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href="/www/command-line-options.html#alpha">‑alpha</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#annotate">‑annotate</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#antialias">‑antialias</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#append">‑append</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#attenuate">‑attenuate</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#authenticate">‑authenticate</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#auto-gamma">‑auto‑gamma</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#auto-level">‑auto‑level</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#auto-orient">‑auto‑orient</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#backdrop">‑backdrop</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#background">‑background</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#bench">‑bench</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#bias">‑bias</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#blackpoint-compensation">‑blackpoint‑compensation</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#black-threshold">‑black‑threshold</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#blend">‑blend</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#blue-primary">‑blue‑primary</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#blue-shift">‑blue‑shift</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#blur">‑blur</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#border">‑border</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#bordercolor">‑bordercolor</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#borderwidth">‑borderwidth</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#brightness-contrast">‑brightness‑contrast</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#cache">‑cache</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#caption">‑caption</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#cdl">‑cdl</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#channel">‑channel</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#charcoal">‑charcoal</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#chop">‑chop</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#clamp">‑clamp</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#clip">‑clip</a> <span 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href="/www/command-line-options.html#combine">‑combine</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#comment">‑comment</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#compose">‑compose</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#composite">‑composite</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#compress">‑compress</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#contrast">‑contrast</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#contrast-stretch">‑contrast‑stretch</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#convolve">‑convolve</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#crop">‑crop</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#cycle">‑cycle</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#debug">‑debug</a> <span 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href="/www/command-line-options.html#magnify">‑magnify</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#map">‑map</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#map_stream_">‑map[stream]</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#mask">‑mask</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#mattecolor">‑mattecolor</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#median">‑median</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#metric">‑metric</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#mode">‑mode</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#modulate">‑modulate</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#monitor">‑monitor</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#monochrome">‑monochrome</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#morph">‑morph</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#morphology">‑morphology</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#mosaic">‑mosaic</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#motion-blur">‑motion‑blur</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#name">‑name</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#negate">‑negate</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#noise">‑noise</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#normalize">‑normalize</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#opaque">‑opaque</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#ordered-dither">‑ordered‑dither</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#orient">‑orient</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#page">‑page</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#paint">‑paint</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#path">‑path</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#pause_animate_">‑pause[animate]</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#pause_import_">‑pause[import]</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#pen">‑pen</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#ping">‑ping</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#pointsize">‑pointsize</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#polaroid">‑polaroid</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#posterize">‑posterize</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#precision">‑precision</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#preview">‑preview</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#print">‑print</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#process">‑process</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#profile">‑profile</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#quality">‑quality</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#quantize">‑quantize</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#quiet">‑quiet</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#radial-blur">‑radial‑blur</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#raise">‑raise</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#random-threshold">‑random‑threshold</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#red-primary">‑red‑primary</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#regard-warnings">‑regard‑warnings</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#region">‑region</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#remap">‑remap</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#remote">‑remote</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#render">‑render</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#repage">‑repage</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#resample">‑resample</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#resize">‑resize</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#respect-parentheses">‑respect‑parentheses</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#reverse">‑reverse</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#roll">‑roll</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#rotate">‑rotate</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#sample">‑sample</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#sampling-factor">‑sampling‑factor</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#scale">‑scale</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#scene">‑scene</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#screen">‑screen</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#seed">‑seed</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#segment">‑segment</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#selective-blur">‑selective‑blur</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#separate">‑separate</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#sepia-tone">‑sepia‑tone</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#set">‑set</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#shade">‑shade</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#shadow">‑shadow</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#shared-memory">‑shared‑memory</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#sharpen">‑sharpen</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#shave">‑shave</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#shear">‑shear</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#sigmoidal-contrast">‑sigmoidal‑contrast</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#silent">‑silent</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#size">‑size</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#sketch">‑sketch</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#smush">‑smush</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#snaps">‑snaps</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#solarize">‑solarize</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#sparse-color">‑sparse‑color</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#splice">‑splice</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#spread">‑spread</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#stegano">‑stegano</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#stereo">‑stereo</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#stretch">‑stretch</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#strip">‑strip</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#stroke">‑stroke</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#strokewidth">‑strokewidth</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#style">‑style</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#subimage-search">‑subimage‑search</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#swap">‑swap</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#swirl">‑swirl</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#synchronize">‑synchronize</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#taint">‑taint</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#text-font">‑text‑font</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#texture">‑texture</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#threshold">‑threshold</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#thumbnail">‑thumbnail</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#tile">‑tile</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#tile-offset">‑tile‑offset</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#tint">‑tint</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#title">‑title</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#transform">‑transform</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#transparent">‑transparent</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#transparent-color">‑transparent‑color</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#transpose">‑transpose</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#transverse">‑transverse</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#treedepth">‑treedepth</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#trim">‑trim</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#type">‑type</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#undercolor">‑undercolor</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#unique-colors">‑unique‑colors</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#units">‑units</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#unsharp">‑unsharp</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#update">‑update</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#verbose">‑verbose</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#version">‑version</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#view">‑view</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#vignette">‑vignette</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#virtual-pixel">‑virtual‑pixel</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#visual">‑visual</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#watermark">‑watermark</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#wave">‑wave</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#weight">‑weight</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#white-point">‑white‑point</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#white-threshold">‑white‑threshold</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#window">‑window</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#window-group">‑window‑group</a> <span class='bull'> • </span> <a href="/www/command-line-options.html#write">‑write</a> ] </p> 203 204<div class="doc-section"> 205 206<p>Below is list of command-line options recognized by the ImageMagick <a 207href="/www/command-line-tools.html">command-line 208tools</a>. If you want a description of a particular option, click on the 209option name in the navigation bar above and you will go right to it. Unless 210otherwise noted, each option is recognized by the commands <a href="/www/convert.html">convert</a>, <a href="/www/mogrify.html">mogrify</a>.</p> 211 212<div style="margin: auto;"> 213 <h4><a id="adaptive-blur"></a>-adaptive-blur <em class="arg">radius</em>[x<em class="arg">sigma</em>]</h4> 214</div> 215 216<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Adaptively blur pixels, with decreasing effect near edges.</td><td style='text-align:right;'></td></tr></table> 217<p>A Gaussian operator of the given radius and standard deviation (<em class="arg">sigma</em>) is used. If <em class="arg">sigma</em> is not given it defaults to 1.</p> 218 219<div style="margin: auto;"> 220 <h4><a id="adaptive-resize"></a>-adaptive-resize <em class="arg">geometry</em></h4> 221</div> 222 223<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Resize the image using data-dependent triangulation.</td><td style='text-align:right;'></td></tr></table> 224 225<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. The <a href="#adaptive-resize">-adaptive-resize</a> option defaults to data-dependent triangulation. Use the <a href="#filter">-filter</a> to choose a different resampling algorithm. Offsets, if present in the geometry string, are ignored, and the <a href="#gravity">-gravity</a> option has no effect.</p> 226 227<div style="margin: auto;"> 228 <h4><a id="adaptive-sharpen"></a>-adaptive-sharpen <em class="arg">radius</em>[x<em class="arg">sigma</em>]</h4> 229</div> 230 231<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Adaptively sharpen pixels, with increasing effect near edges.</td><td style='text-align:right;'></td></tr></table> 232 233<p>A Gaussian operator of the given radius and standard deviation (<em class="arg">sigma</em>) is used. If <em class="arg">sigma</em> is not given it defaults to 1.</p> 234 235<div style="margin: auto;"> 236 <h4><a id="adjoin"></a>-adjoin</h4> 237</div> 238 239<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Join images into a single multi-image file.</td><td style='text-align:right;'></td></tr></table> 240 241<p>This option is enabled by default. An attempt is made to save all 242images of an image sequence into the given output file. 243However, some formats, such as JPEG and PNG, do not support more than one 244image per file, and in that case ImageMagick is forced to write each image as a separate file. As 245such, if more than one image needs to be written, the filename given is 246modified by adding a <a href="#scene">-scene</a> number before the 247suffix, in order to make distinct names for each image. </p> 248 249<p>Use <a href="#adjoin">+adjoin</a> to force each image to be written 250to separate files, whether or not the file format allows multiple images 251per file (for example, GIF, MIFF, and TIFF). </p> 252 253<p>Including a C-style integer format string in the output filename will automagically enable <a href="#adjoin">+adjoin</a> and are used to specify where the <a href="#scene">-scene</a> number is placed in the filenames. These strings, such as '<kbd>%d</kbd>' or '<kbd>%03d</kbd>', are familiar to those who have used the standard <kbd>printf()</kbd>' C-library function. As an example, the command</p> 254 255<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert logo: rose: -morph 15 my%02dmorph.jpg</span></p> 256<p>will create a sequence of 17 images named my00morph.jpg, my01morph.jpg, my02morph.jpg, ..., my16morph.jpg. 257</p> 258 259<p>In summary, ImageMagick tries to write all images to one file, but will use 260multiple files if either<br /> 261 (1) the output image's file format does not allow multi-image files,<br /> 262 (2) the <a href="#adjoin">+adjoin</a> option is given, or<br /> 263 (3) a printf() integer format string (eg: "%d") is present in the output filename. </p> 264 265 266<div style="margin: auto;"> 267 <h4><a id="affine"></a>-affine <em class="arg">s<sub>x</sub></em>,<em class="arg">r<sub>x</sub></em>,<em class="arg">r<sub>y</sub></em>,<em class="arg">s<sub>y</sub></em>,<em class="arg">t<sub>x</sub></em>,<em class="arg">t<sub>y</sub></em><br/> 268 -affine <em class="arg">s<sub>x</sub></em>,<em class="arg">r<sub>x</sub></em>,<em class="arg">r<sub>y</sub></em>,<em class="arg">s<sub>y</sub></em></h4> 269</div> 270 271<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the drawing transformation matrix for combined rotating and scaling.</td><td style='text-align:right;'></td></tr></table> 272 273<p>This option sets a transformation matrix, encoded as (<em class="arg">s<sub>x</sub></em>, <em class="arg">r<sub>x</sub></em>, <em class="arg">r<sub>y</sub></em>, <em class="arg">s<sub>y</sub></em>, <em class="arg">t<sub>x</sub></em>, <em class="arg">t<sub>y</sub></em>), for use by subsequent <a href="#draw">-draw</a> or <a href="#transform">-transform</a> options.</p> 274 275<p>The matrix entries are entered as comma-separated numeric values <i>with no spaces</i>. </p> 276 277<p>Internally, the transformation matrix has 3x3 elements, but three of them are omitted from the input because they are constant. The new (transformed) coordinates (<em class="arg">x'</em>, <em class="arg">y'</em>) of a pixel at position (<em class="arg">x</em>, <em class="arg">y</em>) in the original image are calculated using the following matrix equation.</p> 278 279<div class="eqn"> 280<img alt="affine transformation" src="/images/affine.png"/> 281</div> 282 283<p> 284The size of the resulting image is that of the smallest rectangle that contains the transformed source image. The parameters <em class="arg">t<sub>x</sub></em> and <em class="arg">t<sub>y</sub></em> subsequently shift the image pixels so that those that are moved out of the image area are cut off.</p> 285 286<p>The transformation matrix complies with the left-handed pixel coordinate system: positive <em class="arg">x</em> and <em class="arg">y</em> directions are rightward and downward, resp.; positive rotation is clockwise.</p> 287 288<p> If the translation coefficients <em class="arg">t<sub>x</sub></em> and <em class="arg">t<sub>y</sub></em> are omotted they default to 0,0. Therefore, four parameters suffice for rotation and scaling without translation.</p> 289 290<p>Scaling by the factors <em class="arg">s<sub>x</sub></em> and <em class="arg">s<sub>y</sub></em> in the <em>x</em> and <em>y</em> directions, respectively, is accomplished with the following.</p> 291 292<p class="crtsnip"> 293 -affine <em class="arg">s<sub>x</sub></em>,0,0,<em class="arg">s<sub>y</sub></em> 294</p> 295 296<p>Translation by a displacement (<em class="arg">t<sub>x</sub></em>, <em class="arg">t<sub>y</sub></em>) is accomplished like so:</p> 297 298<p class="crtsnip"> 299 -affine 1,0,0,1,<em class="arg">t<sub>x</sub></em>,<em class="arg">t<sub>y</sub></em> 300</p> 301 302<p>Rotate clockwise about the origin (the upper left-hand corner) by an angle <em>a</em> by letting 303<em>c</em> = cos(<em>a</em>), <em>s</em> = sin(<em>a</em>), and using the following.</p> 304 305<p class="crtsnip"> 306 -affine <em>c</em>,<em>s</em>,-<em>s</em>,<em>c</em> 307</p> 308 309<p>The cumulative effect of a sequence of <a href="#affine" >-affine</a> transformations can be accomplished by instead by a single <a href="#affine" >-affine</a> operation using the matrix equal to the product of the matrices of the individual transformations.</p> 310 311<p>An attempt is made to detect near-singular transformation matrices. If the matrix determinant has a sufficiently small absolute value it is rejected.</p> 312 313<div style="margin: auto;"> 314 <h4><a id="alpha"></a>-alpha <em class="arg">type</em></h4> 315</div> 316 317<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Gives control of the alpha/matte channel of an image.</td><td style='text-align:right;'></td></tr></table> 318 319<p>Used to set a flag on an image indicating whether or not to use existing alpha 320channel data, to create an alpha channel, or to perform other operations on the alpha channel. Choose the argument <em class="arg">type</em> from the list below.</p> 321 322 323<table class="doc"> 324 <tbody> 325 <tr valign="top"> 326 <th align="left" style="width: 8%">type</th> 327 <th align="left">Description</th> 328 </tr> 329 330 <tr valign="top"> 331 <td valign="top"><kbd>Activate</kbd> or <kbd>On</kbd></td> 332 <td valign="top"> 333 Enable the image's transparency channel. Note normally <kbd>Set</kbd> 334 should be used instead of this, unless you specifically need to 335 preserve existing (but specifically turned <kbd>Off</kbd>) transparency 336 channel. </td></tr> 337 338 <tr valign="top"> 339 <td valign="top"><kbd>Deactivate</kbd> or <kbd>Off</kbd></td> 340 <td valign="top"> 341 Disables the image's transparency channel. Does not delete or change the 342 existing data, just turns off the use of that data.</td></tr> 343 344 <tr valign="top"> 345 <td valign="top"><kbd>Set</kbd></td> 346 <td valign="top"> 347 Activates the alpha/matte channel. If it was previously turned off 348 then it also resets the channel to opaque. If the image already had 349 the alpha channel turned on, it will have no effect.</td></tr> 350 351 <tr valign="top"> 352 <td valign="top"><kbd>Opaque</kbd></td> 353 <td valign="top"> 354 Enables the alpha/matte channel and forces it to be fully opaque. 355 </td></tr> 356 357 <tr valign="top"> 358 <td valign="top"><kbd>Transparent</kbd></td> 359 <td valign="top"> 360 Activates the alpha/matte channel and forces it to be fully 361 transparent. This effectively creates a fully transparent image the 362 same size as the original and with all its original RGB data still 363 intact, but fully transparent. </td></tr> 364 365 <tr valign="top"> 366 <td valign="top"><kbd>Extract</kbd></td> 367 <td valign="top"> 368 Copies the alpha channel values into all the color channels and turns 369 '<kbd>Off</kbd>' the the image's transparency, so as to generate 370 a gray-scale mask of the image's shape. The alpha channel data is left 371 intact just deactivated. This is the inverse of '<kbd>Copy</kbd>'. 