class="text-center">
3317log(<var>value</var> × <b><var>u</var></b> + 1) / log(<var>value</var> + 1)
3318</p>
cristyd2432012015-05-04 23:15:15 +00003319
3320<p><code>Pow</code> has been added as of ImageMagick 6.4.1-9, and works on
cristy82a2ff22015-05-12 16:41:32 +00003321normalized 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 +00003322to <b>-evaluate pow 0.5</b>, i.e., a 'square root' function. The value used
cristy82a2ff22015-05-12 16:41:32 +00003323with <a href="command-line-options.html#gamma">-gamma</a> is simply the reciprocal of the value used
cristyd2432012015-05-04 23:15:15 +00003324with <code>Pow</code>.</p>
3325
3326<p><code>Cosine</code> and <code>Sine</code> was added as of IM v6.4.8-8 and
3327converts the image values into a value according to a (co)sine wave function.
3328The synonyms <code>Cos</code> and <code>Sin</code> may also be used. The output
3329is biased 50% and normalized by 50% so as to fit in the respective color value
3330range. The <var>value</var> scaling of the <var>period</var> of the
3331function (its frequency), and thus determines the number of 'waves' that will
3332be 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,
3333then the effective period is the <var>half</var> the <var>QuantumRange</var>.</p>
3334
cristya1890f02015-05-15 23:32:44 +00003335<p class="text-center">
33360.5 + 0.5 × cos(2 π <b><var>u</var></b> × <var>value</var>).
3337</p>
cristyd2432012015-05-04 23:15:15 +00003338
cristy82a2ff22015-05-12 16:41:32 +00003339<p>See also the <a href="command-line-options.html#function">-function</a> operator, which is a
cristyd2432012015-05-04 23:15:15 +00003340multi-value version of evaluate. </p>
3341
3342<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003343 <h3 class="magick-header"><a id="evaluate-sequence"></a>-evaluate-sequence <var>operator</var></h3>
cristyd2432012015-05-04 23:15:15 +00003344</div>
3345
3346<p class="magick-description">Alter channel pixels by evaluating an arithmetic, relational, or
3347logical expression over a sequence of images.</p>
3348
cristy82a2ff22015-05-12 16:41:32 +00003349<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 +00003350
3351<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003352 <h3 class="magick-header"><a id="extent"></a>-extent <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00003353</div>
3354
3355<p class="magick-description">Set the image size and offset.</p>
3356
3357<p>If the image is enlarged, unfilled areas are set to the background color.
3358To position the image, use offsets in the <var>geometry</var>
3359specification or precede with a <a href="command-line-options.html#gravity">-gravity</a> setting. To
cristy82a2ff22015-05-12 16:41:32 +00003360specify 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 +00003361
3362<p>This command reduces or expands a JPEG image to fit on an 800x600
3363display. If the aspect ratio of the input image isn't exactly 4:3, then the
3364image is centered on an 800x600 black canvas: </p>
3365
3366<pre>
3367convert input.jpg -resize 800x600 -background black -compose Copy \
3368 -gravity center -extent 800x600 -quality 92 output.jpg
3369</pre>
3370
3371<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
3372
3373<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003374 <h3 class="magick-header"><a id="extract"></a>-extract <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00003375</div>
3376
3377<p class="magick-description">Extract the specified area from image.</p>
3378
3379<p>This option is most useful for extracting a subregion of a very large raw
3380image. Note that these two commands are equivalent:</p>
3381
3382<pre>
3383convert -size 16000x16000 -depth 8 -extract 640x480+1280+960 \
3384 image.rgb image.png",
3385convert -size 16000x16000 -depth 8 'image.rgb[640x480+1280+960]' \
3386 image.rgb image.png"
3387</pre>
3388
3389<p>If you omit the offsets, as in</p>
3390
3391<pre>
3392convert -size 16000x16000 -depth 8 -extract 640x480 \
3393 image.rgb image.png
3394</pre>
3395
3396<p>the image is <var>resized</var> to the specified dimensions instead,
3397equivalent to:</p>
3398
3399<pre>
3400convert -size 16000x16000 -depth 8 -resize 640x480 image.rgb image.png
3401</pre>
3402
3403<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
3404
3405<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003406 <h3 class="magick-header"><a id="family"></a>-family <var>fontFamily</var></h3>
cristyd2432012015-05-04 23:15:15 +00003407</div>
3408
3409<p class="magick-description">Set a font family for text.</p>
3410
3411<p>This setting suggests a font family that ImageMagick should try to use for
3412rendering text. If the family can be found it is used; if not, a default font
3413(e.g., "Arial") or a family known to be similar is substituted (e.g.,
3414"Courier" might be used if "System" is requested but not found). </p>
3415
cristy82a2ff22015-05-12 16:41:32 +00003416<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 +00003417
3418<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003419 <h3 class="magick-header"><a id="features"></a>-features <var>distance</var></h3>
cristyd2432012015-05-04 23:15:15 +00003420</div>
3421
3422<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>
3423
3424<pre>
cristyb2cad532015-05-16 13:02:45 +00003425Angular Second Moment Sum Entropy
3426Contrast Entropy
3427Correlation Difference Variance
3428Sum of Squares Variance Difference Entropy
3429Inverse Difference Moment Information Measure of Correlation 1
3430Sum Average Information Measure of Correlation 2
3431Sum Variance Maximum Correlation Coefficient
cristyd2432012015-05-04 23:15:15 +00003432</pre>
3433
cristyd2432012015-05-04 23:15:15 +00003434<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003435 <h3 class="magick-header"><a id="fft"></a>-fft</h3>
cristyd2432012015-05-04 23:15:15 +00003436</div>
3437
3438<p class="magick-description">implements the forward discrete Fourier transform (DFT).</p>
3439
3440<p>This option is new as of ImageMagick 6.5.4-3 (and now working for Windows
3441users in ImageMagick 6.6.0-9). It transforms an image from the normal
3442(spatial) domain to the frequency domain. In the frequency domain, an image is
3443represented as a superposition of complex sinusoidal waves of varying
3444amplitudes. The image x and y coordinates are the possible frequencies along
3445the x and y directions, respectively, and the pixel intensity values are
3446complex numbers that correspond to the sinusoidal wave amplitudes. See for
3447example, <a href="http://en.wikipedia.org/wiki/Fourier_transform">Fourier
3448Transform</a>, <a href="http://en.wikipedia.org/wiki/DFT">Discrete Fourier
3449Transform</a> and <a href="http://en.wikipedia.org/wiki/FFT">Fast Fourier
3450Transform</a>.</p>
3451
3452<p>A single image name is provided as output for this option. However, the
3453output result will have two components. It is either a two-frame image or two
3454separate images, depending upon whether the image format specified supports
3455multi-frame images. The reason that we get a dual output result is because the
3456frequency domain represents an image using complex numbers, which cannot be
3457visualized directly. Therefore, the complex values are automagically separated
3458into a two-component image representation. The first component is the
3459magnitude of the complex number and the second is the phase of the complex
cristy82a2ff22015-05-12 16:41:32 +00003460number. See for example, <a href="http://en.wikipedia.org/wiki/Complex_numbers">Complex Numbers</a>.</p>
cristyd2432012015-05-04 23:15:15 +00003461
3462<p>The magnitude and phase component images must be specified using image
3463formats that do not limit the color or compress the image. Thus, MIFF, TIF,
3464PFM, EXR and PNG are the recommended image formats to use. All of these
3465formats, except PNG support multi-frame images. So for example,</p>
3466
3467<pre>
3468convert image.png -fft fft_image.miff
3469</pre>
3470
3471<p>generates a magnitude image as <code>fft_image.miff[0]</code> and a phase
3472image as <code>fft_image.miff[1]</code>. Similarly,</p>
3473
3474<pre>
3475convert image.png -fft fft_image.png
3476</pre>
3477
3478<p>generates a magnitude image as <code>fft_image-0.png</code> and a phase image
3479as <code>fft_image-1.png</code>. If you prefer this representation, then you can
cristy82a2ff22015-05-12 16:41:32 +00003480force 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 +00003481
3482<p>The input image can be any size, but if not square and even-dimensioned, it
3483is padded automagically to the larger of the width or height of the input
3484image and to an even number of pixels. The padding will occur at the bottom
3485and/or right sides of the input image. The resulting output magnitude and
cristy82a2ff22015-05-12 16:41:32 +00003486phase 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 +00003487
3488<p>Both output components will have dynamic ranges that fit within
3489[0, <var>QuantumRange</var>], so that HDRI need not be enabled.
3490Phase values nominally range from 0 to 2*π, but is scaled to span the full
3491dynamic range. (The first few releases had non-HDRI scaled but HDRI not
3492scaled). The magnitude image is not scaled and thus generally will contain
3493very small values. As such, the image normally will appear totally black. In
3494order to view any detail, the magnitude image typically is enhanced with a log
3495function into what is usually called the spectrum. A log function is used to
3496enhance the darker values more in comparison to the lighter values. This can
3497be done, for example, as follows:</p>
3498
3499<pre>
3500convert fft_image.miff[0] -contrast-stretch 0 \
3501 -evaluate log 1000 fft_image_spectrum.png"
3502</pre>
3503
cristy82a2ff22015-05-12 16:41:32 +00003504<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 +00003505range, first. The argument to the <a href="command-line-options.html#evaluate">-evaluate</a> log
3506typically is specified between 100 and 10,000, depending upon the amount of
3507detail that one wants to bring out in the spectrum. Larger values produce more
3508visible detail. Too much detail, however, may hide the important features.</p>
3509
3510<p>The <a href="http://www.fftw.org/">FFTW</a> delegate library is required to
3511use <a href="command-line-options.html#fft">-fft</a>.</p>
3512
3513<p>Use <a href="command-line-options.html#fft">+fft</a> to produce two output images that are the real
3514and imaginary components of the complex valued Fourier transform.</p>
3515
3516<p>However, as the real and imaginary components can contain negative values,
3517this requires that IM be configured with HDRI enabled. In this case, you must
3518use either MIFF, TIF, PFM or MPC formats for the real and imaginary component
3519results, since they are formats that preserve both negative and fractional
3520values without clipping them or truncating the fractional part. With either
3521MIFF or TIF, one should add -define quantum:format=32, to allow those image
3522types to work properly in HDRI mode without clipping.</p>
3523
cristy82a2ff22015-05-12 16:41:32 +00003524<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 +00003525padding that was discussed above for the magnitude and phase component
3526images.</p>
3527
cristy82a2ff22015-05-12 16:41:32 +00003528<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
3529about 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 +00003530 entry. </p>
3531
cristy82a2ff22015-05-12 16:41:32 +00003532<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 +00003533
3534
3535<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003536 <h3 class="magick-header"><a id="fill"></a>-fill <var>color</var></h3>
cristyd2432012015-05-04 23:15:15 +00003537</div>
3538
3539<p class="magick-description">color to use when filling a graphic primitive.</p>
3540
3541<p>This option accepts a color name, a hex color, or a numerical RGB, RGBA,
cristy82a2ff22015-05-12 16:41:32 +00003542HSL, HSLA, CMYK, or CMYKA specification. See <a href="color.html">Color Names</a> for
cristyd2432012015-05-04 23:15:15 +00003543a description of how to properly specify the color argument.</p>
3544
3545<p>Enclose the color specification in quotation marks to prevent the "#" or
3546the parentheses from being interpreted by your shell.</p>
3547
3548<p>For example,</p>
3549
cristy29dc8652015-05-12 16:26:21 +00003550<pre>
3551-fill blue
3552-fill "#ddddff"
3553-fill "rgb(255,255,255)"
3554</pre>
cristyd2432012015-05-04 23:15:15 +00003555
3556<p>See <a href="command-line-options.html#draw">-draw</a> for further details.</p>
3557
3558<p>To print a complete list of color names, use the <a href="command-line-options.html#list">-list color</a> option.</p>
3559
3560<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003561 <h3 class="magick-header"><a id="filter"></a>-filter <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00003562</div>
3563
3564<p class="magick-description">Use this <var>type</var> of filter when resizing or distorting an image.</p>
3565
3566<p>Use this option to affect the resizing operation of an image during
cristy82a2ff22015-05-12 16:41:32 +00003567operations 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 +00003568
3569<pre>
cristy29dc8652015-05-12 16:26:21 +00003570Point Hermite Cubic
3571Box Gaussian Catrom
3572Triangle Quadratic Mitchell
cristyd2432012015-05-04 23:15:15 +00003573</pre>
3574
3575<p>The <code>Bessel</code> and <code>Sinc</code> filter is also provided (as well
3576as a faster <code>SincFast</code> equivalent form). However these filters are
3577generally useless on their own as they are infinite filters that are being
3578clipped to the filters support size. Their direct use is not recommended
3579except via expert settings (see below). </p>
3580
3581<p>Instead these special filter functions are typically windowed by a windowing
cristy82a2ff22015-05-12 16:41:32 +00003582function that the <a href="command-line-options.html#filter">-filter</a> setting defines. That is
cristyd2432012015-05-04 23:15:15 +00003583using these functions will define a 'Windowed' filter, appropriate to the
3584operator involved. Windowed filters include: </p>
3585
3586<pre>
cristy29dc8652015-05-12 16:26:21 +00003587Lanczos Hamming Parzen
3588Blackman Kaiser Welsh
3589Hanning Bartlett Bohman
cristyd2432012015-05-04 23:15:15 +00003590</pre>
3591
3592<p>Also one special self-windowing filter is also provided
3593<code>Lagrange</code>, which will automagically re-adjust its function depending
3594on the current 'support' or 'lobes' expert settings (see below).</p>
3595
3596<p>If you do not select a filter with this option, the filter defaults to
3597<code>Mitchell</code> for a colormapped image, an image with a matte channel, or
3598if the image is enlarged. Otherwise the filter default to
3599<code>Lanczos</code>.</p>
3600
3601<p>To print a complete list of resize filters, use the <a href="command-line-options.html#list">-list
3602filter</a> option.</p>
3603
3604<p>You can modify how the filter behaves as it scales your image through the
cristy82a2ff22015-05-12 16:41:32 +00003605use 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 +00003606
cristy29dc8652015-05-12 16:26:21 +00003607<table class="table table-condensed table-striped">
3608 <tr>
3609 <td>-define filter:blur=<var>factor</var></td>
3610 <td>Scale the X axis of the filter (and its window). Use &gt; 1.0 for
cristyd2432012015-05-04 23:15:15 +00003611 blurry or &lt; 1.0 for sharp. This should only be used with Gaussian and
3612 Gaussian-like filters simple filters, or you may not get the expected
cristy29dc8652015-05-12 16:26:21 +00003613 results. </td>
3614 </tr>
cristyd2432012015-05-04 23:15:15 +00003615
cristy29dc8652015-05-12 16:26:21 +00003616 <tr>
3617 <td>-define filter:support=<var>radius</var></td>
3618 <td>Set the filter support radius. Defines how large the filter should be and
cristyd2432012015-05-04 23:15:15 +00003619 thus directly defines how slow the filtered resampling process is. All
3620 filters have a default 'prefered' support size. Some filters like
3621 <code>Lagrange</code> and windowed filters adjust themselves depending on
3622 this value. With simple filters this value either does nothing (but slow
3623 the resampling), or will clip the filter function in a detrimental way.
cristy29dc8652015-05-12 16:26:21 +00003624 </td>
3625 </tr>
cristyd2432012015-05-04 23:15:15 +00003626
cristy29dc8652015-05-12 16:26:21 +00003627 <tr>
3628 <td>-define filter:lobes=<var>count</var></td>
3629 <td>Set the number of lobes to use for the Sinc/Bessel filter. This an
cristyd2432012015-05-04 23:15:15 +00003630 alternative way of specifying the 'support' range of the filter, that is
3631 designed to be more suited to windowed filters, especially when used for
cristy29dc8652015-05-12 16:26:21 +00003632 image distorts.</td>
3633 </tr>
cristyd2432012015-05-04 23:15:15 +00003634
cristy29dc8652015-05-12 16:26:21 +00003635 <tr>
3636 <td>-define filter:sigma=<var>value</var></td>
3637 <td>The 'sigma' value used to define the <code>Gaussian</code> filter. Default
cristyd2432012015-05-04 23:15:15 +00003638 sigma value is '<code>0.5</code>'. It only effects <code>Gaussian</code> but
3639 does not shrink (but may enlarge) the filter's 'support'. It can be used
3640 to generate very small blurs but without the filter 'missing' pixels due
3641 to using a small support setting. A larger value of '<code>0.707</code>'
cristy29dc8652015-05-12 16:26:21 +00003642 (a value of '1/sqrt(2)') is another common setting. </td>
3643 </tr>
cristyd2432012015-05-04 23:15:15 +00003644
cristy29dc8652015-05-12 16:26:21 +00003645 <tr>
3646 <td>-define filter:b=<var>b-spline_factor</var></td>
cristy82a2ff22015-05-12 16:41:32 +00003647 </tr><tr>
cristy29dc8652015-05-12 16:26:21 +00003648 <td>-define filter:c=<var>keys_alpha_factor</var></td>
3649 <td>Redefine the values used for cubic filters such as <code>Cubic</code>,
cristyd2432012015-05-04 23:15:15 +00003650 <code>Catrom</code>, <code>Mitchel</code>, and <code>Hermite</code>, as well as
3651 the <code>Parzen</code> cubic windowing function. If only one of the values
3652 are defined, the other is set so as to generate a 'Cubic-Keys' filter.
3653 The values meaning was defined by a research paper by
cristy29dc8652015-05-12 16:26:21 +00003654 Mitchell-Netravali.</td>
3655 </tr>
cristyd2432012015-05-04 23:15:15 +00003656
cristy29dc8652015-05-12 16:26:21 +00003657 <tr>
3658 <td>-define filter:kaiser-beta=<var>value</var></td>
3659 <td>The 'alpha' value used to as part of the Kaiser Windowing function.
cristyd2432012015-05-04 23:15:15 +00003660 Default value is '6.5'. It only effects Kaiser windowing function, and
cristy29dc8652015-05-12 16:26:21 +00003661 does not effect any other attributes.
3662 Before ImageMagick v6.7.6-10, this option was known as "filter:alpha", (an
cristyd2432012015-05-04 23:15:15 +00003663 inheritance from the very old "zoom" program). It was changed to bring the
3664 function in line with more modern academic research usage, and better
cristy29dc8652015-05-12 16:26:21 +00003665 assign it be more definitive. </td>
3666 </tr>
cristyd2432012015-05-04 23:15:15 +00003667
cristy29dc8652015-05-12 16:26:21 +00003668 <tr>
3669 <td>-define filter:kaiser-alpha=<var>value</var></td>
3670 <td>This value when multiplied by 'PI' is equivalent to "kaiser-beta", and
cristyd2432012015-05-04 23:15:15 +00003671 will override that setting. It only effects Kaiser windowing function,
cristy29dc8652015-05-12 16:26:21 +00003672 and does not effect any other attributes. </td>
3673 </tr>
cristyd2432012015-05-04 23:15:15 +00003674
cristy29dc8652015-05-12 16:26:21 +00003675 <tr>
3676 <td>-define filter:filter=<var>filter_function</var></td>
3677 <td>Use this function directly as the weighting filter. This will allow
cristyd2432012015-05-04 23:15:15 +00003678 you to directly use a windowing function such as <code>Blackman</code>,
3679 as a resampling filter, rather than as its normal usage as a windowing
cristy29dc8652015-05-12 16:26:21 +00003680 function. If defined, no windowing function also defined, the window function is set
cristyd2432012015-05-04 23:15:15 +00003681 to <code>Box</code>). Directly specifying <code>Sinc</code> or <code>Jinc</code>
cristy29dc8652015-05-12 16:26:21 +00003682 as a filter will also do this. </td>
3683 </tr>
cristyd2432012015-05-04 23:15:15 +00003684
cristy29dc8652015-05-12 16:26:21 +00003685 <tr>
3686 <td>-define filter:window=<var>filter_function</var></td>
3687 <td>The IIR (infinite impulse response) filters <code>Sinc</code> and
cristyd2432012015-05-04 23:15:15 +00003688 <code>Jinc</code> are windowed (brought down to zero over the defined
3689 support range) with the given filter. This allows you to specify a filter
cristy29dc8652015-05-12 16:26:21 +00003690 function to be used as a windowing function for these IIR filters.
3691 Many of the defined filters are actually windowing functions for these IIR
cristyd2432012015-05-04 23:15:15 +00003692 filters. A typical choices is <code>Box</code>, (which effectively turns
cristy29dc8652015-05-12 16:26:21 +00003693 off the windowing function). </td>
3694 </tr>
cristyd2432012015-05-04 23:15:15 +00003695
cristy29dc8652015-05-12 16:26:21 +00003696 <tr>
3697 <td>-define filter:win-support=<var>radius</var></td>
3698 <td>Scale windowing function to this size instead. This causes the windowing
cristyd2432012015-05-04 23:15:15 +00003699 (or self-windowing Lagrange filter) to act is if the support window is
3700 larger than what is actually supplied to the calling operator. The filter
3701 however is still clipped to the real support size given. If unset this
cristy29dc8652015-05-12 16:26:21 +00003702 will equal the normal filter support size. </td>
3703 </tr>
cristyd2432012015-05-04 23:15:15 +00003704
cristy29dc8652015-05-12 16:26:21 +00003705 <tr>
3706 <td>-define filter:verbose=<var>1</var></td>
3707 <td>This causes IM to print information on the final internal filter
cristyd2432012015-05-04 23:15:15 +00003708 selection to standard output. This includes a commented header on the
3709 filter settings being used, and data allowing the filter weights to be
cristy29dc8652015-05-12 16:26:21 +00003710 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 +00003711 a <code>SincFast</code> windowed <code>SincFast</code> filter, while
3712 <code>Mitchell</code> is defined as a general <code>Cubic</code> family filter
cristy29dc8652015-05-12 16:26:21 +00003713 with specific 'B' and 'C' settings. </td>
3714 </tr>
cristyd2432012015-05-04 23:15:15 +00003715
cristy29dc8652015-05-12 16:26:21 +00003716</table>
cristyd2432012015-05-04 23:15:15 +00003717
3718<p>For example, to get a 8 lobe jinc windowed sinc filter (Genseng filter?):</p>
3719
3720<pre>
3721convert image.png \
3722 -filter sinc \
3723 -set filter:window=jinc \
3724 -set filter:lobes=8 \
3725 -resize 150% image.jpg"
3726</pre>
3727
3728<p>Or a raw un-windowed Sinc filter with 4 lobes:</p>
3729
3730<pre>
3731convert image.png \
3732 -set filter:filter=sinc \
3733 -set filter:lobes=4 \
3734 -resize 150% image.jpg"
3735</pre>
3736
3737<p>To extract the data for a raw windowing function, combine it with
3738a '<code>Box</code>' filter. For example the '<code>Welch</code> parabolic
3739windowing function. </p>
3740
3741<pre>
3742convert null: -define filter:filter=Box \
3743 -define filter:window=Welch \
3744 -define filter:support=1.0 \
3745 -define filter:verbose=1 \
cristy82a2ff22015-05-12 16:41:32 +00003746 -resize 2 null: &gt; window_welch.dat
cristyd2432012015-05-04 23:15:15 +00003747gnuplot
3748 set grid
3749 plot \"window_welch.dat\" with lines
3750</pre>
3751
3752<p>Note that the use of expert options is provided for image processing experts
3753who have studied and understand how resize filters work. Without this
3754knowledge, and an understanding of the definition of the actual filters
3755involved, using expert settings are more likely to be detrimental to your image
3756resizing.</p>
3757
3758
3759<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003760 <h3 class="magick-header"><a id="flatten"></a>-flatten</h3>
cristyd2432012015-05-04 23:15:15 +00003761</div>
3762
cristy82a2ff22015-05-12 16:41:32 +00003763<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 +00003764
3765
3766<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003767 <h3 class="magick-header"><a id="flip"></a>-flip</h3>
cristyd2432012015-05-04 23:15:15 +00003768</div>
3769
3770<p class="magick-description">create a <var>mirror image</var></p>
3771
3772<p>reflect the scanlines in the vertical direction. The image will be mirrored
3773upside-down. </p>
3774
3775
3776<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003777 <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 +00003778</div>
3779
3780<p class="magick-description">floodfill the image with color at the specified offset.</p>
3781
3782<p>Flood fill starts from the given 'seed point' which is not gravity effected.
cristy82a2ff22015-05-12 16:41:32 +00003783Any color that matches within <a href="command-line-options.html#fuzz">-fuzz</a> color distance of the
cristyd2432012015-05-04 23:15:15 +00003784given <var>color</var> argument, connected to that 'seed point'
cristy82a2ff22015-05-12 16:41:32 +00003785will be replaced with the current <a href="command-line-options.html#fill">-fill</a> color. </p>
cristyd2432012015-05-04 23:15:15 +00003786
3787<p>Note that if the pixel at the 'seed point' does not itself match the given
cristy82a2ff22015-05-12 16:41:32 +00003788<var>color</var> (according to <a href="command-line-options.html#fuzz">-fuzz</a>), then no
cristyd2432012015-05-04 23:15:15 +00003789action will be taken. </p>
3790
cristy82a2ff22015-05-12 16:41:32 +00003791<p>This operator works more like the <a href="command-line-options.html#opaque">-opaque</a> option, than
cristyd2432012015-05-04 23:15:15 +00003792a more general flood fill that reads the matching color directly at the 'seed
cristy82a2ff22015-05-12 16:41:32 +00003793point'. For this form of flood fill, look at <a href="command-line-options.html#draw">-draw</a> and
cristyd2432012015-05-04 23:15:15 +00003794its 'color floodfill' drawing method. </p>
3795
3796
3797<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003798 <h3 class="magick-header"><a id="flop"></a>-flop</h3>
cristyd2432012015-05-04 23:15:15 +00003799</div>
3800
3801<p class="magick-description">create a <var>mirror image</var>.</p>
3802
3803<p>Reflect the scanlines in the horizontal direction, just like the image in
3804a vertical mirror. </p>
3805
3806
3807<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003808 <h3 class="magick-header"><a id="font"></a>-font <var>name</var></h3>
cristyd2432012015-05-04 23:15:15 +00003809</div>
3810
3811<p class="magick-description">set the font to use when annotating images with text, or creating labels.</p>
3812
3813<p>To print a complete list of fonts, use the <a href="command-line-options.html#list">-list font</a>
3814option (for versions prior to 6.3.6, use 'type' instead of 'font').</p>
3815
3816<p>In addition to the fonts specified by the above pre-defined list, you can
3817also specify a font from a specific source. For example <code>Arial.ttf</code>
3818is a TrueType font file, <code>ps:helvetica</code> is PostScript font, and
3819<code>x:fixed</code> is X11 font.</p>
3820
cristy82a2ff22015-05-12 16:41:32 +00003821<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 +00003822
3823
3824<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003825 <h3 class="magick-header"><a id="foreground"></a>-foreground <var>color</var></h3>
cristyd2432012015-05-04 23:15:15 +00003826</div>
3827
3828<p class="magick-description">Define the foreground color for menus.", "display</p>
3829
cristy82a2ff22015-05-12 16:41:32 +00003830<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 +00003831
3832<p>The default foreground color is black.</p>
3833
3834<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003835 <h3 class="magick-header"><a id="format"></a>-format <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00003836</div>
3837
3838<p class="magick-description">the image format type.</p>
3839
3840<p>When used with the <code>mogrify</code> utility, this option converts any
3841image to the image <a href="formats.html">format</a> you specify.
cristy82a2ff22015-05-12 16:41:32 +00003842For 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 +00003843
3844<p>By default the file is written to its original name. However, if the
3845filename extension matches a supported format, the extension is replaced with
3846the image format type specified with <a href="command-line-options.html#format">-format</a>. For
3847example, if you specify <var>tiff</var> as the format type and the
3848input image filename is <var>image.gif</var>, the output image
3849filename becomes <var>image.tiff</var>.</p>
3850
3851<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003852 <h3 class="magick-header"><a id="format_identify_"></a>-format <var>string</var></h3>
cristyd2432012015-05-04 23:15:15 +00003853</div>
3854
3855<p class="magick-description">output formatted image characteristics.</p>
3856
3857<p>See <a href="escape.html">Format and Print Image
3858Properties</a> for an explanation on how to specify the argument to this
3859option.</p>
3860
3861<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003862 <h3 class="magick-header"><a id="frame"></a>-frame <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00003863</div>
3864
3865<p class="magick-description">Surround the image with a border or beveled frame.</p>
3866
cristy82a2ff22015-05-12 16:41:32 +00003867<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 +00003868
3869<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
3870height that is added to the dimensions of the image. If no offsets are given
3871in the <var>geometry</var> argument, then the border added is
3872a solid color. Offsets <var>x</var> and <var>y</var>, if present, specify that
3873the width and height of the border is partitioned to form an outer bevel of
3874thickness <var>x</var> pixels and an inner bevel of thickness
3875<var>y</var> pixels. Negative offsets make no sense as frame arguments.
3876</p>
3877
cristy82a2ff22015-05-12 16:41:32 +00003878<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 +00003879'<code>Over</code>' composition method. It generates an image of the appropriate
3880size with the current <a href="command-line-options.html#bordercolor">-bordercolor</a> setting, and then
cristy82a2ff22015-05-12 16:41:32 +00003881draws 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 +00003882center of this image. This means that with the default compose method of
cristy82a2ff22015-05-12 16:41:32 +00003883'<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 +00003884
3885<p>The image composition is not
3886affected by the <a href="command-line-options.html#gravity">-gravity</a> option.</p>
3887
3888
3889<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003890 <h3 class="magick-header"><a id="frame_import_"></a>-frame</h3>
cristyd2432012015-05-04 23:15:15 +00003891</div>
3892
3893<p class="magick-description">include the X window frame in the imported image. </p>
3894<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00003895 <h3 class="magick-header"><a id="function"></a>-function <var>function</var> <var>parameters</var></h3>
cristyd2432012015-05-04 23:15:15 +00003896</div>
3897
3898<p class="magick-description">Apply a function to channel values.</p>
3899
3900<p>This operator performs calculations based on the given arguments to modify
cristy82a2ff22015-05-12 16:41:32 +00003901each 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 +00003902calculations are handled.</p>
3903
cristy82a2ff22015-05-12 16:41:32 +00003904<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 +00003905ImageMagick 6.4.8−8.)</p>
3906
3907<p>Here, <var>parameters</var> is a comma-separated list of
3908numerical values. The number of values varies depending on which <var>function</var> is selected. Choose the <var>function</var> from:</p>
3909
3910<pre>
cristy29dc8652015-05-12 16:26:21 +00003911Polynomial
3912Sinusoid
3913Arcsin
3914Arctan
cristyd2432012015-05-04 23:15:15 +00003915</pre>
3916
3917<p>To print a complete list of <a href="command-line-options.html#function">-function</a> operators,
3918use <a href="command-line-options.html#list">-list function</a>. Descriptions follow.</p>
3919
cristy29dc8652015-05-12 16:26:21 +00003920<dl class="dl-horizontal">
3921 <dt>Polynomial</dt>
3922 <dd><p>The <code>Polynomial</code> function takes an arbitrary number of parameters,
cristyd2432012015-05-04 23:15:15 +00003923these being the coefficients of a polynomial, in decreasing order of degree.
3924That is, entering</p>
3925
cristy29dc8652015-05-12 16:26:21 +00003926<pre>
3927-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>
3928</pre>
cristyd2432012015-05-04 23:15:15 +00003929
3930<p>will invoke a polynomial function given by</p>
3931
cristy29dc8652015-05-12 16:26:21 +00003932<pre>
3933<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>,
3934</pre>
cristyd2432012015-05-04 23:15:15 +00003935
3936<p>where <b><var>u</var></b> is pixel's original normalized channel value.</p>
3937
3938<p>The <code>Polynomial</code> function can be used in place of <code>Set</code>
3939(the <var>constant</var> polynomial) and <code>Add</code>, <code>Divide</code>,
3940<code>Multiply</code>, and <code>Subtract</code> (some <var>linear</var>
cristy82a2ff22015-05-12 16:41:32 +00003941polynomials) 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 +00003942correspondences follow.</p>
3943
3944<table class="table table-condensed table-striped">
cristyd2432012015-05-04 23:15:15 +00003945 <tr>
3946 <td>-evaluate Set <var>value</var> </td>
3947 <td>-function Polynomial <var>value</var></td>
3948 <td>(Constant functions; set <var>value</var>×100% gray when channels are RGB.)</td>
3949 </tr>
3950 <tr>
3951 <td>-evaluate Add <var>value</var> </td>
3952 <td>-function Polynomial 1,<var>value</var></td>
3953 </tr>
3954 <tr>
3955 <td>-evaluate Subtract <var>value</var> </td>
3956 <td>-function Polynomial 1,−<var>value</var></td>
3957 </tr>
3958 <tr>
3959 <td>-evaluate Multiply <var>value</var> </td>
3960 <td>-function Polynomial <var>value</var>,0</td>
3961 </tr>
3962 <tr>
3963 <td>+level black% x white%</td>
3964 <td>-function Polynomial A,B</td>
3965 <td>(Reduce contrast. Here, A=(white-black)/100 and B=black/100.)</td>
3966 </tr>
3967</table>
3968
3969<p>The <code>Polynomial</code> function gives great versatility, since
3970polynomials can be used to fit any continuous curve to any degree of accuracy
3971desired.</p>
3972
3973</dd>
cristy29dc8652015-05-12 16:26:21 +00003974<dt>Sinusoid</dt>
cristyd2432012015-05-04 23:15:15 +00003975<dd>
3976<p>The <code>Sinusoid</code> function can be used to vary the channel values
3977sinusoidally by setting frequency, phase shift, amplitude, and a bias. These
3978values are given as one to four parameters, as follows,</p>
3979
cristy29dc8652015-05-12 16:26:21 +00003980<pre>
3981-function <code>Sinusoid</code> <var>freq</var>,[<var>phase</var>,[<var>amp</var>,[<var>bias</var>]]]
3982</pre>
cristyd2432012015-05-04 23:15:15 +00003983
3984<p>where <var>phase</var> is in degrees. (The domain [0,1] of the function
3985corresponds to 0 through <var>freq</var>×360 degrees.)
3986The result is that if a pixel's normalized channel value is originally
3987<b><var>u</var></b>, its resulting normalized value is given by </p>
3988
cristy29dc8652015-05-12 16:26:21 +00003989<pre>
cristyd2432012015-05-04 23:15:15 +00003990<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 +00003991</pre>
cristyd2432012015-05-04 23:15:15 +00003992
3993<p> For example, the following generates a curve that starts and ends at 0.9
3994(when <b><var>u</var></b>=0 and 1, resp.), oscillating three times between
3995.7−.2=.5 and .7+.2=.9. </p>
3996
cristy29dc8652015-05-12 16:26:21 +00003997<pre>
3998-function Sinusoid 3,-90,.2,.7
3999</pre>
cristyd2432012015-05-04 23:15:15 +00004000
4001<p>The default values of <var>amp</var> and <var>bias</var> are both .5. The default for <var>phase</var>
4002is 0.</p>
4003
4004<p>The <code>Sinusoid</code> function generalizes <code>Sin</code> and
4005<code>Cos</code> of the <a href="command-line-options.html#evaluate">-evaluate</a> operator by allowing
4006varying amplitude, phase and bias. The correspondence is as follows.</p>
4007
4008<table class="table table-condensed table-striped">
4009 <tr>
4010 <td>-evaluate Sin <var>freq</var> </td>
4011 <td>-function Sinusoid <var>freq</var>,0 </td>
4012 </tr>
4013 <tr>
4014 <td>-evaluate Cos <var>freq</var> </td>
4015 <td>-function Sinusoid <var>freq</var>,90 </td>
4016 </tr>
4017</table>
cristy29dc8652015-05-12 16:26:21 +00004018 </dd>
4019<dt>ArcSin</dt>
cristyd2432012015-05-04 23:15:15 +00004020<dd>
4021<p>The <code>ArcSin</code> function generates the inverse curve of a Sinusoid,
4022and can be used to generate cylindrical distortion and displacement maps.
4023The curve can be adjusted relative to both the input values and output range
4024of values.</p>
4025
cristy29dc8652015-05-12 16:26:21 +00004026<pre>
4027-function <code>ArcSin</code> <var>width</var>,[<var>center</var>,[<var>range</var>,[<var>bias</var>]]]
4028</pre>
cristyd2432012015-05-04 23:15:15 +00004029
4030<p>with all values given in terms of normalized color values (0.0 for black,
40311.0 for white). Defaulting to values covering the full range from 0.0 to 1.0
4032for bout input (<var>width</var>), and output (<var>width</var>) values. '<code>1.0,0.5,1.0,0.5</code>' </p>
4033
cristy29dc8652015-05-12 16:26:21 +00004034<pre>
cristyd2432012015-05-04 23:15:15 +00004035<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 +00004036</pre>
cristyd2432012015-05-04 23:15:15 +00004037
4038</dd>
cristy29dc8652015-05-12 16:26:21 +00004039<dt>ArcTan</dt>
cristyd2432012015-05-04 23:15:15 +00004040<dd>
4041<p>The <code>ArcTan</code> function generates a curve that smooth crosses from
4042limit values at infinities, though a center using the given slope value.
4043All these values can be adjusted via the arguments.</p>
4044
cristy29dc8652015-05-12 16:26:21 +00004045<pre>
4046-function <code>ArcTan</code> <var>slope</var>,[<var>center</var>,[<var>range</var>,[<var>bias</var>]]]
4047</pre>
cristyd2432012015-05-04 23:15:15 +00004048
4049<p>Defaulting to '<code>1.0,0.5,1.0,0.5</code>'.
4050</p>
4051
cristy29dc8652015-05-12 16:26:21 +00004052<pre>
cristyd2432012015-05-04 23:15:15 +00004053<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 +00004054</pre>
4055 </dd>
cristy82a2ff22015-05-12 16:41:32 +00004056
cristyd2432012015-05-04 23:15:15 +00004057</dl>
4058
4059
cristy29dc8652015-05-12 16:26:21 +00004060
cristyd2432012015-05-04 23:15:15 +00004061<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004062 <h3 class="magick-header"><a id="fuzz"></a>-fuzz <var>distance</var>{<var>%</var>}</h3>
cristyd2432012015-05-04 23:15:15 +00004063</div>
4064
4065<p class="magick-description">Colors within this <var>distance</var> are considered equal.</p>
4066
4067<p>A number of algorithms search for a target color. By default the color must
4068be exact. Use this option to match colors that are close to the target color
4069in RGB space. For example, if you want to automagically trim the edges of an
4070image with <a href="command-line-options.html#trim">-trim</a> but the image was scanned and the target
4071background color may differ by a small amount. This option can account for
4072these differences.</p>
4073
4074<p>The <var>distance</var> can be in absolute intensity units or, by
4075appending <code>%</code> as a percentage of the maximum possible intensity (255,
407665535, or 4294967295).</p>
4077
cristy82a2ff22015-05-12 16:41:32 +00004078<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 +00004079
4080
4081<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004082 <h3 class="magick-header"><a id="fx"></a>-fx <var>expression</var></h3>
cristyd2432012015-05-04 23:15:15 +00004083</div>
4084
4085<p class="magick-description">apply a mathematical expression to an image or image channels.</p>
4086
4087<p>If the first character of <var>expression</var> is <code>@</code>,
4088the expression is read from a file titled by the remaining characters in the
4089string.</p>
4090
4091<p>See <a href="fx.html">FX,
4092The Special Effects Image Operator</a> for a detailed discussion of this
4093option.</p>
4094
4095
4096<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004097 <h3 class="magick-header"><a id="gamma"></a>-gamma <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00004098</div>
4099
4100<p class="magick-description">level of gamma correction.</p>
4101
4102<p>The same color image displayed on two different workstations may look
4103different due to differences in the display monitor. Use gamma correction to
4104adjust for this color difference. Reasonable values extend from
4105<code>0.8</code> to <code>2.3</code>. Gamma less than 1.0 darkens the image and
4106gamma greater than 1.0 lightens it. Large adjustments to image gamma may
4107result in the loss of some image information if the pixel quantum size is only
4108eight bits (quantum range 0 to 255).</p>
4109
4110<p>Gamma adjusts the image's channel values pixel-by-pixel according to
4111a power law, namely, pow(pixel,1/gamma) or pixel^(1/gamma), where pixel is the
4112normalized or 0 to 1 color value. For example, using a value of gamma=2 is the
4113same as taking the square root of the image.</p>
4114
4115<p>You can apply separate gamma values to the red, green, and blue channels of
4116the image with a gamma value list delimited with commas (e.g.,
4117<code>1.7,2.3,1.2</code>).</p>
4118
4119<p>Use <a href="command-line-options.html#gamma">+gamma <var>value</var></a> to set the
4120image gamma level without actually adjusting the image pixels. This option
4121is useful if the image is of a known gamma but not set as an image attribute
4122(e.g. PNG images). Write the "file gamma" which is the reciprocal of the
4123display gamma; e.g., if your image is sRGB and you want to write a PNG gAMA
4124chunk, use</p>
4125
4126<pre>
4127convert input.png +gamma .45455 output.png
4128</pre>
4129
4130<p>(0.45455 is 1/2.2)</p>
4131
4132<p>Note that gamma adjustments are also available via the <a href="command-line-options.html#level">-level</a> operator.</p>
4133
4134<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00004135 <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 +00004136</div>
4137
4138<p class="magick-description">Blur the image with a Gaussian operator.</p>
4139
4140<p>Convolve the image with a Gaussian or normal distribution using the given
cristy82a2ff22015-05-12 16:41:32 +00004141<var>Sigma</var> value. The formula is:</p>
cristyd2432012015-05-04 23:15:15 +00004142
cristyb2cad532015-05-16 13:02:45 +00004143<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 +00004144
cristy82a2ff22015-05-12 16:41:32 +00004145<p>The <var>Sigma</var> value is the important argument, and
cristyd2432012015-05-04 23:15:15 +00004146determines the actual amount of blurring that will take place. </p>
4147
cristy82a2ff22015-05-12 16:41:32 +00004148<p>The <var>Radius</var> is only used to determine the size of the
cristyd2432012015-05-04 23:15:15 +00004149array which will hold the calculated Gaussian distribution. It should be an
4150integer. If not given, or set to zero, IM will calculate the largest possible
4151radius that will provide meaningful results for the Gaussian distribution.
4152</p>
4153
cristy82a2ff22015-05-12 16:41:32 +00004154<p>The larger the <var>Radius</var> the radius the slower the
4155operation is. However too small a <var>Radius</var>, and sever
4156aliasing effects may result. As a guideline, <var>Radius</var>
4157should be at least twice the <var>Sigma</var> value, though three
cristyd2432012015-05-04 23:15:15 +00004158times will produce a more accurate result. </p>
4159
4160<p>This differs from the faster <a href="command-line-options.html#blur">-blur</a> operator in that a
4161full 2-dimensional convolution is used to generate the weighted average of the
4162neighboring pixels. </p>
4163
4164<p>The <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting will determine how
4165pixels which are outside the image proper are blurred into the final result.
4166</p>
4167
4168
4169<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004170 <h3 class="magick-header"><a id="geometry"></a>-geometry <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00004171</div>
4172
4173<p class="magick-description">Set the preferred size and location of the image.</p>
4174
4175<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
4176
4177<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004178 <h3 class="magick-header"><a id="gravity"></a>-gravity <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00004179</div>
4180
4181<p class="magick-description">Sets the current gravity suggestion for various other settings and options.</p>
4182
4183<p>Choices include: <code>NorthWest</code>, <code>North</code>,
4184<code>NorthEast</code>, <code>West</code>, <code>Center</code>, <code>East</code>,
cristy82a2ff22015-05-12 16:41:32 +00004185<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 +00004186installation.</p>
4187
4188<p>The direction you choose specifies where to position text or subimages. For
4189example, a gravity of <code>Center</code> forces the text to be centered within
cristy82a2ff22015-05-12 16:41:32 +00004190the 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
4191text 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 +00004192
4193<p>The <a href="command-line-options.html#gravity">-gravity</a> option is also used in concert with the
4194<a href="command-line-options.html#geometry">-geometry</a> setting and other settings or options that
cristy82a2ff22015-05-12 16:41:32 +00004195take <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 +00004196
4197<p>If a <a href="command-line-options.html#gravity">-gravity</a> setting occurs before another option
4198or setting having a <var>geometry</var> argument that specifies an
4199offset, the offset is usually applied to the point within the image suggested
4200by the <a href="command-line-options.html#gravity">-gravity</a> argument. Thus, in the following
4201command, for example, suppose the file <code>image.png</code> has dimensions
4202200x100. The offset specified by the argument to <a href="command-line-options.html#region">-region</a>
4203is (−40,+20). The argument to <a href="command-line-options.html#gravity">-gravity</a> is
4204<code>Center</code>, which suggests the midpoint of the image, at the point
4205(100,50). The offset (−40,20) is applied to that point, giving
4206(100−40,50+20)=(60,70), so the specified 10x10 region is located at
4207that point. (In addition, the <a href="command-line-options.html#gravity">-gravity</a> affects the
4208region itself, which is <var>centered</var> at the pixel
4209coordinate (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>
4210
4211<pre>
4212convert image.png -gravity Center -region 10x10-40+20 \
4213 -negate output.png
4214</pre>
4215
cristy82a2ff22015-05-12 16:41:32 +00004216<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 +00004217within the composite.</p>
4218
cristy82a2ff22015-05-12 16:41:32 +00004219<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 +00004220within a tile. The default gravity is <code>Center</code> for this purpose.</p>
4221
4222
4223<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004224 <h3 class="magick-header"><a id="grayscale"></a>-grayscale <var>method</var></h3>
cristyd2432012015-05-04 23:15:15 +00004225</div>
4226
4227<p class="magick-description">convert image to grayscale.</p>
4228
cristy82a2ff22015-05-12 16:41:32 +00004229<p>This will use one of the <a href="command-line-options.html#intensity">-intensity</a> methods to
cristyd2432012015-05-04 23:15:15 +00004230convert the given image into a linear-grayscale image. </p>
4231
4232<p>For example, to convert an image to (linear) Rec709Luminance grayscale, type:</p>
4233
4234<pre>
4235convert in.png -grayscale Rec709Luminance out.png
4236</pre>
4237
4238<p>which is equivalent to:</p>
4239
4240<pre>
4241convert in.png -colorspace gray out.png
4242</pre>
4243
4244<p>Similarly, to convert an image to (non-linear) Rec709Luma grayscale, type:</p>
4245
4246<pre>
4247convert in.png -grayscale Rec709Luma out.png
4248</pre>
4249
4250<p>which is equivalent to:</p>
4251
4252<pre>
4253convert in.png -set colorspace RGB -colorspace gray out.png
4254</pre>
4255
4256<p>Note that a 'colorspace' intensity method will produce the same result
4257regardless of the current colorpsace of the image. But a 'mathematical'
4258intensity method will depend on the current colorspace the image is currently
4259using. </p>
4260
cristy82a2ff22015-05-12 16:41:32 +00004261<p>While this operation uses an <a href="command-line-options.html#intensity">-intensity</a> method,
4262it does not use or set the <a href="command-line-options.html#intensity">-intensity</a> setting, so
cristyd2432012015-05-04 23:15:15 +00004263will not effect other operations that may use that setting.</p>
4264
4265
4266<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004267 <h3 class="magick-header"><a id="green-primary"></a>-green-primary <var>x,y</var></h3>
cristyd2432012015-05-04 23:15:15 +00004268</div>
4269
4270<p class="magick-description">green chromaticity primary point.</p>
4271
4272
4273<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004274 <h3 class="magick-header"><a id="hald-clut"></a>-hald-clut</h3>
cristyd2432012015-05-04 23:15:15 +00004275</div>
4276
4277<p class="magick-description">apply a Hald color lookup table to the image.</p>
4278
4279<p>A Hald color lookup table is a 3-dimensional color cube mapped to 2
4280dimensions. Create it with the <code>HALD:</code> prefix (e.g. HALD:8). You
4281can apply any color transformation to the Hald image and then use this option
4282to apply the transform to the image. </p>
4283
4284<pre>
4285convert image.png hald.png -hald-clut transform.png
4286</pre>
4287
4288<p>This option provides a convenient method for you to use Gimp or Photoshop
4289to make color corrections to the Hald CLUT image and subsequently apply them
4290to multiple images using an ImageMagick script. </p>
4291
4292<p>Note that the representation is only of the normal RGB color space and that
4293the whole color value triplet is used for the interpolated lookup of the
cristy82a2ff22015-05-12 16:41:32 +00004294represented 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 +00004295images transparency or alpha/matte channel.</p>
4296
cristy82a2ff22015-05-12 16:41:32 +00004297<p>See also <a href="command-line-options.html#clut">-clut</a> which provides color value replacement
cristyd2432012015-05-04 23:15:15 +00004298of the individual color channels, usually involving a simpler gray-scale
4299image. E.g: gray-scale to color replacement, or modification by a histogram
4300mapping. </p>
4301
4302
4303<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004304 <h3 class="magick-header"><a id="help"></a>-help</h3>
cristyd2432012015-05-04 23:15:15 +00004305</div>
4306
4307<p class="magick-description">print usage instructions.</p>
4308
4309<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004310 <h3 class="magick-header"><a id="highlight-color"></a>-highlight-color <var>color</var></h3>
cristyd2432012015-05-04 23:15:15 +00004311</div>
4312
4313<p class="magick-description">when comparing images, emphasize pixel differences with this color.</p>
4314
4315<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004316 <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 +00004317</div>
4318
4319<p class="magick-description">identify straight lines in the image (e.g. -hough-lines 9x9+195).</p>
4320
4321<p>Use the Hough line detector with any binary edge extracted image to locate and draw any straight lines that it finds.</p>
4322
4323<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>.