372 </td></tr> 373 374 <tr valign="top"> 375 <td valign="top"><kbd>Copy</kbd></td> 376 <td valign="top"> 377 Turns '<kbd>On</kbd>' the alpha/matte channel, then copies the 378 gray-scale intensity of the image, into the alpha channel, converting 379 a gray-scale mask into a transparent shaped mask ready to be colored 380 appropriately. The color channels are not modified. </td></tr> 381 382 <tr valign="top"> 383 <td valign="top"><kbd>Shape</kbd></td> 384 <td valign="top"> 385 As per '<kbd>Copy</kbd>' but also colors the resulting shape mask with 386 the current background color. That is the RGB color channels is 387 replaced, with appropriate alpha shape. 388 </td></tr> 389 390 <tr valign="top"> 391 <td valign="top"><kbd>Background</kbd></td> 392 <td valign="top"> 393 Set any fully-transparent pixel to the background color, while leaving 394 it fully-transparent. This can make some image file formats, such as 395 PNG, smaller as the RGB values of transparent pixels are more uniform, 396 and thus can compress better. 397 </td></tr> 398 </tbody> 399</table> 400 401<p>Note that while the <a href="#matte" >+matte</a> operation is the same as 402"<kbd><a href="#alpha" >-alpha</a> Off</kbd>", the <a href="#matte" 403>-matte</a> operation is the same as "<kbd><a href="#alpha" >-alpha</a> 404Set</kbd>" and not "<kbd><a href="#alpha" >-alpha</a> On</kbd>". </p> 405 406 407<div style="margin: auto;"> 408 <h4><a id="annotate"></a> 409 -annotate <em class="arg">degrees</em> <em class="arg">text</em><br /> 410 -annotate <em class="arg">Xdegrees</em>x<em class="arg">Ydegrees</em> <em class="arg">text</em><br /> 411 -annotate <em class="arg">Xdegrees</em>x<em class="arg">Ydegrees</em> {+-}<em class="arg">t<sub>x</sub></em>{+-}<em class="arg">t<sub>y</sub></em> <em class="arg">text</em></h4> 412</div> 413 414<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Annotate an image with text.</td><td style='text-align:right;'></td></tr></table> 415 416<p>This is a convenience for annotating an image with text. For more precise control over text annotations, use <a href="#draw">-draw</a>.</p> 417 418 419<p>The values <em class="arg">Xdegrees</em> and <em class="arg">Ydegrees</em> control the shears with respect to the , respectively, applied to the text, while <em class="arg">t<sub>x</sub></em> and <em class="arg">t<sub>y</sub></em> are offsets that give the location of the text relative to the upper left corner of the image.</p> 420 421<p>Using <a href="#annotate">-annotate</a> <em class="arg">degrees</em> or <a href="#annotate">-annotate</a> <em class="arg">degrees</em>x<em class="arg">degrees</em> produces an unsheared rotation of the text. The direction of the rotation is positive, which means a clockwise rotation if <em class="arg">degrees</em> is positive. (This conforms to the usual mathematical convention once it is realized that the positive <em>y</em>–direction is conventionally considered to be <em>downward</em> for images.)</p> 422 423<p>The new (transformed) coordinates (<em class="arg">x'</em>, <em class="arg">y'</em>) of a pixel at position (<em class="arg">x</em>, <em class="arg">y</em>) in the image are calculated using the following matrix equation.</p> 424<div class="eqn"><img alt="annotate transformation" src="/images/annotate.png"/></div> 425 426<p>If <em class="arg">t<sub>x</sub></em> and <em class="arg">t<sub>y</sub></em> are omitted, they default to 0. This makes the bottom-left of the text becomes the upper-left corner of the image, which is probably undesirable. Adding a <a href="#gravity" >-gravity</a> option in this case leads to nice results.</p> 427 428<p>Text is any UTF-8 encoded character sequence. If <em class="arg">text</em> is of the form '@mytext.txt', the text is read from the file <kbd>mytext.txt</kbd>. Text in a file is taken literally; no embedded formatting characters are recognized.</p> 429 430<div style="margin: auto;"> 431 <h4><a id="antialias"></a>-antialias</h4> 432</div> 433 434<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Enable/Disable of the rendering of anti-aliasing pixels when 435drawing fonts and lines.</td><td style='text-align:right;'></td></tr></table> 436 437<p>By default, objects (e.g. text, lines, polygons, etc.) are antialiased when 438drawn. Use <a href="#antialias">+antialias</a> to disable the addition of 439antialiasing edge pixels. This will then reduce the number of colors added to 440an image to just the colors being directly drawn. That is, no mixed colors 441are added when drawing such objects. </p> 442 443<div style="margin: auto;"> 444 <h4><a id="append"></a>-append</h4> 445</div> 446 447<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Join current images vertically or horizontally.</td><td style='text-align:right;'></td></tr></table> 448 449<p>This option creates a single longer image image, by joining all the current 450images in sequence top-to-bottom. Use <a href="#append">+append</a> to 451stack images left-to-right. </p> 452 453<p>If they are not of the same width, narrower images are padded with the 454current <a href="#background">-background</a> color setting, and their 455position relative to each other can be controlled by the current <a 456href="#gravity">-gravity</a> setting. </p> 457 458 459<div style="margin: auto;"> 460 <h4><a id="attenuate"></a>-attenuate <em class="arg">value</em></h4> 461</div> 462 463<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Lessen (or intensify) when adding noise to an image.</td><td style='text-align:right;'></td></tr></table> 464 465 466<div style="margin: auto;"> 467 <h4><a id="authenticate"></a>-authenticate <em class="arg">password</em></h4> 468</div> 469 470<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Decrypt a PDF with a password.</td><td style='text-align:right;'></td></tr></table> 471 472<p>Use this option to supply a <em class="arg">password</em> for decrypting a PDF that has been encrypted using Microsoft Crypto API (MSC API). The encrypting using the MSC API is not supported.</p> 473 474<p>For a different encryption method, see <a href="#encipher">-encipher</a> and <a href="#decipher">-decipher</a>. </p> 475 476 477 478<div style="margin: auto;"> 479 <h4><a id="auto-gamma"></a>-auto-gamma</h4> 480</div> 481 482<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Automagically adjust gamma level of image.</td><td style='text-align:right;'></td></tr></table> 483 484<p>This calculates the mean values of an image, then applies a calculated <a 485href="#gamma" >-gamma</a> adjustment so that is the mean color exists in the 486image it will get a have a value of 50%. </p> 487 488<p>This means that any solid 'gray' image becomes 50% gray. </p> 489 490<p>This works well for real-life images with little or no extreme dark and 491light areas, but tend to fail for images with large amounts of bright sky or 492dark shadows. It also does not work well for diagrams or cartoon like images. 493</p> 494 495<p>It uses the <a href="#channel" >-channel</a> setting, (including the 496'<em>sync</em>' flag for channel syncronization), to determine which color 497values is used and modified. As the default <a href="#channel" 498>-channel</a> setting is '<em>RGB,sync</em>', channels are modified 499together by the same gamma value, preserving colors. </p> 500 501 502 503<div style="margin: auto;"> 504 <h4><a id="auto-level"></a>-auto-level</h4> 505</div> 506 507<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Automagically adjust color levels of image.</td><td style='text-align:right;'></td></tr></table> 508 509<p>This is a 'perfect' image normalization operator. It finds the exact 510minimum and maximum color values in the image and then applies a <a 511href="#level" >-level</a> operator to stretch the values to the full range of 512values. </p> 513 514<p>The operator is not typically used for real-life images, image scans, or 515JPEG format images, as a single 'out-rider' pixel can set a bad min/max values 516for the <a href="#level" >-level</a> operation. On the other hand it is the 517right operator to use for color stretching gradient images being used to 518generate Color lookup tables, distortion maps, or other 'mathematically' 519defined images. </p> 520 521<p>The operator is very similar to the <a href="#normalize">-normalize</a>, <a 522href="#contrast-stretch" >-contrast-stretch</a>, and <a href="#linear-stretch" 523>-linear-stretch</a> operators, but without 'histogram binning' or 'clipping' 524problems that these operators may have. That is <a href="#auto-level" 525>-auto-level</a> is the perfect or ideal version these operators. </p> 526 527<p>It uses the <a href="#channel" >-channel</a> setting, (including the 528special '<em>sync</em>' flag for channel syncronization), to determine 529which color values are used and modified. As the default <a 530href="#channel" >+channel</a> setting is '<em>RGB,sync</em>', the 531'<em>sync</em>' ensures that the color channels will are modified 532together by the same gamma value, preserving colors, and ignoring 533transparency. </p> 534 535 536<div style="margin: auto;"> 537 <h4><a id="auto-orient"></a>-auto-orient</h4> 538</div> 539 540<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Automagically orient (rotate) an image created by a digital camera.</td><td style='text-align:right;'></td></tr></table> 541 542<p>This operator reads and resets the EXIF image profile setting 'Orientation' 543and then performs the appropriate 90 degree rotation on the image to orient 544the image, for correct viewing. </p> 545 546<p>This EXIF profile setting is usually set using a gravity sensor in digital 547camara, however photos taken directly downward or upward may not have an 548appropriate value. Also images that have been orientation 'corrected' without 549reseting this setting, may be 'corrected' again resulting in a incorrect 550result. If the he EXIF profile was previously stripped, the <a 551href="#auto-orient" >-auto-orient</a> operator will do nothing. </p> 552 553 554<div style="margin: auto;"> 555 <h4><a id="average"></a>-average</h4> 556</div> 557 558<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Average a set of images.</td><td style='text-align:right;'></td></tr></table> 559 560<p>An error results if the images are not identically sized.</p> 561 562 563<div style="margin: auto;"> 564 <h4><a id="backdrop"></a>-backdrop</h4> 565</div> 566 567<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Display the image centered on a backdrop.</td><td style='text-align:right;'>[<a href="/www/animate.html">animate</a>, <a href="/www/display.html">display</a>]</td></tr></table> 568 569<p>This backdrop covers the entire workstation screen and is useful for hiding other X window activity while viewing the image. The color of the backdrop is specified as the background color. The color is specified using the format described under the <a href="#fill">-fill</a> option.</p> 570 571<div style="margin: auto;"> 572 <h4><a id="background"></a>-background <em class="arg">color</em></h4> 573</div> 574 575<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the background color.</td><td style='text-align:right;'></td></tr></table> 576 577<p>The color is specified using the format described under the <a href="#fill">-fill</a> option. The default background color (if none is specified or found in the image) is white.</p> 578 579<div style="margin: auto;"> 580 <h4><a id="bench"></a>-bench <em class="arg">iterations</em></h4> 581</div> 582 583<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Measure performance.</td><td style='text-align:right;'></td></tr></table> 584 585<p>Repeat the entire command for the given number of <em class="arg">iterations</em> and report the user-time and elapsed time. For instance, consider the following command and its output. Modify the benchmark with the -duration to run the benchmark for a fixed number of seconds and -concurrent to run the benchmark in parallel (requires the OpenMP feature).</p> 586 587<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert logo: -resize 1000% -bench 5 logo.png</span><span class='crtout'>Performance: 5i 0.875657ips 6.880u 0:05.710</span></p> 588<p>In this example, 5 iterations were completed at 0.875657 iterations per second, using 6.88 seconds of the user's allotted time, for a total elapsed time of 5.71 seconds.</p> 589 590<div style="margin: auto;"> 591 <h4><a id="bias"></a>-bias <em class="arg">value</em>{<em class="arg">%</em>}</h4> 592</div> 593 594<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Add bias when convolving an image.</td><td style='text-align:right;'></td></tr></table> 595 596<p>This option shifts the output of <a href="/www/command-line-options.html#convolve">‑convolve</a> so that positive and negative results are relative to the specified bias value. </p> 597 598<p>This is important for non-HDRI compilations of ImageMagick when dealing with convolutions that contain negative as well as positive values. This is especially the case with convolutions involving high pass filters or edge detection. Without an output bias, the negative values are clipped at zero.</p> 599 600<p>When using an ImageMagick with the HDRI compile-time setting, <a href="/www/command-line-options.html#bias">‑bias</a> is not needed, as ImageMagick is able to store/handle any 601negative results without clipping to the color value range 602(0..QuantumRange).</p> 603 604<p>See the discussion on HDRI implementations of ImageMagick on the page 605<a href="/www/high-dynamic-range.html">High Dynamic-Range Images</a>. For more about HDRI go the ImageMagick <a href="http://www.imagemagick.org/Usage/basics/#hdri">Usage</a> pages or this <a href="http://en.wikipedia.org/wiki/High_dynamic_range_imaging">Wikipedia</a> entry. 606</p> 607 608<div style="margin: auto;"> 609 <h4><a id="black-point-compensation"></a>-black-point-compensation</h4> 610</div> 611 612<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Use black point compensation.</td><td style='text-align:right;'></td></tr></table> 613 614<div style="margin: auto;"> 615 <h4><a id="black-threshold"></a>-black-threshold <em class="arg">value</em>{<em class="arg">%</em>}</h4> 616</div> 617 618<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Force to black all pixels below the threshold while leaving all pixels at or above the threshold unchanged.</td><td style='text-align:right;'></td></tr></table> 619 620<p> The threshold value can be given as a percentage or as an absolute integer value within [0, <em class="QR">QuantumRange</em>] corresponding to the desired <a href="/www/command-line-options.html#channel">‑channel</a> value. See <a href="/www/command-line-options.html#threshold">‑threshold</a> for more details on thresholds and resulting values. 621</p> 622 623 624<div style="margin: auto;"> 625 <h4><a id="blend"></a>-blend <em class="arg">geometry</em></h4> 626</div> 627 628<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>blend an image into another by the given absolute value or percent.</td><td style='text-align:right;'>[<a href="/www/composite.html">composite</a>]</td></tr></table> 629 630<p>Blend will average the images together ('plus') according to the 631percentages given and each pixels transparency. If only a single percentage 632value is given it sets the weight of the composite or 'source' image, while 633the background image is weighted by the exact opposite amount. That is a 634<kbd>-blend 30%</kbd> merges 30% of the 'source' image with 70% of the 635'destination' image. Thus it is equivalent to <kbd>-blend 30x70%</kbd>.</p> 636 637 638<div style="margin: auto;"> 639 <h4><a id="blue-primary"></a>-blue-primary <em class="arg">x</em>,<em class="arg">y</em></h4> 640</div> 641 642<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the blue chromaticity primary point.</td><td style='text-align:right;'></td></tr></table> 643 644<div style="margin: auto;"> 645 <h4><a id="blue-shift"></a>-blue-shift <em class="arg">factor</em></h4> 646</div> 647 648<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>simulate a scene at nighttime in the moonlight. Start with a factor of 1.5</td><td style='text-align:right;'></td></tr></table> 649 650<div style="margin: auto;"> 651 652<div style="margin: auto;"> 653 <h4><a id="blur"></a>-blur <em class="arg">radius</em><br />-blur <em class="arg">radius</em>x<em class="arg">sigma</em></h4> 654</div> 655 656<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Reduce image noise and reduce detail levels.</td><td style='text-align:right;'></td></tr></table> 657 658<p>Convolve the image with a Gaussian or normal distribution using the given 659<em class="arg" >Sigma</em> value. The formula is:</p> 660 661<div class="eqn"><img alt="gaussian distribution" width="243px" height="42px" src="/images/gaussian-blur.png"/> 662</div> 663 664<p>The <em class="arg" >Sigma</em> value is the important argument, and 665determines the actual amount of blurring that will take place. </p> 666 667<p>The <em class="arg" >Radius</em> is only used to determine the size of the 668array which will hold the calculated Gaussian distribution. It should be an 669integer. If not given, or set to zero, IM will calculate the largest possible 670radius that will provide meaningful results for the Gaussian distribution. 671</p> 672 673<p>The larger the <em class="arg" >Radius</em> the radius the slower the 674operation is. However too small a <em class="arg" >Radius</em>, and sever 675aliasing effects may result. As a guideline, <em class="arg" >Radius</em> 676should be at least twice the <em class="arg" >Sigma</em> value, though three 677times will produce a more accurite result. </p> 678 679<p>This option differs from <a href="#gaussian-blur">-gaussian-blur</a> simply 680by taking advantage of the separability properties of the distribution. Here 681we apply a single-dimensional Gaussian matrix in the horizontal direction, 682then repeat the process in the vertical direction.</p> 683 684<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how 685pixels which are outside the image proper are blurred into the final result. 686</p> 687 688 689<div style="margin: auto;"> 690 <h4>-blur <em class="arg">Width</em>[x<em class="arg">Height</em>[+<em class="arg">Angle</em>]]</h4> 691</div> 692 693<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Variably blur and image according to the overlay mapping.</td><td style='text-align:right;'>[<a href="/www/composite.html">composite</a>]</td></tr></table> 694 695<p>Each pixel in the overlaid region is replaced with an Elliptical Weighted 696Average (EWA) of the source image, scaled according to the grayscale 697mapping. </p> 698 699<p>The ellipse is weighted with sigma set to the given <em class="arg" 700>Width</em> and <em class="arg" >Height</em>. The <em class="arg" >Height</em> 701defaults to the <em class="arg" >Width</em> for a normal circular Guassian 702weighting. The <em class="arg" >Angle</em> will rotate the ellipse from 703horizontal clock-wise. </p> 704 705<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how 706pixels which are outside the image proper are blurred into the final result. 707</p> 708 709 710<div style="margin: auto;"> 711 <h4><a id="border"></a>-border <em class="arg">geometry</em></h4> 712</div> 713 714<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Surround the image with a border of color. </td><td style='text-align:right;'></td></tr></table> 715 716<p>Set the width and height using the <em class="arg">size</em> portion of the 717<em class="arg">gravity</em> argument. See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. Offsets are 718ignored. </p> 719 720<p>Set the border color by preceding with the <a 721href="#bordercolor">-bordercolor</a> setting.</p> 722 723<p>The <a href="#border">-border</a> operation is affected by the current <a 724href="#compose">-compose</a> setting and assumes that this is using the default 725'<kbd>Over</kbd>' composition method. It generates a image of the appropriate 726size colors by the current <a href="#bordercolor">-bordercolor</a> before 727overlaying the original image in the center of this net image. This means that 728with the default compose method of '<kbd>Over</kbd>' any transparent parts may 729be replaced by the current <a href="#bordercolor">-bordercolor</a> setting.</p> 730<p>See also the <a href="#frame">-frame</a> option, which has more 731functionality.</p> 732 733<div style="margin: auto;"> 734 <h4><a id="bordercolor"></a>-bordercolor <em class="arg">color</em></h4> 735</div> 736 737<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the border color.</td><td style='text-align:right;'></td></tr></table> 738 739<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p> 740 741<p>The default border color is <kbd>#DFDFDF</kbd>, <span style="background-color: #dfdfdf;">this shade of gray</span>.</p> 742 743<div style="margin: auto;"> 744 <h4><a id="borderwidth"></a>-borderwidth <em class="arg">geometry</em> </h4> 745</div> 746 747<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the border width.</td><td style='text-align:right;'>[<a href="/www/animate.html">animate</a>, <a href="/www/display.html">display</a>]</td></tr></table> 748 749<div style="margin: auto;"> 750 <h4><a id="brightness-contrast"></a>-brightness-contrast <em class="arg">brightness</em><br />-brightness-contrast <em class="arg">brightness</em>{x<em class="arg">contrast</em>}{<em class="arg">%</em>}}</h4> 751</div> 752 753<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Adjust the brightness and/or contrast of the image.</td><td style='text-align:right;'></td></tr></table> 754 755<p>Brightness and Contrast values apply changes to the input image. They are 756not absolute settings. A brightness or contrast value of zero means no change. 757The range of values is -100 to +100 on each. Positive values increase the 758brightness or contrast and negative values decrease the brightness or contrast. 759To control only contrast, set the brightness=0. To control only brightness, 760set contrast=0 or just leave it off.</p> 761 762<p>You may also use <a href="#fill">-channel</a> to control which channels to 763apply the brightness and/or contrast change. The default is to apply the same 764transformation to all channels.</p> 765 766<p>Brightness and Contrast arguments are converted to offset and slope of a 767linear transform and applied 768using <a href="#fill">-function polynomial "slope,offset"</a>.</p> 769 770<p>The slope varies from 0 at contrast=-100 to almost vertical at 771contrast=+100. For brightness=0 and contrast=-100, the result are totally 772midgray. For brightness=0 and contrast=+100, the result will approach but 773not quite reach a threshold at midgray; that is the linear transformation 774is a very steep vertical line at mid gray.