4324
4325<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>
4326
cristy82a2ff22015-05-12 16:41:32 +00004327<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 +00004328
cristy82a2ff22015-05-12 16:41:32 +00004329<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 +00004330
cristy82a2ff22015-05-12 16:41:32 +00004331<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 +00004332
4333<p>A text file listing the endpoints and counts may be created by using the suffix, .mvg, for the output image.</p>
4334
cristy82a2ff22015-05-12 16:41:32 +00004335<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 +00004336
4337<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004338 <h3 class="magick-header"><a id="iconGeometry"></a>-iconGeometry <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00004339</div>
4340
4341<p class="magick-description">specify the icon geometry.</p>
4342
4343<p>Offsets, if present in the geometry specification, are handled in the same
4344manner as the <a href="command-line-options.html#geometry">-geometry</a> option, using X11 style to
4345handle negative offsets.</p>
4346
4347<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
4348
4349<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004350 <h3 class="magick-header"><a id="iconic"></a>-iconic</h3>
cristyd2432012015-05-04 23:15:15 +00004351</div>
4352
4353<p class="magick-description">start in icon mode in X Windows", 'animate', 'display</p>
4354
4355<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004356 <h3 class="magick-header"><a id="identify"></a>-identify</h3>
cristyd2432012015-05-04 23:15:15 +00004357</div>
4358
4359<p class="magick-description">identify the format and characteristics of the image.</p>
4360
4361<p>This information is printed: image scene number; image name; image size;
4362the image class (<var>DirectClass</var> or <var>PseudoClass</var>); the total number of unique colors; and the
4363number of seconds to read and transform the image. Refer to <a href="miff.html">MIFF</a> for
4364a description of the image class.</p>
4365
4366<p>If <a href="command-line-options.html#colors">-colors</a> is also specified, the total unique colors
cristy82a2ff22015-05-12 16:41:32 +00004367in the image and color reduction error values are printed. Refer to <a href="quantize.html">color
cristyd2432012015-05-04 23:15:15 +00004368reduction algorithm</a> for a description of these values.</p>
4369
4370<p>If <a href="command-line-options.html#verbose">-verbose</a> precedes this option, copious
4371amounts of image properties are displayed including image statistics, profiles,
4372image histogram, and others.</p>
4373
4374<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004375 <h3 class="magick-header"><a id="ift"></a>-ift</h3>
cristyd2432012015-05-04 23:15:15 +00004376</div>
4377
4378<p class="magick-description">implements the inverse discrete Fourier transform (DFT).</p>
4379
4380<p>This option is new as of ImageMagick 6.5.4-3 (and now working for Windows
4381users in ImageMagick 6.6.0-9). It transforms a pair of magnitude and phase
4382images from the frequency domain to a single image in the normal or spatial
cristy82a2ff22015-05-12 16:41:32 +00004383domain. See for example, <a href="http://en.wikipedia.org/wiki/Fourier_transform">Fourier Transform</a>,
cristyd2432012015-05-04 23:15:15 +00004384<a href="http://en.wikipedia.org/wiki/DFT">Discrete Fourier Transform</a> and
4385<a href="http://en.wikipedia.org/wiki/FFT">Fast Fourier Transform</a>.</p>
4386
4387<p>For example, depending upon the image format used to store the result of
4388the <a href="command-line-options.html#fft">-fft</a>, one would use either</p>
4389
4390<pre>
4391convert fft_image.miff -ift fft_image_ift.png
4392</pre>
4393
4394<p>or</p>
4395
4396<pre>
4397convert fft_image-0.png fft_image-1.png -ift fft_image_ift.png
4398</pre>
4399
4400<p>The resulting image may need to be cropped due to padding introduced when
cristy82a2ff22015-05-12 16:41:32 +00004401the 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 +00004402the right and/or bottom sides of the image.</p>
4403
4404<p>The <a href="http://www.fftw.org/">FFTW</a> delegate library is required to
4405use <a href="command-line-options.html#ift">-ift</a>.</p>
4406
4407<p>Use <a href="command-line-options.html#ift">+ift</a> (with HDRI enabled) to transform a pair of real
4408and imaginary images from the frequency domain to a single image in the normal
4409(spatial) domain.</p>
4410
cristy82a2ff22015-05-12 16:41:32 +00004411<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 +00004412
4413<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004414 <h3 class="magick-header"><a id="immutable"></a>-immutable</h3>
cristyd2432012015-05-04 23:15:15 +00004415</div>
4416
4417<p class="magick-description">make image immutable.</p>
4418
4419<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004420 <h3 class="magick-header"><a id="implode"></a>-implode <var>factor</var></h3>
cristyd2432012015-05-04 23:15:15 +00004421</div>
4422
4423<p class="magick-description">implode image pixels about the center.</p>
4424
4425<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004426 <h3 class="magick-header"><a id="insert"></a>-insert <var>index</var></h3>
cristyd2432012015-05-04 23:15:15 +00004427</div>
4428
4429<p class="magick-description">insert the last image into the image sequence.</p>
4430
4431<p>This option takes last image in the current image sequence and inserts it
4432at the given index. If a negative index is used, the insert position is
4433calculated before the last image is removed from the sequence. As such
4434<code>-insert -1</code> will result in no change to the image sequence.</p>
4435
4436<p>The <code>+insert</code> option is equivalent to <code>-insert -1</code>. In
4437other words, insert the last image, at the end of the current image sequence.
4438Consequently this has no effect on the image sequence order.</p>
4439
4440<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004441 <h3 class="magick-header"><a id="intensity"></a>-intensity <var>method</var></h3>
cristyd2432012015-05-04 23:15:15 +00004442</div>
4443
4444<p class="magick-description">method to generate intensity value from pixel.</p>
4445
4446<p>ImageMagick provides a number of methods used in situations where an
4447operatory needs to determine a single grayscale value for some purpose, from
4448an image with red, green, and blue pixel components. Typically the linear
4449<code>Rec709Luminance</code> formula is used, which is the same formula used when
4450converting images to <code>-colorspace gray</code>. </p>
4451
4452<p>The following formulas are currently provided, and will first convert
4453the pixel values to linear-RGB or non-linear sRGB colorspace before
4454being applied to calulate the final greyscale value. </p>
4455
cristyb2cad532015-05-16 13:02:45 +00004456<dl class="dl-horizontal">
4457<dt>Rec601Luma</dt><dd> 0.298839R' + 0.586811G'+ 0.114350B'</dd>
4458<dt>Rec601Luminance</dt><dd> 0.298839R + 0.586811G + 0.114350B</dd>
4459<dt>Rec709Luma</dt><dd> 0.212656R' + 0.715158G' + 0.072186B'</dd>
4460<dt>Rec709Luminance</dt><dd> 0.212656R + 0.715158G + 0.072186B</dd>
4461<dt>Brightness</dt><dd> max(R', G', B')</dd>
4462<dt>Lightness</dt><dd> (min(R', G', B') + max(R', G', B')) / 2.0</dd>
4463</dl>
4464
cristyd2432012015-05-04 23:15:15 +00004465<p>Note that the above R,G,B values is the image's linear-RGB values, while
4466R',G',B' are sRGB non-linear values. </p>
4467
4468<p>These intensity methods are mathematical in nature and will use the
4469current value in the images respective R,G,B channel regardless of
4470what that is, or what colorspace the image is currently using.</p>
4471
cristyb2cad532015-05-16 13:02:45 +00004472<dl class="dl-horizontal">
4473<dt>Average</dt><dd>(R + G + B) / 3.0</dd>
4474<dt>MS</dt><dd>(R^2 + G^2 + B^2) / 3.0</dd>
4475<dt>RMS</dt><dd>sqrt( (R^2 + G^2 + B^2) / 3.0 )</dd>
4476</dl>
cristyd2432012015-05-04 23:15:15 +00004477
4478<p>These methods are often used for other purposes, such as generating a
cristy82a2ff22015-05-12 16:41:32 +00004479grayscale 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 +00004480
4481<p> For example The 'MS' (Mean Squared) setting is good for minimizing color
4482error comparisions. While... The method 'RMS' (Root Mean Squared) for
4483example is appropriate for calculating color vector distance, from a color
cristy82a2ff22015-05-12 16:41:32 +00004484difference 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 +00004485
cristy82a2ff22015-05-12 16:41:32 +00004486<p>See also <a href="command-line-options.html#grayscale">-grayscale</a> which applies one of the above
4487grayscaling 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 +00004488
cristy82a2ff22015-05-12 16:41:32 +00004489<p>The <a href="command-line-options.html#colorspace">-colorspace gray</a> image conversion also uses
cristyd2432012015-05-04 23:15:15 +00004490the current intensity setting, but will always convert the image to the
4491appropriate sRGB or linear-RGB colorspace before appling the above
4492function.</p>
4493
4494<p>To print a complete list of posible pixel intensity setting methods, use <a href="command-line-options.html#list">-list intensity</a>.</p>
4495
cristy82a2ff22015-05-12 16:41:32 +00004496<p>Operators affected by the <a href="command-line-options.html#intensity">-intensity</a> setting include:</p>
cristyd2432012015-05-04 23:15:15 +00004497
4498<pre>
4499-adaptive-blur
4500-adaptive-sharpen
4501-black-threshold
4502-clut (when mapping greyscale CLUT image to alpha channel if set by -channels)
4503-colors for gray colorspace
4504-compose {LightenIntensity, DarkenIntensity, CopyOpacity, CopyBlack}
4505-contrast-stretch
4506-distort {ErodeIntensity, DilateIntensity}
4507-normalize
4508-random-threshold
4509-selective-blur
4510-shade
4511-threshold
4512-tint
4513-white-threshold
4514</pre>
4515
4516<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004517 <h3 class="magick-header"><a id="intent"></a>-intent <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00004518</div>
4519
4520<p class="magick-description">use this type of rendering intent when managing the image color.</p>
4521
4522<p>Use this option to affect the color management operation of an image (see
4523<a href="command-line-options.html#profile">-profile</a>). Choose from these intents: <code>Absolute,
4524Perceptual, Relative, Saturation</code>.</p>
4525
4526<p>The default intent is Perceptual for the sRGB colorspace and undefined for the RGB and gray colorspaces.</p>
4527
4528<p>To print a complete list of rendering intents, use <a href="command-line-options.html#list">-list intent</a>.</p>
4529
4530<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004531 <h3 class="magick-header"><a id="interlace"></a>-interlace <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00004532</div>
4533
4534<p class="magick-description">the type of interlacing scheme.</p>
4535
4536<p>Choose from:</p>
4537
4538<pre>
cristyb2cad532015-05-16 13:02:45 +00004539none
4540line
4541plane
4542partition
4543JPEG
4544GIF
4545PNG
cristyd2432012015-05-04 23:15:15 +00004546</pre>
4547
4548<p>This option is used to specify the type of interlacing scheme for raw image
4549formats such as <code>RGB</code> or <code>YUV</code>.</p>
4550
4551<p><code>None</code> means do not interlace (RGBRGBRGBRGBRGBRGB...),</p>
4552
4553<p><code>Line</code> uses scanline interlacing (RRR...GGG...BBB...RRR...GGG...BBB...), and.</p>
4554
4555<p><code>Plane</code> uses plane interlacing (RRRRRR...GGGGGG...BBBBBB...).</p>
4556
4557<p><code>Partition</code> is like plane except the different planes are saved to
4558individual files (e.g. image.R, image.G, and image.B).</p>
4559
4560<p>Use <code>Line</code> or <code>Plane</code> to create an <code>interlaced
4561PNG</code> or <code>GIF</code> or <code>progressive JPEG</code> image.</p>
4562
4563<p>To print a complete list of interlacing schemes, use <a href="command-line-options.html#list">-list
4564interlace</a>.</p>
4565
4566<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004567 <h3 class="magick-header"><a id="interpolate"></a>-interpolate <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00004568</div>
4569
4570<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>
4571
4572<p>When looking up the color of a pixel using a non-integer floating point
4573value, you typically fall in between the pixel colors defined by the source
4574image. This setting determines how the color is determined from the colors of
4575the pixels surrounding that point. That is how to determine the color of a
4576point that falls between two, or even four different colored pixels. </p>
4577
cristy29dc8652015-05-12 16:26:21 +00004578<dl class="dl-horizontal">
4579 <dt>integer</dt>
4580 <dd>The color of the top-left pixel (floor function)</dd>
4581 <dt>nearest-neighbor</dt>
4582 <dd>The nearest pixel to the lookup point (rounded function)</dd>
4583 <dt>average</dt>
4584 <dd>The average color of the surrounding four pixels</dd>
4585 <dt>bilinear</dt>
4586 <dd>A double linear interpolation of pixels (the default)</dd>
4587 <dt>mesh</dt>
4588 <dd>Divide area into two flat triangular interpolations</dd>
4589 <dt>bicubic</dt>
4590 <dd>Fitted bicubic-spines of surrounding 16 pixels</dd>
4591 <dt>spline</dt>
4592 <dd>Direct spline curves (colors are blurred)</dd>
4593 <dt>filter</dt>
4594 <dd>Use resize <a href="command-line-options.html#filter">-filter</a> settings</dd>
4595</dl>
cristyd2432012015-05-04 23:15:15 +00004596
cristy82a2ff22015-05-12 16:41:32 +00004597<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 +00004598
4599<p>To print a complete list of interpolation methods, use <a href="command-line-options.html#list">-list interpolate</a>.</p>
4600
cristy82a2ff22015-05-12 16:41:32 +00004601<p>See also <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a>, for control of the
cristyd2432012015-05-04 23:15:15 +00004602lookup for positions outside the boundaries of the image. </p>
4603
4604
4605<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004606 <h3 class="magick-header"><a id="interline-spacing"></a>-interline-spacing <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00004607</div>
4608
4609<p class="magick-description">the space between two text lines.</p>
4610
4611<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004612 <h3 class="magick-header"><a id="interword-spacing"></a>-interword-spacing <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00004613</div>
4614
4615<p class="magick-description">the space between two words.</p>
4616
4617<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004618 <h3 class="magick-header"><a id="kerning"></a>-kerning <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00004619</div>
4620
4621<p class="magick-description">the space between two letters.</p>
4622
4623<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00004624 <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 +00004625</div>
4626
4627<p class="magick-description">edge preserving noise reduction filter.</p>
4628
cristy82a2ff22015-05-12 16:41:32 +00004629<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 +00004630
4631
4632<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004633 <h3 class="magick-header"><a id="label"></a>-label <var>name</var></h3>
cristyd2432012015-05-04 23:15:15 +00004634</div>
4635
4636<p class="magick-description">assign a label to an image.</p>
4637
4638<p>Use this option to assign a specific label to the image, as it is read in
cristy82a2ff22015-05-12 16:41:32 +00004639or created. You can use the <a href="command-line-options.html#set">-set</a> operation to re-assign
cristyd2432012015-05-04 23:15:15 +00004640a the labels of images already read in. Image formats such as TIFF, PNG,
4641MIFF, supports saving the label information with the image.</p>
4642
4643<p>When saving an image to a <var>PostScript</var> file, any label
4644assigned to an image is used as a header string to print above the postscript
4645image. </p>
4646
4647<p>You can include the image filename, type, width, height, or other image
4648attribute by embedding special format character. See <a href="escape.html">Format and Print Image
4649Properties</a> for details of the percent escape codes.</p>
4650
4651<p>For example,</p>
4652
cristy29dc8652015-05-12 16:26:21 +00004653<pre>
4654-label "%m:%f %wx%h" bird.miff
4655</pre>
cristyd2432012015-05-04 23:15:15 +00004656
4657<p>assigns an image label of <code>MIFF:bird.miff 512x480</code> to the
4658"<code>bird.miff</code>" image and whose width is 512 and height is 480, as it
4659is read in. If a <a href="command-line-options.html#label">+label</a> option was used instead, any
4660existing label present in the image would be used. You can remove all labels
4661from an image by assigning the empty string. </p>
4662
4663<p>A label is not drawn on the image, but is embedded in the image datastream
4664via <var>Label</var> tag or similar mechanism. If you want the label to be
4665visible on the image itself, use the <a href="command-line-options.html#draw">-draw</a> option, or
4666during the final processing in the creation of an image montage.</p>
4667
4668<p>If the first character of <var>string</var> is <var>@</var>, the image label is read from a file titled by the
4669remaining characters in the string. Labels in a file are literal, no embedded
4670formatting characters are recognized.</p>
4671
4672
4673<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00004674 <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 +00004675</div>
4676
4677<p class="magick-description">perform local adaptive threshold.</p>
4678
4679<p>Adaptively threshold each pixel based on the value of pixels in a
4680surrounding window. If the current pixel is lighter than this average plus
4681the optional <code>offset</code>, then it is made white, otherwise it is made
4682black. Small variations in pixel values such as found in scanned documents
4683can be ignored if offset is positive. A negative offset will make it more
4684sensitive to those small variations. </p>
4685
4686<p>This is commonly used to threshold images with an uneven background. It is
4687based on the assumption that average color of the small window is the
4688the local background color, from which to separate the foreground color. </p>
4689
4690
4691<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004692 <h3 class="magick-header"><a id="layers"></a>-layers <var>method</var></h3>
cristyd2432012015-05-04 23:15:15 +00004693</div>
4694
4695<p class="magick-description">handle multiple images forming a set of image layers or animation frames.</p>
4696
4697<p>Perform various image operation methods to a ordered sequence of images
4698which may represent either a set of overlaid 'image layers', a GIF disposal
4699animation, or a fully-'coalesced' animation sequence. </p>
4700
4701<table class="table table-condensed table-striped">
4702 <tbody>
4703 <tr>
4704 <th style="width: 8%">Method</th>
4705 <th>Description</th>
4706 </tr>
4707
4708 <tr>
4709 <td>compare-any</td>
4710 <td>Crop the second and later frames to the smallest rectangle
cristy82a2ff22015-05-12 16:41:32 +00004711 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 +00004712 </tr>
4713
cristy82a2ff22015-05-12 16:41:32 +00004714 <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 +00004715 working, especially when animation used layer disposal methods such as
4716 '<code>Previous</code>' or '<code>Background</code>'. </td>
4717 </tr>
4718
4719 <tr>
4720 <td>compare-clear</td>
4721 <td>As '<code>compare-any</code>' but crop to the bounds of any
4722 opaque pixels which become transparent in the second frame. That is the
4723 smallest image needed to mask or erase pixels for the next frame. </td>
4724 </tr>
4725
4726 <tr>
4727 <td>compare-overlay</td>
4728 <td>As '<code>compare-any</code>' but crop to pixels that add
4729 extra color to the next image, as a result of overlaying color pixels.
4730 That is the smallest single overlaid image to add or change colors. </td>
4731 </tr>
4732
cristy82a2ff22015-05-12 16:41:32 +00004733 <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 +00004734 composition method '<code>change-mask</code>', to reduce the image to
4735 just the pixels that need to be overlaid. </td>
4736 </tr>
4737
4738 <tr>
4739 <td>coalesce</td>
cristy82a2ff22015-05-12 16:41:32 +00004740 <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 +00004741 current image sequence to form a fully defined animation sequence, as
4742 it should be displayed. Effectively converting a GIF animation into a
4743 'film strip'-like animation. </td>
4744 </tr>
4745
4746 <tr>
4747 <td>composite</td>
4748 <td>Alpha Composition of two image lists, separated by a
4749 "<code>null:</code>" image, with the destination image list first, and
4750 the source images last. An image from each list are composited
4751 together until one list is finished. The separator image and source
4752 image lists are removed. </td>
4753 </tr>
4754
4755
4756 <tr><td></td>
cristy82a2ff22015-05-12 16:41:32 +00004757 <td>The <a href="command-line-options.html#geometry">-geometry</a> offset is adjusted according
4758 to <a href="command-line-options.html#gravity">-gravity</a> in accordance of the virtual
4759 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 +00004760 added to the final composite positioning of each image. </td> </tr>
4761
4762 <tr><td></td>
4763 <td>If one of the image lists only contains one image, that image is
4764 applied to all the images in the other image list, regardless of which
4765 list it is. In this case it is the image meta-data of the list which
4766 preserved. </td>
4767 </tr>
4768
4769
4770 <tr>
4771 <td>dispose</td>
4772 <td>This like '<code>coalesce</code>' but shows the look of
4773 the animation after the layer disposal method has been applied, before
4774 the next sub-frame image is overlaid. That is the 'dispose' image that
cristy82a2ff22015-05-12 16:41:32 +00004775 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 +00004776 is going wrong with a particular animation you may be developing.
4777 </td>
4778 </tr>
4779
4780 <tr>
4781 <td>flatten</td>
4782 <td>Create a canvas the size of the first images virtual
cristy82a2ff22015-05-12 16:41:32 +00004783 canvas using the current <a href="command-line-options.html#background">-background</a> color,
4784 and <a href="command-line-options.html#compose">-compose</a> each image in turn onto that
cristyd2432012015-05-04 23:15:15 +00004785 canvas. Images falling outside that canvas is clipped. Final
4786 image will have a zero virtual canvas offset. </td>
4787 </tr>
4788
4789 <tr><td></td>
4790 <td>This usually used as one of the final 'image layering' operations
4791 overlaying all the prepared image layers into a final image. </td>
4792 </tr>
4793
4794 <tr><td></td>
4795 <td>For a single image this method can also be used to fillout a virtual
4796 canvas with real pixels, or to underlay an opaque color to remove
4797 transparency from an image.</td>
4798 </tr>
4799
4800
4801 <tr>
4802 <td>merge</td>
4803 <td>As 'flatten' method but merging all the given image
4804 layers to create a new layer image just large enough to hold all the
4805 image without clipping or extra space. The new images virtual offset
4806 will preserve the position of the new layer, even if this offset is
4807 negative. The virtual canvas size of the first image is preserved.
4808 </td>
4809 </tr>
4810
4811 <tr><td></td><td>Caution is advised when handling image layers with
4812 negative offsets as few image file formats handle them correctly.
cristy82a2ff22015-05-12 16:41:32 +00004813 Following this operation method with <a href="command-line-options.html#repage">+repage</a>
cristyd2432012015-05-04 23:15:15 +00004814 will remove the layer offset, and create an image in which all the
4815 overlaid image positions relative to each other is preserved, though
4816 not necessarily exactly where you specified them.
4817 </td>
4818 </tr>
4819
4820 <tr><td></td><td>See also 'trim-bounds' below which is closely related but
4821 without doing the'flatten' to merge the images together. </td>
4822 </tr>
4823
4824 <tr>
4825 <td>mosaic</td>
4826 <td>As 'flatten' method but expanding the initial canvas size
4827 of the first image in a positive direction only so as to hold all the
4828 image layers. However as a virtual canvas is 'locked' to the origin,
4829 by its own definition, image layers with a negative offsets will still
4830 become clipped by the top and left edges. See 'merge' or 'trim-bounds'
4831 if this could be a problem. </td>
4832
4833 </tr>
4834
4835 <tr><td></td><td>This method is commonly used to layout individual image
4836 using various offset but without knowing the final canvas size. The
4837 resulting image will, like 'flatten' not have any virtual offset, so
4838 can be saved to any image file format. </td>
4839 </tr>
4840
4841
4842 <tr>
4843 <td>optimize</td>
4844 <td>Optimize a coalesced animation, into GIF animation using
4845 a number of general techniques. This currently a short cut to
4846 apply both the '<code>optimize-frame</code>', and
4847 '<code>optimize-transparency</code>' methods but may be expanded to
4848 include other optimization methods as they are developed. </td>
4849 </tr>
4850
4851 <tr>
4852 <td>optimize-frame</td>
4853 <td>Optimize a coalesced animation, into GIF animation by
4854 reducing the number of pixels per frame as much as possible by
4855 attempting to pick the best layer disposal method to use, while ensuring
4856 the result will continue to animate properly. </td>
4857 </tr>
4858
4859 <tr><td></td><td> There is no guarantee that the best optimization is found.
4860 But then no reasonably fast GIF optimization algorithm can do this.
4861 However this does seem to do better than most other GIF frame
4862 optimizers seen. </td>
4863 </tr>
4864
4865 <tr>
4866 <td>optimize-plus</td>
4867 <td>As '<code>optimize-frame</code>' but attempt to improve the
4868 overall optimization by adding extra frames to the animation, without
4869 changing the final look or timing of the animation. The frames are
4870 added to attempt to separate the clearing of pixels from the
4871 overlaying of new additional pixels from one animation frame to the
4872 next. If this does not improve the optimization (for the next frame
4873 only), it will fall back to the results of the previous normal
4874 '<code>optimize-frame</code>' technique. </td>
4875 </tr>
4876
4877 <tr><td></td><td>There is the possibility that the change in the disposal
4878 style will result in a worsening in the optimization of later frames,
4879 though this is unlikely. In other words there no guarantee that it is
4880 better than the normal '<code>optimize-frame</code>' technique. For some
4881 animations however you can get a vast improvement in the final
4882 animation size. </td>
4883 </tr>
4884
4885 <tr>
4886 <td>optimize-transparency</td>
4887 <td>Given a GIF animation, replace any pixel in the sub-frame
4888 overlay images with transparency, if it does not change the resulting
cristy82a2ff22015-05-12 16:41:32 +00004889 animation by more than the current <a href="command-line-options.html#fuzz">-fuzz</a> factor.
cristyd2432012015-05-04 23:15:15 +00004890 </td>
4891 </tr>
4892
4893 <tr><td></td><td>This should allow a existing frame optimized GIF animation
4894 to compress into a smaller file size due to larger areas of one
4895 (transparent) color rather than a pattern of multiple colors repeating
4896 the current disposed image of the last frame. </td>
4897 </tr>
4898
4899 <tr>
4900 <td>remove-dups</td>
4901 <td>Remove (and merge time delays) of duplicate consecutive
4902 images, so as to simplify layer overlays of coalesced animations.
4903 </td>
4904 </tr>
4905
4906 <tr><td></td><td>Usually this a result of using a constant time delay
4907 across the whole animation, or after a larger animation was split into
4908 smaller sub-animations. The duplicate frames could also have been
4909 used as part of some frame optimization methods. </td>
4910 </tr>
4911
4912 <tr>
4913 <td>remove-zero</td>
4914 <td>Remove any image with a zero time delay, unless ALL the
4915 images have a zero time delay (and is not a proper timed animation, a
4916 warning is then issued). </td>
4917 </tr>
4918
4919 <tr><td></td><td>In a GIF animation, such images are usually frames which
4920 provide partial intermediary updates between the frames that are
4921 actually displayed to users. These frames are usually added for
4922 improved frame optimization in GIF animations. </td>
4923 </tr>
4924
4925 <tr>
4926 <td>trim-bounds</td>
4927 <td>Find the bounds of all the images in the current
4928 image sequence, then adjust the offsets so all images are contained on
4929 a minimal positive canvas. None of the image data is modified or
4930 merged, only the individual image virtual canvas size and offset.
4931 All the images is given the same canvas size, and and will have
4932 a positive offset, but will remain in the same position relative to
4933 each other. As a result of the minimal canvas size at least one image
4934 will touch every edge of that canvas. The image data touching those
4935 edges however may be transparent. </td>
4936 </tr>
4937
4938 <tr><td></td><td>The result is much like if you used 'merge' followed by a
cristy82a2ff22015-05-12 16:41:32 +00004939 <a href="command-line-options.html#repage">+repage</a> option, except that all the images
cristyd2432012015-05-04 23:15:15 +00004940 have been kept separate. If 'flatten' is used after using
4941 'trim-bounds' you will get the same result. </td>
4942 </tr>
4943
4944 </tbody>
4945</table>
4946
4947<p>To print a complete list of layer types, use <a href="command-line-options.html#list">-list layers</a>.</p>
4948
cristy82a2ff22015-05-12 16:41:32 +00004949<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
4950the 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
4951GIF <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 +00004952settings. </p>
4953
4954
4955<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004956 <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 +00004957</div>
4958
4959<p class="magick-description">adjust the level of image channels.</p>
4960
4961<p>Given one, two or three values delimited with commas: black-point,
4962white-point, gamma (for example: 10,250,1.0 or 2%,98%,0.5). The black and
4963white points range from 0 to <var>QuantumRange</var>, or from 0 to
4964100%; if the white point is omitted it is set to (<var>QuantumRange</var> - black_point), so as to center contrast changes.
4965If a <code>%</code> sign is present anywhere in the string, both black and white
cristy82a2ff22015-05-12 16:41:32 +00004966points 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 +00004967default of 1.0 (no gamma correction) is assumed.</p>
4968
4969<p>In normal usage (<code>-level</code>) the image values are stretched so that
4970the given '<code>black_point</code>' value in the original image is set to zero
4971(or black), while the given '<code>white_point</code>' value is set to <var>QuantumRange</var> (or white). This provides you with direct
4972contrast adjustments to the image. The '<code>gamma</code>' of the resulting
4973image will then be adjusted. </p>
4974
4975<p>From ImageMagick v6.4.1-9 using the plus form of the operator
4976(<code>+level</code>) or adding the special '!' flag anywhere in the argument
4977list, will cause the operator to do the reverse of the level adjustment. That
4978is a zero, or <var>QuantumRange</var> value (black, and white, resp.)
4979in the original image, is adjusted to the given level values, allowing you to
4980de-contrast, or compress the channel values within the image. The
4981'<code>gamma</code>' is adjusted before the level adjustment to de-contrast the
4982image is made. </p>
4983
4984<p>Only the channels defined by the current <a href="command-line-options.html#channel">-channel</a>
4985setting are adjusted (defaults to RGB color channels only), allowing you to
4986limit the effect of this operator. </p>
4987
4988<p>Please note that the transparency channel is treated as 'matte'
4989values (0 is opaque) and not as 'alpha' values (0 is transparent).</p>
4990
4991
4992<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00004993 <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 +00004994</div>
4995
4996<p class="magick-description">adjust the level of an image using the provided dash separated colors.</p>
4997
4998<p>This function is exactly like <a href="command-line-options.html#level">-level</a>, except that the
4999value value for each color channel is determined by the
5000'<code>black_color</code>' and '<code>white_color</code>' colors given (as
5001described under the <a href="command-line-options.html#fill">-fill</a> option). </p>
5002
5003<p>This effectually means the colors provided to <code>-level-colors</code>
5004is mapped to become 'black' and 'white' respectively, with all the other
5005colors linearly adjusted (or clipped) to match that change. Each channel is
5006adjusted separately using the channel values of the colors specified. </p>
5007
5008<p>On the other hand the plus form of the operator (<code>+level-colors</code>)
5009will map the image color 'black' and 'white' to the given colors
5010respectively, resulting in a gradient (de-contrasting) tint of the image to
5011those colors. This can also be used to convert a plain gray-scale image into a
5012one using the gradient of colors specified. </p>
5013
5014<p>By supplying a single color with a comma separator either before or after
5015that color, will just replace the respective 'black' or 'white' point
5016respectively. But if no comma separator is provided, the given color is
5017used for both the black and white color points, making the operator either
5018threshold the images around that color (- form) or set all colors to that
5019color (+ form). </p>
5020
5021
5022<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005023 <h3 class="magick-header"><a id="limit"></a>-limit <var>type value</var></h3>
cristyd2432012015-05-04 23:15:15 +00005024</div>
5025
5026<p class="magick-description">Set the pixel cache resource limit.</p>
5027
5028<p>Choose from: <code>area</code>, <code>disk</code>, <code>file</code>,
5029<code>map</code>, <code>memory</code>, <code>thread</code>, or <code>time</code>.</p>
5030
5031<p>The value for <code>file</code> is in number of files. The other limits are
5032in bytes. Define arguments for the memory, map, area, and disk resource limits
5033with SI prefixes (.e.g 100MB).</p>
5034
5035<p>By default the limits are 768 files, 3GB of image area, 1.5GiB memory, 3GiB
5036memory map, and 18.45EB of disk. These limits are adjusted relative to the
5037available resources on your computer if this information is available. When
5038any limit is reached, ImageMagick fails in some fashion but attempts to take
5039compensating actions, if possible. For example, the following limits
5040memory:</p>
5041
cristy29dc8652015-05-12 16:26:21 +00005042<pre>
5043-limit memory 32MiB -limit map 64MiB
5044</pre>
cristyd2432012015-05-04 23:15:15 +00005045
5046<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>
5047
5048<pre>
cristy82a2ff22015-05-12 16:41:32 +00005049-&gt; identify -list resource
cristyd2432012015-05-04 23:15:15 +00005050Resource limits:
5051 Width: 100MP
5052 Height: 100MP
5053 Area: 25.181GB
5054 Memory: 11.726GiB
5055 Map: 23.452GiB
5056 Disk: unlimited
5057 File: 768
5058 Thread: 12
5059 Throttle: 0
5060 Time: unlimited
5061</pre>
5062
5063<p>Requests for pixel storage to keep intermediate images are satisfied by one
5064of three resource categories: in-memory pool, memory-mapped files pool, and
cristy82a2ff22015-05-12 16:41:32 +00005065disk pool (in that order) depending on the <a href="command-line-options.html#limit">‑limit</a> settings
cristyd2432012015-05-04 23:15:15 +00005066and whether the system honors a resource request. If the total size of
5067allocated pixel storage in the given pool reaches the corresponding limit, the
5068request is passed to the next pool. Additionally, requests that exceed the
5069<code>area</code> limit automagically are allocated on disk.</p>
5070
5071<p>To illustrate how ImageMagick utilizes resource limits, consider a typical
5072image resource request. First, ImageMagick tries to allocate the pixels in
5073memory. The request might be denied if the resource request exceeds the
5074<code>memory</code> limit or if the system does not honor the request. If
5075a memory request is not honored, the pixels are allocated to disk and the file
5076is memory-mapped. However, if the allocation request exceeds the
5077<code>map</code> limit, the resource allocation goes to disk. In all cases, if
5078the resource request exceeds the <code>area</code> limit, the pixels are
5079automagically cached to disk. If the disk has a hard limit, the program
5080fails.</p>
5081
5082<p>In most cases you simply do not need to concern yourself with resource
5083limits. ImageMagick chooses reasonable defaults and most images do not tax
5084your computer resources. Where limits do come in handy is when you process
5085images that are large or on shared systems where ImageMagick can consume all
5086or most of the available memory. In this case, the ImageMagick workflow slows
5087other processes or, in extreme cases, brings the system to a halt. Under
5088these circumstances, setting limits give some assurances that the ImageMagick
5089workflow will not interfere with other concurrent uses of the computer. For
5090example, assume you have a web interface that processes images uploaded from
5091the Internet. To assure ImageMagick does not exceed 10MiB of memory you can
5092simply set the area limit to 10MiB:</p>
5093
cristy29dc8652015-05-12 16:26:21 +00005094<pre>
cristyd2432012015-05-04 23:15:15 +00005095-limit area 10MB
cristy29dc8652015-05-12 16:26:21 +00005096</pre>
cristyd2432012015-05-04 23:15:15 +00005097
5098<p>Now whenever a large image is processed, the pixels are automagically
5099cached to disk instead of memory. This of course implies that large images
5100typically process very slowly, simply because pixel processing in memory can
5101be an order of magnitude faster than on disk. Because your web site users
5102might inadvertently upload a huge image to process, you should set a disk
5103limit as well:</p>
5104
cristy29dc8652015-05-12 16:26:21 +00005105<pre>
cristyd2432012015-05-04 23:15:15 +00005106-limit area 10MB -limit disk 500MB
cristy29dc8652015-05-12 16:26:21 +00005107</pre>
cristyd2432012015-05-04 23:15:15 +00005108
5109<p>Here ImageMagick stops processing if an image requires more than 500MB of disk storage.</p>
5110
5111<p>In addition to command-line resource limit option, resources can be set
cristy82a2ff22015-05-12 16:41:32 +00005112with <a href="resources.html#environment">environment variables</a>. Set the
cristyd2432012015-05-04 23:15:15 +00005113environment variables <code>MAGICK_AREA_LIMIT</code>,
5114<code>MAGICK_DISK_LIMIT</code>, <code>MAGICK_FILE_LIMIT</code>,
5115<code>MAGICK_MEMORY_LIMIT</code>, <code>MAGICK_MAP_LIMIT</code>,
5116<code>MAGICK_THREAD_LIMIT</code>, <code>MAGICK_TIME_LIMIT</code> for limits of
5117image area, disk space, open files, heap memory, memory map, number of threads
5118of execution, and maximum elapsed time in seconds respectively.</p>
5119
5120<p> Inquisitive users can try adding <a href="command-line-options.html#debug">-debug cache</a> to
5121their commands and then scouring the generated output for references to the
5122pixel cache, in order to determine how the pixel cache was allocated and how
5123resources were consumed. Advanced Unix/Linux users can pipe that output
5124through <code>grep memory|open|destroy|disk</code> for more readable sifting.
5125</p>
5126
5127<p>For more about ImageMagick's use of resources, see the section <b>Cache
cristy82a2ff22015-05-12 16:41:32 +00005128Storage and Resource Requirements</b> on the <a href="architecture.html#cache%0A">Architecture</a> page. </p>
cristyd2432012015-05-04 23:15:15 +00005129
5130<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00005131 <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 +00005132</div>
5133
5134<p class="magick-description">Linear with saturation stretch.</p>
5135
cristy82a2ff22015-05-12 16:41:32 +00005136<p>This is very similar to <a href="command-line-options.html#contrast-stretch">-contrast-stretch</a>,
cristyd2432012015-05-04 23:15:15 +00005137and uses a 'histogram bin' to determine the range of color values that needs to
cristy82a2ff22015-05-12 16:41:32 +00005138be 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 +00005139
5140<p>As such while the initial determination may have 'binning' round off
5141effects, the image colors are stretched mathematically, rather than using the
5142histogram bins. This makes the operator more accurate. </p>
5143
cristy82a2ff22015-05-12 16:41:32 +00005144<p>note however that a <a href="command-line-options.html#linear-stretch">-linear-stretch</a> of
cristyd2432012015-05-04 23:15:15 +00005145'<code>0</code>' does nothing, while a value of '<code>1</code>' does a near
5146perfect stretch of the color range. </p>
5147
cristy82a2ff22015-05-12 16:41:32 +00005148<p>See also <a href="command-line-options.html#auto-level">-auto-level</a> for a 'perfect'
cristyd2432012015-05-04 23:15:15 +00005149normalization of mathematical images. </p>
5150
5151<p>This operator is under review for re-development. </p>
5152
5153
5154<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005155 <h3 class="magick-header"><a id="linewidth"></a>-linewidth</h3>
cristyd2432012015-05-04 23:15:15 +00005156</div>
5157
5158<p class="magick-description">the line width for subsequent draw operations.</p>
5159
5160<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005161 <h3 class="magick-header"><a id="liquid-rescale"></a>-liquid-rescale <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00005162</div>
5163
5164<p class="magick-description">rescale image with seam-carving.</p>
5165
5166<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
5167
5168<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005169 <h3 class="magick-header"><a id="list"></a>-list <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00005170</div>
5171
5172<p class="magick-description">Print a list of supported arguments for various options or settings. Choose from these list types:</p>
5173
cristyb2cad532015-05-16 13:02:45 +00005174<pre class="pre-scrollable">
5175Align
5176Alpha
5177Boolean
5178Cache
5179Channel
5180Class
5181ClipPath
5182Coder
5183Color
5184Colorspace
5185Command
5186Complex
5187Compose
5188Compress
5189Configure
5190DataType
5191Debug
5192Decoration
5193Delegate
5194Direction
5195Dispose
5196Distort
5197Dither
5198Endian
5199Evaluate
5200FillRule
5201Filter
5202Font
5203Format
5204Function
5205Gravity
5206Intensity
5207Intent
5208Interlace
5209Interpolate
5210Kernel
5211Layers
5212LineCap
5213LineJoin
5214List
5215Locale
5216LogEvent
5217Log
5218Magic
5219Method
5220Metric
5221Mime
5222Mode
5223Morphology
5224Module
5225Noise
5226Orientation
5227PixelIntensity
5228Policy
5229PolicyDomain
5230PolicyRights
5231Preview
5232Primitive
5233QuantumFormat
5234Resource
5235SparseColor
5236Statistic
5237Storage
5238Stretch
5239Style
5240Threshold
5241Type
5242Units
5243Validate
5244VirtualPixel
cristyd2432012015-05-04 23:15:15 +00005245</pre>
5246
5247<p>These lists vary depending on your version of ImageMagick. Use "<code>-list
5248list</code>" to get a complete listing of all the "<code>-list</code>" arguments
5249available:</p>
5250
5251<pre>
5252identify -list list
5253</pre>
5254
5255<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005256 <h3 class="magick-header"><a id="log"></a>-log <var>string</var></h3>
cristyd2432012015-05-04 23:15:15 +00005257</div>
5258
5259<p class="magick-description">Specify format for debug log.</p>
5260
cristy82a2ff22015-05-12 16:41:32 +00005261<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 +00005262
5263<p>You can display the following components by embedding special format
5264characters:</p>
5265
cristyb2cad532015-05-16 13:02:45 +00005266<dl class="dl-horizontal">
5267<dt>%d</dt><dd>domain</dd>
5268<dt>%e</dt><dd>event</dd>
5269<dt>%f</dt><dd>function</dd>
5270<dt>%l</dt><dd>line</dd>
5271<dt>%m</dt><dd>module</dd>
5272<dt>%p</dt><dd>process ID</dd>
5273<dt>%r</dt><dd>real CPU time</dd>
5274<dt>%t</dt><dd>wall clock time</dd>
5275<dt>%u</dt><dd>user CPU time</dd>
5276<dt>%%</dt><dd>percent sign</dd>
5277<dt>\n</dt><dd>newline</dd>
5278<dt>\r</dt><dd>carriage return</dd>
5279</dl>
cristyd2432012015-05-04 23:15:15 +00005280
5281<p>For example:</p>
5282
5283<pre>
5284convert -debug coders -log "%u %m:%l %e" in.gif out.png
5285</pre>
5286
5287<p>The default behavior is to print all of the components.</p>
5288
5289<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005290 <h3 class="magick-header"><a id="loop"></a>-loop <var>iterations</var></h3>
cristyd2432012015-05-04 23:15:15 +00005291</div>
5292
5293<p class="magick-description">add Netscape loop extension to your GIF animation.</p>
5294
5295<p>Set iterations to zero to repeat the animation an infinite number of times,
5296otherwise the animation repeats itself up to <var>iterations</var>
5297times.</p>
5298
5299<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005300 <h3 class="magick-header"><a id="lowlight-color"></a>-lowlight-color <var>color</var></h3>
cristyd2432012015-05-04 23:15:15 +00005301</div>
5302
5303<p class="magick-description">when comparing images, de-emphasize pixel differences with this color.</p>
5304
5305<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005306 <h3 class="magick-header"><a id="magnify"></a>-magnify</h3>
cristyd2432012015-05-04 23:15:15 +00005307</div>
5308
5309<p class="magick-description">double the size of the image with pixel art scaling.</p>
5310
5311
5312<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005313 <h3 class="magick-header"><a id="map"></a>-map <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00005314</div>
5315
5316<p class="magick-description">Display image using this <var>type</var>.</p>
5317
5318<p>Choose from these <var>Standard Colormap</var> types:</p>
5319
5320<pre>
cristy29dc8652015-05-12 16:26:21 +00005321best
5322default
5323gray
5324red
5325green
5326blue
cristyd2432012015-05-04 23:15:15 +00005327</pre>
5328
5329<p>The <var>X server</var> must support the <var>Standard
5330Colormap</var> you choose, otherwise an error occurs. Use <code>list</code> as
5331the type and <code>display</code> searches the list of colormap types in
5332<code>top-to-bottom</code> order until one is located. See <var>xstdcmap(1)</var> for one way of creating Standard Colormaps.</p>
5333
5334
5335<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005336 <h3 class="magick-header"><a id="map_stream_"></a>-map <var>components</var></h3>
cristyd2432012015-05-04 23:15:15 +00005337</div>
5338
5339<p class="magick-description">pixel map.</p>
5340
5341<p>Here are the valid components of a map:</p>
5342
cristyb2cad532015-05-16 13:02:45 +00005343<dl class="dl-horizontal">
5344<dt>r</dt><dd> red pixel component</dd>
5345<dt>g</dt><dd> green pixel component</dd>
5346<dt>b</dt><dd> blue pixel component</dd>
5347<dt>a</dt><dd> alpha pixel component (0 is transparent)</dd>
5348<dt>o</dt><dd> opacity pixel component (0 is opaque)</dd>
5349<dt>i</dt><dd> grayscale intensity pixel component</dd>
5350<dt>c</dt><dd> cyan pixel component</dd>
5351<dt>m</dt><dd> magenta pixel component</dd>
5352<dt>y</dt><dd> yellow pixel component</dd>
5353<dt>k</dt><dd> black pixel component</dd>
5354<dt>p</dt><dd> pad component (always 0)</dd>
5355</dl>
cristyd2432012015-05-04 23:15:15 +00005356
5357<p>You can specify as many of these components as needed in any order (e.g.
5358bgr). The components can repeat as well (e.g. rgbr).</p>
5359
5360
5361<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005362 <h3 class="magick-header"><a id="mask"></a>-mask
5363<var>filename</var></h3>
cristyd2432012015-05-04 23:15:15 +00005364</div>
5365
5366<p class="magick-description">Prevent updates to image pixels specified by the mask.</p>
5367
5368<p>This the same as using a mask used for composite masking operations, with
5369grayscale values causing blended updates of the image the mask is attached to.