</p> 775 776<p>Negative slopes, i.e. negating the image, are not possible with this 777function. All achievable slopes are zero or positive.</p> 778 779<p>The offset varies from -0.5 at brightness=-100 to 0 at brightness=0 to +0.5 780at brightness=+100. Thus, when contrast=0 and brightness=100, the result is 781totally white. Similarly, when contrast=0 and brightness=-100, the result is 782totally black.</p> 783 784<p>As the range of values for the arguments are -100 to +100, adding the '%' 785symbol is no different than leaving it off.</p> 786 787<div style="margin: auto;"> 788 <h4><a id="cache"></a>-cache <em class="arg">threshold</em></h4> 789</div> 790 791<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>(This option has been replaced by the <a href='#limit'>-limit</a> option.)</td><td style='text-align:right;'></td></tr></table> 792 793<div style="margin: auto;"> 794 <h4><a id="caption"></a>-caption <em class="arg">string</em></h4> 795</div> 796 797<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Assign a caption to an image.</td><td style='text-align:right;'></td></tr></table> 798 799<p>This option sets the caption meta-data of an image read in after this 800option has been given. To modify a caption of images already in memory use 801"<kbd><a href="#set">-set</a> caption</kbd>". </p> 802 803<p>The caption can contain special format characters listed in the <a 804href="/www/escape.html">Format and 805Print Image Properties</a>. These attributes are expanded when the caption 806is finally assigned to the individual images. </p> 807 808<p>If the first character of <em class="arg">string</em> is <em 809class="arg">@</em>, the image caption is read from a file titled by the 810remaining characters in the string. Comments read in from a file are literal; 811no embedded formatting characters are recognized.</p> 812 813<p>Caption meta-data ais not visible on the image itself. To do that use the 814<a href="#annotate">-annotate</a> or <a href="#draw">-draw</a> options 815instead.</p> 816 817<p>For example,</p> 818 819<p class="crtsnip"> 820 -caption "%m:%f %wx%h" bird.miff 821</p> 822 823<p>produces an image caption of <kbd>MIFF:bird.miff 512x480</kbd> (assuming 824that the image <kbd>bird.miff</kbd> has a width of 512 and a height of 825480.</p> 826 827 828<div style="margin: auto;"> 829 <h4><a id="cdl"></a>-cdl <em class="arg">filename</em></h4> 830</div> 831 832<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>color correct with a color decision list.</td><td style='text-align:right;'></td></tr></table> 833 834<p>Here is an example color correction collection:</p> 835 836<pre class="text"> 837<?xml version="1.0" encoding="UTF-8"?> 838<ColorCorrectionCollection xmlns="urn:ASC:CDL:v1.2"> 839 <ColorCorrection id="cc06668"> 840 <SOPNode> 841 <Slope> 0.9 1.2 0.5 </Slope> 842 <Offset> 0.4 -0.5 0.6 </Offset> 843 <Power> 1.0 0.8 1.5 </Power> 844 </SOPNode> 845 <SATNode> 846 <Saturation> 0.85 </Saturation> 847 </SATNode> 848 </ColorCorrection> 849</ColorCorrectionCollection> 850</pre> 851 852<div style="margin: auto;"> 853 <h4><a id="channel"></a>-channel <em class="arg">type</em></h4> 854</div> 855 856<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Specify those image color channels to which subsequent operators are limited.</td><td style='text-align:right;'></td></tr></table> 857 858<p>Choose from: <kbd>Red</kbd>, <kbd>Green</kbd>, <kbd>Blue</kbd>, 859<kbd>Alpha</kbd>, <kbd>Cyan</kbd>, <kbd>Magenta</kbd>, <kbd>Yellow</kbd>, 860<kbd>Black</kbd>, <kbd>Opacity</kbd>, <kbd>Index</kbd>, <kbd>RGB</kbd>, 861<kbd>RGBA</kbd>, <kbd>CMYK</kbd>, or <kbd>CMYKA</kbd>.</p> 862 863<p>The channels above can also be specified as a comma-separated list or can be 864abbreviated as a concatenation of the letters '<kbd>R</kbd>', '<kbd>G</kbd>', 865'<kbd>B</kbd>', '<kbd>A</kbd>', '<kbd>O</kbd>', '<kbd>C</kbd>', 866'<kbd>M</kbd>', '<kbd>Y</kbd>', '<kbd>K</kbd>'. 867 868For example, to only select the <kbd>Red</kbd> and <kbd>Blue</kbd> channels 869you can either use </p> 870<p class="crtsnip"> 871 -channel Red,Blue 872</p> 873<p>or you can use the short hand form</p> 874<p class="crtsnip"> 875 -channel RB 876</p> 877 878<p>All the channels that is present in an image can be specified using the 879special channel type <kbd>All</kbd>. Not all operators are 'channel capable', 880but generally any operators that are generally 'grey-scale' image operators, 881will understand this setting. See individual operator documentation. </p> 882 883<br /> 884 885<p>On top of the normal channel selection a extra flag can be specified, 886'<kbd>Sync</kbd>'. This is turned on by default and if set means that 887operators that understand this flag should perform: cross-channel 888syncronization of the channels. If not specified, then most grey-scale 889operators will apply their image processing operations to each individual 890channel (as specified by the rest of the <a href="#channel">-channel</a> 891setting) completely independently from each other. </p> 892 893<p>For example for operators such as <a href="#auto-level">-auto-level</a> and 894<a href="#auto-gamma">-auto-gamma</a> the color channels are modified 895together in exactly the same way so that colors will remain in-sync. Without 896it being set, then each channel is modified separately and 897independently, which may produce color distortion. </p> 898 899<p>The <a href="#morphology">-morphology</a> '<kbd>Convolve</kbd>' method 900and the <a href="#compose">-compose</a> mathematical methods, also understands 901the '<kbd>Sync</kbd>' flag to modify the behaviour of pixel colors according 902to the alpha channel (if present). That is to say it will modify the image 903processing with the understanding that fully-transparent colors should not 904contribute to the final result. </p> 905 906<p>Basically, by default, operators work with color channels in syncronous, and 907treats transparency as special, unless the <a href="#channel">-channel</a> 908setting is modified so as to remove the effect of the '<kbd>Sync</kbd>' flag. 909How each operator does this depends on that operators current implementation. 910Not all operators understands this flag at this time, but that is changing. 911</p> 912 913<p>To print a complete list of channel types, use <a href="#list">-list 914channel</a>.</p> 915 916<br /> 917 918<p>By default, ImageMagick sets <a href="#channel">-channel</a> to the value 919'<kbd>RGBK,sync</kbd>', which specifies that operators act on all color 920channels except the transparency channel, and that all the color channels are 921to be modified in exactly the same way, with a understanding of transprancy 922(depending on the operation being applied). The 'plus' form <a 923href="#channel" >+channel</a> will reset the value back to this default. </p> 924 925<p>Options that are affected by the <a href="#channel" >-channel</a> setting 926include the following. 927 928<a href="#auto-gamma">-auto-gamma</a>, 929<a href="#auto-level">-auto-level</a>, 930<a href="#black-threshold">-black-threshold</a>, 931<a href="#blur">-blur</a>, 932<a href="#clamp">-clamp</a>, 933<a href="#clut">-clut</a>, 934<a href="#combine">-combine</a>, 935<a href="#composite">-composite</a> (Mathematical compose methods only), 936<a href="#convolve">-convolve</a>, 937<a href="#contrast-stretch">-contrast-stretch</a>, 938<a href="#evaluate">-evaluate</a>, 939<a href="#function">-function</a>, 940<a href="#fx">-fx</a>, 941<a href="#gaussian-blur">-gaussian-blur</a>, 942<a href="#hald-clut">-hald-clut</a>, 943<a href="#motion-blur">-motion-blur</a>, 944<a href="#morphology">-morphology</a>, 945<a href="#negate">-negate</a>, 946<a href="#normalize">-normalize</a>, 947<a href="#ordered-dither">-ordered-dither</a>, 948<a href="#radial-blur">-radial-blur</a>, 949<a href="#random-threshold">-random-threshold</a>, 950<a href="#separate">-separate</a>, 951<a href="#threshold">-threshold</a>, and 952<a href="#white-threshold">-white-threshold</a>. 953</p> 954 955<p>Warning, some operators behave differently when the <a href="#channel" 956>+channel</a> default setting is in effect, verses ANY user defined <a 957href="#channel" >-channel</a> setting (including the equivalent of the 958default). These operators have yet to be made to understand the newer 'Sync' 959flag. </p> 960 961<p>For example <a href="#threshold">-threshold</a> will by default gray-scale 962the image before thresholding, if no <a href="#channel" >-channel</a> setting 963has been defined. This is not 'Sync flag controlled, yet. </p> 964 965<p>Also some operators such as <a href="#blur">-blur</a>, <a 966href="#gaussian-blur">-gaussian-blur</a>, will modify their handling of the 967color channels if the '<kbd>alpha</kbd>' channel is also enabled by <a 968href="#channel" >-channel</a>. Generally this done to ensure that 969fully-transparent colors are treated as being fully-transparent, and thus any 970underlying 'hidden' color has no effect on the final results. Typically 971resulting in 'halo' effects. The newer <a href="#morphology">-morphology</a> 972convolution equivalents however does have a understanding of the 'Sync' flag 973and will thus handle transparency correctly by default. </p> 974 975<p>As a alpha channel is optional within images, some operators will read the 976color channels of an image as a greyscale alpha mask, when the image has no 977alpha channel present, and the <a href="#channel" >-channel</a> setting tells 978the operator to apply the operation using alpha channels. The <a 979href="#clut">-clut</a> operator is a good example of this. </p> 980 981 982<div style="margin: auto;"> 983 <h4><a id="clamp"></a>-clamp</h4> 984</div> 985 986<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Restrict image colors from 0 to the quantum depth.</td><td style='text-align:right;'></td></tr></table> 987 988<div style="margin: auto;"> 989 <h4><a id="charcoal"></a>-charcoal <em class="arg">factor</em></h4> 990</div> 991 992<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Simulate a charcoal drawing.</td><td style='text-align:right;'></td></tr></table> 993 994<div style="margin: auto;"> 995 <h4><a id="chop"></a>-chop <em class="arg">geometry</em></h4> 996</div> 997 998<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Remove pixels from the interior of an image.</td><td style='text-align:right;'></td></tr></table> 999 1000<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. The <em class="arg">width</em> 1001and <em class="arg">height</em> given in the of the <em class="arg">size</em> 1002portion of the <em class="arg">geometry</em> argument give the number of 1003columns and rows to remove. The <em class="arg">offset</em> portion of 1004the <em class="arg">geometry</em> argument is influenced by 1005a <a href="#gravity">-gravity</a> setting, if present.</p> 1006 1007<p>The <a href="#chop">-chop</a> option removes entire rows and columns, 1008and moves the remaining corner blocks leftward and upward to close the gaps.</p> 1009 1010<p>While it can remove internal rows and columns of pixels, it is more typically 1011used with as <a href="#gravity">-gravity</a> setting and a '<kbd>+0+0</kbd>' offset 1012so as to remove a single edge from an image. Compare this to <a href="#shave" 1013>-shave</a> whcih removes equal numbers of pixels from oppisite sides of the image. 1014</p> 1015 1016<p>Using <a href="#chop">-chop</a> will effectivally undo the results of a 1017<a href="#splice">-splice</a> that was given the same <em class="arg">geometry</em> 1018and <a href="#gravity">-gravity</a> settings. </p> 1019 1020 1021<div style="margin: auto;"> 1022 <h4><a id="clip"></a>-clip</h4> 1023</div> 1024 1025<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Apply the clipping path if one is present.</td><td style='text-align:right;'></td></tr></table> 1026 1027<p>If a clipping path is present, it is applied to subsequent operations.</p> 1028 1029<p>For example, in the command</p> 1030 1031<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert -clip -negate cockatoo.tif negated.tif</span></p> 1032<p>only the pixels within the clipping path are negated.</p> 1033 1034<p>The <a href="#clip">-clip</a> feature requires the XML library. If the XML library is not present, the option is ignored.</p> 1035 1036<div style="margin: auto;"> 1037 <h4><a id="clip-mask"></a>-clip-mask</h4> 1038</div> 1039 1040<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Clip the image as defined by this mask.</td><td style='text-align:right;'></td></tr></table> 1041 1042<div style="margin: auto;"> 1043 <h4><a id="clip-path"></a>-clip-path <em class="arg">id</em></h4> 1044</div> 1045 1046<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Clip along a named path from the 8BImageMagick profile.</td><td style='text-align:right;'></td></tr></table> 1047 1048<div style="margin: auto;"> 1049 <h4><a id="clone"></a>-clone <em class="arg">index(s)</em></h4> 1050</div> 1051 1052<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Make a copy of an image (or images).</td><td style='text-align:right;'></td></tr></table> 1053 1054<p>Inside parenthesis (where the operator is normally used) it will make a 1055clone of the images from the last 'pushed' image sequence, and adds them to 1056the end of the current image sequence. Outside parenthesis 1057(not recommended) it clones the images from the current image sequence. </p> 1058 1059<p>Specify the image by its index in the sequence. The first image is index 10600. Negative indexes are relative to the end of the sequence; for 1061example, <kbd>−1</kbd> 1062represents the last image of the sequence. Specify a range of images with a 1063dash (e.g. <kbd>0−4</kbd>). Separate multiple indexes with commas but no 1064spaces (e.g. <kbd>0,2,5</kbd>). A value of '<kbd>0−−1</kbd> will 1065effectivally clone all the images. </p> 1066 1067<p>The <a href="#clone">+clone</a> will simply make a copy of the last image 1068in the image sequence, and is thus equivelent to using a argument of 1069'<kbd>−1</kbd>'. </p> 1070 1071<div style="margin: auto;"> 1072 <h4><a id="clut"></a>-clut</h4> 1073</div> 1074 1075<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Replace the channel values in the first image using each 1076corresponding channel in the second image as a <b>c</b>olor 1077<b>l</b>ook<b>u</b>p <b>t</b>able.</td><td style='text-align:right;'></td></tr></table> 1078 1079<p>The second (LUT) image is ordinarily a gradient image containing the 1080histogram mapping of how each channel should be modified. Typically it is a 1081either a single row or column image of replacement color values. If larger 1082than a single row or column, values are taken from a diagonal line from 1083top-left to bottom-right corners.</p> 1084 1085<p>The lookup is further controlled by the <a 1086href="#interpolate">-interpolate</a> setting, which is especially handy for an 1087LUT which is not the full length needed by the ImageMagick installed Quality 1088(Q) level. Good settings for this are the '<kbd>bilinear</kbd>' and 1089'<kbd>bicubic</kbd>' interpolation settings, which give smooth color 1090gradients, and the '<kbd>integer</kbd>' setting for a direct, unsmoothed 1091lookup of color values. </p> 1092 1093<p>This operator is especially suited to replacing a grayscale image with a 1094specific color gradient from the CLUT image. </p> 1095 1096<p>Only the channel values defined by the <a href="#channel">-channel</a> 1097setting will have their values replaced. In particular, since the default <a 1098href="#channel">-channel</a> setting is <kbd>RGB</kbd>, this means that 1099transparency (alpha/matte channel) is not affected, unless the <a 1100href="#channel">-channel</a> setting is modified. When the alpha channel is 1101set, it is treated by the <a href="#clut" >-clut</a> operator in the same way 1102as the other channels, implying that alpha/matte values are replaced using the 1103alpha/matte values of the original image. </p> 1104 1105<p>If either the image being modified, or the lookup image, contains no 1106transparency (i.e. <a href="#alpha" >-alpha</a> is turned 'off') but the <a 1107href="#channel">-channel</a> setting includes alpha replacement, then it is 1108assumed that image represents a gray-scale gradient which is used for the 1109replacement alpha values. That is you can use a gray-scale CLUT image to 1110adjust a existing images alpha channel, or you can color a gray-scale image 1111using colors form CLUT containing the desired colors, including transparency. 1112</p> 1113 1114<p>See also <a href="#hald-clut" >-hald-clut</a> which replaces colors 1115according to the lookup of the full color RGB value from a 2D representation 1116of a 3D color cube. </p> 1117 1118 1119<div style="margin: auto;"> 1120 <h4><a id="coalesce"></a>-coalesce</h4> 1121</div> 1122 1123<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Fully define the look of each frame of an GIF animation sequence, to form a 'film strip' animation.</td><td style='text-align:right;'></td></tr></table> 1124 1125<p>Overlay each image in an image sequence according to 1126its <a href="#dispose">-dispose</a> meta-data, to reproduce the look of 1127an animation at each point in the animation sequence. All images should be 1128the same size, and are assigned appropriate GIF disposal settings for the 1129animation to continue working as expected as a GIF animation. Such frames 1130are more easily viewed and processed than the highly optimized GIF overlay 1131images. </p> 1132 1133<p>The animation can be re-optimized after processing using 1134the <a href="#layers">-layers</a> method '<kbd>optimize</kbd>', although 1135there is no guarantee that the restored GIF animation optimization is 1136better than the original. </p> 1137 1138 1139<div style="margin: auto;"> 1140 <h4><a id="colorize"></a>-colorize <em class="arg">value</em></h4> 1141</div> 1142 1143<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Colorize the image by an amount specified by <em class="arg">value</em> using the color specified by the most recent <a href="#fill" >-fill</a> setting.</td><td style='text-align:right;'></td></tr></table> 1144 1145<p>Specify the amount of colorization as a percentage. Separate colorization 1146values can be applied to the red, green, and blue channels of the image with 1147a comma-delimited list of colorization 1148values (e.g., <kbd>-colorize 0,0,50</kbd>).</p> 1149 1150<div style="margin: auto;"> 1151 <h4><a id="colormap"></a>-colormap <em class="arg">type</em></h4> 1152</div> 1153 1154<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Define the colormap type.</td><td style='text-align:right;'>[<a href="/www/animate.html">animate</a>, <a href="/www/display.html">display</a>]</td></tr></table> 1155 1156<p>The <em class="arg">type</em> can be <kbd>shared</kbd> or <kbd>private</kbd>.</p> 1157 1158<p>This option only applies when the default X server visual 1159is <kbd>PseudoColor</kbd> or <kbd>GrayScale</kbd>. Refer 1160to <a href="#visual">-visual</a> for more details. By default, 1161a shared colormap is allocated. The image shares colors with 1162other X clients. Some image colors could be approximated, 1163therefore your image may look very different than intended. 1164If <kbd>private</kbd> is chosen, the image colors appear exactly 1165as they are defined. However, other clients may go <em>technicolor</em> 1166when the image colormap is installed.</p> 1167 1168<div style="margin: auto;"> 1169 <h4><a id="colors"></a>-colors <em class="arg">value</em></h4> 1170</div> 1171 1172<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the preferred number of colors in the image.</td><td style='text-align:right;'></td></tr></table> 1173 1174<p>The actual number of colors in the image may be less than your request, 1175but never more. Note that this a color reduction option. Images with fewer 1176unique colors than specified by <em class="arg">value</em> will have any 1177duplicate or unused colors removed. The ordering of an existing color 1178palette may be altered. When converting an image from color to grayscale, 1179it is more efficient to convert the image to the gray colorspace before 1180reducing the number of colors. Refer to 1181the <a href="/www/quantize.html"> 1182color reduction algorithm</a> for more details.</p> 1183 1184<div style="margin: auto;"> 1185 <h4><a id="color-matrix"></a>-color-matrix <em class="arg">matrix</em></h4> 1186</div> 1187 1188<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>apply color correction to the image.</td><td style='text-align:right;'></td></tr></table> 1189 1190<p>This option permits saturation changes, hue rotation, luminance to alpha, 1191and various other effects. Although variable-sized transformation matrices 1192can be used, typically one uses a 5x5 matrix for an RGBA image and a 6x6 1193for CMYKA (or RGBA with offsets). The matrix is similar to those used by 1194Adobe Flash except offsets are in column 6 rather than 5 (in support of 1195CMYKA images) and offsets are normalized (divide Flash offset by 255).</p> 1196 1197<p>As an example, to add contrast to an image with offsets, try this command:</p> 1198 1199<pre class="text"> 1200convert kittens.jpg -color-matrix \ 1201 " 1.5 0.0 0.0 0.0, 0.0, -0.157 \ 1202 0.0 1.5 0.0 0.0, 0.0, -0.157 \ 1203 0.0 0.0 1.5 0.0, 0.0, -0.157 \ 1204 0.0 0.0 0.0 1.0, 0.0, 0.0 \ 1205 0.0 0.0 0.0 0.0, 1.0, 0.0 \ 1206 0.0 0.0 0.0 0.0, 0.0, 1.0" kittens.png 1207</pre> 1208<div style="margin: auto;"> 1209 <h4><a id="colorspace"></a>-colorspace <em class="arg">value</em></h4> 1210</div> 1211 1212<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the image colorspace.</td><td style='text-align:right;'></td></tr></table> 1213 1214<p>Choices are:</p> 1215 1216<pre class="text"> 1217 CMY 1218 CMYK 1219 Gray 1220 HSB 1221 HSL 1222 HWB 1223 Lab 1224 Log 1225 OHTA 1226 Rec601Luma 1227 Rec601YCbCr 1228 Rec709Luma 1229 Rec709YCbCr 1230 RGB 1231 sRGB 1232 Transparent 1233 XYZ 1234 YCbCr 1235 YCC 1236 YIQ 1237 YPbPr 1238 YUV 1239</pre> 1240 1241<p>To print a complete list of colorspaces, use <a href="#list">-list colorspace</a>.</p> 1242 1243<p>For a more accurate color conversion to or from the RGB, CMYK, or grayscale colorspaces, use the <a href="#profile">-profile</a> option.</p> 1244 1245<table class="doc"> 1246 <caption>Conversion Of RGB To Other Color Spaces</caption> 1247 <tr><th align="left" valign="middle">CMY</th></tr> 1248 <tr><td align="left" valign="middle">C=<em class="QR">QuantumRange</em>−R</td></tr> 1249 <tr><td align="left" valign="middle">M=<em class="QR">QuantumRange</em>−G</td></tr> 1250 <tr><td align="left" valign="middle">Y=<em class="QR">QuantumRange</em>−B</td></tr> 1251 <tr><th align="left" valign="middle">CMYK — starts with CMY from above</th></tr> 1252 <tr><td align="left" valign="middle">K=min(C,Y,M)</td></tr> 1253 <tr><td align="left" valign="middle">C=<em class="QR">QuantumRange</em>*(C−K)/(<em class="QR">QuantumRange</em>−K)</td></tr> 1254 <tr><td align="left" valign="middle">M=<em class="QR">QuantumRange</em>*(M−K)/(<em class="QR">QuantumRange</em>−K)</td></tr> 1255 <tr><td align="left" valign="middle">Y=<em class="QR">QuantumRange</em>*(Y−K)/(<em class="QR">QuantumRange</em>−K)</td></tr> 1256 1257 <tr><th align="left" valign="middle">Gray</th></tr> 1258 <tr><td align="left" valign="middle">Gray = 0.29900*R+0.58700*G+0.11400*B</td></tr> 1259 1260 <tr><th align="left" valign="middle">HSB — Hue, Saturation, Brightness; like a cone peak downward</th></tr> 1261 <tr><td align="left" valign="middle">H=angle around perimeter (0 to 360 deg); H=0 is red; increasing angles toward green</td></tr> 1262 <tr><td align="left" valign="middle">S=distance from axis outward</td></tr> 1263 <tr><td align="left" valign="middle">B=distance along axis from bottom upward; B=max(R,G,B); <em>intensity-like</em></td></tr> 1264 1265 <tr><th align="left" valign="middle">HSL — Hue, Saturation, Lightness; like a double cone end-to-end with peaks at very top and bottom</th></tr> 1266 <tr><td align="left" valign="middle">H=angle around perimeter (0 to 360 deg); H=0 is red; increasing angles toward green</td></tr> 1267 <tr><td align="left" valign="middle">S=distance from axis outward</td></tr> 1268 <tr><td align="left" valign="middle">L=distance along axis from bottom upward; L=0.5*max(R,G,B) + 0.5*min(R,G,B); <em>intensity-like</em></td></tr> 1269 1270 <tr><th align="left" valign="middle">HWB — Hue, Whiteness, Blackness</th></tr> 1271 <tr><td align="left" valign="middle">Hue (complicated equation)</td></tr> 1272 <tr><td align="left" valign="middle">Whiteness (complicated equation)</td></tr> 1273 <tr><td align="left" valign="middle">Blackness (complicated equation)</td></tr> 1274 1275 <tr><th align="left" valign="middle">LAB</th></tr> 1276 <tr><td align="left" valign="middle">L (complicated equation relating X,Y,Z)</td></tr> 1277 <tr><td align="left" valign="middle">A (complicated equation relating X,Y,Z)</td></tr> 1278 <tr><td align="left" valign="middle">B (complicated equation relating X,Y,Z)</td></tr> 1279 1280 <tr><th align="left" valign="middle">LOG</th></tr> 1281 <tr><td align="left" valign="middle">I1 (complicated equation involving logarithm of R)</td></tr> 1282 <tr><td align="left" valign="middle">I2 (complicated equation involving logarithm of G)</td></tr> 1283 <tr><td align="left" valign="middle">I3 (complicated equation involving logarithm of B)</td></tr> 1284 1285 <tr><th align="left" valign="middle">OHTA — approximates principal components transformation</th></tr> 1286 <tr><td align="left" valign="middle">I1=0.33333*R+0.33334*G+0.33333*B; <em>intensity-like</em></td></tr> 1287 <tr><td align="left" valign="middle">I2=(0.50000*R+0.00000*G−0.50000*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1288 <tr><td align="left" valign="middle">I3=(−0.25000*R+0.50000*G−0.25000*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1289 1290 <tr><th align="left" valign="middle">Rec601Luma</th></tr> 1291 <tr><td align="left" valign="middle">Gray = 0.29900*R+0.58700*G+0.11400*B</td></tr> 1292 1293 <tr><th align="left" valign="middle">Rec601YCbCr</th></tr> 1294 <tr><td align="left" valign="middle">Y=0.299000*R+0.587000*G+0.114000*B; <em>intensity-like</em></td></tr> 1295 <tr><td align="left" valign="middle">Cb=(−0.168736*R-0.331264*G+0.500000*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1296 <tr><td align="left" valign="middle">Cr=(0.500000*R−0.418688*G−0.081312*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1297 1298 <tr><th align="left" valign="middle">Rec709Luma</th></tr> 1299 <tr><td align="left" valign="middle">Gray=0.21260*R+0.71520*G+0.07220*B</td></tr> 1300 1301 <tr><th align="left" valign="middle">Rec709YCbCr</th></tr> 1302 <tr><td align="left" valign="middle">Y=0.212600*R+0.715200*G+0.072200*B; <em>intensity-like</em></td></tr> 1303 <tr><td align="left" valign="middle">Cb=(−0.114572*R−0.385428*G+0.500000*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1304 <tr><td align="left" valign="middle">Cr=(0.500000*R−0.454153*G−0.045847*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1305 1306 <tr><th align="left" valign="middle">sRGB</th></tr> 1307 <tr><td align="left" valign="middle">if Rs ≤ .03928 then Rs=R/12.92 else Rs=((R+.055)/1.055)^2.4</td></tr> 1308 <tr><td align="left" valign="middle">if Gs ≤ .03928 then Gs=B/12.92 else Gs=((G+.055)/1.055)^2.4</td></tr> 1309 <tr><td align="left" valign="middle">if Bs ≤ .03928 then Bs=B/12.92 else Bs=((B+.055)/1.055)^2.4</td></tr> 1310 1311 <tr><th align="left" valign="middle">XYZ</th></tr> 1312 <tr><td align="left" valign="middle">X=0.4124240*R+0.3575790*G+0.1804640*B</td></tr> 1313 <tr><td align="left" valign="middle">Y=0.2126560*R+0.7151580*G+0.0721856*B</td></tr> 1314 <tr><td align="left" valign="middle">Z=0.0193324*R+0.1191930*G+0.9504440*B</td></tr> 1315 1316 <tr><th align="left" valign="middle">YCC</th></tr> 1317 <tr><td align="left" valign="middle">Y=(0.29900*R+0.58700*G+0.11400*B) (with complicated scaling); <em>intensity-like</em></td></tr> 1318 <tr><td align="left" valign="middle">C1=(−0.29900*R−0.58700*G+0.88600*B) (with complicated scaling)</td></tr> 1319 <tr><td align="left" valign="middle">C2=(0.70100*R−0.58700*G−0.11400*B) (with complicated scaling)</td></tr> 1320 1321 <tr><th align="left" valign="middle">YCbCr</th></tr> 1322 <tr><td align="left" valign="middle">Y=0.299000*R+0.587000*G+0.114000*B; <em>intensity-like</em></td></tr> 1323 <tr><td align="left" valign="middle">Cb=(−0.168736*R−0.331264*G+0.500000*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1324 <tr><td align="left" valign="middle">Cr=(0.500000*R−0.418688*G−0.081312*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1325 1326 <tr><th align="left" valign="middle">YIQ</th></tr> 1327 <tr><td align="left" valign="middle">Y=0.29900*R+0.58700*G+0.11400*B; <em>intensity-like</em></td></tr> 1328 <tr><td align="left" valign="middle">I=(0.59600*R−0.27400*G−0.32200*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1329 <tr><td align="left" valign="middle">Q=(0.21100*R−0.52300*G+0.31200*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1330 1331 <tr><th align="left" valign="middle">YPbPr</th></tr> 1332 <tr><td align="left" valign="middle">Y=0.299000*R+0.587000*G+0.114000*B; <em>intensity-like</em></td></tr> 1333 <tr><td align="left" valign="middle">Pb=(−0.168736*R−0.331264*G+0.500000*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1334 <tr><td align="left" valign="middle">Pr=(0.500000*R−0.418688*G−0.081312*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1335 1336 <tr><th align="left" valign="middle">YUV</th></tr> 1337 <tr><td align="left" valign="middle">Y=0.29900*R+0.58700*G+0.11400*B; <em>intensity-like</em></td></tr> 1338 <tr><td align="left" valign="middle">U=(−0.14740*R−0.28950*G+0.43690*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1339 <tr><td align="left" valign="middle">V=(0.61500*R−0.51500*G−0.10000*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr> 1340</table> 1341 1342<div style="margin: auto;"> 1343 <h4><a id="combine"></a>-combine</h4> 1344</div> 1345 1346<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Combine one or more images into a single image.</td><td style='text-align:right;'></td></tr></table> 1347 1348<p>The channels (previously set by <a href="#channel">-channel</a>) of the combined image are taken from the grayscale values of each image in the sequence, in order. For the default -channel setting of <kbd>RGB</kbd>, this means the first image is assigned to the <kbd>Red</kbd> channel, the second to the <kbd>Green</kbd> channel, the third to the <kbd>Blue</kbd>.</p> 1349 1350<p>This option can be thought of as the inverse to <a href="#separate">-separate</a>, so long as the channel settings are the same. Thus, in the following example, the final image should be a copy of the original. 1351</p> 1352 1353<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert original.png -channel RGB -separate sepimage.png</span><span class='crtout'></span><span class="crtprompt"> $magick> </span><span class='crtin'>convert sepimage-0.png sepimage-1.png sepimage-2.png -channel RGB \ <br/> -combine imagecopy.png</span></p> 1354<div style="margin: auto;"> 1355 <h4><a id="comment"></a>-comment <em class="arg">string</em></h4> 1356</div> 1357 1358<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Embed a comment in an image.</td><td style='text-align:right;'></td></tr></table> 1359 1360<p>This option sets the comment meta-data of an image read in after this 1361option has been given. To modify a comment of images already in memory use 1362"<kbd><a href="#set">-set</a> comment</kbd>". </p> 1363 1364<p>The comment can contain special format characters listed in the <a 1365href="/www/escape.html">Format and 1366Print Image Properties</a>. These attributes are expanded when the comment 1367is finally assigned to the individual images. </p> 1368 1369<p>If the first character of <em class="arg">string</em> is <em 1370class="arg">@</em>, the image comment is read from a file titled by the 1371remaining characters in the string. Comments read in from a file are literal; 1372no embedded formatting characters are recognized.</p> 1373 1374<p>Comment meta-data are not visible on the image itself. To do that use the 1375<a href="#annotate">-annotate</a> or <a href="#draw">-draw</a> options 1376instead.</p> 1377 1378<p>For example,</p> 1379 1380<p class="crtsnip"> 1381 -comment "%m:%f %wx%h" bird.miff 1382</p> 1383 1384<p>produces an image comment of <kbd>MIFF:bird.miff 512x480</kbd> (assuming 1385that the image <kbd>bird.miff</kbd> has a width of 512 and a height of 1386480.</p> 1387 1388<div style="margin: auto;"> 1389 <h4><a id="compose"></a>-compose <em class="arg">operator</em></h4> 1390</div> 1391 1392<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the type of image composition.</td><td style='text-align:right;'></td></tr></table> 1393 1394<p>See <a href="/www/compose.html">Alpha Compositing</a> for 1395a detailed discussion of alpha compositing.</p> 1396 1397<p>This setting effects image processing operators that merge two (or more) 1398images together in some way. This includes the operators, 1399<a href="#composite">-composite</a>, 1400<a href="#layers">-layers</a> composite, 1401<a href="#flatten">-flatten</a>, 1402<a href="#mosaic">-mosaic</a>, 1403<a href="#layers">-layers</a> merge, 1404<a href="#border">-border</a>, 1405<a href="#frame">-frame</a>, 1406and <a href="#extent">-extent</a>. </p> 1407 1408<p>It is also one of the primary options for the "<kbd>composite</kbd>" 1409command. </p> 1410 1411 1412<div style="margin: auto;"> 1413 <h4><a id="composite"></a>-composite</h4> 1414</div> 1415 1416<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Perform alpha composition on two images and an optional mask</td><td style='text-align:right;'></td></tr></table> 1417 1418<p>Take the first image 'destination' and overlay the second 'source' image 1419according to the current <a href="#compose">-compose</a> setting. The location 1420of the 'source' or 'overlay' image is controlled according to <a 1421href="#geometry" >-geometry</a>, and <a href="#geometry" >-geometry</a> 1422settings. </p> 1423 1424<p>If a third image is given this is treated as a gray-scale 'mask' image 1425relative to the first 'destination' image. This mask will limit what parts of 1426the destination can be modified by the image composition. However for the 1427'<kbd>displace</kbd>' compose method, the mask is used to provide a separate 1428Y-displacement image instead. </p> 1429 1430<p>If a <a href="#compose">-compose</a> method requires extra numerical 1431arguments or flags these can be provided by setting the <a 1432href="#set">-set</a> '<kbd class="arg">option:compose:args</kbd>' 1433appropriately for the compose method. </p> 1434 1435<p>Some <a href="#compose">-compose</a> methods can modify the 'destination' 1436image outside the overlay area. You can disable this by setting the special <a 1437href="#set">-set</a> '<kbd class="arg">option:compose:outside-overlay</kbd>' 1438to '<kbd>false</kbd>'. </p> 1439 1440 1441<div style="margin: auto;"> 1442 <h4><a id="compress"></a>-compress <em class="arg">type</em></h4> 1443</div> 1444 1445<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Use pixel compression specified by <em class="arg">type</em> when writing the image.</td><td style='text-align:right;'></td></tr></table> 1446 1447<p>Choices are: <kbd class="arg">None</kbd>, <kbd class="arg">BZip</kbd>, <kbd class="arg">Fax</kbd>, <kbd class="arg">Group4</kbd>, <kbd class="arg">JPEG</kbd>, <kbd class="arg">JPEG2000</kbd>, <kbd class="arg">Lossless</kbd>, <kbd class="arg">LZW</kbd>, <kbd class="arg">RLE</kbd> or <kbd class="arg">Zip</kbd>.</p> 1448 1449<p>To print a complete list of compression types, use <a href="#list">-list compress</a>.</p> 1450 1451<p>Specify <a href="#compress">+compress</a> to store the binary image in an uncompressed format. The default is the compression type of the specified image file.</p> 1452 1453<p>If <kbd>LZW</kbd> compression is specified but LZW compression has not been enabled, the image data is written in an uncompressed LZW format that can be read by LZW decoders. This may result in larger-than-expected GIF files.</p> 1454 1455<p><kbd>Lossless</kbd> refers to lossless JPEG, which is only available if the JPEG library has been patched to support it. Use of lossless JPEG is generally not recommended.</p> 1456 1457<p>Use the <a href="#quality">-quality</a> option to set the compression level to be used by JPEG, PNG, MIFF, and MPEG encoders. Use the <a href="#sampling-factor">-sampling-factor</a> option to set the sampling factor to be used by JPEG, MPEG, and YUV encoders for down-sampling the chroma channels.</p> 1458 1459<div style="margin: auto;"> 1460 <h4><a id="contrast"></a>-contrast</h4> 1461</div> 1462 1463<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Enhance or reduce the image contrast.</td><td style='text-align:right;'></td></tr></table> 1464 1465<p>This option enhances the intensity differences between the lighter and darker elements of the image. Use <a href="#contrast">-contrast</a> to enhance the image or <a href="#contrast">+contrast</a> to reduce the image contrast.</p> 1466 1467<p>For a more pronounced effect you can repeat the option:</p> 1468 1469<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert rose: -contrast -contrast rose_c2.png</span></p> 1470<div style="margin: auto;"> 1471 <h4><a id="contrast-stretch"></a>-contrast-stretch <em class="arg">black-point</em><br />-contrast-stretch <em class="arg">black-point</em>{x<em class="arg">white-point</em>}{<em class="arg">%</em>}}</h4> 1472</div> 1473 1474<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Increase the contrast in an image by <em>stretching</em> the range of intensity values.</td><td style='text-align:right;'></td></tr></table> 1475 1476<p>While performing the stretch, black-out at most <em 1477class="arg" >black-point</em> pixels and white-out at most <em 1478class="arg" >white-point</em> pixels. Or, if percent is used, black-out at most 1479<em class="arg" >black-point %</em> pixels and white-out at most <em 1480class="arg" >white-point %</em> pixels.</p> 1481 1482<p>Prior to ImageMagick 6.4.7-0, <a href="#contrast-stretch" 1483>-contrast-stretch</a> will black-out at most <em class="arg" 1484>black-point</em> pixels and white-out at most <em class="arg" >total pixels 1485minus white-point</em> pixels. Or, if percent is used, black-out at most <em 1486class="arg">black-point %</em> pixels and white-out at most <em class="arg" 1487>100% minus white-point %</em> pixels.</p> 1488 1489<p>Note that <kbd>-contrast-stretch 0</kbd> will modify the image such that 1490the image's min and max values are stretched to 0 and <em class="QR" 1491>QuantumRange</em>, respectively, without any loss of data due to burn-out or 1492clipping at either end. This is not the same as <a href="#normalize" 1493>-normalize</a>, which is equivalent to <kbd>-contrast-stretch 0.15x0.05%</kbd> (or 1494prior to ImageMagick 6.4.7-0, <kbd>-contrast-stretch 2%x99%</kbd>).</p> 1495 1496<p>Internally operator works by creating a histogram bin, and then uses that 1497bin to modify the image. As such some colors may be merged together when they 1498originally fell into the same 'bin'. </p> 1499 1500<p>All the channels are normalized in concert by the came amount so as to 1501preserve color integrity, when the default <a href="#channel" >+channel</a> 1502setting is in use. Specifying any other <a href="#channel" >-channel</a> 1503setting will normalize the RGB channels independently.</p> 1504 1505<p>See also <a href="#auto-level" >-auto-level</a> for a 'perfect' 1506normalization of mathematical images. </p> 1507 1508<p>This operator is under review for re-development. </p> 1509 1510 1511<div style="margin: auto;"> 1512 <h4><a id="convolve"></a>-convolve <em class="arg">kernel</em></h4> 1513</div> 1514 1515<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Convolve an image with a user-supplied convolution kernel.</td><td style='text-align:right;'></td></tr></table> 1516 1517<p>The <em class="arg">kernel</em> is a matrix specified as 1518a comma-separated list of integers (with no spaces), ordered left-to right, 1519starting with the top row. Presently, only odd-dimensioned kernels are 1520supported, and therefore the number of entries in the specified <em 1521class="arg">kernel</em> must be 3<sup>2</sup>=9, 5<sup>2</sup>=25, 15227<sup>2</sup>=49, etc. </p> 1523 1524<p>Note that the <a href="/www/command-line-options.html#convolve">‑convolve</a> operator supports the <a href="/www/command-line-options.html#bias">‑bias</a> setting. This option shifts the convolution so that 1525positive and negative results are relative to a user-specified bias value. 1526This is important for non-HDRI compilations of ImageMagick when dealing with 1527convolutions that contain negative as well as positive values. This is 1528especially the case with convolutions involving high pass filters or edge 1529detection. Without an output bias, the negative values is clipped at zero. 1530</p> 1531 1532<p>When using an ImageMagick with the HDRI compile-time setting, <a href="/www/command-line-options.html#bias">‑bias</a> is not needed, as ImageMagick is able to store/handle any 1533negative results without clipping to the color value range (0..QuantumRange). 1534See the discussion on HDRI implementations of ImageMagick on the page <a 1535href="/www/high-dynamic-range.html">High 1536Dynamic-Range Images</a>. For more about HDRI go the ImageMagick <a 1537href="http://www.imagemagick.org/Usage/basics/#hdri">Usage</a> pages or this 1538<a href="http://en.wikipedia.org/wiki/High_dynamic_range_imaging">Wikipedia</a> 1539entry. </p> 1540 1541 1542<div style="margin: auto;"> 1543 <h4><a id="crop"></a>-crop <em class="arg">geometry</em></h4> 1544</div> 1545 1546<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Cut out one or more rectangular regions of the image.</td><td style='text-align:right;'></td></tr></table> 1547 1548<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 1549 1550<p>The <em class="arg">width</em> and <em class="arg">height</em> of the <em class="arg">geometry</em> argument give the size of the image that remains after cropping, and <em class="arg">x</em> and <em class="arg">y</em> in the <em class="arg">offset</em> (if present) gives the location of the top left corner of the cropped image with respect to the original image. To specify the amount to be removed, use <a href="#shave">-shave</a> instead.</p> 1551 1552<p>If the <em class="arg">x</em> and <em class="arg">y</em> offsets are present, a single image is generated, consisting of the pixels from the cropping region. The offsets specify the location of the upper left corner of the cropping region measured downward and rightward with respect to the upper left corner of the image. If the <a href="#gravity">-gravity</a> option is present with <kbd>NorthEast</kbd>, <kbd>East</kbd>, or <kbd>SouthEast</kbd> gravity, it gives the distance leftward from the right edge of the image to the right edge of the cropping region. Similarly, if the <a href="#gravity">-gravity</a> option is present with <kbd>SouthWest</kbd>, <kbd>South</kbd>, or <kbd>SouthEast</kbd> gravity, the distance is measured upward between the bottom edges.</p> 1553 1554<p>If the <em class="arg">x</em> and <em class="arg">y</em> offsets are omitted, a set of tiles of the specified geometry, covering the entire input image, is generated. The rightmost tiles and the bottom tiles are smaller if the specified geometry extends beyond the dimensions of the input image.</p> 1555 1556<p>By adding a exclamation character flag to the geometry argument, the 1557cropped images virtual canvas page size and offset is set as if the 1558geometry argument was a viewport or window. This means the canvas page size 1559is set to exactly the same size you specified, the image offset set 1560relative top left corner of the region cropped. </p> 1561 1562<p>If the cropped image 'missed' the actual image on its virtual canvas, a 1563special single pixel transparent 'missed' image is returned, and a 'crop 1564missed' warning given. </p> 1565 1566<p>It might be necessary to <a href="#repage" >+repage</a> the image prior to cropping the image to ensure the crop coordinate frame is relocated to the upper-left corner of the visible image.</p> 1567 1568<div style="margin: auto;"> 1569 <h4><a id="cycle"></a>-cycle <em class="arg">amount</em></h4> 1570</div> 1571 1572<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>displace image colormap by amount.</td><td style='text-align:right;'></td></tr></table> 1573 1574<p><em class="arg">Amount</em> defines the number of positions each 1575colormap entry is shifted.</p> 1576 1577 1578<div style="margin: auto;"> 1579 <h4><a id="debug"></a>-debug <em class="arg">events</em></h4> 1580</div> 1581 1582<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>enable debug printout.</td><td style='text-align:right;'></td></tr></table> 1583 1584<p>The <kbd>events</kbd> parameter specifies which events are to be logged. It can be either <kbd>None</kbd>, <kbd>All</kbd>, <kbd>Trace</kbd>, or a comma-separated list consisting of one or more of the following domains: <kbd>Annotate</kbd>, <kbd>Blob</kbd>, <kbd>Cache</kbd>, <kbd>Coder</kbd>, <kbd>Configure</kbd>, <kbd>Deprecate</kbd>, <kbd>Exception</kbd>, <kbd>Locale</kbd>, <kbd>Render</kbd>, <kbd>Resource</kbd>, <kbd>Security</kbd>, <kbd>TemporaryFile</kbd>, <kbd>Transform</kbd>, <kbd>X11</kbd>, or <kbd>User</kbd>. </p> 1585 1586 1587<p>For example, to log cache and blob events, use.</p> 1588 1589<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert -debug "Cache,Blob" rose: rose.png</span></p> 1590<p>The <kbd>User</kbd> domain is normally empty, but developers can log user events in their private copy of ImageMagick.</p> 1591 1592<p>To print the complete list of debug methods, use <a href="#list">-list debug</a>.</p> 1593 1594<p>Use the <a href="#log">-log</a> option to specify the format for debugging output.