5370</p>
5371
5372<p>Use <a href="command-line-options.html#mask">+mask</a> to remove the mask from images.</p>
5373
5374<p>Also see <a href="command-line-options.html#clip-mask">-clip-mask</a> which work in the same way,
5375but with strict boolean masking. </p>
5376
5377<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005378 <h3 class="magick-header"><a id="mattecolor"></a>-mattecolor <var>color</var></h3>
cristyd2432012015-05-04 23:15:15 +00005379</div>
5380
5381<p class="magick-description">Specify the color to be used with the <a href="command-line-options.html#frame">-frame</a> option.</p>
5382
5383<p>The color is specified using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p>
5384
cristy82a2ff22015-05-12 16:41:32 +00005385<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 +00005386
5387<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005388 <h3 class="magick-header"><a id="maximum"></a>-maximum</h3>
cristyd2432012015-05-04 23:15:15 +00005389</div>
5390
5391<p class="magick-description">return the maximum intensity of an image sequence.</p>
5392
5393<p>Select the 'maximum' value from all the surrounding pixels. </p>
5394
cristy82a2ff22015-05-12 16:41:32 +00005395<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 +00005396name. </p>
5397
5398<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005399 <h3 class="magick-header"><a id="median"></a>-median <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00005400</div>
5401
5402<p class="magick-description">apply a median filter to the image.</p>
5403
5404<p>Select the 'middle' value from all the surrounding pixels. </p>
5405
cristy82a2ff22015-05-12 16:41:32 +00005406<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 +00005407name. </p>
5408
5409<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005410 <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 +00005411</div>
5412
5413<p class="magick-description">image noise removal and color reduction/segmentation (e.g. -mean-shift 7x7+10%).</p>
5414
5415<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>
5416
cristyb2cad532015-05-16 13:02:45 +00005417<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 +00005418
5419<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005420 <h3 class="magick-header"><a id="metric"></a>-metric <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00005421</div>
5422
5423<p class="magick-description">Output to STDERR a measure of the differences between images according to the <var>type</var> given metric.</p>
5424
5425<p>Choose from:</p>
5426
cristy29dc8652015-05-12 16:26:21 +00005427<dl class="dl-horizontal">
5428<dt>AE</dt><dd> absolute error count, number of different pixels (-fuzz effected)</dd>
5429<dt>FUZZ</dt><dd> mean color distance</dd>
5430<dt>MAE</dt><dd> mean absolute error (normalized), average channel error distance</dd>
5431<dt>MEPP</dt><dd> mean error per pixel (normalized mean error, normalized peak error)</dd>
5432<dt>MSE</dt><dd> mean error squared, average of the channel error squared</dd>
5433<dt>NCC</dt><dd> normalized cross correlation</dd>
5434<dt>PAE</dt><dd> peak absolute (normalized peak absolute)</dd>
5435<dt>PHASH</dt><dd> perceptual hash</dd>
5436<dt>PSNR</dt><dd> peak signal to noise ratio</dd>
5437<dt>RMSE</dt><dd> root mean squared (normalized root mean squared)</dd>
5438</dl>
cristyd2432012015-05-04 23:15:15 +00005439
5440<p>Control the '<code>AE</code>', or absolute count of pixels that are different,
cristy82a2ff22015-05-12 16:41:32 +00005441with the <a href="command-line-options.html#fuzz">-fuzz</a> factor (ignore pixels which
cristyd2432012015-05-04 23:15:15 +00005442only changed by a small amount). Use '<code>PAE</code>' to find the
cristy82a2ff22015-05-12 16:41:32 +00005443size of the <a href="command-line-options.html#fuzz">-fuzz</a> factor needed to make all pixels
cristyd2432012015-05-04 23:15:15 +00005444'similar', while '<code>MAE</code>' determines the factor needed
5445for about half the pixels to be similar. </p>
5446
5447<p>The '<code>MEPP</code>' metric returns three different metrics
5448('<code>MAE</code>', '<code>MAE</code>' normalized, and '<code>PAE</code>'
5449normalized) from a single comparison run. </p>
5450
5451<p>To print a complete list of metrics, use the <a href="command-line-options.html#list">-list
5452metric</a> option.</p>
5453
5454
5455<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005456 <h3 class="magick-header"><a id="minimum"></a>-minimum</h3>
cristyd2432012015-05-04 23:15:15 +00005457</div>
5458
5459<p class="magick-description">return the minimum intensity of an image sequence.</p>
5460
5461<p>Select the 'minimal' value from all the surrounding pixels. </p>
5462
cristy82a2ff22015-05-12 16:41:32 +00005463<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 +00005464name. </p>
5465
5466
5467
5468<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005469 <h3 class="magick-header"><a id="mode"></a>-mode <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00005470</div>
5471
5472<p class="magick-description">make each pixel the \'predominant color\' of the neighborhood.'</p>
5473
5474<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005475 <h3 class="magick-header">-mode <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00005476</div>
5477
5478<p class="magick-description">Mode of operation.</p>
5479
5480<p>Choose the <var>value</var> from these styles: <code>Frame,
5481Unframe, or Concatenate</code></p>
5482
cristy82a2ff22015-05-12 16:41:32 +00005483<p>Use the <a href="command-line-options.html#list">-list</a> option with a '<code>Mode</code>' argument
5484for a list of <a href="command-line-options.html#mode">-mode</a> arguments available in your
cristyd2432012015-05-04 23:15:15 +00005485ImageMagick installation.</p>
5486
5487
5488<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005489 <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 +00005490</div>
5491
5492<p class="magick-description">Vary the <var>brightness</var>, <var>saturation</var>, and <var>hue</var> of an image.</p>
5493
5494<p>The arguments are given as a percentages of variation. A value of 100 means
5495no change, and any missing values are taken to mean 100.</p>
5496
5497<p>The <var>brightness</var> is a multiplier of the overall
5498brightness of the image, so 0 means pure black, 50 is half as bright, 200 is
5499twice as bright. To invert its meaning <a href="command-line-options.html#negate">-negate</a> the image
5500before and after. </p>
5501
5502<p>The <var>saturation</var> controls the amount of color in an
5503image. For example, 0 produce a grayscale image, while a large value such as
5504200 produce a very colorful, 'cartoonish' color.</p>
5505
5506<p>The <var>hue</var> argument causes a "rotation" of the colors
5507within the image by the amount specified. For example, 50 results in
5508a counter-clockwise rotation of 90, mapping red shades to purple, and so on.
5509A value of either 0 or 200 results in a complete 180 degree rotation of the
5510image. Using a value of 300 is a 360 degree rotation resulting in no change to
5511the original image. </p>
5512
5513<p>For example, to increase the color brightness by 20% and decrease the color
cristy82a2ff22015-05-12 16:41:32 +00005514saturation 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 +00005515
cristy82a2ff22015-05-12 16:41:32 +00005516<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 +00005517modulate. 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>
5518
5519<pre>
5520convert image.png -set option:modulate:colorspace hsb -modulate 120,90 modulate.png
5521</pre>
5522
5523<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005524 <h3 class="magick-header"><a id="moments"></a>-moments</h3>
cristyd2432012015-05-04 23:15:15 +00005525</div>
5526
5527<p class="magick-description">report image moments and perceptual hash.</p>
5528
5529
5530<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005531 <h3 class="magick-header"><a id="monitor"></a>-monitor</h3>
cristyd2432012015-05-04 23:15:15 +00005532</div>
5533
5534<p class="magick-description">monitor progress.</p>
5535
5536
5537<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005538 <h3 class="magick-header"><a id="monochrome"></a>-monochrome</h3>
cristyd2432012015-05-04 23:15:15 +00005539</div>
5540
5541<p class="magick-description">transform the image to black and white.</p>
5542
5543<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005544 <h3 class="magick-header"><a id="morph"></a>-morph <var>frames</var></h3>
cristyd2432012015-05-04 23:15:15 +00005545</div>
5546
5547<p class="magick-description">morphs an image sequence.</p>
5548
5549<p>Both the image pixels and size are linearly interpolated to give the
5550appearance of a metamorphosis from one image to the next, over all the images
cristy82a2ff22015-05-12 16:41:32 +00005551in 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 +00005552argument determine how many images to interpolate between each image. </p>
5553
5554
5555<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005556 <h3 class="magick-header"><a id="morphology"></a>-morphology</h3>
5557 <h3 class="magick-header">-morphology <var>method</var> <var>kernel</var></h3>
cristyd2432012015-05-04 23:15:15 +00005558</div>
5559
5560<p class="magick-description">apply a morphology method to the image.</p>
5561
cristy82a2ff22015-05-12 16:41:32 +00005562<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 +00005563Morphology</a>. </p>
5564
5565
5566<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005567 <h3 class="magick-header"><a id="mosaic"></a>-mosaic</h3>
cristyd2432012015-05-04 23:15:15 +00005568</div>
5569
cristy82a2ff22015-05-12 16:41:32 +00005570<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 +00005571
5572
5573<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00005574 <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 +00005575</div>
5576
5577<p class="magick-description">simulate motion blur.</p>
5578
5579<p>Blur with the given radius, standard deviation (sigma), and angle. The
5580angle given is the angle toward which the image is blurred. That is the
5581direction people would consider the object is coming from. </p>
5582
5583<p>Note that the blur is not uniform distribution, giving the motion a
5584definite sense of direction of movement. </p>
5585
5586<p>The <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting will determine how
5587pixels which are outside the image proper are blurred into the final result.
5588</p>
5589
5590<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005591 <h3 class="magick-header"><a id="name"></a>-name</h3>
cristyd2432012015-05-04 23:15:15 +00005592</div>
5593
5594<p class="magick-description">name an image.</p>
5595<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005596 <h3 class="magick-header"><a id="negate"></a>-negate</h3>
cristyd2432012015-05-04 23:15:15 +00005597</div>
5598
5599<p class="magick-description">replace each pixel with its complementary color.</p>
5600
5601<p>The red, green, and blue intensities of an image are negated. White becomes
5602black, yellow becomes blue, etc. Use <a href="command-line-options.html#negate">+negate</a> to only
5603negate the grayscale pixels of the image.</p>
5604
5605<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00005606 <h3 class="magick-header"><a id="noise"></a>-noise <var>geometry</var><br>
cristy29dc8652015-05-12 16:26:21 +00005607 +noise <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00005608</div>
5609
5610<p class="magick-description">Add or reduce noise in an image.</p>
5611
5612<p>The principal function of noise peak elimination filter is to smooth the
5613objects within an image without losing edge information and without creating
5614undesired structures. The central idea of the algorithm is to replace a pixel
5615with its next neighbor in value within a pixel window, if this pixel has been
5616found to be noise. A pixel is defined as noise if and only if this pixel is
5617a maximum or minimum within the pixel window.</p>
5618
5619<p>Use <code><a href="command-line-options.html#noise">-noise</a> <var>radius</var></code> to
5620specify the width of the neighborhood when reducing noise. This is equivalent
cristy82a2ff22015-05-12 16:41:32 +00005621to using a <code><a href="command-line-options.html#statistic">-statistic</a> NonPeak</code> operation,
cristyd2432012015-05-04 23:15:15 +00005622which should be used in preference.</p>
5623
5624<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
5625types:</p>
5626
5627<pre>
cristy29dc8652015-05-12 16:26:21 +00005628Gaussian
5629Impulse
5630Laplacian
5631Multiplicative
5632Poisson
5633Random
5634Uniform
cristyd2432012015-05-04 23:15:15 +00005635</pre>
5636
cristy82a2ff22015-05-12 16:41:32 +00005637<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 +00005638equivalent to 1.0, or a maximum noise addition.</p>
5639
5640<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>
5641
5642<p>To print a complete list of noises, use the <a href="command-line-options.html#list">-list noise</a> option.</p>
5643
5644<p>Also see the <a href="command-line-options.html#evaluate">-evaluate</a> noise functions that allows
5645the use of a controlling value to specify the amount of noise that should be
5646added to an image. </p>
5647
5648
5649<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005650 <h3 class="magick-header"><a id="normalize"></a>-normalize</h3>
cristyd2432012015-05-04 23:15:15 +00005651</div>
5652
5653<p class="magick-description">Increase the contrast in an image by <var>stretching</var> the range of intensity values.</p>
5654
5655<p>The intensity values are stretched to cover the entire range of possible
5656values. While doing so, black-out at most <var>2%</var> of the pixels and
5657white-out at most <var>1%</var> of the pixels.</p>
5658
cristy82a2ff22015-05-12 16:41:32 +00005659<p>Note that as of ImageMagick 6.4.7-0, <a href="command-line-options.html#normalize">-normalize</a>
5660is equivalent to <a href="command-line-options.html#contrast-stretch">-contrast-stretch 2%x1%</a>.
5661(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 +00005662
5663<p>All the channels are normalized in concert by the came amount so as to
cristy82a2ff22015-05-12 16:41:32 +00005664preserve color integrity, when the default <a href="command-line-options.html#channel">+channel</a>
5665setting is in use. Specifying any other <a href="command-line-options.html#channel">-channel</a>
cristyd2432012015-05-04 23:15:15 +00005666setting will normalize the RGB channels independently.</p>
5667
cristy82a2ff22015-05-12 16:41:32 +00005668<p>See <a href="command-line-options.html#contrast-stretch">-contrast-stretch</a> for more details.
5669Also see <a href="command-line-options.html#auto-level">-auto-level</a> for a 'perfect' normalization
cristyd2432012015-05-04 23:15:15 +00005670that is better suited to mathematically generated images. </p>
5671
5672<p>This operator is under review for re-development. </p>
5673
5674
5675<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005676 <h3 class="magick-header"><a id="opaque"></a>-opaque <var>color</var></h3>
cristyd2432012015-05-04 23:15:15 +00005677</div>
5678
5679<p class="magick-description">change this color to the fill color within the image.</p>
5680
5681<p>The <var>color</var> argument is defined using the format
cristy82a2ff22015-05-12 16:41:32 +00005682described 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 +00005683given.</p>
5684
5685<p>Use <a href="command-line-options.html#opaque">+opaque</a> to paint any pixel that does not match
5686the target color. </p>
5687
5688<p>The <a href="command-line-options.html#transparent">-transparent</a> operator is exactly the same
cristy82a2ff22015-05-12 16:41:32 +00005689as <a href="command-line-options.html#opaque">-opaque</a> but replaces the matching color with
cristyd2432012015-05-04 23:15:15 +00005690transparency rather than the current <a href="command-line-options.html#fill">-fill</a> color setting.
5691To ensure that it can do this it also ensures that the image has an alpha
cristy82a2ff22015-05-12 16:41:32 +00005692channel enabled, as per "<code><a href="command-line-options.html#alpha">-alpha</a> set</code>", for
5693the 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 +00005694
5695
5696<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005697 <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 +00005698</div>
5699
5700<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
5701given number of <var>levels</var> per color channel.</p>
5702
5703<p>You can choose from these standard threshold maps:</p>
5704
cristyb2cad532015-05-16 13:02:45 +00005705<pre class="pre-scrollable">
cristy29dc8652015-05-12 16:26:21 +00005706threshold 1x1 Threshold 1x1 (non-dither)
5707checks 2x1 Checkerboard 2x1 (dither)
5708o2x2 2x2 Ordered 2x2 (dispersed)
5709o3x3 3x3 Ordered 3x3 (dispersed)
5710o4x4 4x4 Ordered 4x4 (dispersed)
5711o8x8 8x8 Ordered 8x8 (dispersed)
5712h3x4a 4x1 Halftone 4x4 (angled)
5713h6x6a 6x1 Halftone 6x6 (angled)
5714h8x8a 8x1 Halftone 8x8 (angled)
5715h3x4o Halftone 4x4 (orthogonal)
5716h6x6o Halftone 6x6 (orthogonal)
5717h8x8o Halftone 8x8 (orthogonal)
5718h36x16o Halftone 16x16 (orthogonal)
5719c5x5b c5x5 Circles 5x5 (black)
5720c5x5w Circles 5x5 (white)
5721c6x6b c6x6 Circles 6x6 (black)
5722c6x6w Circles 6x6 (white)
5723c7x7b c7x7 Circles 7x7 (black)
5724c7x7w Circles 7x7 (white)
cristyd2432012015-05-04 23:15:15 +00005725</pre>
5726
5727<p> The <code>threshold</code> generated a simple 50% threshold of the image.
cristy82a2ff22015-05-12 16:41:32 +00005728This 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 +00005729</p>
5730
5731<p>The <code>checks</code> pattern produces a 3 level checkerboard dither
5732pattern. That is a grayscale will become a pattern of solid black, solid
5733white, and mid-tone colors into a checkerboard pattern of black and white.
5734</p>
5735
cristy82a2ff22015-05-12 16:41:32 +00005736<p>You can define your own <var>threshold map</var> for ordered
cristyd2432012015-05-04 23:15:15 +00005737dithering and halftoning your images, in either personal or system
cristy82a2ff22015-05-12 16:41:32 +00005738<code>thresholds.xml</code> XML file. See <a href="resources.html">Resources</a>
cristyd2432012015-05-04 23:15:15 +00005739for more details of configuration files. </p>
5740
5741<p>To print a complete list of the thresholds that have been defined, use the
cristy82a2ff22015-05-12 16:41:32 +00005742<a href="command-line-options.html#list">-list threshold</a> option.</p>
cristyd2432012015-05-04 23:15:15 +00005743
5744<p>Note that at this time the same threshold dithering map is used for all
5745color channels, no attempt is made to offset or rotate the map for different
5746channels is made, to create an offset printing effect. Also as the maps are
5747simple threshold levels, the halftone and circle maps will create incomplete
5748circles along the edges of a colored area. Also all the effects are purely
5749on/off boolean effects, without anti-aliasing to make the circles smooth
5750looking. Large dots can be made to look better with a small amount of blurring
5751after being created. </p>
5752
5753
5754<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005755 <h3 class="magick-header"><a id="orient"></a>-orient <var>image orientation</var></h3>
cristyd2432012015-05-04 23:15:15 +00005756</div>
5757
5758<p class="magick-description">specify orientation of a digital camera image.</p>
5759
5760<p>Choose from these orientations:</p>
5761
5762<pre>
cristyb2cad532015-05-16 13:02:45 +00005763bottom-left right-top
5764bottom-right top-left
5765left-bottom top-right
5766left-top undefined
cristy29dc8652015-05-12 16:26:21 +00005767right-bottom
cristyd2432012015-05-04 23:15:15 +00005768</pre>
5769
cristy82a2ff22015-05-12 16:41:32 +00005770<p>To print a complete list of orientations, use the <a href="command-line-options.html#list">-list
cristyd2432012015-05-04 23:15:15 +00005771orientation</a> option.</p>
5772
5773
5774<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00005775 <h3 class="magick-header"><a id="page"></a>-page <var>geometry</var><br>
5776 -page <var>media</var>[<var>offset</var>][{<var>^!&lt;&gt;</var>}]<br>
cristyd2432012015-05-04 23:15:15 +00005777 +page
cristy29dc8652015-05-12 16:26:21 +00005778 </h3>
cristyd2432012015-05-04 23:15:15 +00005779</div>
5780
5781<p class="magick-description">Set the size and location of an image on the larger virtual canvas.</p>
5782
5783<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
5784
5785<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 +00005786<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 +00005787
5788<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.
5789The choices for a PostScript page are:</p>
5790
cristyb2cad532015-05-16 13:02:45 +00005791<dl class="dl-horizontal">
5792<dt> 11x17 </dt> <dd> 792 x 1224</dd>
5793<dt> Ledger </dt> <dd> 1224 x 792</dd>
5794<dt> Legal </dt> <dd> 612 x 1008</dd>
5795<dt> Letter </dt> <dd> 612 x 792</dd>
5796<dt> LetterSmall</dt> <dd> 612 x 792</dd>
5797<dt> ArchE </dt> <dd> 2592 x 3456</dd>
5798<dt> ArchD </dt> <dd> 1728 x 2592</dd>
5799<dt> ArchC </dt> <dd> 1296 x 1728</dd>
5800<dt> ArchB </dt> <dd> 864 x 1296</dd>
5801<dt> ArchA </dt> <dd> 648 x 864</dd>
5802<dt> A0 </dt> <dd> 2380 x 3368</dd>
5803<dt> A1 </dt> <dd> 1684 x 2380</dd>
5804<dt> A2 </dt> <dd> 1190 x 1684</dd>
5805<dt> A3 </dt> <dd> 842 x 1190</dd>
5806<dt> A4 </dt> <dd> 595 x 842</dd>
5807<dt> A4Small </dt> <dd> 595 x 842</dd>
5808<dt> A5 </dt> <dd> 421 x 595</dd>
5809<dt> A6 </dt> <dd> 297 x 421</dd>
5810<dt> A7 </dt> <dd> 210 x 297</dd>
5811<dt> A8 </dt> <dd> 148 x 210</dd>
5812<dt> A9 </dt> <dd> 105 x 148</dd>
5813<dt> A10 </dt> <dd> 74 x 105</dd>
5814<dt> B0 </dt> <dd> 2836 x 4008</dd>
5815<dt> B1 </dt> <dd> 2004 x 2836</dd>
5816<dt> B2 </dt> <dd> 1418 x 2004</dd>
5817<dt> B3 </dt> <dd> 1002 x 1418</dd>
5818<dt> B4 </dt> <dd> 709 x 1002</dd>
5819<dt> B5 </dt> <dd> 501 x 709</dd>
5820<dt> C0 </dt> <dd> 2600 x 3677</dd>
5821<dt> C1 </dt> <dd> 1837 x 2600</dd>
5822<dt> C2 </dt> <dd> 1298 x 1837</dd>
5823<dt> C3 </dt> <dd> 918 x 1298</dd>
5824<dt> C4 </dt> <dd> 649 x 918</dd>
5825<dt> C5 </dt> <dd> 459 x 649</dd>
5826<dt> C6 </dt> <dd> 323 x 459</dd>
5827<dt> Flsa </dt> <dd> 612 x 936</dd>
5828<dt> Flse </dt> <dd> 612 x 936</dd>
5829<dt> HalfLetter </dt> <dd> 396 x 612</dd>
5830</dl>
cristyd2432012015-05-04 23:15:15 +00005831
5832<p>This option is also used to place subimages when writing to a multi-image
5833format that supports offsets, such as GIF89 and MNG. When used for this
5834purpose the offsets are always measured from the top left corner of the canvas
5835and are not affected by the <a href="command-line-options.html#gravity">-gravity</a> option. To
5836position 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
5837file, a <a href="command-line-options.html#page">-page</a> option appearing ahead of the first image in
5838the sequence with nonzero width and height defines the width and height values
5839that are written in the <code>MHDR</code> chunk. Otherwise, the MNG width and
5840height are computed from the bounding box that contains all images in the
5841sequence. When writing a GIF89 file, only the bounding box method is used to
5842determine its dimensions.</p>
5843
cristy82a2ff22015-05-12 16:41:32 +00005844<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
5845left-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 +00005846page. If the image size exceeds the PostScript page, it is reduced to fit the
5847page. 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
5848corner of the page, unless the <a href="command-line-options.html#gravity">-gravity</a> option is
5849present with a value other than <var>NorthWest</var>.</p>
5850
5851<p>The default page dimensions for a TEXT image is 612x792.</p>
5852
5853<p>This option is used in concert with <a href="command-line-options.html#density">-density</a>.</p>
5854
5855<p>Use <a href="command-line-options.html#page">+page</a> to remove the page settings for an image.</p>
5856
5857<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005858 <h3 class="magick-header"><a id="paint"></a>-paint <var>radius</var></h3>
cristyd2432012015-05-04 23:15:15 +00005859</div>
5860
5861<p class="magick-description">simulate an oil painting.</p>
5862
5863<p>Each pixel is replaced by the most frequent color in a circular
5864neighborhood whose width is specified with <var>radius</var>.</p>
5865
5866<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005867 <h3 class="magick-header"><a id="path"></a>-path <var>path</var></h3></div>
cristyd2432012015-05-04 23:15:15 +00005868
5869<p class="magick-description">write images to this path on disk.</p>
5870
5871<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005872 <h3 class="magick-header"><a id="pause_animate_"></a>-pause <var>seconds</var></h3>
cristyd2432012015-05-04 23:15:15 +00005873</div>
5874
5875<p class="magick-description">Pause between animation loops</p>
5876
5877<p>Pause for the specified number of seconds before repeating the animation.</p>
5878
5879<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005880 <h3 class="magick-header"><a id="pause_import_"></a>-pause <var>seconds</var></h3>
cristyd2432012015-05-04 23:15:15 +00005881</div>
5882
5883<p class="magick-description">Pause between snapshots.</p>
5884
5885<p>Pause for the specified number of seconds before taking the next snapshot.</p>
5886
5887<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005888 <h3 class="magick-header"><a id="perceptible"></a>-perceptible <var>epsilon</var></h3>
cristyd2432012015-05-04 23:15:15 +00005889</div>
5890
5891<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>
5892
5893<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005894 <h3 class="magick-header"><a id="ping"></a>-ping</h3>
cristyd2432012015-05-04 23:15:15 +00005895</div>
5896
5897<p class="magick-description">efficiently determine image characteristics.</p>
5898
5899<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005900 <h3 class="magick-header"><a id="pointsize"></a>-pointsize <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00005901</div>
5902
5903<p class="magick-description">pointsize of the PostScript, OPTION1, or TrueType font.</p>
5904
5905<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005906 <h3 class="magick-header"><a id="polaroid"></a>-polaroid <var>angle</var></h3>
cristyd2432012015-05-04 23:15:15 +00005907</div>
5908
5909<p class="magick-description">simulate a Polaroid picture.</p>
5910
5911<p>Use <code>+polaroid</code> to rotate the image at a random angle between -15 and +15 degrees.</p>
5912
5913<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005914 <h3 class="magick-header"><a id="poly"></a>-poly <var>"wt,exp ..."</var></h3>
cristyd2432012015-05-04 23:15:15 +00005915</div>
5916
5917<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>
5918
5919<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>
5920
5921<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>
5922
cristyb2cad532015-05-16 13:02:45 +00005923<p>The format is: <var>output = wt1*image1^exp1 + wt2*image2^exp2 </var>...</p>
cristyd2432012015-05-04 23:15:15 +00005924
5925<p>Some simple uses are:</p>
5926<ul>
5927<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>
5928<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>
5929</ul>
5930
5931<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>
5932
5933<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>
5934
5935
5936<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005937 <h3 class="magick-header"><a id="posterize"></a>-posterize <var>levels</var></h3>
cristyd2432012015-05-04 23:15:15 +00005938</div>
5939
5940<p class="magick-description">reduce the image to a limited number of color levels per channel.</p>
5941
5942<p>Very low values of <var>levels</var>, e.g., 2, 3, 4, have the most
5943visible effect.</p>
5944
5945<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005946 <h3 class="magick-header"><a id="precision"></a>-precision <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00005947</div>
5948
5949<p class="magick-description">set the maximum number of significant digits to be printed.</p>
5950
5951<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005952 <h3 class="magick-header"><a id="preview"></a>-preview <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00005953</div>
5954
5955<p class="magick-description">image preview type.</p>
5956
5957<p>Use this option to affect the preview operation of an image (e.g.