</p> 1595 1596<p>Use <a href="#debug">+debug</a> to turn off all logging.</p> 1597 1598<p>Debugging may also be set using the <kbd>MAGICK_DEBUG</kbd> <a href="/www/resources.html#environment">environment variable</a>. The allowed values for the <kbd>MAGICK_DEBUG</kbd> environment variable are the same as for the <a href="#debug">-debug</a> option.</p> 1599 1600 1601<div style="margin: auto;"> 1602 <h4><a id="decipher"></a>-decipher <em class="arg">filename</em></h4> 1603</div> 1604 1605<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Decipher and restore pixels that were previously transformed by <a href="#encipher">-encipher</a>.</td><td style='text-align:right;'></td></tr></table> 1606 1607<p>Get the passphrase from the file specified by <em class="arg">filename</em>.</p> 1608 1609<p>For more information, see the webpage, <a href="http://www.imagemagick.org/www/cipher.html">ImageMagick: Encipher or Decipher an Image</a>.</p> 1610 1611 1612<div style="margin: auto;"> 1613 <h4><a id="deconstruct"></a>-deconstruct</h4> 1614</div> 1615 1616<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>find areas that has changed between images </td><td style='text-align:right;'></td></tr></table> 1617 1618<p>Given a sequence of images all the same size, such as produced by <a href="#coalesce">-coalesce</a>, replace the second and later images, with a smaller image of just the area that changed relative to the previous image. </p> 1619 1620<p>The resulting sequence of images can be used to optimize an animation sequence, though will not work correctly for GIF animations when parts of the animation can go from opaque to transparent. </p> 1621 1622<p>This option is actually equivalent to the <a href="#layers">-layers</a> method '<kbd>compare-any</kbd>'. </p> 1623 1624 1625<div style="margin: auto;"> 1626 <h4><a id="define"></a>-define <em class="arg">key</em>{<em class="arg">=value</em>}<em class="arg">...</em></h4> 1627</div> 1628 1629<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>add specific global settings generally used to control 1630coders and image processing operations.</td><td style='text-align:right;'></td></tr></table> 1631 1632<p>This option creates one or more definitions for coders and decoders to use 1633while reading and writing image data. Definitions are generally used to 1634control image file format coder modules, and image processing operations, 1635beyond what is provided by normal means. Defined settings are listed in <a 1636href="#verbose" >-verbose</a> information ("<kbd>info:</kbd>" output format) 1637as "Artifacts". </p> 1638 1639<p>If <em class="arg">value</em> is missing for a definition, an empty-valued 1640definition of a flag is created with that name. This used to control on/off 1641options. Use <a href="#define">+define key</a> to remove definitions 1642previously created. Use <a href="#define">+define "*"</a> to remove all 1643existing definitions.</p> 1644 1645<p>The same 'artifact' settings can also be defined using the <a 1646href="#set" >-set "option:<em class="arg">key</em>" "<em class="arg" 1647>value</em>"</a> option, which also allows the use of <a href="/www/escape.html" >Format and Print Image 1648Properties</a> in the defined value. </p> 1649 1650<p>The <em>option</em> and <em>key</em> are case-independent (they are 1651converted to lowercase for use within the decoders) while the <em>value</em> 1652is case-dependent.</p> 1653 1654<p>Such settings are global in scope, and effect all images and operations. </p> 1655 1656<p>The following definitions are just some of the artifacts that are 1657available:</p> 1658 1659<dl> 1660<dt>dcm:display-range=reset</dt> 1661<dd>Set the display range to the minimum and maximum pixel values for the 1662 DCM image format.</dd> 1663 1664<dt>dot:layout-engine=<em class="arg">value</em></dt> 1665<dd>Set the specify the layout engine for the DOT image format (e.g. 1666 <kbd>neato</kbd>).</dd> 1667 1668<dt>jpeg:extent=<em class="arg">value</em></dt> 1669<dd>Restrict the maximum JPEG file size, for example <kbd>-define 1670 jpeg:extent=400kb</kbd>.</dd> 1671 1672<dt>jpeg:size=<em class="arg">geometry</em></dt> 1673<dd>Set the size hint of a JPEG image, for example, -define jpeg:size=128x128. 1674 It is most useful for increasing performance and reducing the memory 1675 requirements when reducing the size of a large JPEG image.</dd> 1676 1677<dt>jp2:rate=<em class="arg">value</em></dt> 1678<dd>Specify the compression factor to use while writing JPEG-2000 files. The 1679 compression factor is the reciprocal of the compression ratio. The valid 1680 range is 0.0 to 1.0, with 1.0 indicating lossless compression. If defined, 1681 this value overrides the -quality setting. A quality setting of 75 1682 results in a rate value of 0.06641.</dd> 1683 1684<dt>mng:need-cacheoff</dt> 1685 <dd>turn playback caching off for streaming MNG.</dd> 1686 1687<dt>png:bit-depth=<em class="arg">value</em></dt> 1688<dt>png:color-type=<em class="arg">value</em></dt> 1689<dd>desired bit-depth and color-type for PNG output. You can force the PNG 1690 encoder to use a different bit-depth and color-type than it would have 1691 normally selected, but only if this does not cause any loss of image 1692 quality. Any attempt to reduce image quality is treated as an error and no 1693 PNG file is written. E.g., if you have a 1-bit black-and-white image, you 1694 can use these "defines" to cause it to be written as an 8-bit grayscale, 1695 indexed, or even a 64-bit RGBA. But if you have a 16-million color image, 1696 you cannot force it to be written as a grayscale or indexed PNG. If you 1697 wish to do this, you must use the appropriate <a href="#depth">-depth</a>, 1698 <a href="#colors">-colors</a>, or <a href="#type">-type</a> directives to 1699 reduce the image quality prior to using the PNG encoder. Note that in 1700 indexed PNG files, "bit-depth" refers to the number of bits per index, 1701 which can be 1, 2, 4, or 8. In such files, the color samples always have 1702 8-bit depth.</dd> 1703 1704<dt>png:exclude-chunk=<em class="arg">value</em></dt> 1705<dt>png:include-chunk=<em class="arg">value</em></dt> 1706<dd>ancillary chunks to be excluded from or included in PNG output. 1707 1708 <p>The<em class="arg">value</em> can be the name of a PNG chunk-type such 1709 as <em class="arg">bKGD</em>, a comma-separated list of chunk-types, 1710 or the word <em class="arg">all</em> or 1711 the word <em class="arg">none</em>. There must be no spaces in the 1712 list. Although PNG chunk-names are case-dependent, you can use 1713 all lowercase names if you prefer.</p> 1714 1715 <p>As a special case, if the <kbd>sRGB</kbd> chunk is excluded and 1716 the <kbd>gAMA</kbd> chunk is included, the <kbd>gAMA</kbd> chunk will 1717 only be written if gamma is not 1/2.2, since most decoders assume 1718 sRGB and gamma=1/2.2 when no colorspace information is included in 1719 the PNG file. Because the list is processed from left to right, you 1720 can achieve this with a single define:</p> 1721 1722<pre class="text"> 1723 -define png:include-chunk=none,gAMA 1724</pre> 1725 1726 <p>The critical PNG chunks <kbd>IHDR</kbd>, <kbd>PLTE</kbd>, 1727 <kbd>IDAT</kbd>, and <kbd>IEND</kbd> cannot be excluded. Any of 1728 these entries appearing in the list will be ignored.</p> 1729 1730 <p>If the ancillary PNG <kbd>tRNS</kbd> chunk is excluded and the 1731 image has transparency, the PNG colortype is forced to be 4 or 6 1732 (GRAY_ALPHA or RGBA). If the image is not transparent, then the 1733 <kbd>tRNS</kbd> chunk isn't written anyhow, and there is no effect 1734 on the PNG colortype of the output image.</p> 1735 1736 <p>The <a href="#strip">-strip</a> option does the equivalent of the 1737 following for PNG output:</p> 1738 1739<pre class="text"> 1740 -define png:include-chunk=none,gama 1741</pre> 1742 1743 <p>The default behavior is to include all known PNG ancillary chunks 1744 plus ImageMagick's private <kbd>vpAg</kbd> ("virtual page") chunk, 1745 and to exclude all PNG chunks that are unknown to ImageMagick, 1746 regardless of their PNG "copy-safe" status as described in the 1747 PNG specification.</p> 1748 </dd> 1749 1750<dt>ps:imagemask</dt> 1751<dd>If the ps:imagemask flag is defined, the PS3 and EPS3 coders will create 1752 Postscript files that render bilevel images with the Postscript imagemask 1753 operator instead of the image operator.</dd> 1754 1755<dt>quantum:format=<em class="arg">type</em></dt> 1756<dd>Set the type to <kbd>floating-point</kbd> to specify a floating-point 1757 format for raw files (e.g. GRAY:) or for MIFF and TIFF images in HDRI mode 1758 to preserve negative values. If <a href="#depth">-depth</a> 16 is 1759 included, the result is a single precision floating point format. 1760 If <a href="#depth">-depth</a> 32 is included, the result is 1761 double precision floating point format.</dd> 1762 1763</dl> 1764 1765<p>For example, to create a postscript file that will render only the black 1766pixels of a bilevel image, use:</p> 1767 1768<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert bilevel.tif -define ps:imagemask eps3:stencil.ps</span></p> 1769<p>Set attributes of the image registry by prefixing the value with 1770<kbd>registry:</kbd>. For example, to set a temporary path to put work files, 1771use:</p> 1772 1773<p class="crtsnip"> 1774-define registry:temporary-path=/data/tmp 1775</p> 1776 1777 1778 1779<div style="margin: auto;"> 1780 <h4><a id="delay"></a>-delay <em class="arg">ticks</em> <br />-delay <em class="arg">ticks</em>x<em class="arg">ticks-per-second</em> {<em class="arg"><</em>} {<em class="arg">></em>}</h4> 1781</div> 1782 1783<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>display the next image after pausing.</td><td style='text-align:right;'></td></tr></table> 1784 1785<p>This option is useful for regulating the animation of image sequences <em>ticks/ticks-per-second</em> seconds must expire before the display of the next image. The default is no delay between each showing of the image sequence. The default ticks-per-second is 100.</p> 1786 1787<p>Use <kbd>></kbd> to change the image delay <em>only</em> if its current value exceeds the given delay. <kbd><</kbd> changes the image delay <em>only</em> if current value is less than the given delay. For example, if you specify <kbd>30></kbd> and the image delay is 20, the image delay does not change. However, if the image delay is 40 or 50, the delay it is changed to 30. Enclose the given delay in quotation marks to prevent the <kbd><</kbd> or <kbd>></kbd> from being interpreted by your shell as a file redirection.</p> 1788 1789 1790<div style="margin: auto;"> 1791 <h4><a id="delete"></a>-delete <em class="arg">index</em></h4> 1792</div> 1793 1794<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>delete the image, specified by its index, from the image sequence.</td><td style='text-align:right;'></td></tr></table> 1795 1796<p>Specify the image by its index in the sequence. The first image is index 0. Negative indexes are relative to the end of the sequence, for example, -1 represents the last image of the sequence. Specify a range of images with a dash (e.g. 0-4). Separate indexes with a comma (e.g. 0,2). Use <kbd>+delete</kbd> to delete the last image in the current image sequence.</p> 1797 1798 1799<div style="margin: auto;"> 1800 <h4><a id="density"></a>-density <em class="arg">width</em><br />-density <em class="arg">width</em>x<em class="arg">height</em></h4> 1801</div> 1802 1803<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the horizontal and vertical resolution of an image for rendering to devices.</td><td style='text-align:right;'></td></tr></table> 1804 1805<p>This option specifies the image resolution to store while encoding a raster image or the canvas resolution while rendering (reading) vector formats such as Postscript, PDF, WMF, and SVG into a raster image. Image resolution provides the unit of measure to apply when rendering to an output device or raster image. The default unit of measure is in dots per inch (DPI). The <a href="#units">-units</a> option may be used to select dots per centimeter instead.</p> 1806 1807<p>The default resolution is 72 dots per inch, which is equivalent to one point per pixel (Macintosh and Postscript standard). Computer screens are normally 72 or 96 dots per inch, while printers typically support 150, 300, 600, or 1200 dots per inch. To determine the resolution of your display, use a ruler to measure the width of your screen in inches, and divide by the number of horizontal pixels (1024 on a 1024x768 display).</p> 1808 1809<p>If the file format supports it, this option may be used to update the stored image resolution. Note that Photoshop stores and obtains image resolution from a proprietary embedded profile. If this profile is not stripped from the image, then Photoshop will continue to treat the image using its former resolution, ignoring the image resolution specified in the standard file header.</p> 1810 1811<p>The <a href="#density">-density</a> option sets an <em>attribute</em> and does not alter the underlying raster image. It may be used to adjust the rendered size for desktop publishing purposes by adjusting the scale applied to the pixels. To resize the image so that it is the same size at a different resolution, use the <a href="#resample">-resample</a> option.</p> 1812 1813<div style="margin: auto;"> 1814 <h4><a id="depth"></a>-depth <em class="arg">value</em></h4> 1815</div> 1816 1817<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>depth of the image.</td><td style='text-align:right;'></td></tr></table> 1818 1819<p>This the number of bits in a color sample within a pixel. Use this option to specify the depth of raw images whose depth is unknown such as GRAY, RGB, or CMYK, or to change the depth of any image after it has been read.</p> 1820 1821<div style="margin: auto;"> 1822 <h4><a id="descend"></a>-descend</h4> 1823</div> 1824 1825<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>obtain image by descending window hierarchy.</td><td style='text-align:right;'></td></tr></table> 1826 1827<div style="margin: auto;"> 1828 <h4><a id="deskew"></a>-deskew <em class="arg">threshold</em></h4> 1829</div> 1830 1831<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>straighten an image. A threshold of 40% works for most images.</td><td style='text-align:right;'></td></tr></table> 1832 1833<p>Use <a href="#set">-set</a> <kbd>option:deskew:auto-crop <em>width</em></kbd> to auto crop the image. The set argument is the pixel width of the image background (e.g 40).</p> 1834 1835<div style="margin: auto;"> 1836 <h4><a id="despeckle"></a>-despeckle</h4> 1837</div> 1838 1839<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>reduce the speckles within an image.</td><td style='text-align:right;'></td></tr></table> 1840 1841<div style="margin: auto;"> 1842 <h4><a id="direction"></a>-direction <em class="arg">type</em></h4> 1843</div> 1844 1845<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>render text right-to-left or left-to-right.</td><td style='text-align:right;'></td></tr></table> 1846 1847<div style="margin: auto;"> 1848 <h4><a id="displace"></a>-displace <em class="arg">horizontal-scale</em><br />-displace <em class="arg">horizontal-scale</em>x<em class="arg">vertical-scale</em></h4> 1849</div> 1850 1851<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>shift image pixels as defined by a displacement map.</td><td style='text-align:right;'>[<a href="/www/composite.html">composite</a>]</td></tr></table> 1852 1853<p>With this option, the 'overlay' image, and optionally the 'mask' image, 1854is used as a displacement map, which is used to displace the lookup of 1855what part of the 'background' image is seen at each point of the overlaid 1856area. Much like the displacement map is a 'lens' that redirects light shining 1857through it so as to present a distorted view the original 'background' image 1858behind it. </p> 1859 1860<p>Any perfect grey areas of the displacement map produce a zero 1861displacement of the image. Black areas produce the given maximum negative 1862displacement of the lookup point, while white produce a maximum positive 1863displacement of the lookup. </p> 1864 1865<p>Note that it is the lookup of the 'background' that is displaced, not a 1866displacement of the image itself. As such an area of the displacement map 1867containing 'white' will have the lookup point 'shifted' by a positive amount, 1868and thus generating a copy of the destination image to the right/downward from 1869the correct position. That is the image will look like it may have been 1870'shifted' in a negative left/upward direction. Understanding this is a very 1871important in understanding how displacement maps work. </p> 1872 1873<p>The given arguments define the maximum amount of displacement in pixels 1874that a particular map can produce. If the displacement scale is large enough 1875it is also possible to lookup parts of the 'background' image that lie well 1876outside the bounds of the displacement map itself. That is you could very 1877easily copy a section of the original image from outside the overlay area 1878into the overlay area. </p> 1879 1880<p>The '%' flag makes the displacement scale relative to the size of the 1881overlay image (100% = half width/height of image). Using '!' switches 1882percentage arguments to refer to the destination image size instead. 1883these flags were added as of IM v6.5.3-5.</p> 1884 1885<p>Normally a single grayscale displacement map is provided, which with the 1886given scaling values will determine a single direction (vector) in which 1887displacements can occur (positively or negatively). However, if you also 1888specify a third image which is normally used as a <em class="arg">mask</em>, 1889the <em class="arg">composite image</em> is used for horizontal X 1890displacement, while the <em class="arg">mask image</em> is used for vertical Y 1891displacement. This allows you to define completely different displacement 1892values for the X and Y directions, and allowing you to lookup any point within 1893the <em class="arg">scale</em> bounds. In other words each pixel can lookup 1894any other nearby pixel, producing complex 2 dimensional displacements, rather 1895than a simple 1 dimensional vector displacements. </p> 1896 1897<p>Alteratively rather than suppling two separate images, as of IM v6.4.4-0, 1898you can use the 'red' channel of the overlay image to specify the horizontal 1899or X displacement, and the 'green' channel for the vertical or Y displacement. 1900</p> 1901 1902<p>As of IM v6.5.3-5 any alpha channel in the overlay image is used as a 1903mask the transparency of the destination image. However areas outside the 1904overlaid areas will not be effected. </p> 1905 1906 1907<div style="margin: auto;"> 1908 <h4><a id="display"></a>-display <em class="arg">host:display[.screen]</em></h4> 1909</div> 1910 1911<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Specifies the X server to contact.</td><td style='text-align:right;'>[<a href="/www/animate.html">animate</a>, <a href="/www/display.html">display</a>]</td></tr></table> 1912 1913<p>This option is used with convert for obtaining image or font from this X server. See <em class="arg">X(1)</em>.</p> 1914 1915<div style="margin: auto;"> 1916 <h4><a id="dispose"></a>-dispose <em class="arg">method</em></h4> 1917</div> 1918 1919<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>define the GIF disposal image setting for images that are being created or read in. </td><td style='text-align:right;'></td></tr></table> 1920 1921<p>The layer disposal method defines the way each the displayed image is to be 1922modified after the current 'frame' of an animation has finished being 1923displayed (after its 'delay' period), but before the next frame on an 1924animation is to be overlaid onto the display. </p> 1925 1926<p>Here are the valid methods:</p> 1927 1928<pre class="text"> 1929Undefined 0 No disposal specified (equivalent to '<kbd>none</kbd>'). 1930None 1 Do not dispose, just overlay next frame image. 1931Background 2 Clear the frame area with the background color. 1932Previous 3 Clear to the image prior to this frames overlay. 1933</pre> 1934 1935<p>You can also use the numbers given above, which is what the GIF format 1936uses internally to represent the above settings. </p> 1937 1938<p>To print a complete list of dispose methods, use <a href="#list">-list dispose</a>.</p> 1939 1940<p>Use <a href="#dispose" >+dispose</a>, turn off the setting and prevent 1941resetting the layer disposal methods of images being read in. </p> 1942 1943<p>Use <a href="#set">-set</a> '<kbd>dispose</kbd>' method to set the image 1944disposal method for images already in memory.</p> 1945 1946<div style="margin: auto;"> 1947 <h4><a id="dissimilarity-threshold"></a>-dissimilarity-threshold <em class="arg">value</em></h4> 1948</div> 1949 1950<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>maximum RMSE for subimage match (default 0.2).</td><td style='text-align:right;'>[<a href="/www/compare.html">compare</a>]</td></tr></table> 1951 1952 1953<div style="margin: auto;"> 1954 <h4><a id="dissolve"></a>-dissolve <em class="arg">src_percent</em>[x<em class="arg">dst_percent</em>]</h4> 1955</div> 1956 1957<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>dissolve an image into another by the given percent.</td><td style='text-align:right;'>[<a href="/www/composite.html">composite</a>]</td></tr></table> 1958 1959<p>The opacity of the composite image is multiplied by the given percent, then 1960it is composited 'over' the main image. If <em class="arg">src_percent</em> 1961is greater than 100, start dissolving the main image so it becomes 1962transparent at a value of '<kbd class="arg">200</kbd>'. If both percentages 1963are given, each image are dissolved to the percentages given. </p> 1964 1965<p>Note that dissolve percentages do not add, two opaque images dissolved 1966'50,50', produce a 75% transparency. For a 50% + 50% blending of the two 1967images, you would need to use dissolve values of '50,100'. </p> 1968 1969<div style="margin: auto;"> 1970 <h4><a id="distort"></a>-distort <em class="arg">method arguments</em></h4> 1971</div> 1972 1973<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>distort an image, using the given <em class="arg">method</em> and its required <em class="arg">arguments</em>.</td><td style='text-align:right;'></td></tr></table> 1974 1975<p>The <em class="arg">arguments</em> is a single string containing a list 1976of floating point numbers separated by commas or spaces. The number of 1977and meaning of the floating point values depends on the distortion <em 1978class="arg">method</em> being used. </p> 1979 1980<p>Choose from these distortion types:</p> 1981 1982<table class="doc"> 1983 <tr valign="top"> 1984 <th align="left" style="width: 8%">Method</th> 1985 <th align="left">Description</th> 1986 </tr> 1987 1988 <tr valign="top"> 1989 <td valign="top"><kbd>ScaleRotateTranslate</kbd> 1990 <br/>or <kbd>SRT</kbd></td> 1991 <td valign="top"> 1992 Distort image by first scaling and rotating about a given 'center', 1993 before translating that 'center' to the new location, in that order. It 1994 is an alternative method of specifying a '<kbd>Affine</kbd>' type of 1995 distortion, but without shearing effects. It also provides a good way 1996 of rotating and displacing a smaller image for tiling onto a larger 1997 background (IE 2-dimensional animations). <br/> 1998 1999 The number of arguments determine the specific meaning of each 2000 argument for the scales, rotation, and translation operations. <br/> 2001 2002 <table style="margin-left:auto; margin-right:auto;"> 2003 <tr><td># </td><td>arguments meaning</td></tr> 2004 <tr><td>1:</td><td><em>Angle_of_Rotation</em></td></tr> 2005 <tr><td>2:</td><td><em>Scale Angle</em></td></tr> 2006 <tr><td>3:</td><td><em>X,Y Angle</em></td></tr> 2007 <tr><td>4:</td><td><em>X,Y Scale Angle</em></td></tr> 2008 <tr><td>5:</td> 2009 <td><em>X,Y ScaleX,ScaleY Angle</em></td></tr> 2010 <tr><td>6:</td> 2011 <td><em>X,Y Scale Angle NewX,NewY</em></td></tr> 2012 <tr><td>7:</td> 2013 <td><em>X,Y ScaleX,ScaleY Angle 2014 NewX,NewY</em></td></tr> 2015 </table> 2016 2017 This is actually an alternative way of specifying a 2 dimensional linear 2018 '<kbd>Affine</kbd>' or '<kbd>AffineProjection</kbd>' distortion. </td> </tr> 2019 2020 <tr valign="top"> 2021 <td valign="top"><kbd>Affine</kbd></td> 2022 <td valign="top"> 2023 Distort the image linearly by moving a list of at least 3 or more sets 2024 of control points (as defined below). Ideally 3 sets or 12 floating 2025 point values are given allowing the image to be linearly scaled, 2026 rotated, sheared, and translated, according to those three points. See 2027 also the related '<kbd>AffineProjection</kbd>' and '<kbd>SRT</kbd>' 2028 distortions. <br/> 2029 2030 More than 3 sets given control point pairs (12 numbers) is least 2031 squares fitted to best match a lineary affine distortion. If only 2 2032 control point pairs (8 numbers) are given a two point image translation 2033 rotation and scaling is performed, without any possible shearing, 2034 flipping or changes in aspect ratio to the resulting image. If only one 2035 control point pair is provides the image is only translated, (which may 2036 be a floating point non-integer translation). <br/> 2037 2038 This distortion does not include any form of perspective distortion. 2039 </td> 2040 2041 </tr> 2042 2043 <tr valign="top"> 2044 <td valign="top"><kbd>AffineProjection</kbd></td> 2045 <td valign="top"> 2046 Linearly distort an image using the given Affine Matrix of 6 2047 pre-calculated coefficients forming a set of Affine Equations to map 2048 the source image to the destination image. 2049 2050 <div style="text-align: center"><em> 2051 s<sub>x</sub>, r<sub>x</sub>, 2052 r<sub>y</sub>, s<sub>y</sub>, 2053 t<sub>x</sub>, t<sub>y</sub> 2054 </em></div> 2055 2056 See <a href="#affine" >-affine</a> setting for more detail, and 2057 meanings of these coefficients. <br/> 2058 2059 The distortions '<kbd>Affine</kbd>' and '<kbd>SRT</kbd>' provide 2060 alternative methods of defining this distortion, with ImageMagick doing 2061 the calculations needed to generate the required coefficients. You can 2062 see the internally generated coefficients, by using a <a 2063 href="#verbose" >-verbose</a> setting with those other varients. </td> 2064 2065 </tr> 2066 2067 <tr valign="top"> 2068 <td valign="top"><kbd>BilinearForward</kbd><br/> 2069 <kbd>BilinearReverse</kbd></td> 2070 <td valign="top"> 2071 Bilinear Distortion, given a minimum of 4 sets of coordinate pairs, or 2072 16 values (see below). Not that lines may not appear straight after 2073 distortion, though the distance between coordinates will remain 2074 consistent. <br/> 2075 2076 The '<kbd>BilinearForward</kbd>' is used to map rectangles to any 2077 quadrilateral, while the '<kbd>BilinearReverse</kbd>' form maps any 2078 quadrilateral to a rectangle, while preserving the straigth line edges 2079 in each case. <br/> 2080 2081 Note that '<kbd>BilinearForward</kbd>' can generate invalid pixels 2082 which will be colored using the <a href="#mattecolor" >-mattecolor</a> 2083 color setting. Also if the quadraterial becomes 'flipped' the image 2084 may dissappear. <br/> 2085 2086 There are future plans to produce a true Bilinear distortion that will 2087 attempt to map any quadrilateral to any other quadrilateral, while 2088 preserving edges (and edge distance ratios). 2089 2090 </td> 2091 </tr> 2092 2093 <tr valign="top"> 2094 <td valign="top"><kbd>Perspective</kbd></td> 2095 <td valign="top"> 2096 Perspective distort the images, using a list of 4 or more sets of 2097 control points (as defined below). More that 4 sets (16 numbers) of 2098 control points provide least squares fitting for more accurate 2099 distortions (for the purposes of image registration and panarama 2100 effects). Less than 4 sets will fall back to a '<kbd>Affine</kbd>' 2101 linear distortion. <br/> 2102 2103 Perspective Distorted images ensures that straight lines remain 2104 straight, but the scale of the distorted image will vary. The horizon 2105 is anti-aliased, and the 'sky' color may be set using the 2106 <a href="#mattecolor" >-mattecolor</a> setting. </td> 2107 </tr> 2108 2109 <tr valign="top"> 2110 <td valign="top"><kbd>PerspectiveProjection</kbd> </td> 2111 <td valign="top"> 2112 Do a '<kbd>Perspective</kbd>' distortion biased on a set of 8 2113 pre-calculated coefficients. You can get these coefficients by looking 2114 at the <a href="#verbose" >-verbose</a> output of a 2115 '<kbd>Prespective</kbd>' distortion, or by calculating them yourself. 2116 If the last two perspective scaling coefficients are zero, the 2117 remaining 6 represents a transposed 'Affine Matrix'. </td> 2118 2119 </tr> 2120 2121 <tr valign="top"> 2122 <td valign="top"><kbd>Arc</kbd></td> 2123 <td valign="top"> 2124 Arc the image (variation of polar mapping) over the angle given around 2125 a circle. <br/> 2126 <table width="90%" style = "margin-left: auto; margin-right: auto;"> 2127 <tr valign="top"><td>Argument</td> 2128 <td>Meaning</td></tr> 2129 <tr valign="top"><td><em>arc_angle</em></td> 2130 <td>The angle over which to arc the image side-to-side</td></tr> 2131 <tr valign="top"><td><em>rotate_angle</em></td> 2132 <td>Angle to rotate resulting image from vertical center</td></tr> 2133 <tr valign="top"><td><em>top_radius</em></td> 2134 <td>Set top edge of source image at this radius</td></tr> 2135 <tr valign="top"><td><em>bottom_radius</em> </td> 2136 <td>Set bottom edge to this radius (radial scaling)</td></tr> 2137 </table> 2138 2139 The resulting image is always resized to best fit the resulting image, 2140 (as if using <a href="#distort" >+distort</a>) while attempting to 2141 preserve scale and aspect ratio of the original image as much as 2142 possible with the arguments given by the user. All four arguments will 2143 be needed to change the overall aspect ratio of an 'Arc'ed image. <br/> 2144 2145 This a variation of a polar distortion designed to try to preserve the 2146 aspect ratio of the image rather than direct Cartesian to Polar 2147 conversion. </td> 2148 </tr> 2149 2150 <tr valign="top"> 2151 <td valign="top"><kbd>Polar</kbd></td> 2152 <td valign="top"> 2153 Like '<kbd>Arc</kbd>' but do a complete Cartesian to Polar mapping of 2154 the image. that is the height of the input image is mapped to the 2155 radius limits, while the width is wrapped around between the 2156 angle limits. <br/> 2157 2158 Arguments: <em>Rmax,Rmin CenterX,CenterY, start,end_angle</em> <br/> 2159 2160 All arguments are optional. With <em>Rmin</em> defaulting to zero, the 2161 center to the center of the image, and the angles going from -180 (top) 2162 to +180 (top). If <em>Rmax</em> is given the special value of 2163 '<code>0</code>', the the distance from the center to the nearest edge 2164 is used for the radius of the output image, which will ensure the whole 2165 image is visible (though scaled smaller). However a special value of 2166 '<code>-1</code>' will use the distance from the center to the furthest 2167 corner, This may 'clip' the corners from the input rectangular image, 2168 but will generate the exact reverse of a '<kbd>DePolar</kbd>' with 2169 the same arguments. <br/> 2170 2171 If the plus form of distort (<a href="#distort" >+distort</a>) is used 2172 output image center will default to <code>0,0</code> of the virtual 2173 canvas, and the image size adjusted to ensure the whole input image is 2174 made visible in the output image on the virtual canvas. </td> 2175 2176 </tr> 2177 2178 <tr valign="top"> 2179 <td valign="top"><kbd>DePolar</kbd></td> 2180 <td valign="top"> 2181 Uses the same arguments and meanings as a '<kbd>Polar</kbd>' distortion 2182 but generates the reverse Polar to Cartesian distortion. <br/> 2183 2184 The special <em>Rmax</em> setting of '<code>0</code>' may however clip 2185 the corners of the input image. However using the special 2186 <em>Rmax</em> setting of '<code>-1</code>' (maximum center to corner 2187 distance) will ensure the whole distorted image is preserved in the 2188 generated result, so that the same argument to '<kbd>Polar</kbd>' will 2189 reverse the distortion re-producing the original. 2190 2191 Note that as this distortion requires the area resampling of a circular 2192 arc, which can not be handled by the builtin EWA resampling function. 2193 As such the normal EWA filters are turned off. It is recommended some 2194 form of 'super-sampling' image processing technique be used to produce 2195 a high quality result. </td> 2196 2197 </tr> 2198 2199 <tr valign="top"> 2200 <td valign="top"><kbd>Barrel</kbd></td> 2201 <td valign="top"> 2202 Given the four coefficients (A,B,C,D) as defined by <a 2203 href="http://wiki.panotools.org/Lens_correction_model" >Helmut 2204 Dersch</a>, perform a barrell or pin-cushion distortion appropriate to 2205 correct radial lens distortions. That is in photographs, make straight 2206 lines straight again. <br/> 2207 2208 Arguments: <em>A B C</em> [ <em>D</em> [ 2209 <em>X</em> , <em>Y</em> ] ] <br/> 2210 or <em>A<sub>x</sub> B<sub>x</sub> C<sub>x</sub> D<sub>x</sub> 2211 A<sub>y</sub> B<sub>y</sub> C<sub>y</sub> D<sub>y</sub></em> 2212 [ <em>X</em> , <em>Y</em> ] <br/> 2213 So that it forms the function <br/> 2214 Rsrc = r * ( <em>A</em>*r<sup>3</sup> + <em>B</em>*r<sup>2</sup> + 2215 <em>C</em>*r + <em>D</em> )<br/> 2216 2217 Where <em>X</em>,<em>Y</em> is the optional center of the distortion 2218 (defaulting to the center of the image). <br/> 2219 The second form is typically used to distort images, rather than 2220 correct lens distortions. <br/> 2221 </td> 2222 2223 </tr> 2224 2225 <tr valign="top"> 2226 <td valign="top"><kbd>BarrelInverse</kbd></td> 2227 <td valign="top"> 2228 This is very simular to '<kbd>Barrel</kbd>' with the same set of 2229 arguments, and argument handling. However it uses the inverse 2230 of the radial polynomial, 2231 so that it forms the function <br/> 2232 Rsrc = r / ( <em>A</em>*r<sup>3</sup> + <em>B</em>*r<sup>2</sup> + 2233 <em>C</em>*r + <em>D</em> )<br/> 2234 Note that this is not the reverse of the '<kbd>Barrel</kbd>' 2235 distortion, just a different barrel-like radial distortion method. 2236 2237 </td> 2238 </tr> 2239 2240 <tr valign="top"> 2241 <td valign="top"><kbd>Shepards</kbd></td> 2242 <td valign="top"> 2243 Distort the given list control points (any number) using an Inverse 2244 Squared Distance Interpolation Method (<a 2245 href="http://en.wikipedia.org/wiki/Shepard%27s_method" >Shepards 2246 Method</a>). The control points in effect do 'localized' displacement 2247 of the image around the given control point (preserving the look and 2248 the rotation of the area near the control points. For best results 2249 extra control points should be added to 'lock' the positions of the 2250 corners, edges and other unchanging parts of the image, to prevent 2251 their movement. <br/> 2252 2253 The distortion has been likened to 'taffy pulling' using nails, or 2254 pins' stuck in a block of 'jelly' which is then moved to the new 2255 position, distorting te surface of the jelly. <br/> 2256 2257 Internally it is equivelent to generating a displacement map (see <a 2258 href="#displace" >-displace</a>) for source image color look-up using 2259 the <a href="#sparse-color" >-sparse-color</a> method of the same name. 2260 2261 </td> 2262 </tr> 2263 2264</table> 2265 2266<p>To print a complete list of distortion methods, use <a href="#list">-list 2267distort</a>.</p> 2268 2269<p>Many of the above distortion methods such as '<kbd>Affine</kbd>', 2270'<kbd>Perspective</kbd>', and '<kbd>Shepards</kbd>' use a list control points 2271defining how these points in the given image should be distorted in the 2272destination image. Each set of four floating point values represent a source 2273image coordinate, followed immediately by the destination image coordinate. 2274This produces a list of values such as...</p> 2275<div style="text-align: center"><em> 2276 U<sub>1</sub>,V<sub>1</sub> X<sub>1</sub>,Y<sub>1</sub> 2277 U<sub>2</sub>,V<sub>2</sub> X<sub>2</sub>,Y<sub>2</sub> 2278 U<sub>3</sub>,V<sub>3</sub> X<sub>3</sub>,Y<sub>3</sub> 2279 ... 2280 U<sub>n</sub>,V<sub>n</sub> X<sub>n</sub>,Y<sub>n</sub> 2281</em></div> 2282<p>where <em>U,V</em> on the source image is mapped to <em>X,Y</em> on the 2283destination image. </p> 2284 2285<p>For example, to warp an image using '<kbd>perspective</kbd>' distortion, 2286needs a list of at least 4 sets of coordinates, or 16 numbers. Here is the 2287perspective distortion of the built-in "rose:" image. Note how spaces were 2288used to group the 4 sets of coordinate pairs, to make it easier to read and 2289understand.</p> 2290 2291<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'> 2292convert rose: -virtual-pixel black \<br/> 2293 -distort Perspective '0,0,0,0 0,45,0,45 69,0,60,10 69,45,60,35' \<br/> 2294 rose_3d_rotated.gif</span></p> 2295<p>If more that the required number of coordinate pairs are given for 2296a distortion, the distortion method is 'least squares' fitted to produce the 2297best result for all the coordinate pairs given. If less than the ideal number 2298of points are given, the distort will generally fall back to a simpler form of 2299distortion that can handles the smaller number of coordinates (usally a linear 2300'<kbd>Affine</kbd>' distortion). </p> 2301 2302<p>By using more coordinates you can make use of image registration tool to 2303find matching coordinate pairs in overlapping images, so as to improve the 2304'fit' of the distortion. Of course a bad coordinate pair can also make the 2305'fit' worse. Caution is always advised. </p> 2306 2307<p>Colors are acquired from the source image according to the <a 2308href="#interpolate" >-interpolate</a> color lookup setting, when the image is 2309magnified. However if the viewed image is minified (image becomes smaller), 2310a special area resampling function (added ImageMagick v6.3.5-9), is used to 2311produce a higher quality image. For example you can use 2312a '<kbd>perspective</kbd>' distortion to view a infinitely tiled 'plane' all 2313the way to the horizon. </p> 2314 2315<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'> 2316convert -size 90x90 pattern:checkerboard -normalize -virtual-pixel tile \<br/> 2317 -distort perspective '0,0,5,45 89,0,45,46 0,89,0,89 89,89,89,89' \<br/> 2318 checks_tiled.jpg</span></p> 2319<p>Note that a infinitely tiled perspective images involving the horizon can 2320be very slow to generate due to the use of the high quality 'area resampling' 2321function (added ImageMagick v6.3.5-9). You can turn off 'area resampling' 2322using a <a href="#filter" >-filter</a> setting of '<kbd>point</kbd>' 2323(recommended if you plan to use super-sampling instead). </p> 2324 2325<p>If an image generates <i>invalid pixels</i>, such as the 'sky' in the last 2326'<kbd>perspective</kbd>' distortion example, <a href="#distort" >-distort</a> 2327will use the current <a href="#mattecolor" >-mattecolor</a> setting for these 2328pixels. If you do not what these pixels to be visible, set the color to match 2329the rest of the ground. </p> 2330 2331<p>The output image size will by default be the same as the input image. This 2332means that if the part of the distorted image falls outside the viewed area of 2333the 'distorted space', those parts is clipped and lost. However if you use 2334the plus form of the operator (<a href="#distort" >+distort</a>) the operator 2335will attempt (if possible) to show the whole of the distorted image, while 2336retaining a correct 'virtual canvas' offset, for image layering. This offset 2337may need to be removed using <a href="#repage" >+repage</a>, to remove if it 2338is unwanted. </p> 2339 2340<p>You can alternatively specify a special "<kbd><a href="#set" >-set</a> 2341option:distort:viewport {geometry_string}</kbd>" setting which will specify 2342the size and the offset of the generated 'viewport' image of the distorted 2343image space.</p> 2344 2345<p>Adding a "<kbd><a href="#set" >-set</a> option:distort:scale 2346{scale_factor}</kbd>" will scale the output image (viewport or otherwise) by 2347that factor without changing the viewed contents of the distorted image. This 2348can be used either for 'super-sampling' the image for a higher quality result, 2349or for panning and zooming around the image (with appropriate viewport 2350changes, or post-distort cropping and resizing). </p> 2351 2352<p>Setting <a href="#verbose" >-verbose</a> setting, will cause <a 2353href="#distort" >-distort</a> to attempt to output the internal coefficients, 2354and the <a href="#fx" >-fx</a> equivalent to the distortion, for expert study, 2355and debugging purposes. This many not be available for all distorts. </p> 2356 2357<p>Affine rotations and shears (such as '<kbd>SRT</kbd>' distortion), tend to 2358produce a cleaner result that the equivalent <a href="#rotate" >-rotate</a> 2359and/or <a href="#shear" >-shear</a> operation, with more control of due to the 2360above settings. It is algorithmically slower however, though that may not be 2361the case in ImageMagick's implementation. </p> 2362 2363 2364<div style="margin: auto;"> 2365 <h4><a id="dither"></a>-dither <em class="arg">method</em></h4> 2366</div> 2367 2368<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Apply a Riemersma or Floyd-Steinberg error diffusion dither to images when general color reduction is applied via an option, or automagically when saving to specific formats. This enabled by default. </td><td style='text-align:right;'></td></tr></table> 2369 2370<p>Dithering places two or more colors in neighboring pixels so that to the eye a closer approximation of the images original color is reproduced. This reduces the number of colors needed to reproduce the image but at the cost of a lower level pattern of colors. Error diffusion dithers can use any set of colors (generated or user defined) to an image. </p> 2371 2372<p>Dithering is turned on by default, to turn it off use the plus form of the 2373setting, <a href="#dither">+dither</a>. This will also also render PostScript 2374without text or graphic aliasing. Disabling dithering often (but not always) 2375leads to faster process, a smaller number of colors, but more cartoon like 2376image coloring. Generally resulting in 'color banding' effects in areas with 2377color gradients. </p> 2378 2379<p>The color reduction operators <a href="#colors">-colors</a>, <a 2380href="#monochrome">-monochrome</a>, <a href="#remap ">-remap</a>, and <a href="#posterize">-posterize</a>, apply dithering to images using the reduced color set they created. These operators are also used as part of automatic color reduction when saving images to formats with limited color support, such as <kbd>GIF:</kbd>, <kbd>XBM:</kbd>, and others, so dithering may also be used in these cases. </p> 2381 2382<p>Alternatively you can use <a href="#random-threshold">-random-threshold</a> to generate purely random dither. Or use <a href="#ordered-dither">-ordered-dither</a> to apply threshold mapped dither patterns, using uniform color maps, rather than specific color maps. </p> 2383 2384 2385<div style="margin: auto;"> 2386 <h4><a id="draw"></a>-draw <em class="arg">string</em></h4> 2387</div> 2388 2389<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Annotate an image with one or more graphic primitives.</td><td style='text-align:right;'></td></tr></table> 2390 2391<p>Use this option to annotate or decorate an image with one or more graphic primitives. The primitives include shapes, text, transformations, and pixel operations.</p> 2392 2393<p>The shape primitives:</p> 2394 2395<pre class="text"> 2396 point x,y 2397 line x0,y0 x1,y1 2398 rectangle x0,y0 x1,y1 2399 roundRectangle x0,y0 x1,y1 wc,hc 2400 arc x0,y0 x1,y1 a0,a1 2401 ellipse x0,y0 rx,ry a0,a1 2402 circle x0,y0 x1,y1 2403 polyline x0,y0 ... xn,yn 2404 polygon x0,y0 ... xn,yn 2405 bezier x0,y0 ... xn,yn 2406 path path specification 2407 image operator x0,y0 w,h filename 2408</pre> 2409 2410<p>The text primitive:</p> 2411 2412<pre class="text"> 2413 text x0,y0 string 2414</pre> 2415<p>The text gravity primitive:</p> 2416 2417<pre class="text"> 2418 gravity NorthWest, North, NorthEast, West, Center, 2419 East, SouthWest, South, or SouthEast 2420</pre> 2421 2422<p>The text gravity primitive only affects the placement of text and does not interact with the other primitives. It is equivalent to using the <a href="#gravity">-gravity</a> command-line option, except that it is limited in scope to the <a href="#draw">-draw</a> option in which it appears.</p> 2423 2424<p>The transformation primitives:</p> 2425 2426<pre class="text"> 2427 rotate degrees 2428 translate dx,dy 2429 scale sx,sy 2430 skewX degrees 2431 skewY degrees 2432</pre> 2433 2434<p>The pixel operation primitives:</p> 2435 2436<pre class="text"> 2437 color x0,y0 method 2438 matte x0,y0 method 2439</pre> 2440 2441<p>The shape primitives are drawn in the color specified by the preceding <a href="#fill">-fill</a> setting. For unfilled shapes, use <a href="#fill">-fill none</a>. You can optionally control the stroke (the "outline" of a shape) with the <a href="#stroke">-stroke</a> and <a href="#strokewidth">-strokewidth</a> settings.</p> 2442 2443<p>A <kbd>point</kbd> primitive is specified by a single <em>point</em> in the pixel plane, that is, by an ordered pair of integer coordinates, <em>x</em>,<em>y</em>. (As it involves only a single pixel, a <kbd>point</kbd> primitive is not affected by <a href="#stroke">-stroke</a> or <a href="#strokewidth">-strokewidth</a>.)</p> 2444 2445<p>A <kbd>line</kbd> primitive requires a start point and end point.</p> 2446 2447<p>A <kbd>rectangle</kbd> primitive is specified by the pair of points at the upper left and lower right corners.