5958<code>convert file.png -preview Gamma Preview:gamma.png</code>). Choose from
5959these previews:</p>
5960
cristyb2cad532015-05-16 13:02:45 +00005961<pre class="pre-scrollable">
5962AddNoise
5963Blur
5964Brightness
5965Charcoal
5966Despeckle
5967Dull
5968EdgeDetect
5969Gamma
5970Grayscale
5971Hue
5972Implode
cristy29dc8652015-05-12 16:26:21 +00005973JPEG
cristyb2cad532015-05-16 13:02:45 +00005974OilPaint
5975Quantize
5976Raise
5977ReduceNoise
5978Roll
5979Rotate
5980Saturation
5981Segment
5982Shade
5983Sharpen
5984Shear
5985Solarize
5986Spiff
5987Spread
5988Swirl
5989Threshold
5990Wave
cristyd2432012015-05-04 23:15:15 +00005991</pre>
5992
5993<p>To print a complete list of previews, use the <a href="command-line-options.html#list">-list preview</a> option.</p>
5994
5995<p>The default preview is <code>JPEG</code>.</p>
5996
5997<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00005998 <h3 class="magick-header"><a id="print"></a>-print <var>string</var></h3>
cristyd2432012015-05-04 23:15:15 +00005999</div>
6000
6001<p class="magick-description">interpret string and print to console.</p>
6002
6003<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006004 <h3 class="magick-header"><a id="process"></a>-process <var>command</var></h3>
cristyd2432012015-05-04 23:15:15 +00006005</div>
6006
6007<p class="magick-description">process the image with a custom image filter.</p>
6008
6009<p>The command arguments has the form <code>"module arg1 arg2 arg3 ...
6010argN"</code> where <code>module</code> is the name of the module to invoke (e.g.
6011"Analyze") and arg1 arg2 arg3 ... argN are an arbitrary number of arguments to
6012pass to the process module.</p>
6013
6014<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00006015 <h3 class="magick-header"><a id="profile"></a>-profile <var>filename</var><br>
cristy29dc8652015-05-12 16:26:21 +00006016 +profile <var>profile_name</var></h3>
cristyd2432012015-05-04 23:15:15 +00006017</div>
6018
6019<p class="magick-description">Manage ICM, IPTC, or generic profiles in an image.</p>
6020
6021<p>Using <a href="command-line-options.html#profile">-profile</a> <var>filename</var> adds an
6022ICM (ICC color management), IPTC (newswire information), or a generic profile
6023to the image.</p>
6024
6025<p>Use <a href="command-line-options.html#profile">+profile <var>profile_name</var></a> to
6026remove the indicated profile. ImageMagick uses standard filename globbing, so
6027wildcard expressions may be used to remove more than one profile. Here we
6028remove all profiles from the image except for the XMP profile: <code>+profile
6029"!xmp,*"</code>. </p>
6030
6031<p>Use <code>identify -verbose</code> to find out which profiles are in the
6032image file. Use <a href="command-line-options.html#strip">-strip</a> to remove all profiles (and
6033comments).</p>
6034
6035<p>To extract a profile, the <a href="command-line-options.html#profile">-profile</a> option is not
6036used. Instead, simply write the file to an image format such as <var>APP1, 8BIM, ICM,</var> or <var>IPTC</var>.</p>
6037
6038<p>For example, to extract the Exif data (which is stored in JPEG files in the
6039<var>APP1</var> profile), use.</p>
6040
6041<pre>
6042convert cockatoo.jpg profile.exif
6043</pre>
6044
6045<p>It is important to note that results may depend on whether or not the
cristy82a2ff22015-05-12 16:41:32 +00006046original 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 +00006047therefore a conversion is made each time it is encountered, in order, in the
6048command-line. For instance, in the following example, if the original image is
6049CMYK with profile, a CMYK-CMYK-RGB conversion results.</p>
6050
6051<pre>
6052convert CMYK.tif -profile "CMYK.icc" -profile "RGB.icc" RGB.tiff
6053</pre>
6054
6055<p>Furthermore, since ICC profiles are not necessarily symmetric, extra
6056conversion steps can yield unwanted results. CMYK profiles are often very
6057asymmetric since they involve 3−&gt;4 and 4−&gt;3 channel mapping.
6058</p>
6059
6060<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006061 <h3 class="magick-header"><a id="quality"></a>-quality <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00006062</div>
6063
6064<p class="magick-description">JPEG/MIFF/PNG compression level.</p>
6065
6066<p>For the JPEG and MPEG image formats, quality is 1 (lowest image quality and
6067highest compression) to 100 (best quality but least effective compression).
6068The default is to use the estimated quality of your input image if it can
6069be determined, otherwise 92. When the quality is greater than 90, then the
6070chroma channels are not downsampled.
6071Use the <a href="command-line-options.html#sampling-factor">-sampling-factor</a> option to specify the
6072factors for chroma downsampling.</p>
6073
6074<p>For the MIFF image format, quality/10 is the zlib compression level, which
6075is 0 (worst but fastest compression) to 9 (best but slowest). It has no effect
6076on the image appearance, since the compression is always lossless.</p>
6077
6078<p>For the JPEG-2000 image format, quality is mapped using a non-linear
6079equation to the compression ratio required by the Jasper library. This
6080non-linear equation is intended to loosely approximate the quality provided by
6081the JPEG v1 format. The default quality value 100, a request for non-lossy
6082compression. A quality of 75 results in a request for 16:1 compression.</p>
6083
6084<p>For the MNG and PNG image formats, the quality value sets the zlib
6085compression level (quality / 10) and filter-type (quality % 10). The default
6086PNG "quality" is 75, which means compression level 7 with adaptive PNG
6087filtering, unless the image has a color map, in which case it means
6088compression level 7 with no PNG filtering.</p>
6089
6090<p>For compression level 0 (quality value less than 10), the Huffman-only
6091strategy is used, which is fastest but not necessarily the worst
6092compression.</p>
6093
6094<p>If filter-type is 4 or less, the specified PNG filter-type is used for
6095all scanlines:</p>
6096
cristyb2cad532015-05-16 13:02:45 +00006097<dl class="dl-horizontal">
6098<dt>0</dt><dd>none</dd>
6099<dt>1</dt><dd>sub</dd>
6100<dt>2</dt><dd>up</dd>
6101<dt>3</dt><dd>average</dd>
6102<dt>4</dt><dd>Paeth</dd>
6103</dl>
cristyd2432012015-05-04 23:15:15 +00006104
6105<p>If filter-type is 5, adaptive filtering is used when quality is greater
6106than 50 and the image does not have a color map, otherwise no filtering is
6107used.</p>
6108
6109<p>If filter-type is 6, adaptive filtering
6110with <var>minimum-sum-of-absolute-values</var> is used.</p>
6111
6112<p>Only if the output is MNG, if filter-type is 7, the LOCO color
6113transformation (intrapixel differencing) and adaptive filtering
6114with <var>minimum-sum-of-absolute-values</var> are used.</p>
6115
6116<p>If the filter-type is 8 the zlib Z_RLE compression strategy (or the
6117Z_HUFFMAN_ONLY strategy, when compression level is 0) is used with
6118adaptive PNG filtering.</p>
6119
6120<p>If the filter-type is 9 the zlib Z_RLE compression strategy (or the
6121Z_HUFFMAN_ONLY strategy, when compression level is 0) is used with
6122no PNG filtering.</p>
6123
6124<p>The quality setting has no effect on the appearance or signature of PNG
6125and MNG images, since the compression is always lossless.</p>
6126
6127<p>Not all combinations of compression level, strategy, and PNG filter type
6128can be obtained using the -quality option. For more precise control,
6129you can use the PNG:compression-level=N, PNG:compression-strategy=N, and
6130PNG:compression-filter=N defines, respectively, instead.
6131See <a href="command-line-options.html#define">-define</a>. Values from the defines take precedence
6132over values from the -quality option.</p>
6133
6134<p>For further information, see
6135the <a href="http://www.w3.org/pub/WWW/TR">PNG</a> specification.</p>
6136
6137<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006138 <h3 class="magick-header"><a id="quantize"></a>-quantize <var>colorspace</var></h3>
cristyd2432012015-05-04 23:15:15 +00006139</div>
6140
6141<p class="magick-description">reduce colors using this colorspace.</p>
6142
6143<p>This setting defines the colorspace used to sort out and reduce the number
cristy82a2ff22015-05-12 16:41:32 +00006144of 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 +00006145automatically when saving images to color-limited image file formats, such as
6146GIF, and PNG8.</p>
6147
6148
6149<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006150 <h3 class="magick-header"><a id="quiet"></a>-quiet</h3>
cristyd2432012015-05-04 23:15:15 +00006151</div>
6152
6153<p class="magick-description">suppress all warning messages. Error messages are still reported.</p>
6154
6155<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006156 <h3 class="magick-header"><a id="radial-blur"></a>-radial-blur <var>angle</var></h3>
cristyd2432012015-05-04 23:15:15 +00006157</div>
6158
6159<p class="magick-description">Blur around the center of the image.</p>
6160
6161<p>Note that this is actually a rotational blur rather than a radial and as
6162such actually mis-named. </p>
6163
6164<p>The <a href="command-line-options.html#virtual-pixel">-virtual-pixel</a> setting will determine how
6165pixels which are outside the image proper are blurred into the final result.
6166</p>
6167
6168
6169<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006170 <h3 class="magick-header"><a id="raise"></a>-raise <var>thickness</var></h3>
cristyd2432012015-05-04 23:15:15 +00006171</div>
6172
6173<p class="magick-description">Lighten or darken image edges.</p>
6174
6175<p>This will create a 3-D effect. Use <a href="command-line-options.html#raise">-raise</a> to create
6176a raised effect, otherwise use <a href="command-line-options.html#raise">+raise</a>. </p>
6177
cristy82a2ff22015-05-12 16:41:32 +00006178<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 +00006179
6180<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006181 <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 +00006182</div>
6183
6184<p class="magick-description">Apply a random threshold to the image.</p>
6185
6186<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006187 <h3 class="magick-header"><a id="red-primary"></a>-red-primary <var>x,y</var></h3>
cristyd2432012015-05-04 23:15:15 +00006188</div>
6189
6190<p class="magick-description">Set the red chromaticity primary point.</p>
6191
6192<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006193 <h3 class="magick-header"><a id="regard-warnings"></a>-regard-warnings</h3>
cristyd2432012015-05-04 23:15:15 +00006194</div>
6195
6196<p class="magick-description">Pay attention to warning messages.</p>
6197
6198<p>This option causes some warnings in some image formats to be treated
6199as errors. </p>
6200
6201<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006202 <h3 class="magick-header"><a id="remap"></a>-remap <var>filename</var></h3>
cristyd2432012015-05-04 23:15:15 +00006203</div>
6204
6205<p class="magick-description">Reduce the number of colors in an image to the colors used by this image.</p>
6206
6207<p>If the <a href="command-line-options.html#dither">-dither</a> setting is enabled (the default) then
6208the given colors are dithered over the image as necessary, otherwise the closest
6209color (in RGB colorspace) is selected to replace that pixel in the image. </p>
6210
6211<p>As a side effect of applying a <a href="command-line-options.html#remap">-remap</a> of colors across all
6212images in the current image sequence, all the images will have the same color
6213table. That means that when saved to a file format such as GIF, it will use
6214that color table as a single common or global color table, for all the images,
6215without requiring extra local color tables. </p>
6216
6217<p>Use <a href="command-line-options.html#remap">+remap</a> to reduce all images in the current image
6218sequence to use a common color map over all the images. This equivalent to
6219appending all the images together (without extra background colors) and color
6220reducing those images using <a href="command-line-options.html#colors">-colors</a> with a 256 color
6221limit, then <a href="command-line-options.html#remap">-remap</a> those colors over the original list of
6222images. This ensures all the images follow a single color map. </p>
6223
cristy82a2ff22015-05-12 16:41:32 +00006224<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 +00006225no color changes are needed. In that case, its only effect is to force the use
cristy82a2ff22015-05-12 16:41:32 +00006226of 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 +00006227reduce the number of colors in an animated image sequence. </p>
6228
6229<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>
6230
6231<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006232 <h3 class="magick-header"><a id="region"></a>-region <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00006233</div>
6234
6235<p class="magick-description">Set a region in which subsequent operations apply.</p>
6236
6237<p>The <var>x</var> and <var>y</var> offsets are treated
6238in the same manner as in <a href="command-line-options.html#crop">-crop</a>.</p>
6239
6240<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
6241
6242<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006243 <h3 class="magick-header"><a id="remote"></a>-remote</h3>
cristyd2432012015-05-04 23:15:15 +00006244</div>
6245
6246<p class="magick-description">perform a remote operation.</p>
6247
6248<p>The only command recognized is the name of an image file to load.</p>
6249
6250<p>If you have more than one <a href="display.html">display</a> application
6251running simultaneously, use the <a href="command-line-options.html#window"> window</a> option to
6252specify which application to control.</p>
6253
6254<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006255 <h3 class="magick-header"><a id="render"></a>-render</h3>
cristyd2432012015-05-04 23:15:15 +00006256</div>
6257
6258<p class="magick-description">render vector operations.</p>
6259
6260<p>Use <a href="command-line-options.html#render">+render</a> to turn off rendering vector operations.
6261This useful when saving the result to vector formats such as MVG or SVG.</p>
6262
6263<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006264<h3 class="magick-header"><a id="repage"></a>-repage <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00006265</div>
6266
6267<p class="magick-description">Adjust the canvas and offset information of the image.</p>
6268
6269<p>This option is like <a href="command-line-options.html#page">-page</a> but acts as an image operator
6270rather than a setting. You can separately set the canvas size or the offset
6271of the image on that canvas by only providing those components. </p>
6272
6273<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
6274
6275<p>If a <code>!</code> flag is given the offset given is added to the existing
6276offset to move the image relative to its previous position. This useful for
6277animation sequences. </p>
6278
6279<p>A given a canvas size of zero such as '<code>0x0</code>' forces it to
6280recalculate the canvas size so the image (at its current offset) will appear
6281completely on that canvas (unless it has a negative offset).</p>
6282
6283<p>Use <a href="command-line-options.html#repage">+repage</a> to completely remove/reset the virtual
6284canvas meta-data from the images. </p>
6285
6286<p>The <a href="command-line-options.html#set">-set</a> '<code>page</code>' option can be used to
6287directly assign virtual canvas meta-data. </p>
6288
6289
6290<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006291 <h3 class="magick-header"><a id="resample"></a>-resample <var>horizontal</var>x<var>vertical</var></h3>
cristyd2432012015-05-04 23:15:15 +00006292</div>
6293
6294<p class="magick-description">Resample image to specified horizontal and vertical resolution.</p>
6295
6296<p>Resize the image so that its rendered size remains the same as the original
6297at the specified target resolution. For example, if a 300 DPI image renders at
62983 inches by 2 inches on a 300 DPI device, when the image has been resampled to
629972 DPI, it will render at 3 inches by 2 inches on a 72 DPI device. Note that
6300only a small number of image formats (e.g. JPEG, PNG, and TIFF) are capable of
6301storing the image resolution. For formats which do not support an image
cristy82a2ff22015-05-12 16:41:32 +00006302resolution, 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 +00006303resample resolution.</p>
6304
6305<p>Note that Photoshop stores and obtains image resolution from a proprietary
6306embedded profile. If this profile exists in the image, then Photoshop will
6307continue to treat the image using its former resolution, ignoring the image
6308resolution specified in the standard file header.</p>
6309
6310<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006311 <h3 class="magick-header"><a id="resize"></a>-resize <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00006312</div>
6313
6314<p class="magick-description">Resize an image.</p>
6315
6316<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
6317ignored, and the <a href="command-line-options.html#gravity">-gravity</a> option has no effect.</p>
6318
6319<p>If the <a href="command-line-options.html#filter">-filter</a> option
cristy82a2ff22015-05-12 16:41:32 +00006320or <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 +00006321filter.</p>
6322
6323<p>Many image processing algorithms assume your image is in a linear-light
6324coding. If your image is gamma-corrected, you can remove the nonlinear gamma
6325correction, apply the transform, then restore it like this:</p>
6326
6327<pre>
cristy29dc8652015-05-12 16:26:21 +00006328convert portrait.jpg -gamma .45455 -resize 25% -gamma 2.2 \
6329 -quality 92 passport.jpg
cristyd2432012015-05-04 23:15:15 +00006330</pre>
6331
6332<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006333 <h3 class="magick-header"><a id="respect-parentheses"></a>-respect-parentheses</h3>
cristyd2432012015-05-04 23:15:15 +00006334</div>
6335
6336<p class="magick-description">settings remain in effect until parenthesis boundary.</p>
6337
6338<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006339 <h3 class="magick-header"><a id="reverse"></a>-reverse</h3>
cristyd2432012015-05-04 23:15:15 +00006340</div>
6341
6342<p class="magick-description">Reverse the order of images in the current image list.</p>
6343
6344
6345<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006346 <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 +00006347</div>
6348
6349<p class="magick-description">roll an image vertically or horizontally by the amount given.</p>
6350
6351<p>A negative <var>x</var> offset rolls the image right-to-left.
6352A negative <var>y</var> offset rolls the image bottom-to-top.</p>
6353
6354
6355<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006356 <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 +00006357</div>
6358
6359<p class="magick-description">Apply Paeth image rotation (using shear operations) to the image.</p>
6360
6361<p>Use <code>&gt;</code> to rotate the image only if its width exceeds the
6362height. <code>&lt;</code> rotates the image <var>only</var> if its width is less
6363than the height. For example, if you specify <code>-rotate "-90&gt;"</code> and
6364the image size is 480x640, the image is not rotated. However, if the image is
6365640x480, it is rotated by -90 degrees. If you use <code>&gt;</code> or
6366<code>&lt;</code>, enclose it in quotation marks to prevent it from being
6367misinterpreted as a file redirection.</p>
6368
6369<p>Empty triangles in the corners, left over from rotating the image, are
6370filled with the <code>background</code> color. </p>
6371
6372<p>See also the <a href="command-line-options.html#distort">-distort</a> operator and specifically the
6373'<code>ScaleRotateTranslate</code>' distort method. </p>
6374
6375
6376<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006377 <h3 class="magick-header"><a id="sample"></a>-sample <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00006378</div>
6379
6380<p class="magick-description">minify / magnify the image with pixel subsampling and pixel replication, respectively.</p>
6381
6382<p>Change the image size simply by directly sampling the pixels original
6383from the image. When magnifying, pixels are replicated in blocks. When
6384minifying, pixels are sub-sampled (i.e., some rows and columns are skipped
6385over). </p>
6386
6387<p>The results are thus equivalent to using <a href="command-line-options.html#resize">-resize</a> with
6388a <a href="command-line-options.html#filter">-filter</a> setting of <code>point</code> (nearest
6389neighbour), though <a href="command-line-options.html#sample">-sample</a> is a lot faster, as it
6390avoids all the filter processing of the image. As such it completely ignores
6391the current <a href="command-line-options.html#filter">-filter</a> setting. </p>
6392
6393<p>The key feature of the <a href="command-line-options.html#sample">-sample</a> is that no new colors
6394will be added to the resulting image, though some colors may disappear. </p>
6395
6396<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
6397ignored, unlike <a href="command-line-options.html#resize">-resize</a>. </p>
6398
6399
6400<p>The actual sampling point is the middle of the sub-region being sampled.
6401As such a single pixel sampling of an image will take the middle pixel, (or
cristy82a2ff22015-05-12 16:41:32 +00006402top-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 +00006403this position some other location within each sub-region being sampled, as
6404a percentage offset.</p>
6405
6406<p>By default this value is '<code>50</code>' for the midpoint, but could be set
6407to '<code>0</code>' for top-left, '<code>100</code>' for bottom-right, or with
6408separate X and Y offsets such as '<code>0x50</code>' for left-middle edge of
6409sampling sub-region.</p>
6410
6411
6412<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006413 <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 +00006414</div>
6415
6416<p class="magick-description">sampling factors used by JPEG or MPEG-2 encoder and YUV decoder/encoder.</p>
6417
6418<p>This option specifies the sampling factors to be used by the JPEG encoder
6419for chroma downsampling. If this option is omitted, the JPEG library will use
6420its own default values. When reading or writing the YUV format and when
cristy82a2ff22015-05-12 16:41:32 +00006421writing 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 +00006422downsampling method.</p>
6423
6424<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006425 <h3 class="magick-header"><a id="scale"></a>-scale <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00006426</div>
6427
6428<p class="magick-description">minify / magnify the image with pixel block averaging and pixel replication, respectively.</p>
6429
6430<p>Change the image size simply by replacing pixels by averaging pixels
6431together when minifying, or replacing pixels when magnifying. </p>
6432
6433<p>The results are thus equivalent to using <a href="command-line-options.html#resize">-resize</a> with
6434a <a href="command-line-options.html#filter">-filter</a> setting of <code>box</code>. Though it is a lot
6435faster, as it avoids all the filter processing of the image. As such it
6436completely ignores the current <a href="command-line-options.html#filter">-filter</a> setting. </p>
6437
6438<p>If when shrinking (minifying) images the original image is some integer
6439multiple of the new image size, the number of pixels averaged together to
6440produce the new pixel color is the same across the whole image. This is
6441a special case known as 'binning' and is often used as a method of reducing
6442noise in image such as those generated by digital cameras, especially in low
6443light conditions. </p>
6444
6445
6446<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006447 <h3 class="magick-header"><a id="scene"></a>-scene <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00006448</div>
6449
6450<p class="magick-description">set scene number.</p>
6451
6452<p>This option sets the scene number of an image or the first image in an image sequence.</p>
6453
6454<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006455 <h3 class="magick-header"><a id="screen"></a>-screen</h3>
cristyd2432012015-05-04 23:15:15 +00006456</div>
6457
6458<p class="magick-description">specify the screen to capture.</p>
6459
6460<p>This option indicates that the GetImage request used to obtain the image
6461should be done on the root window, rather than directly on the specified
6462window. In this way, you can obtain pieces of other windows that overlap the
6463specified window, and more importantly, you can capture menus or other popups
6464that are independent windows but appear over the specified window.</p>
6465
6466<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006467 <h3 class="magick-header"><a id="seed"></a>-seed</h3>
cristyd2432012015-05-04 23:15:15 +00006468</div>
6469
6470<p class="magick-description">seed a new sequence of pseudo-random numbers</p>
6471
6472<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006473 <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 +00006474</div>
6475
6476<p class="magick-description">segment the colors of an image.</p>
6477
6478<p>Segment an image by analyzing the histograms of the color components and
6479identifying units that are homogeneous with the fuzzy c-means technique. This
6480is part of the ImageMagick color quantization routines. </p>
6481
6482<p>Specify <var>cluster threshold</var> as the number of pixels in
6483each cluster that must exceed the cluster threshold to be considered valid.