</p> 2448 2449<p>A <kbd>roundRectangle</kbd> primitive takes the same corner points as a <kbd>rectangle</kbd> followed by the width and height of the rounded corners to be removed.</p> 2450 2451<p>The <kbd>circle</kbd> primitive makes a disk (filled) or circle (unfilled). Give the center and any point on the perimeter (boundary).</p> 2452 2453<p>The <kbd>arc</kbd> primitive is used to inscribe an elliptical segment in to a given rectangle. An <kbd>arc</kbd> requires the two corners used for <kbd>rectangle</kbd> (see above) followed by the start and end angles of the arc of the segment segment (e.g. 130,30 200,100 45,90). The start and end points produced are then joined with a line segment and the resulting segment of an ellipse is filled.</p> 2454 2455<p>Use <kbd>ellipse</kbd> to draw a partial (or whole) ellipse. Give the center point, the horizontal and vertical "radii" (the <em>semi-axes</em> of the ellipse) and start and end angles in degrees (e.g. 100,100 100,150 0,360).</p> 2456 2457<p>The <kbd>polyline</kbd> and <kbd>polygon</kbd> primitives require three or more points to define their perimeters. A <kbd>polyline</kbd> is simply a <kbd>polygon</kbd> in which the final point is not stroked to the start point. When unfilled, this is a <em>polygonal line</em>. If the <a href="#stroke">-stroke</a> setting is <kbd>none</kbd> (the default), then a <kbd>polyline</kbd> is identical to a <kbd>polygon</kbd>. 2458</p> 2459 2460<p>A <em>coordinate</em> is a pair of integers separated by a space or optional comma. </p> 2461 2462<p>As an example, to define a circle centered at 100,100 that extends to 150,150 use:</p> 2463 2464<p class="crtsnip"> 2465 -draw 'circle 100,100 150,150' 2466</p> 2467 2468<p>The <kbd>Bezier</kbd> primitive creates a spline curve and requires three or points to define its shape. The first and last points are the <em>knots</em> and these points are attained by the curve, while any intermediate coordinates are <em>control points</em>. If two control points are specified, the line between each end knot and its sequentially respective control point determines the tangent direction of the curve at that end. If one control point is specified, the lines from the end knots to the one control point determines the tangent directions of the curve at each end. If more than two control points are specified, then the additional control points act in combination to determine the intermediate shape of the curve. In order to 2469draw complex curves, it is highly recommended either to use the <kbd>path</kbd> primitive or to draw multiple four-point bezier segments with the start and end knots of each successive segment repeated. For example:</p> 2470 2471<p class="crtsnip"> 2472 -draw 'bezier 20,50 45,100 45,0 70,50' 2473</p> 2474<p class="crtsnip"> 2475 -draw 'bezier 70,50 95,100 95,0 120,50' 2476</p> 2477 2478 2479<p>A <kbd>path</kbd> represents an outline of an object, defined in terms of moveto (set a new current point), lineto (draw a straight line), curveto (draw a Bezier curve), arc (elliptical or circular arc) and closepath (close the current shape by drawing a line to the last moveto) elements. Compound paths (i.e., a path with subpaths, each consisting of a single moveto followed by one or more line or curve operations) are possible to allow effects such as <em>donut holes</em> in objects. (See <a href="http://www.w3.org/TR/SVG/paths.html">Paths</a>.)</p> 2480 2481<p>Use <kbd>image</kbd> to composite an image with another image. Follow the image keyword with the composite operator, image location, image size, and filename:</p> 2482 2483<p class="crtsnip"> 2484 -draw 'image SrcOver 100,100 225,225 image.jpg' 2485</p> 2486 2487<p>You can use 0,0 for the image size, which means to use the actual 2488dimensions found in the image header. Otherwise, it is scaled to the given 2489dimensions. See <a href="/www/compose.html">Alpha Compositing</a> for 2490a detailed discussion of alpha composition methods that are available. </p> 2491 2492<p>Use <kbd>text</kbd> to annotate an image with text. Follow the text coordinates with a string. If the string has embedded spaces, enclose it in single or double quotes.</p> 2493 2494<p>For example, the following annotates the image with <kbd>Works like magick!</kbd> for an image titled <kbd>bird.miff</kbd>. </p> 2495 2496<p class="crtsnip"> 2497 -draw 'text 100,100 "Works like magick!"' 2498</p> 2499 2500<p>See the <a href="#annotate">-annotate</a> option for another convenient way to annotate an image with text.</p> 2501 2502<p>The <kbd>rotate</kbd> primitive rotates subsequent shape primitives and text primitives about the origin of the main image. If the <a href="#region">-region</a> option precedes the <a href="#draw">-draw</a> option, the origin for transformations is the upper left corner of the region.</p> 2503 2504<p>The <kbd>translate</kbd> primitive translates subsequent shape and text primitives.</p> 2505 2506<p>The <kbd>scale</kbd> primitive scales them.</p> 2507 2508<p>The <kbd>skewX</kbd> and <kbd>skewY</kbd> primitives skew them with respect to the origin of the main image or the region.</p> 2509 2510<p>The transformations modify the current affine matrix, which is initialized from the initial affine matrix defined by the <a href="#affine">-affine</a> option. Transformations are cumulative within the <a href="#draw">-draw</a> option. The initial affine matrix is not affected; that matrix is only changed by the appearance of another <a href="#affine">-affine</a> option. If another <a href="#draw">-draw</a> option appears, the current affine matrix is reinitialized from the initial affine 2511matrix.</p> 2512 2513<p>Use the <kbd>color</kbd> primitive to change the color of a pixel to the fill color (see <a href="#fill">-fill</a>). Follow the pixel coordinate with a method:</p> 2514 2515<pre class="text"> 2516 point 2517 replace 2518 floodfill 2519 filltoborder 2520 reset 2521</pre> 2522 2523<p>Consider the target pixel as that specified by your coordinate. The <kbd>point</kbd> method recolors the target pixel. The <kbd>replace</kbd> method recolors any pixel that matches the color of the target pixel. <kbd>Floodfill</kbd> recolors any pixel that matches the color of the target pixel and is a neighbor, whereas <kbd>filltoborder</kbd> recolors any neighbor pixel that is not the border color. Finally, <kbd>reset</kbd> recolors all pixels.</p> 2524 2525<p>Use <kbd>matte</kbd> to the change the pixel matte value to transparent. Follow the pixel coordinate with a method (see the <kbd>color</kbd> primitive for a description of methods). The <kbd>point</kbd> method changes the matte value of the target pixel. The <kbd>replace</kbd> method changes the matte value of any pixel that matches the color of the target pixel. <kbd>Floodfill</kbd> changes the matte value of any pixel that matches the color of the target pixel and is a neighbor, whereas <kbd>filltoborder</kbd> changes the matte value of any neighbor pixel that is not the border color (<a href="#bordercolor">-bordercolor</a>). Finally <kbd>reset</kbd> changes the matte value of all pixels.</p> 2526 2527<p>You can set the primitive color, font, and font bounding box color with <a href="#fill">-fill</a>, <a href="#font">-font</a>, and <a href="#box">-box</a> respectively. Options are processed in command line order so be sure to use these options <em>before</em> the <a href="#draw">-draw</a> option.</p> 2528 2529<p>Strings that begin with a number must be quoted (e.g. use '1.png' rather than 1.png).</p> 2530 2531<p>Drawing primitives conform to the <a href="/www/magick-vector-graphics.html">Magick Vector Graphics</a> format.</p> 2532 2533 2534<div style="margin: auto;"> 2535 <h4><a id="edge"></a>-edge <em class="arg">radius</em></h4> 2536</div> 2537 2538<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>detect edges within an image.</td><td style='text-align:right;'></td></tr></table> 2539 2540<div style="margin: auto;"> 2541 <h4><a id="emboss"></a>-emboss <em class="arg">radius</em></h4> 2542</div> 2543 2544<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>emboss an image.</td><td style='text-align:right;'></td></tr></table> 2545 2546<div style="margin: auto;"> 2547 <h4><a id="encipher"></a>-encipher <em class="arg">filename</em></h4> 2548</div> 2549 2550<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Encipher pixels for later deciphering by <a href="#decipher">-decipher</a>.</td><td style='text-align:right;'></td></tr></table> 2551 2552<p>Get the passphrase from the file specified by <em class="arg">filename</em>.</p> 2553 2554<p>For more information, see the webpage, <a href="http://www.imagemagick.org/www/cipher.html">ImageMagick: Encipher or Decipher an Image</a>.</p> 2555 2556 2557 2558<div style="margin: auto;"> 2559 <h4><a id="encoding"></a>-encoding <em class="arg">type</em></h4> 2560</div> 2561 2562<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>specify the text encoding.</td><td style='text-align:right;'></td></tr></table> 2563 2564<p>Choose from <kbd>AdobeCustom</kbd>, <kbd>AdobeExpert</kbd>, <kbd>AdobeStandard</kbd>, <kbd>AppleRoman</kbd>, <kbd>BIG5</kbd>, <kbd>GB2312</kbd>, <kbd>Latin 2</kbd>, <kbd>None</kbd>, <kbd>SJIScode</kbd>, <kbd>Symbol</kbd>, <kbd>Unicode</kbd>, <kbd>Wansung</kbd>.</p> 2565 2566<div style="margin: auto;"> 2567 <h4><a id="endian"></a>-endian <em class="arg">type</em></h4> 2568</div> 2569 2570<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Specify endianness (<kbd>MSB</kbd> or <kbd>LSB</kbd>) of the image.</td><td style='text-align:right;'></td></tr></table> 2571 2572<p>To print a complete list of endian types, use the <a href="#list">-list endian</a> option.</p> 2573 2574<p>Use <a href="#endian">+endian</a> to revert to unspecified endianness.</p> 2575 2576 2577<div style="margin: auto;"> 2578 <h4><a id="enhance"></a>-enhance</h4> 2579</div> 2580 2581<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Apply a digital filter to enhance a noisy image.</td><td style='text-align:right;'></td></tr></table> 2582 2583 2584<div style="margin: auto;"> 2585 <h4><a id="equalize"></a>-equalize</h4> 2586</div> 2587 2588<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>perform histogram equalization on the image channel-by-channel.</td><td style='text-align:right;'></td></tr></table> 2589 2590<p>To perform histogram equalization on all channels in concert, transform the image into some other color space, such as HSL, OHTA, YIQ or YUV, then equalize the appropriate intensity-like channel, then convert back to RGB.</p> 2591 2592<p>For example using HSL, we have: ... <kbd>-colorspace HSL -channel lightness -equalize -colorspace RGB</kbd> ...</p> 2593 2594<p>For YIQ, YUV and OHTA use the red channel. For example, OHTA is a principal components transformation that puts most of the information in the first channel. Here we have ... <kbd>-colorspace OHTA -channel red -equalize -colorspace RGB</kbd> ...</p> 2595 2596<div style="margin: auto;"> 2597 <h4><a id="evaluate"></a>-evaluate <em class="arg">operator value</em></h4> 2598</div> 2599 2600<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Alter channel pixels by evaluating an arithmetic, relational, or logical expression.</td><td style='text-align:right;'></td></tr></table> 2601 2602<p>(See the <a href="#function" >-function</a> operator for some multi-parameter functions. See the <a href="#fx" >-fx</a> operator if more elaborate calculations are needed.)</p> 2603 2604<p>The behaviors of each <em class="arg">operator</em> are summarized in the following list. For brevity, the numerical value of a "pixel" referred to below is the value of the corresponding channel of that pixel, while a "normalized pixel" is that number divided by the maximum (installation-dependent) value <em class="QR">QuantumRange</em>. (If normalized pixels are used, they are restored, following the other calculations, to the full range by multiplying by <em class="QR">QuantumRange</em>.)</p> 2605 2606<table class="doc"> 2607 <col width="25%" /> 2608 <col width="75%" /> 2609 <thead> 2610 <tr> 2611 <th><em class="arg">operator</em></th> 2612 <th>Summary (see further below for details)</th> 2613 </tr> 2614 </thead> 2615 <tbody> 2616 2617 <tr><td>Abs </td> <td>Add <em class="arg">value</em> to pixels and return absolute value. </td></tr> 2618 <tr><td>Add </td> <td>Add <em class="arg">value</em> to pixels. </td></tr> 2619 <tr><td>AddModulus </td> <td>Add <em class="arg">value</em> to pixels modulo <em class="QR">QuantumRange</em>.</td></tr> 2620 <tr><td>And </td> <td>Binary AND of pixels with <em class="arg">value</em>.</td></tr> 2621 <tr><td>Cos, Cosine </td> <td>Apply cosine to pixels with frequency <em class="arg">value</em> with 50% bias added.</td></tr> 2622 <tr><td>Divide </td> <td>Divide pixels by <em class="arg">value</em>.</td></tr> 2623 <tr><td>Exp </td> <td>base-e exponential function</td></tr> 2624 <tr><td>Exponential </td> <td>base-e exponential function</td></tr> 2625 <tr><td>LeftShift </td> <td>Shift the pixel values left by <em class="arg">value</em> bits (i.e., multiply pixels by 2<sup><em class="arg">value</em></sup>).</td></tr> 2626 <tr><td>Log </td> <td>Apply scaled logarithm to normalized pixels.</td></tr> 2627 <tr><td>Max </td> <td>Clip pixels at lower bound <em class="arg">value</em>.</td></tr> 2628 <tr><td>Mean </td> <td>Add the <em class="arg">value</em> and divide by 2.</td></tr> 2629 <tr><td>Median </td> <td>Choose the median value from an image sequence.</td></tr> 2630 <tr><td>Min </td> <td>Clip pixels at upper bound <em class="arg">value</em>.</td></tr> 2631 <tr><td>Multiply </td> <td>Multiply pixels by <em class="arg">value</em>.</td></tr> 2632 <tr><td>Or </td> <td>Binary OR of pixels with <em class="arg">value</em>.</td></tr> 2633 <tr><td>Pow </td> <td>Raise normalized pixels to the power <em class="arg">value</em>.</td></tr> 2634 <tr><td>RightShift </td> <td>Shift the pixel values right by <em class="arg">value</em> bits (i.e., divide pixels by 2<sup><em class="arg">value</em></sup>).</td></tr> 2635 <tr><td>Set </td> <td>Set pixel equal to <em class="arg">value</em>.</td></tr> 2636 <tr><td>Sin, Sine </td> <td>Apply sine to pixels with frequency <em class="arg">value</em> with 50% bias added.</td></tr> 2637 <tr><td>Subtract </td> <td>Subtract <em class="arg">value</em> from pixels.</td></tr> 2638 <tr><td>Xor </td> <td>Binary XOR of pixels with <em class="arg">value.</em></td></tr> 2639 2640 <tr><td> </td></tr> 2641 2642 <tr><td>Gaussian-noise</td></tr> 2643 <tr><td>Impulse-noise</td></tr> 2644 <tr><td>Laplacian-noise</td></tr> 2645 <tr><td>Multiplicative-noise</td> <td>(These are equivalent to the corresponding <a href="#noise" >-noise</a> operators.)</td></tr> 2646 <tr><td>PoissonNoise</td></tr> 2647 <tr><td>Uniform-noise</td></tr> 2648 2649 <tr><td> </td></tr> 2650 2651 <tr><td>Threshold </td> <td>Threshold pixels larger than <em class="arg">value</em>.</td></tr> 2652 <tr><td>ThresholdBlack </td> <td>Threshold pixels to zero values equal to or below <em class="arg">value</em>.</td></tr> 2653 <tr><td>ThresholdWhite </td> <td>Threshold pixels to maximum values above <em class="arg">value</em>. </td></tr> 2654 </tbody> 2655 </table> 2656 2657<p>The specified functions are applied only to each previously set <a 2658href="#channel" >-channel</a> in the image. If necessary, the results of the 2659calculations are truncated (clipped) to fit in the interval [0, <em 2660class="QR">QuantumRange</em>]. The transparency channel of the image is 2661represented as a 'alpha' values (0 = fully transparent), so, for example, a 2662<kbd>Divide</kbd> by 2 of the alpha channel will make the image 2663semi-transparent. Append the percent symbol '<kbd>%</kbd>' to specify a value 2664as a percentage of the <em class="QR">QuantumRange</em>.</p> 2665 2666<p>To print a complete list of <a href="#evaluate">-evaluate</a> operators, use 2667<a href="#list">-list evaluate</a>.</p> 2668 2669<p>The results of the <kbd>Add</kbd>, <kbd>Subtract</kbd> and 2670<kbd>Multiply</kbd> methods can also be achieved using either the <a 2671href="#level" >-level</a> or the <a href="#level" >+level</a> operator, with 2672appropriate argument, to linearly modify the overall range of color values. 2673Please note, however, that <a href="#level" >-level</a> treats transparency as 2674'matte' values (0 = opaque), while <a href="#level" >-evaluate</a> works with 2675'alpha' values.</p> 2676 2677<p><kbd>AddModulus</kbd> has been added as of ImageMagick 6.4.8-4 and provides addition modulo the <em class="QR">QuantumRange</em>. It is therefore equivalent to <kbd>Add</kbd> unless the resulting pixel value is outside the interval [0, <em class="QR">QuantumRange</em>]. </p> 2678 2679<p><kbd>Exp or Exponential</kbd> has been added as of ImageMagick 6.6.5-1 and works on normalized pixel values. The <em class="arg">value</em> used with <kbd>Exp</kbd> should be negative so as to produce a decaying exponential function. Non-negative values will always produce results larger unity and thus outside the interval [0, <em class="QR">QuantumRange</em>]. The formula is expressed below. </p> 2680 2681 <div style="text-align:center;"> 2682 exp(<em class="arg">value</em> × <b><em>u</em></b>) 2683 </div> 2684 2685<p> If the input image is squared, for example, using <a 2686href="#-function" >-function polynomial "2 0 0"</a>, then a decaying Gaussian function will be the result.</p> 2687 2688<p><kbd>Log</kbd> has been added as of ImageMagick 6.4.2-1 and works on normalized pixel values. This a <em>scaled</em> log function. The <em class="arg">value</em> used with <kbd>Log</kbd> provides a <em>scaling factor</em> that adjusts the curvature in the graph of the log function. The formula applied to a normalized value <b><em>u</em></b> is below. </p> 2689 2690 <div style="text-align:center;"> 2691 log(<em class="arg">value</em> × <b><em>u</em></b> + 1) / log(<em class="arg">value</em> + 1) 2692 </div> 2693 2694<p><kbd>Pow</kbd> has been added as of ImageMagick 6.4.1-9, and works on 2695normalized pixel values. Note that <kbd>Pow</kbd> is related to the <a 2696href="#gamma" >-gamma</a> operator. For example, <b>-gamma 2</b> is equivalent 2697to <b>-evaluate pow 0.5</b>, i.e., a 'square root' function. The value used 2698with <a href="#gamma" >-gamma</a> is simply the reciprocal of the value used 2699with <kbd>Pow</kbd>.</p> 2700 2701<p><kbd>Cosine</kbd> and <kbd>Sine</kbd> was added as of IM v6.4.8-8 and 2702converts the image values into a value according to a (co)sine wave function. 2703The synonyms <kbd>Cos</kbd> and <kbd>Sin</kbd> may also be used. The output 2704is biased 50% and normalized by 50% so as to fit in the respective color value 2705range. The <em class="arg">value</em> scaling of the <em>period</em> of the 2706function (its frequency), and thus determines the number of 'waves' that will 2707be generated over the input color range. For example, if the <em 2708class="arg">value</em> is 1, the effective period is simply the <em 2709class="QR">QuantumRange</em>; but if the <em class="arg">value</em> is 2, 2710then the effective period is the <em>half</em> the <em 2711class="QR">QuantumRange</em>.</p> 2712 2713 <div style="text-align:center;"> 2714 0.5 + 0.5 × cos(2 π <b><em>u</em></b> × <em class="arg">value</em>). 2715 </div> 2716 2717<p>See also the <a href="#function" >-function</a> operator, which is a 2718multi-value version of evaluate. </p> 2719 2720<div style="margin: auto;"> 2721 <h4><a id="evaluate-sequence"></a>-evaluate-sequence <em class="arg">operator</em></h4> 2722</div> 2723 2724<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Alter channel pixels by evaluating an arithmetic, relational, or logical expression over a sequence of images.</td><td style='text-align:right;'></td></tr></table> 2725 2726<div style="margin: auto;"> 2727 <h4><a id="extent"></a>-extent <em class="arg">geometry</em></h4> 2728</div> 2729 2730<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the image size and offset.</td><td style='text-align:right;'></td></tr></table> 2731 2732<p>If the image is enlarged, unfilled areas are set to the background color. To position the image, use offsets in the <em class="arg">geometry</em> specification or precede with a <a href="#gravity">-gravity</a> setting. To specify how to compose the image with the background, use <a href="#compose" >-compose</a>.</p> 2733<p>This command reduces or expands a JPEG image to fit on an 800x600 2734display. If the aspect ratio of the input image isn't exactly 4:3, then the 2735image is centered on an 800x600 black canvas: </p> 2736 2737<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert input.jpg -resize 800x600 -background black -compose Copy \ <br /> -gravity center -extent 800x600 -quality 92 output.jpg</span></p> 2738 2739 2740<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 2741 2742<div style="margin: auto;"> 2743 <h4><a id="extract"></a>-extract <em class="arg">geometry</em></h4> 2744</div> 2745 2746<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Extract the specified area from image.</td><td style='text-align:right;'></td></tr></table> 2747 2748<p>This option is most useful for extracting a subregion of a very large raw image. Note that these two commands are equivalent:</p> 2749 2750<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert -size 16000x16000 -depth 8 -extract 640x480+1280+960 \ <br/> image.rgb image.png</span><span class='crtout'></span><span class="crtprompt"> $magick> </span><span class='crtin'>convert -size 16000x16000 -depth 8 'image.rgb[640x480+1280+960]' \ <br/> image.rgb image.png</span></p><p>If you omit the offsets, as in</p> 2751 2752<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert -size 16000x16000 -depth 8 -extract 640x480 \ <br/> image.rgb image.png</span></p> 2753<p>the image is <em>resized</em> to the specified dimensions instead, 2754equivalent to:</p> 2755 2756<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert -size 16000x16000 -depth 8 -resize 640x480 image.rgb image.png</span></p> 2757<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 2758 2759<div style="margin: auto;"> 2760 <h4><a id="family"></a>-family <em class="arg">fontFamily</em></h4> 2761</div> 2762 2763<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set a font family for text.</td><td style='text-align:right;'></td></tr></table> 2764 2765<p>This setting suggests a font family that ImageMagick should try to use for rendering text. If the family can be found it is used; if not, a default font (e.g., "Arial") or a family known to be similar is substituted (e.g., "Courier" might be used if "System" is requested but not found). 2766</p> 2767 2768<p>For other settings that affect fonts, see the options <a href="#font">-font</a>, <a href="#stretch">-stretch</a>, <a href="#style">-style</a>, and <a href="#weight">-weight</a>. 2769</p> 2770 2771<div style="margin: auto;"> 2772 <h4><a id="features"></a>-features <em class="arg">distance</em></h4> 2773</div> 2774 2775<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>display features for each channel in the image in each of four directions (horizontal, vertical, left and right diagonals) for the specified distance.