6484<var>Smoothing threshold</var> eliminates noise in the second
6485derivative of the histogram. As the value is increased, you can expect
6486a smoother second derivative. The default is 1.5.</p>
6487
6488<p>If the <a href="command-line-options.html#verbose">-verbose</a> setting is defined, a detailed report
6489of the color clusters is returned.</p>
6490
6491
6492<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00006493 <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 +00006494</div>
6495
6496<p class="magick-description">Selectively blur pixels within a contrast threshold.</p>
6497
6498<p>Blurs those pixels that are less than or equal to the threshold in
6499contrast. The threshold may be expressed as a fraction of <var>QuantumRange</var> or as a percentage.</p>
6500
6501<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006502 <h3 class="magick-header"><a id="separate"></a>-separate</h3>
cristyd2432012015-05-04 23:15:15 +00006503</div>
6504
6505<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>
6506
6507<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006508 <h3 class="magick-header"><a id="sepia-tone"></a>-sepia-tone <var>threshold</var></h3>
cristyd2432012015-05-04 23:15:15 +00006509</div>
6510
6511<p class="magick-description">simulate a sepia-toned photo.</p>
6512
6513<p>Specify <var>threshold</var> as the percent threshold of the intensity (0 - 99.9%).</p>
6514
6515<p>This option applies a special effect to the image, similar to the effect
6516achieved 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
6517toning. A threshold of 80% is a good starting point for a reasonable
6518tone.</p>
6519
6520
6521
6522<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006523 <h3 class="magick-header"><a id="set"></a>-set <var>key value</var></h3>
6524 <h3 class="magick-header">+set <var>key</var></h3>
cristyd2432012015-05-04 23:15:15 +00006525</div>
6526
6527<p class="magick-description">sets image attributes and properties for images in the current image sequence.</p>
6528
6529<p>This will assign (or modify) specific settings attached to all the images
6530in the current image sequence. Using the <a href="command-line-options.html#set">+set</a> form of the
6531option will either remove, or reset that setting to a default state, as
6532appropriate. </p>
6533
6534<p>For example, it will modify specific well known image meta-data
cristy82a2ff22015-05-12 16:41:32 +00006535'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 +00006536assigned before the image is read in, by using a <var>key</var> of
6537the same name. </p>
6538
6539<p>If the given <var>key</var> does not match a specific known
6540'attribute ', such as shown above, the setting is stored as a a free form
cristy82a2ff22015-05-12 16:41:32 +00006541'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 +00006542</p>
6543
6544<p>This includes string 'properties' that are set by and assigned to images
cristy82a2ff22015-05-12 16:41:32 +00006545using 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
6546a global 'artifact' which are automatically assigned (and any <a href="escape.html">Format Percent
cristyd2432012015-05-04 23:15:15 +00006547Escapes</a> expanded) to images as they are read in. For example:</p>
6548
6549<pre>
cristyb2cad532015-05-16 13:02:45 +00006550-&gt; convert rose: -set comment 'Rose is a rose is a rose is a rose' rose.png
cristyd2432012015-05-04 23:15:15 +00006551identify -format %c rose.png
6552Rose is a rose is a rose is a rose
6553</pre>
6554
cristy82a2ff22015-05-12 16:41:32 +00006555<p>The set value can also make use of <a href="escape.html">Format and Print Image
cristyd2432012015-05-04 23:15:15 +00006556Properties</a> in the defined value. For example:</p>
6557
6558<pre>
cristyb2cad532015-05-16 13:02:45 +00006559-&gt; convert rose: -set origsize '%wx%h' -resize 50% \
cristyd2432012015-05-04 23:15:15 +00006560 -format 'Old size = %[origsize] New size = %wx%h' info:
6561Old size = 70x46 New size = 35x23
6562</pre>
6563
6564<p>Other well known 'properties' that are availible include:
6565'<code>date:create</code>' and '<code>date:modify</code>' and
6566'<code>signature</code>'. </p>
6567
6568<p>The <a href="command-line-options.html#repage">-repage</a> operator will also allow you to modify
6569the '<code>page</code>' attribute of an image for images already in memory (also
6570see <a href="command-line-options.html#repage">-page</a>). However it is designed to provide a finer
6571control of the sub-parts of this 'attribute'. The <a href="command-line-options.html#set">-set page</a>
6572option will only provide a direct, unmodified assignment of '<code>page</code>'
6573attribute. </p>
6574
6575<p>This option can also associate a colorspace or profile with your image.
6576For example,</p>
6577
6578<pre>
6579convert image.psd -set profile ISOcoated_v2_eci.icc image-icc.psd
6580</pre>
6581
6582<p>Some 'properties' must be defined in a specific way to be used. For
6583example only 'properties' prefixed with "<code>filename:</code>" can be used to
6584modify the output filename of an image. For example</p>
6585
6586<pre>
6587convert rose: -set filename:mysize '%wx%h' 'rose_%[filename:mysize].png'
6588</pre>
6589
6590<p>If the setting value is prefixed with "<code>option:</code>" the setting will
cristy82a2ff22015-05-12 16:41:32 +00006591be 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 +00006592can be used to pass 'attributes' and 'properties' of one specific image,
6593in a way that allows you to use them in a completely different image, even if
6594the original image has long since been modified or destroyed. For example: </p>
6595
6596<pre>
6597convert rose: -set option:rosesize '%wx%h' -delete 0 \
6598 label:'%[rosesize]' label_size_of_rose.gif"
6599</pre>
6600
cristy82a2ff22015-05-12 16:41:32 +00006601<p>Note that <a href="escape.html">Format Percent Escapes</a> will only match
cristyd2432012015-05-04 23:15:15 +00006602a 'artifact' if the given <var>key</var> does not match an existing
6603'attribute' or 'property'. </p>
6604
6605<p>You can set the attributes of the image registry by prefixing the value
6606with <code>registry:</code>.</p>
6607
6608<p>The <a href="command-line-options.html#set">-set profile</a> option can also be used to inject
6609previously-formatted ancillary chunks into the output PNG file, using
6610the commandline option as shown below or by setting the profile via a
6611programming interface:</p>
6612
6613<pre>
6614convert in.png -set profile PNG-chunk-x:&lt;filename&gt; out.png
6615</pre>
6616
6617<p>where <var>x</var> is a location flag and
6618<var>filename</var> is a file containing the chunk
6619name in the first 4 bytes, then a colon (":"), followed by the chunk data.
6620This encoder will compute the chunk length and CRC, so those must not
6621be included in the file.</p>
6622
6623<p>"x" can be "b" (before PLTE), "m" (middle, i.e., between PLTE and IDAT),
6624or "e" (end, i.e., after IDAT). If you want to write multiple chunks
6625of the same type, then add a short unique string after the "x" to prevent
6626subsequent profiles from overwriting the preceding ones, e.g.,</p>
6627
6628
6629<pre>
6630convert in.png -set profile PNG-chunk-b01:file01 \
6631 -profile PNG-chunk-b02:file02 out.png
6632</pre>
6633
6634<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006635 <h3 class="magick-header"><a id="shade"></a>-shade <var>azimuth</var>x<var>elevation</var></h3>
cristyd2432012015-05-04 23:15:15 +00006636</div>
6637
6638<p class="magick-description">shade the image using a distant light source.</p>
6639
6640<p>Specify <var>azimuth</var> and <var>elevation</var> as
6641the position of the light source. Use <a href="command-line-options.html#shade">+shade</a> to return
6642the shading results as a grayscale image.</p>
6643
6644<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006645 <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 +00006646</div>
6647
6648<p class="magick-description">simulate an image shadow.</p>
6649
6650<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00006651 <h3 class="magick-header"><a id="shared-memory"></a>-shared-memory</h3>
cristyd2432012015-05-04 23:15:15 +00006652</div>
6653
6654<p class="magick-description">use shared memory.</p>
6655
6656<p>This option specifies whether the utility should attempt to use shared
6657memory for pixmaps. ImageMagick must be compiled with shared memory support,
6658and the display must support the <var>MIT-SHM</var> extension.
6659Otherwise, this option is ignored. The default is <code>True</code>.</p>
6660
6661<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00006662 <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 +00006663</div>
6664
6665<p class="magick-description">sharpen the image.</p>
6666
6667<p>Use a Gaussian operator of the given radius and standard deviation (sigma).</p>
6668
6669<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006670 <h3 class="magick-header"><a id="shave"></a>-shave <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00006671</div>
6672
6673<p class="magick-description">Shave pixels from the image edges.</p>
6674
6675<p>The <var>size</var> portion of the <var>geometry</var>
6676argument specifies the width of the region to be removed from both sides of
6677the image and the height of the regions to be removed from top and bottom.
6678Offsets are ignored.</p>
6679
6680<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
6681
6682<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006683 <h3 class="magick-header"><a id="shear"></a>-shear <var>Xdegrees</var>[x<var>Ydegrees</var>]</h3>
cristyd2432012015-05-04 23:15:15 +00006684</div>
6685
6686<p class="magick-description">Shear the image along the x-axis and/or y-axis.</p>
6687
6688<p>The shear angles may be positive, negative, or zero. When <var>Ydegrees</var> is omitted it defaults to 0. When both angles are
6689given, the horizontal component of the shear is performed before the vertical
6690component.</p>
6691
6692<p>Shearing slides one edge of an image along the x-axis or y-axis (i.e.,
6693horizontally or vertically, respectively),creating a parallelogram. The amount
6694of each is controlled by the respective shear angle. For horizontal shears,
6695<var>Xdegrees</var> is measured clockwise relative to "up" (the
6696negative 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
6697positive 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>
6698
6699<p>Empty triangles left over from shearing the image are filled with the color
6700defined by the <a href="command-line-options.html#fill">-background</a> option. The color is specified
6701using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p>
6702
6703<p>The horizontal shear is performed before the vertical part. This is
6704important to note, since horizontal and vertical shears do not
6705<var>commute</var>, i.e., the order matters in a sequence of shears. For
6706example, the following two commands are not equivalent.</p>
6707
6708<pre>
6709convert logo: -shear 20x0 -shear 0x60 logo-sheared.png
6710convert logo: -shear 0x60 -shear 20x0 logo-sheared.png
6711</pre>
6712
6713<p>The first of the two commands above is equivalent to the following, except
6714for the amount of empty space created; the command that follows generates
6715a smaller image, and so is a better choice in terms of time and space.</p>
6716
6717<pre>
6718convert logo: -shear 20x60 logo-sheared.png
6719</pre>
6720
6721<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006722 <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 +00006723</div>
6724
6725<p class="magick-description">increase the contrast without saturating highlights or shadows.</p>
6726
6727<p>Increase the contrast of the image using a sigmoidal transfer function
6728without saturating highlights or shadows. <var>Contrast</var>
6729indicates how much to increase the contrast. For example, 0 is none, 3 is
6730typical and 20 is a lot.
6731</p>
6732
6733<p>The <var>mid-point</var> indicates where the maximum change
6734'slope' in contrast should fall in the resultant image (0 is white; 50% is
6735middle-gray; 100% is black). </p>
6736
6737<p>By default the image contrast is increased, use <var>+sigmoidal-contrast</var> to decrease the contrast.</p>
6738
6739<p>To achieve the equivalent of a sigmoidal brightness change (similar to
6740a gamma adjustment), you would use <var>-sigmoidal-contrast
6741{brightness}x0%</var> to increase brightness and <var>+sigmoidal-contrast {brightness}x0%</var> to decrease brightness.
6742Note the use of '0' fo rthe mid-point of the sigmoidal curve. </p>
6743
6744<p>Using a very high <var>contrast</var> will produce a sort of
6745'smoothed thresholding' of the image. Not as sharp (with high aliasing
6746effects) of a true threshold, but with tapered gray-levels around the threshold
6747<var>mid-point</var>. </p>
6748
6749<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006750 <h3 class="magick-header"><a id="silent"></a>-silent</h3>
cristyd2432012015-05-04 23:15:15 +00006751</div>
6752
6753<p class="magick-description">operate silently.</p>
6754
6755<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006756 <h3 class="magick-header"><a id="similarity-threshold"></a>-similarity-threshold <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00006757</div>
6758
6759<p class="magick-description">minimum RMSE for subimage match.</p>
6760
6761<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>
6762
6763<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006764 <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 +00006765</div>
6766
6767<p class="magick-description">set the width and height of the image.</p>
6768
6769<p>Use this option to specify the width and height of raw images whose
6770dimensions are unknown such as <code>GRAY</code>, <code>RGB</code>, or
cristy82a2ff22015-05-12 16:41:32 +00006771<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 +00006772image or tell the number of colors in a <code>MAP</code> image file, (e.g. -size
6773640x512+256).</p>
6774
6775<p>For Photo CD images, choose from these sizes:</p>
6776
6777<pre>
cristy29dc8652015-05-12 16:26:21 +00006778192x128
6779384x256
6780768x512
67811536x1024
67823072x2048
cristyd2432012015-05-04 23:15:15 +00006783</pre>
6784
6785<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00006786 <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 +00006787</div>
6788
6789<p class="magick-description">simulate a pencil sketch.</p>
6790
6791<p>Sketch with the given radius, standard deviation (sigma), and angle. The
6792angle given is the angle toward which the image is sketched. That is the
6793direction people would consider the object is coming from. </p>
6794
6795<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006796 <h3 class="magick-header"><a id="smush"></a>-smush <var>offset</var></h3>
cristyd2432012015-05-04 23:15:15 +00006797</div>
6798
6799<p class="magick-description">smush an image sequence together.</p>
6800
6801<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006802 <h3 class="magick-header"><a id="snaps"></a>-snaps <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00006803</div>
6804
6805<p class="magick-description">Set the number of screen snapshots.</p>
6806
6807<p>Use this option to grab more than one image from the X server screen, to create an animation sequence.</p>
6808
6809<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006810 <h3 class="magick-header"><a id="solarize"></a>-solarize <var>threshold</var></h3>
cristyd2432012015-05-04 23:15:15 +00006811</div>
6812
6813<p class="magick-description">negate all pixels above the threshold level.</p>
6814
6815<p>Specify <var>factor</var> as the percent threshold of the intensity (0 - 99.9%).</p>
6816
6817<p>This option produces a <var>solarization</var> effect seen when
6818exposing a photographic film to light during the development process.</p>
6819
6820<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006821 <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 +00006822</div>
6823
6824<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>
6825
6826
cristyb2cad532015-05-16 13:02:45 +00006827<dl class="dl-horizontal">
6828 <dt>barycentric</dt>
6829 <dd>three point triangle of color given 3 points.
cristyd2432012015-05-04 23:15:15 +00006830 Giving only 2 points will form a linear gradient between those points.
6831 The gradient generated extends beyond the triangle created by those
cristyb2cad532015-05-16 13:02:45 +00006832 3 points. </dd>
6833 <dt>bilinear</dt>
6834 <dd>Like barycentric but for 4 points. Less than 4 points
6835 fall back to barycentric. </dd>
6836 <dt>voronoi</dt>
6837 <dd>Simply map each pixel to the to nearest color point
6838 given. The result are polygonal 'cells' of solid color. </dd>
6839 <dt>shepards</dt>
6840 <dd>Colors points biased on the ratio of inverse distance
cristyd2432012015-05-04 23:15:15 +00006841 squared. Generating spots of color in a sea of the average of
cristyb2cad532015-05-16 13:02:45 +00006842 colors. </dd>
6843 <dt>inverse</dt>
6844 <dd>Colors points biased on the ratio of inverse distance.
cristyd2432012015-05-04 23:15:15 +00006845 This generates sharper points of color rather than rounded spots of
6846 '<code>shepards</code>' Generating spots of color in a sea of the
cristyb2cad532015-05-16 13:02:45 +00006847 average of colors. </dd>
6848</dl>
cristyd2432012015-05-04 23:15:15 +00006849
6850<p>The points are placed according to the images location on the virtual
cristy82a2ff22015-05-12 16:41:32 +00006851canvas (<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 +00006852offset), and do not actually have to exist on the given image, but may be
6853some point beyond the edge of the image. All points are floating point values.
6854</p>
6855
cristy82a2ff22015-05-12 16:41:32 +00006856<p>Only the color channels defined by the <a href="command-line-options.html#channel">-channel</a> are
cristyd2432012015-05-04 23:15:15 +00006857modified, which means that by default matte/alpha transparency channel is not
6858effected. Typically transparency channel is turned off either before or after
6859the operation. </p>
6860
6861<p>Of course if some color points are transparent to generate a transparent
6862gradient, then the image also requires transparency enabled to store the
6863values. </p>
6864
6865<p>All the above methods when given a single point of color will replace all
6866the colors in the image with the color given, regardless of the point. This is
6867logical, and provides an alternative technique to recolor an image to some
6868default value. </p>
6869
6870
6871<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006872 <h3 class="magick-header"><a id="splice"></a>-splice <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00006873</div>
6874
6875<p class="magick-description">Splice the current background color into the image.</p>
6876
cristy82a2ff22015-05-12 16:41:32 +00006877<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 +00006878given <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
6879image into four quadrants, separating them by the inserted rows and columns.
6880</p>
6881
6882<p>If a dimension of geometry is zero no rows or columns will be added for that
cristy82a2ff22015-05-12 16:41:32 +00006883dimension. 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
6884the 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 +00006885
cristy82a2ff22015-05-12 16:41:32 +00006886<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 +00006887added added all splices removed. </p>
6888
6889<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006890 <h3 class="magick-header"><a id="spread"></a>-spread <var>amount</var></h3>
cristyd2432012015-05-04 23:15:15 +00006891</div>
6892
6893<p class="magick-description">displace image pixels by a random amount.</p>
6894
6895<p>The argument <var>amount</var> defines the size of the
6896neighborhood around each pixel from which to choose a candidate pixel to
6897swap.</p>
6898
6899<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006900 <h3 class="magick-header"><a id="statistic"></a>-statistic <var>type</var> <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00006901</div>
6902
6903<p class="magick-description">replace each pixel with corresponding statistic from the neighborhood.</p>
6904
6905<p>Choose from these statistic types:</p>
cristy29dc8652015-05-12 16:26:21 +00006906<dl class="dl-horizontal">
6907<dt>Gradient</dt><dd>maximum difference (max - min) value in neighborhood</dd>
6908<dt>Maximum</dt><dd>maximum value per channel in neighborhood</dd>
6909<dt>Minimum</dt><dd>minimum value per channel in neighborhood</dd>
6910<dt>Mean</dt><dd>average value per channel in neighborhood</dd>
6911<dt>Median</dt><dd>median value per channel in neighborhood</dd>
6912<dt>Mode</dt><dd>mode (most frequent) value per channel in neighborhood</dd>
6913<dt>Nonpeak</dt><dd>value just before or after the median value per channel in neighborhood</dd>
6914<dt>RMS</dt><dd>root mean square value per channel in neighborhood</dd>
6915<dt>StandardDeviation</dt><dd> standard deviation value per channel in neighborhood</dd>
6916</dl>
cristyd2432012015-05-04 23:15:15 +00006917
6918<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006919 <h3 class="magick-header"><a id="stegano"></a>-stegano <var>offset</var></h3>
cristyd2432012015-05-04 23:15:15 +00006920</div>
6921
6922<p class="magick-description">hide watermark within an image.</p>
6923
6924<p>Use an offset to start the image hiding some number of pixels from the
6925beginning of the image. Note this offset and the image size. You will need
6926this information to recover the steganographic image (e.g. display -size
6927320x256+35 stegano:image.png).</p>
6928
6929<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006930 <h3 class="magick-header"><a id="stereo"></a>-stereo <var>+x</var>{<var>+y</var>}</h3>
cristyd2432012015-05-04 23:15:15 +00006931</div>
6932
6933<p class="magick-description">composite two images to create a red / cyan stereo anaglyph.</p>
6934
6935<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>
6936
6937<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006938 <h3 class="magick-header"><a id="storage-type"></a>-storage-type <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00006939</div>
6940
6941<p class="magick-description">pixel storage type. Here are the valid types:</p>
6942
cristyb2cad532015-05-16 13:02:45 +00006943<dl class="dl-horizontal">
6944<dt>char</dt><dd>unsigned characters</dd>
6945<dt>double</dt><dd>doubles</dd>
6946<dt>float</dt><dd>floats</dd>
6947<dt>integer</dt><dd>integers</dd>
6948<dt>long</dt><dd>longs</dd>
6949<dt>quantum</dt><dd>pixels in the native depth of your ImageMagick distribution</dd>
6950<dt>short</dt><dd>unsigned shorts</dd>
6951</dl>
cristyd2432012015-05-04 23:15:15 +00006952
6953<p>Float and double types are normalized from 0.0 to 1.0 otherwise the pixels
6954values range from 0 to the maximum value the storage type can support.</p>
6955
6956<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006957 <h3 class="magick-header"><a id="stretch"></a>-stretch <var>fontStretch</var></h3>
cristyd2432012015-05-04 23:15:15 +00006958</div>
6959
6960<p class="magick-description">Set a type of stretch style for fonts.</p>
6961
6962<p>This setting suggests a type of stretch that ImageMagick should try to
6963apply to the currently selected font family. Select <var>fontStretch</var> from the following.</p>
6964
6965<pre>
cristy29dc8652015-05-12 16:26:21 +00006966Any
6967Condensed
6968Expanded
6969ExtraCondensed
6970ExtraExpanded
6971Normal
6972SemiCondensed
6973SemiExpanded
6974UltraCondensed
6975UltraExpanded
cristyd2432012015-05-04 23:15:15 +00006976</pre>
6977
6978<p>To print a complete list of stretch types, use <a href="command-line-options.html#list">-list
6979stretch</a>.</p>
6980
cristy82a2ff22015-05-12 16:41:32 +00006981<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 +00006982
6983<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006984 <h3 class="magick-header"><a id="strip"></a>-strip</h3>
cristyd2432012015-05-04 23:15:15 +00006985</div>
6986
6987<p class="magick-description">strip the image of any profiles or comments.</p>
6988
6989<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00006990 <h3 class="magick-header"><a id="stroke"></a>-stroke <var>color</var></h3>
cristyd2432012015-05-04 23:15:15 +00006991</div>
6992
6993<p class="magick-description">color to use when stroking a graphic primitive.</p>
6994
6995<p>The color is specified using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p>
6996
6997<p>See <a href="command-line-options.html#draw">-draw</a> for further details.</p>
6998
6999<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007000 <h3 class="magick-header"><a id="strokewidth"></a>-strokewidth <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00007001</div>
7002
7003<p class="magick-description">set the stroke width.</p>
7004
7005<p>See <a href="command-line-options.html#draw">-draw</a> for further details.</p>
7006
7007<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007008 <h3 class="magick-header"><a id="style"></a>-style <var>fontStyle</var></h3>
cristyd2432012015-05-04 23:15:15 +00007009</div>
7010
7011<p class="magick-description">Set a font style for text.</p>
7012
7013<p>This setting suggests a font style that ImageMagick should try to apply to
7014the currently selected font family. Select <var>fontStyle</var> from
7015the following.</p>
7016
7017<pre>
cristy29dc8652015-05-12 16:26:21 +00007018Any
7019Italic
7020Normal
7021Oblique
cristyd2432012015-05-04 23:15:15 +00007022</pre>
7023
cristy82a2ff22015-05-12 16:41:32 +00007024<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 +00007025
7026<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007027 <h3 class="magick-header"><a id="subimage-search"></a>-subimage-search</h3>
cristyd2432012015-05-04 23:15:15 +00007028</div>
7029
7030<p class="magick-description">search for subimage.</p>
7031
7032<p>This option is required to have compare search for the best match location
7033of a small image within a larger image. This search will produce two images
7034(or two frames). The first is the "difference" image and the second will
7035be the "match score" image.</p>
7036
7037<p>The "match-score" image is smaller containing a pixel for ever possible
7038position of the top-left corner of the given sub-image. that is its size will
7039be the size of the larger_image - sub_image + 1. The brightest location in
7040this image is the location s the locate on the best match that is also
7041reported. Note that this may or may not be a perfect match, and the actual
7042brightness will reflect this. Other bright 'peaks' can be used to locate other
7043possible matching locations. </p>
7044
7045<p>Note that the search will try to compare the sub-image at every possible
7046location in the larger image, as such it can be very slow. The smaller the
7047sub-image the faster this search is. </p>
7048
7049
7050<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007051 <h3 class="magick-header"><a id="swap"></a>-swap <var>index,index</var></h3>
cristyd2432012015-05-04 23:15:15 +00007052</div>
7053
7054<p class="magick-description">Swap the positions of two images in the image sequence.</p>
7055
7056<p>For example, <a href="command-line-options.html#swap">-swap 0,2</a> swaps the first and the third
7057images in the current image sequence. Use <a href="command-line-options.html#swap">+swap</a> to switch
7058the last two images in the sequence.</p>
7059
7060<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007061 <h3 class="magick-header"><a id="swirl"></a>-swirl <var>degrees</var></h3>
cristyd2432012015-05-04 23:15:15 +00007062</div>
7063
7064<p class="magick-description">swirl image pixels about the center.</p>
7065
7066<p><var>Degrees</var> defines the tightness of the swirl.</p>
7067
7068<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007069 <h3 class="magick-header"><a id="synchronize"></a>-synchronize</h3>
cristyd2432012015-05-04 23:15:15 +00007070</div>
7071
7072<p class="magick-description">synchronize image to storage device.</p>
7073
7074<p>Set to "true" to ensure all image data is fully flushed and synchronized
7075to disk. There is a performance penalty, but the benefits include ensuring a
7076valid image file in the event of a system crash and early reporting if there
7077is not enough disk space for the image pixel cache.</p>
7078
7079<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007080 <h3 class="magick-header"><a id="taint"></a>-taint</h3>
cristyd2432012015-05-04 23:15:15 +00007081</div>
7082
7083<p class="magick-description">Mark the image as modified.</p>
7084
7085<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007086 <h3 class="magick-header"><a id="text-font"></a>-text-font <var>name</var></h3>
cristyd2432012015-05-04 23:15:15 +00007087</div>
7088
7089<p class="magick-description">font for writing fixed-width text.</p>
7090
7091<p>Specifies the name of the preferred font to use in fixed (typewriter style)
7092formatted text. The default is 14 point <var>Courier</var>.</p>
7093
7094<p>You can tag a font to specify whether it is a PostScript, TrueType, or
7095OPTION1 font. For example, <code>Courier.ttf</code> is a TrueType font and
7096<code>x:fixed</code> is OPTION1.</p>
7097
7098<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007099 <h3 class="magick-header"><a id="texture"></a>-texture <var>filename</var></h3>
cristyd2432012015-05-04 23:15:15 +00007100</div>
7101
7102<p class="magick-description">name of texture to tile onto the image background.</p>
7103
7104<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007105 <h3 class="magick-header"><a id="threshold"></a>-threshold <var>value</var>{<var>%</var>}</h3>
cristyd2432012015-05-04 23:15:15 +00007106</div>
7107
7108<!-- {<var>green,blue,opacity</var>}
7109<p>If the green or blue value is omitted, these channels use the same value as
7110the first one provided. If all three color values are the same, the result is
7111a bi-level image. If the opacity threshold is omitted, OpaqueOpacity is used
7112and any partially transparent pixel becomes fully transparent.</p>
7113-->
7114
7115<p class="magick-description">Apply simultaneous black/white threshold to the image.</p>
7116
cristy82a2ff22015-05-12 16:41:32 +00007117<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 +00007118maximum channel value, while all other values are assigned the minimum.</p>
7119
7120<p> The threshold value can be given as a percentage or as an absolute integer
7121value corresponding to the desired channel value. When given as an integer,
7122the minimum attainable value is 0 (corresponding to black when all channels
7123are affected), but the maximum value (corresponding to white) is that of the
7124<code>quantum depth</code> of the particular build of ImageMagick, and is
7125therefore dependent on the installation. For that reason, a reasonable
7126recommendation for most applications is to specify the threshold values as
7127a percentage. </p>
7128
7129<p> The following would force pixels with red values above 50% to have 100%
7130red values, while those at or below 50% red would be set to 0 in the red
7131channel. The green, blue, and alpha channels (if present) would be unchanged.
7132</p>
7133
7134<pre>
7135convert in.png -channel red -threshold 50% out.png
7136</pre>
7137
7138<p>As (possibly) impractical but instructive examples, the following would
7139generate an all-black and an all-white image with the same dimensions as the
7140input image.</p>
7141
7142
7143<pre>
7144convert in.png -threshold 100% black.png
7145convert in.png -threshold -1 white.png
7146</pre>
7147
7148<p>Note that the values of the transparency channel is treated as 'matte'
7149values (0 is opaque) and not as 'alpha' values (0 is transparent).</p>
7150
cristy82a2ff22015-05-12 16:41:32 +00007151<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 +00007152</p>
7153
7154<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007155 <h3 class="magick-header"><a id="thumbnail"></a>-thumbnail <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00007156</div>
7157
7158<p class="magick-description">Create a thumbnail of the image.</p>
7159
7160<p>This is similar to <a href="command-line-options.html#resize">-resize</a>, except it is optimized
7161for speed and any image profile, other than a color profile, is removed to
cristy82a2ff22015-05-12 16:41:32 +00007162reduce 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 +00007163
7164<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
7165
7166<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007167 <h3 class="magick-header"><a id="tile"></a>-tile <var>filename</var></h3>
cristyd2432012015-05-04 23:15:15 +00007168</div>
7169
7170<p class="magick-description">Set the tile image used for filling a subsequent graphic primitive.</p>
7171
7172<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007173 <h3 class="magick-header">-tile <var>geometry</var></h3>
cristyd2432012015-05-04 23:15:15 +00007174</div>
7175
7176<p class="magick-description">Specify the layout of images.</p>
7177
7178<p>See <a href="command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p>
7179
7180<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007181 <h3 class="magick-header">-tile</h3>
cristyd2432012015-05-04 23:15:15 +00007182</div>
7183
7184<p class="magick-description">Specifies that a subsequent composite operation is repeated across and down image.</p>
7185
7186<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007187 <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 +00007188</div>
7189
7190<p class="magick-description">Specify the offset for tile images, relative to the background image it is tiled on.</p>
7191
cristy82a2ff22015-05-12 16:41:32 +00007192<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 +00007193creating a tiled canvas using <code>TILE:</code> or <code>PATTERN:</code> input
7194formats. </p>
7195
cristy82a2ff22015-05-12 16:41:32 +00007196<p>Internally ImageMagick does a <a href="command-line-options.html#roll">-roll</a> of the tile image
cristyd2432012015-05-04 23:15:15 +00007197by the arguments given when the tile image is set. </p>
7198
7199<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007200 <h3 class="magick-header"><a id="tint"></a>-tint <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00007201</div>
7202
7203<p class="magick-description">Tint the image with the fill color.</p>
7204
7205<p>Tint the image with the fill color.</p>
7206
7207<p>Specify the amount of tinting as a percentage. Pure colors like black,
7208white red, yellow, will not be affected by -tint. Only mid-range colors such
7209as the various shades of grey.</p>
7210
7211<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007212 <h3 class="magick-header"><a id="title"></a>-title <var>string</var></h3>
cristyd2432012015-05-04 23:15:15 +00007213</div>
7214
7215<p class="magick-description">Assign a title to displayed image.", "animate", "display", "montage</p>
7216
7217<p>Use this option to assign a specific title to the image. This assigned to
7218the image window and is typically displayed in the window title bar.
7219Optionally you can include the image filename, type, width, height, Exif data,
7220or other image attribute by embedding special format characters described
7221under the <a href="command-line-options.html#format">-format</a> option.</p>
7222
7223<p>For example,</p>
7224
cristy29dc8652015-05-12 16:26:21 +00007225<pre>
7226-title "%m:%f %wx%h"
7227</pre>
cristyd2432012015-05-04 23:15:15 +00007228
7229<p>produces an image title of <code>MIFF:bird.miff 512x480</code> for an image
7230titled <code>bird.miff</code> and whose width is 512 and height is 480.</p>
7231
7232
7233<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007234 <h3 class="magick-header"><a id="transform"></a>-transform</h3>
cristyd2432012015-05-04 23:15:15 +00007235</div>
7236
7237<p class="magick-description">transform the image.</p>
7238
7239<p>This option applies the transformation matrix from a previous <a href="command-line-options.html#affine">-affine</a> option.</p>
7240
7241<pre>
7242convert -affine 2,2,-2,2,0,0 -transform bird.ppm bird.jpg
7243</pre>
7244
7245
cristy82a2ff22015-05-12 16:41:32 +00007246<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 +00007247
7248
7249<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007250 <h3 class="magick-header"><a id="transparent"></a>-transparent <var>color</var></h3>
cristyd2432012015-05-04 23:15:15 +00007251</div>
7252
7253<p class="magick-description">Make this color transparent within the image.</p>
7254
7255<p>The <var>color</var> argument is defined using the format
cristy82a2ff22015-05-12 16:41:32 +00007256described 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 +00007257given. </p>
7258
cristy82a2ff22015-05-12 16:41:32 +00007259<p>Use <a href="command-line-options.html#transparent">+transparent</a> to invert the pixels matched.
cristyd2432012015-05-04 23:15:15 +00007260that is make all non-matching colors transparent. </p>
7261
cristy82a2ff22015-05-12 16:41:32 +00007262<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 +00007263current <a href="command-line-options.html#fill">-fill</a> color setting, rather than transparent.
cristy82a2ff22015-05-12 16:41:32 +00007264However the <a href="command-line-options.html#transparent">-transparent</a> operator also ensures
7265that 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 +00007266
7267<p>Note that this does not define the color as being the 'transparency color'
cristy82a2ff22015-05-12 16:41:32 +00007268used 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 +00007269
7270
7271<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007272 <h3 class="magick-header"><a id="transparent-color"></a>-transparent-color <var>color</var></h3>
cristyd2432012015-05-04 23:15:15 +00007273</div>
7274
7275<p class="magick-description">Set the transparent color.</p>
7276
7277<p>Sometimes this is used for saving to image formats such as
7278GIF and PNG8 which uses this color to represent boolean transparency. This
7279does not make a color transparent, it only defines what color the transparent
cristy82a2ff22015-05-12 16:41:32 +00007280color 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 +00007281
7282<p>This option allows you to have both an opaque visible color, as well as a
7283transparent color of the same color value without conflict. That is, you can
7284use the same color for both the transparent and opaque color areas within an
7285image. This, in turn, frees to you to select a transparent color that is
7286appropriate when an image is displayed by an application that does not handle a
7287transparent color index, while allowing ImageMagick to correctly handle images of this
7288type. </p>
7289
7290<p>The default transparent color is <code>#00000000</code>, which is fully transparent black.</p>
7291
7292<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007293 <h3 class="magick-header"><a id="transpose"></a>-transpose</h3>
cristyd2432012015-05-04 23:15:15 +00007294</div>
7295
7296<p class="magick-description">Mirror the image along the top-left to bottom-right diagonal.</p>
7297
7298<p> This option mathematically transposes the pixel array. It is equivalent to the sequence <code>-flip -rotate 90</code>.
7299</p>
7300
7301<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007302 <h3 class="magick-header"><a id="transverse"></a>-transverse</h3>
cristyd2432012015-05-04 23:15:15 +00007303</div>
7304
7305<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>
7306
7307
7308<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007309 <h3 class="magick-header"><a id="treedepth"></a>-treedepth <var>value</var></h3>
cristyd2432012015-05-04 23:15:15 +00007310</div>
7311
7312<p class="magick-description">tree depth for the color reduction algorithm.</p>
7313
7314<p>Normally, this integer value is zero or one. A value of zero or one causes
7315the use of an optimal tree depth for the color reduction algorithm.</p>
7316
7317<p>An optimal depth generally allows the best representation of the source
7318image with the fastest computational speed and the least amount of memory.
7319However, the default depth is inappropriate for some images. To assure the
7320best representation, try values between 2 and 8 for this parameter. Refer to
cristy82a2ff22015-05-12 16:41:32 +00007321the <a href="quantize.html">color reduction algorithm</a> for more details.</p>
cristyd2432012015-05-04 23:15:15 +00007322
7323<p>The <a href="command-line-options.html#colors">-colors</a> or <a href="command-line-options.html#monochrome">-monochrome</a>
7324option, or writing to an image format which requires color reduction, is
7325required for this option to take effect.</p>
7326
7327<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007328 <h3 class="magick-header"><a id="trim"></a>-trim</h3>
cristyd2432012015-05-04 23:15:15 +00007329</div>
7330
7331<p class="magick-description">trim an image.</p>
7332
7333<p>This option removes any edges that are exactly the same color as the corner
7334pixels. Use <a href="command-line-options.html#fuzz">-fuzz</a> to make <a href="command-line-options.html#trim">-trim</a> remove
7335edges that are nearly the same color as the corner pixels.</p>
7336
7337<p>The page or virtual canvas information of the image is preserved allowing
7338you to extract the result of the <a href="command-line-options.html#trim">-trim</a> operation from the
7339image. Use a <a href="command-line-options.html#repage">+repage</a> to remove the virtual canvas page
7340information if it is unwanted.</p>
7341
7342<p>If the trimmed image 'disappears' an warning is produced, and a special
7343single pixel transparent 'missed' image is returned, in the same way as when a
7344<a href="command-line-options.html#crop">-crop</a> operation 'misses' the image proper. </p>
7345
7346
7347<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007348 <h3 class="magick-header"><a id="type"></a>-type <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00007349</div>
7350
7351<p class="magick-description">the image type.</p> <p>Choose from: <code>Bilevel</code>,
7352<code>Grayscale</code>, <code>GrayscaleMatte</code>, <code>Palette</code>,
7353<code>PaletteMatte</code>, <code>TrueColor</code>, <code>TrueColorMatte</code>,
7354<code>ColorSeparation</code>, or <code>ColorSeparationMatte</code>.</p>
7355
7356<p>Normally, when a format supports different subformats such as grayscale and
cristy82a2ff22015-05-12 16:41:32 +00007357truecolor, 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 +00007358example, to prevent a JPEG from being written in grayscale format even though
7359only gray pixels are present, use.</p>
7360
7361<pre>
7362convert bird.png -type TrueColor bird.jpg
7363</pre>
7364
7365<p>Similarly, use <a href="command-line-options.html#type">-type TrueColorMatte</a> to force the
7366encoder to write an alpha channel even though the image is opaque, if the
7367output format supports transparency.</p>
7368
7369<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>
7370
7371<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007372 <h3 class="magick-header"><a id="undercolor"></a>-undercolor <var>color</var></h3>
cristyd2432012015-05-04 23:15:15 +00007373</div>
7374
7375<p class="magick-description">set the color of the annotation bounding box.</p>
7376
7377<p>The color is specified using the format described under the <a href="command-line-options.html#fill">-fill</a> option.</p>
7378
7379<p>See <a href="command-line-options.html#draw">-draw</a> for further details.</p>
7380
7381
7382<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007383 <h3 class="magick-header"><a id="update"></a>-update <var>seconds</var></h3>
cristyd2432012015-05-04 23:15:15 +00007384</div>
7385
7386<p class="magick-description">detect when image file is modified and redisplay.</p>
7387
7388<p>Suppose that while you are displaying an image the file that is currently
7389displayed is over-written. <code>display</code> will automagically detect that
7390the input file has been changed and update the displayed image
7391accordingly.</p>
7392
7393
7394<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007395 <h3 class="magick-header"><a id="unique-colors"></a>-unique-colors</h3>
cristyd2432012015-05-04 23:15:15 +00007396</div>
7397
7398<p class="magick-description">discard all but one of any pixel color.</p>
7399
7400
7401<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007402 <h3 class="magick-header"><a id="units"></a>-units <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00007403</div>
7404
7405<p class="magick-description">the units of image resolution.</p>
7406
7407<p>Choose from: <code>Undefined</code>, <code>PixelsPerInch</code>, or
7408<code>PixelsPerCentimeter</code>. This option is normally used in conjunction
7409with the <a href="command-line-options.html#density">-density</a> option.</p>
7410
7411
7412<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00007413 <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 +00007414</div>
7415
7416<p class="magick-description">sharpen the image with an unsharp mask operator.</p>
7417
7418<p>The <a href="command-line-options.html#unsharp">-unsharp</a> option sharpens an image. The image is
7419convolved with a Gaussian operator of the given radius and standard deviation
7420(sigma). For reasonable results, radius should be larger than sigma. Use
7421a radius of 0 to have the method select a suitable radius.</p>
7422
7423<p>The parameters are:</p>
7424
cristyb2cad532015-05-16 13:02:45 +00007425<dl class="dl-horizontal">
7426<dt>radius</dt>
7427<dd>The radius of the Gaussian, in pixels, not counting the center pixel (default 0).</dd>
7428<dt>sigma</dt>
7429<dd>The standard deviation of the Gaussian, in pixels (default 1.0).</dd>
7430<dt>gain</dt>
7431<dd>The fraction of the difference between the original and the blur image that is added back into the original (default 1.0).</dd>
7432<dt>threshold</dt>
7433<dd>The threshold, as a fraction of <var>QuantumRange</var>, needed to apply the difference amount (default 0.05).</dd>
7434</dl>
cristyd2432012015-05-04 23:15:15 +00007435
7436<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007437 <h3 class="magick-header"><a id="verbose"></a>-verbose</h3>
cristyd2432012015-05-04 23:15:15 +00007438</div>
7439
7440<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>
7441
7442
7443<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007444 <h3 class="magick-header"><a id="version"></a>-version</h3>
cristyd2432012015-05-04 23:15:15 +00007445</div>
7446
7447<p class="magick-description">print ImageMagick version string and exit.</p>
7448
7449
7450<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007451 <h3 class="magick-header"><a id="view"></a>-view <var>string</var></h3>
cristyd2432012015-05-04 23:15:15 +00007452</div>
7453
7454<p class="magick-description">FlashPix viewing parameters.</p>
7455
7456
7457<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007458 <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 +00007459</div>
7460
7461<p class="magick-description">soften the edges of the image in vignette style.</p>
7462
7463<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>
7464
7465<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007466 <h3 class="magick-header"><a id="virtual-pixel"></a>-virtual-pixel <var>method</var></h3>
cristyd2432012015-05-04 23:15:15 +00007467</div>
7468
7469<p class="magick-description">Specify contents of <var>virtual pixels</var>.</p>
7470
7471<p>This option defines what color source should be used if and when a color
7472lookup completely 'misses' the source image. The color(s) that appear to
7473surround the source image. Generally this color is derived from the source
7474image, but could also be set to a specify background color. </p>
7475
7476<p>Choose from these methods:</p>
7477
cristy29dc8652015-05-12 16:26:21 +00007478<dl class="dl-horizontal">
7479<dt>background</dt><dd>the area surrounding the image is the background color</dd>
7480<dt>black</dt><dd>the area surrounding the image is black</dd>
7481<dt>checker-tile</dt><dd>alternate squares with image and background color</dd>
7482<dt>dither</dt><dd>non-random 32x32 dithered pattern</dd>
7483<dt>edge</dt><dd>extend the edge pixel toward infinity</dd>
7484<dt>gray</dt><dd>the area surrounding the image is gray</dd>
7485<dt>horizontal-tile</dt><dd>horizontally tile the image, background color above/below</dd>
7486<dt>horizontal-tile-edge</dt><dd>horizontally tile the image and replicate the side edge pixels</dd>
7487<dt>mirror</dt><dd>mirror tile the image</dd>
7488<dt>random</dt><dd>choose a random pixel from the image</dd>
7489<dt>tile</dt><dd>tile the image (default)</dd>
7490<dt>transparent</dt><dd>the area surrounding the image is transparent blackness</dd>
7491<dt>vertical-tile</dt><dd>vertically tile the image, sides are background color</dd>
7492<dt>vertical-tile-edge</dt><dd>vertically tile the image and replicate the side edge pixels</dd>
7493<dt>white</dt><dd>the area surrounding the image is white</dd>
7494</dl>
cristyd2432012015-05-04 23:15:15 +00007495
7496<p>The default value is "edge".</p>
7497
cristy82a2ff22015-05-12 16:41:32 +00007498<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 +00007499However it also effects operations that may access pixels just outside the
cristy82a2ff22015-05-12 16:41:32 +00007500image 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 +00007501
cristy82a2ff22015-05-12 16:41:32 +00007502<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 +00007503
7504
7505<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007506 <h3 class="magick-header"><a id="visual"></a>-visual <var>type</var></h3>
cristyd2432012015-05-04 23:15:15 +00007507</div>
7508
7509<p class="magick-description">Animate images using this X visual type.", 'animate', 'display'</p>
7510
7511<p>Choose from these visual classes:</p>
7512
7513<pre>
cristyb2cad532015-05-16 13:02:45 +00007514StaticGray TrueColor
7515GrayScale DirectColor
7516StaticColor default
7517PseudoColor visual id
cristyd2432012015-05-04 23:15:15 +00007518</pre>
7519
7520<p>The X server must support the visual you choose, otherwise an error occurs.
7521If a visual is not specified, the visual class that can display the most
7522simultaneous colors on the default screen is chosen.</p>
7523
7524
7525<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007526 <h3 class="magick-header"><a id="watermark"></a>-watermark <var>brightness</var>x<var>saturation</var></h3>
cristyd2432012015-05-04 23:15:15 +00007527</div>
7528
7529<p class="magick-description">Watermark an image using the given percentages of brightness and saturation.</p>
7530
7531<p>Take a grayscale image (with alpha mask) and modify the destination image's
7532brightness according to watermark image's grayscale value and the
7533<var>brightness</var> percentage. The destinations color saturation
7534attribute is just direct modified by the <var>saturation</var>
7535percentage, which defaults to 100 percent (no color change). </p>
7536
7537
7538<div style="margin: auto;">
cristy82a2ff22015-05-12 16:41:32 +00007539 <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 +00007540</div>
7541
7542<p class="magick-description">Shear the columns of an image into a sine wave.</p>
7543
7544<p>Specify <var>amplitude</var> and <var>wavelength</var>
7545of the wave.</p>
7546
7547<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007548 <h3 class="magick-header"><a id="weight"></a>-weight <var>fontWeight</var></h3>
cristyd2432012015-05-04 23:15:15 +00007549</div>
7550
7551<p class="magick-description">Set a font weight for text.</p>
7552
7553<p>This setting suggests a font weight that ImageMagick should try to apply to
7554the currently selected font family. Use a positive integer for
7555<var>fontWeight</var> or select from the following.</p>
7556
cristyb2cad532015-05-16 13:02:45 +00007557<dl class="dl-horizontal">
7558<dt>All </dt>
7559<dd>No effect. </dd>
7560<dt>Bold </dt>
7561<dd>Same as <var>fontWeight</var> = 700.</dd>
7562<dt>Bolder </dt>
7563<dd>Add 100 to font weight if currently ≤ 800.</dd>
7564<dt>Lighter </dt>
7565<dd>Subtract 100 to font weight if currently ≤ 100.</dd>
7566<dt>Normal </dt>
7567<dd>Same as <var>fontWeight</var> = 400.</dd>
cristyd2432012015-05-04 23:15:15 +00007568
cristyb2cad532015-05-16 13:02:45 +00007569<br>
7570
7571<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 +00007572
cristy82a2ff22015-05-12 16:41:32 +00007573<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 +00007574
7575<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007576 <h3 class="magick-header"><a id="white-point"></a>-white-point <var>x,y</var></h3>
cristyd2432012015-05-04 23:15:15 +00007577</div>
7578
7579<p class="magick-description">chromaticity white point.</p>
7580
7581<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007582 <h3 class="magick-header"><a id="white-threshold"></a>-white-threshold <var>value</var>{<var>%</var>}</h3>
cristyd2432012015-05-04 23:15:15 +00007583</div>
7584
7585<p class="magick-description">Force to white all pixels above the threshold while leaving all pixels at or below the threshold unchanged.</p>
7586
7587<p> The threshold value can be given as a percentage or as an absolute integer
7588value within [0, <var>QuantumRange</var>] corresponding to the
cristy82a2ff22015-05-12 16:41:32 +00007589desired <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 +00007590
7591<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007592 <h3 class="magick-header"><a id="window"></a>-window <var>id</var></h3>
cristyd2432012015-05-04 23:15:15 +00007593</div>
7594
7595<p class="magick-description">Make the image the background of a window.", 'animate', 'display'</p>
7596
7597<p><var>id</var> can be a window id or name. Specify <code>root</code>
7598to select X's root window as the target window.</p>
7599
7600<p>By default the image is tiled onto the background of the target window. If
7601<code>backdrop</code> or <a href="command-line-options.html#geometry">-resize</a> are specified, the
7602image is surrounded by the background color. Refer to <code>X RESOURCES</code>
7603for details.</p>
7604
7605<p>The image will not display on the root window if the image has more unique
cristy82a2ff22015-05-12 16:41:32 +00007606colors 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 +00007607
7608<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007609 <h3 class="magick-header"><a id="window-group"></a>-window-group</h3>
cristyd2432012015-05-04 23:15:15 +00007610</div>
7611
7612<p class="magick-description">specify the window group.</p>
7613
7614<div style="margin: auto;">
cristy29dc8652015-05-12 16:26:21 +00007615 <h3 class="magick-header"><a id="write"></a>-write <var>filename</var></h3>
cristyd2432012015-05-04 23:15:15 +00007616</div>
7617
7618<p class="magick-description">write an image sequence.</p>
7619
7620<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>
7621
7622<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 +00007623</dl></div>
cristyd2432012015-05-04 23:15:15 +00007624</div>
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