</td><td style='text-align:right;'></td></tr></table> 2776 2777<div style="margin: auto;"> 2778 <h4><a id="fft"></a>-fft</h4> 2779</div> 2780 2781<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>implements the forward discrete Fourier transform (DFT).</td><td style='text-align:right;'></td></tr></table> 2782 2783<p>This option is new as of ImageMagick 6.5.4-3 (and now working for Windows users in ImageMagick 6.6.0-9). It transforms an image from the normal (spatial) domain to the frequency domain. In the frequency domain, an image is represented as a superposition of complex sinusoidal waves of varying amplitudes. The image x and y coordinates are the possible frequencies along the x and y directions, respectively, and the pixel intensity values are complex numbers that correspond to the sinusoidal wave amplitudes. See for example, <a href="http://en.wikipedia.org/wiki/Fourier_transform">Fourier Transform</a>, <a href="http://en.wikipedia.org/wiki/DFT">Discrete Fourier Transform</a> and <a href="http://en.wikipedia.org/wiki/FFT">Fast Fourier Transform</a>.</p> 2784 2785<p>A single image name is provided as output for this option. However, the output result will have two components. It is either a two-frame image or two separate images, depending upon whether the image format specified supports multi-frame images. The reason that we get a dual output result is because the frequency domain represents an image using complex numbers, which cannot be visualized directly. Therefore, the complex values are automagically separated into a two-component image representation. The first component is the magnitude of the complex number and the second is the phase of the complex number. See for example, <a href="http://en.wikipedia.org/wiki/Complex_numbers">Complex Numbers</a>.</p> 2786 2787<p>The magnitude and phase component images must be specified using image formats that do not limit the color or compress the image. Thus, MIFF, TIF, PFM, EXR and PNG are the recommended image formats to use. All of these formats, except PNG support multi-frame images. So for example,</p> 2788 2789<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert image.png -fft fft_image.miff</span></p> 2790<p>generates a magnitude image as <kbd>fft_image.miff[0]</kbd> and a phase image as <kbd>fft_image.miff[1]</kbd>. Similarly,</p> 2791 2792<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert image.png -fft fft_image.png</span></p> 2793<p>generates a magnitude image as <kbd>fft_image-0.png</kbd> and a phase image as <kbd>fft_image-1.png</kbd>. If you prefer this representation, then you can force any of the other formats to produce two output images by including <a href="#adjoin">+adjoin</a> following -fft in the command line.</p> 2794 2795<p>The input image can be any size, but if not square and even-dimensioned, it is padded automagically to the larger of the width or height of the input image and to an even number of pixels. The padding will occur at the bottom and/or right sides of the input image. The resulting output magnitude and phase images is square at this size. The kind of padding relies on the <a href="#virtual-pixel">-virtual-pixel</a> setting.</p> 2796 2797<p>Both output components will have dynamic ranges that fit within [0, <em class="QR">QuantumRange</em>], so that HDRI need not be enabled. Phase values nominally range from 0 to 2*π, but for non-HDRI compilations of ImageMagick, the phase image is scaled to span the full dynamic range. The magnitude image is not scaled and thus generally will contain very small values. As such, the image normally will appear totally black. In order to view any detail, the magnitude image typically is enhanced with a log function into what is usually called the spectrum. A log function is used to enhance the darker values more in comparison to the lighter values. This can be done, for example, as follows:</p> 2798 2799<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert fft_image.miff[0] -contrast-stretch 0 \ <br /> 2800 -evaluate log 1000 fft_image_spectrum.png</span></p> 2801<p>where the <a href="#contrast-stretch">-contrast-stretch</a> 0 is used to scale the image to full dynamic range, first. The argument to the <a href="#evaluate">-evaluate</a> log typically is specified between 100 and 10,000, depending upon the amount of detail that one wants to bring out in the spectrum. Larger values produce more visible detail. Too much detail, however, may hide the important features.</p> 2802 2803<p>The <a href="http://www.fftw.org/">FFTW</a> delegate library is required to use <a href="#fft">-fft</a>.</p> 2804 2805<p>Use <a href="#fft">+fft</a> to produce two output images that are the real and imaginary components of the complex valued Fourier transform.</p> 2806 2807<p>However, as the real and imaginary components can contain negative values, this requires that IM be configured with HDRI enabled. In this case, you must use either MIFF, TIF or PFM formats for the real and imaginary component results, since they are formats that preserve both negative and fractional values without clipping them or truncating the fractional part.</p> 2808 2809<p>The real and imaginary component images resulting from <a href="#fft">+fft</a> is also square, even dimensioned images due to the same padding that was discussed above for the magnitude and phase component images.</p> 2810 2811<p>See the discussion on HDRI implementations of ImageMagick on the page 2812<a href="/www/high-dynamic-range.html">High Dynamic-Range Images</a>. For more about HDRI go the ImageMagick <a href="http://www.imagemagick.org/Usage/basics/#hdri">Usage</a> pages or this <a href="http://en.wikipedia.org/wiki/High_dynamic_range_imaging">Wikipedia</a> entry. 2813</p> 2814 2815 2816<div style="margin: auto;"> 2817 <h4><a id="fill"></a>-fill <em class="arg">color</em></h4> 2818</div> 2819 2820<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>color to use when filling a graphic primitive.</td><td style='text-align:right;'></td></tr></table> 2821 2822<p>This option accepts a color name, a hex color, or a numerical RGB, RGBA, HSL, HSLA, CMYK, or CMYKA specification. See <a href="/www/color.html">Color Names</a> for a description of how to properly specify the color argument.</p> 2823 2824<p>Enclose the color specification in quotation marks to prevent the "#" or the parentheses from being interpreted by your shell.</p> 2825 2826<p>For example,</p> 2827 2828<p class="crtsnip"> 2829 -fill blue 2830</p> 2831<p class="crtsnip"> 2832 -fill "#ddddff" 2833</p> 2834<p class="crtsnip"> 2835 -fill "rgb(255,255,255)" 2836</p> 2837 2838<p>See <a href="#draw">-draw</a> for further details.</p> 2839 2840<p>To print a complete list of color names, use the <a href="#list">-list color</a> option.</p> 2841 2842<div style="margin: auto;"> 2843 <h4><a id="filter"></a>-filter <em class="arg">type</em></h4> 2844</div> 2845 2846<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Use this <em class="arg">type</em> of filter when resizing or 2847distorting an image.</td><td style='text-align:right;'></td></tr></table> 2848 2849<p>Use this option to affect the resizing operation of an image during 2850operations such as <a href="#resize">-resize</a> and <a href="#distort" 2851>-distort</a>. For example you can use a simple resize filter such as:</p> 2852 2853<pre class="text"> 2854 Point Hermite Cubic 2855 Box Gaussian Catrom 2856 Triangle Quadratic Mitchell 2857</pre> 2858 2859<p>The <kbd>Bessel</kbd> and <kbd>Sinc</kbd> filter is also provided (as well 2860as a faster <kbd>SincFast</kbd> equivalent form). However these filters are 2861generally useless on their own as they are infinite filters that are being 2862clipped to the filters support size. Their direct use is not recommended 2863except via expert settings (see below). </p> 2864 2865<p>Instead these special filter functions are typically windowed by a windowing 2866function that the <a href="#filter" >-filter</a> setting defines. That is 2867using these functions will define a 'Windowed' filter, appropriate to the 2868operator involved. Windowed filters include: </p> 2869 2870<pre class="text"> 2871 Lanczos Hamming Parzen 2872 Blackman Kaiser Welsh 2873 Hanning Bartlett Bohman 2874</pre> 2875 2876<p>Also one special self-windowing filter is also provided 2877<kbd>Lagrange</kbd>, which will automagically re-adjust its function depending 2878on the current 'support' or 'lobes' expert settings (see below).</p> 2879 2880<p>If you do not select a filter with this option, the filter defaults to 2881<kbd>Mitchell</kbd> for a colormapped image, a image with a matte channel, or 2882if the image is enlarged. Otherwise the filter default to 2883<kbd>Lanczos</kbd>.</p> 2884 2885<p>To print a complete list of resize filters, use the <a href="#list">-list 2886filter</a> option.</p> 2887 2888<p>You can modify how the filter behaves as it scales your image through the 2889use of these expert settings (see also <a href="#define" >-define</a> and <a 2890href="#set" >-set</a>):-</p> 2891 2892<dl class="doc"> 2893<dt>-define filter:blur=<em>factor</em></dt> 2894<dd>Scale the X axis of the filter (and its window). Use > 1.0 for 2895 blurry or < 1.0 for sharp. This should only be used with Gaussian and 2896 Gaussian-like filters simple filters, or you may not get the expected 2897 results. </dd> 2898 2899<dt>-define filter:support=<em>radius</em></dt> 2900<dd>Set the filter support radius. Defines how large the filter should be and 2901 thus directly defines how slow the filtered resampling process is. All 2902 filters have a default 'prefered' support size. Some filters like 2903 <kbd>Lagrange</kbd> and windowed filters adjust themselves depending on 2904 this value. With simple filters this value either does nothing (but slow 2905 the resampling), or will clip the filter function in a detrimental way. 2906 </dd> 2907 2908<dt>-define filter:lobes=<em>count</em></dt> 2909<dd>Set the number of lobes to use for the Sinc/Bessel filter. This an 2910 alternative way of specifying the 'support' range of the filter, that is 2911 designed to be more suited to windowed filters, especially when used for 2912 image distorts.</dd> 2913 2914<dt>-define filter:b=<em>b-spline_factor</em></dt> 2915<dt>-define filter:c=<em>keys_alpha_factor</em></dt> 2916<dd>Redefine the values used for cubic filters such as <kbd>Cubic</kbd>, 2917 <kbd>Catrom</kbd>, <kbd>Mitchel</kbd>, and <kbd>Hermite</kbd>, as well as 2918 the <kbd>Parzen</kbd> Sinc windowing function. If only one of the values 2919 are defined, the other is set so as to generate a 'Keys' type cubic 2920 filter. Values meaning was defined by a research paper by 2921 Mitchell-Netravali.</dd> 2922 2923<dt>-define filter:filter=<em>filter_function</em></dt> 2924<dd>Use this function directly as the scaling filter. This will allow 2925 you to directly use a windowing filter such as <kbd>Blackman</kbd>, 2926 rather than as its normal usage as a windowing function for 'Sinc' or 2927 'Bessel' functions. If defined, no windowing function is used, unless the 2928 following expert setting is also defined.</dd> 2929 2930<dt>-define filter:window=<em>filter_function</em></dt> 2931<dd>The IIR (infinite impulse response) filters <kbd>Bessel</kbd> and 2932 <kbd>Sinc</kbd> are windowed (brought down to zero over the defined 2933 support range) with the given filter. This allows you to specify a filter 2934 function that is not normally used as a windowing function, such as 2935 <kbd>Box</kbd>, (which effectively turns off the windowing function), 2936 to window a <kbd>Sinc</kbd>, or the function the previous setting defined. 2937 </dd> 2938 2939<dt>-define filter:verbose=<em>1</em></dt> 2940<dd>This causes IM to print information on the final internal filter 2941 selection to standard output. This includes a commented header on the 2942 filter settings being used, and data allowing the filter weights to be 2943 easily graphed. </dd> 2944 2945<dd>Note however that some filters are internally defined in terms of other 2946 filters. The <kbd>Lanczos</kbd> filter for example is defined in terms of 2947 a <kbd>SincFast</kbd> windowed <kbd>SincFast</kbd> filter, while 2948 <kbd>Mitchell</kbd> is defined as a <kbd>Cubic</kbd> filter with specific 2949 'B' and 'C' settings. </dd> 2950 2951</dl> 2952 2953<p>For example, to get a 8 lobe Bessel windowed Bessel filter:</p> 2954 2955<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert image.png -filter bessel \ <br/> 2956 -set filter:window=bessel -set filter:lobes=8 \ <br/> 2957 -resize 150% image.jpg</span></p> 2958<p>Or a raw un-windowed Sinc filter with 4 lobes:</p> 2959 2960<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert image.png -set filter:filter=sinc -set filter:lobes=4 \ <br/> 2961 -resize 150% image.jpg</span></p> 2962<p>Note that the use of expert options (except for 'blur' with simple resize 2963filters, and 'verbose' for viewing the internal filter selection), are 2964provided for image processing experts who have studied and understood how 2965resize filters work. Without this knowledge, and an understanding of the 2966definition of the actual filters involved, using expert settings are more 2967likely to be detrimental to your image resizing.</p> 2968 2969 2970<div style="margin: auto;"> 2971 <h4><a id="flatten"></a>-flatten</h4> 2972</div> 2973 2974<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>This is a simple alias for the <a href="#layers" >-layers</a> method "flatten".</td><td style='text-align:right;'></td></tr></table> 2975 2976 2977<div style="margin: auto;"> 2978 <h4><a id="flip"></a>-flip</h4> 2979</div> 2980 2981<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>create a <em>mirror image</em>.</td><td style='text-align:right;'></td></tr></table> 2982 2983<p>reflect the scanlines in the vertical direction.</p> 2984 2985<div style="margin: auto;"> 2986 <h4><a id="floodfill"></a>-floodfill {<em class="arg">+-</em>}<em class="arg">x</em>{<em class="arg">+-</em>}<em class="arg">y</em> <em class="arg">color</em></h4> 2987</div> 2988 2989<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>floodfill the image with color at the specified offset. Using <a href="#fuzz" >-fuzz</a> to floodfill pixels which only change by a small amount.</td><td style='text-align:right;'></td></tr></table> 2990 2991<div style="margin: auto;"> 2992 <h4><a id="flop"></a>-flop</h4> 2993</div> 2994 2995<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>create a <em>mirror image</em>.</td><td style='text-align:right;'></td></tr></table> 2996 2997<p>reflect the scanlines in the horizontal direction.</p> 2998 2999 3000<div style="margin: auto;"> 3001 <h4><a id="font"></a>-font <em class="arg">name</em></h4> 3002</div> 3003 3004<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>set the font to use when annotating images with text, or creating labels.</td><td style='text-align:right;'></td></tr></table> 3005 3006<p>To print a complete list of fonts, use the <a href="#list">-list font</a> option (for versions prior to 6.3.6, use 'type' instead of 'font').</p> 3007 3008<p>In addition to the fonts specified by the above pre-defined list, you can 3009also specify a font from a specific source. For example <kbd>Arial.ttf</kbd> 3010is a TrueType font file, <kbd>ps:helvetica</kbd> is PostScript font, and 3011<kbd>x:fixed</kbd> is X11 font.</p> 3012 3013<p>For other settings that affect fonts, see the options <a href="#family">-family</a>, <a href="#stretch">-stretch</a>, <a href="#style">-style</a>, and <a href="#weight">-weight</a>. </p> 3014 3015 3016<div style="margin: auto;"> 3017 <h4><a id="foreground"></a>-foreground <em class="arg">color</em></h4> 3018</div> 3019 3020<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Define the foreground color.</td><td style='text-align:right;'></td></tr></table> 3021 3022<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p> 3023 3024<p>The default foreground color is black.</p> 3025 3026<div style="margin: auto;"> 3027 <h4><a id="format"></a>-format <em class="arg">type</em></h4> 3028</div> 3029 3030<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>the image format type.</td><td style='text-align:right;'></td></tr></table> 3031 3032<p>When used with the <kbd>mogrify</kbd> utility, this option converts any image to the image <a href="/www/formats.html">format</a> you specify. For a list of image format types supported by ImageMagick, use <a href="#list">-list format</a>.</p> 3033 3034<p>By default the file is written to its original name. However, if the filename extension matches a supported format, the extension is replaced with the image format type specified with <a href="#format">-format</a>. For example, if you specify <em class="arg">tiff</em> as the format type and the input image filename is <em class="arg">image.gif</em>, the output image filename becomes <em class="arg">image.tiff</em>.</p> 3035 3036<div style="margin: auto;"> 3037 <h4><a id="format_identify_"></a>-format <em class="arg">string</em></h4> 3038</div> 3039 3040<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>output formatted image characteristics.</td><td style='text-align:right;'>[<a href="/www/identify.html">identify</a>]</td></tr></table> 3041 3042<p>See <a href="/www/escape.html">Format and Print Image Properties</a> for an explanation on how to specify the argument to this option.</p> 3043 3044<div style="margin: auto;"> 3045 <h4><a id="frame"></a>-frame <em class="arg">geometry</em></h4> 3046</div> 3047 3048<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Surround the image with a border or beveled frame.</td><td style='text-align:right;'></td></tr></table> 3049 3050<p>The color of the border is specified with the <a href="#mattecolor" 3051>-mattecolor</a> command line option. </p> 3052 3053<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. The <em class="arg">size</em> portion of the <em 3054class="arg">geometry</em> argument indicates the amount of extra width and 3055height that is added to the dimensions of the image. If no offsets are given 3056in the <em class="arg">geometry</em> argument, then the border added is 3057a solid color. Offsets <em>x</em> and <em>y</em>, if present, specify that 3058the width and height of the border is partitioned to form an outer bevel of 3059thickness <em>x</em> pixels and an inner bevel of thickness 3060<em>y</em> pixels. Negative offsets make no sense as frame arguments. 3061</p> 3062 3063<p>The <a href="#frame">-frame</a> option is affected by the current <a 3064href="#compose">-compose</a> setting and assumes that this is using the default 3065'<kbd>Over</kbd>' composition method. It generates a image of the appropriate 3066size with the current <a href="#bordercolor">-bordercolor</a> setting, and then 3067draws the frame of four distinct colors close to the current <a 3068href="#mattecolor">-mattecolor</a>. The original image is then overlaid onto 3069center of this image. This means that with the default compose method of 3070'<kbd>Over</kbd>' any transparent parts may be replaced by the current <a 3071href="#bordercolor">-bordercolor</a> setting.</p> 3072 3073<p>The image composition is not 3074affected by the <a href="#gravity">-gravity</a> option.</p> 3075 3076 3077<div style="margin: auto;"> 3078 <h4><a id="frame_import_"></a>-frame</h4> 3079</div> 3080 3081<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>include the X window frame in the imported image.</td><td style='text-align:right;'>[<a href="/www/import.html">import</a>]</td></tr></table> 3082 3083<div style="margin: auto;"> 3084 <h4><a id="function"></a>-function <em class="arg">function</em> <em class="arg">parameters</em></h4> 3085</div> 3086 3087<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Apply a function to channel values.</td><td style='text-align:right;'></td></tr></table> 3088 3089<p>This operator performs calculations based on the given arguments to modify each of the color values for each previously set <a href="#channel">-channel</a> in the image. See <a href="#evaluate">-evaluate</a> for details concerning how the results of the calculations are handled.</p> 3090 3091<p>This is can be considered a multi-argument version of the <a href="#evaluate">-evaluate</a> operator. (Added in ImageMagick 6.4.8−8.)</p> 3092 3093<p>Here, <em class="arg">parameters</em> is a comma-separated list of numerical values. The number of values varies depending on which <em class="arg">function</em> is selected. Choose the <em class="arg">function</em> from:</p> 3094 3095<pre class="text"> 3096 Polynomial 3097 Sinusoid 3098 Arcsin 3099 Arctan 3100</pre> 3101 3102<p>To print a complete list of <a href="#function">-function</a> operators, use <a href="#list">-list function</a>. Descriptions follow.</p> 3103 3104<dl class="doc"> 3105<dt><kbd>Polynomial</kbd></dt> 3106<dd> 3107<p>The <kbd>Polynomial</kbd> function takes an arbitrary number of parameters, these being the coefficients of a polynomial, in decreasing order of degree. That is, entering</p> 3108 3109<div style="text-align: center"> 3110 -function Polynomial <em>a</em><sub><em>n</em></sub>,<em>a</em><sub><em>n</em>-1</sub>,...<em>a</em><sub>1</sub>,<em>a</em><sub>0</sub> 3111</div> 3112 3113<p>will invoke a polynomial function given by</p> 3114 3115<div style="text-align: center"> 3116 <em>a</em><sub><em>n</em></sub> <b><em>u</em></b><sup><em>n</em></sup> + 3117 <em>a</em><sub><em>n</em>-1</sub> <b><em>u</em></b><sup><em>n</em>-1</sup> + 3118 ··· <em>a</em><sub>1</sub> <b><em>u</em></b> + <em>a</em><sub>0</sub>, 3119</div> 3120 3121<p>where <b><em>u</em></b> is pixel's original normalized channel value.</p> 3122 3123<p>The <kbd>Polynomial</kbd> function can be used in place of <kbd>Set</kbd> (the <em>constant</em> polynomial) and <kbd>Add</kbd>, <kbd>Divide</kbd>, <kbd>Multiply</kbd>, and <kbd>Subtract</kbd> (some <em>linear</em> polynomials) of the <a href="#evaluate">-evaluate</a> operator. The <a href="#level">-level</a> operator also affects channels linearly. Some correspondences follow.</p> 3124 3125<table class="doc"> 3126 <col width="35%" /> 3127 <col width="35%" /> 3128 <col width="30%" /> 3129 <tr> 3130 <td>-evaluate Set <em class="arg">value</em> </td> 3131 <td>-function Polynomial <em class="arg">value</em></td> 3132 <td>(Constant functions; set <em class="arg">value</em>×100% gray when channels are RGB.)</td> 3133 </tr> 3134 <tr> 3135 <td>-evaluate Add <em class="arg">value</em> </td> 3136 <td>-function Polynomial 1,<em class="arg">value</em></td> 3137 </tr> 3138 <tr> 3139 <td>-evaluate Subtract <em class="arg">value</em> </td> 3140 <td>-function Polynomial 1,−<em class="arg">value</em></td> 3141 </tr> 3142 <tr> 3143 <td>-evaluate Multiply <em class="arg">value</em> </td> 3144 <td>-function Polynomial <em class="arg">value</em>,0</td> 3145 </tr> 3146 <tr> 3147 <td>+level black% x white%</td> 3148 <td>-function Polynomial A,B</td> 3149 <td>(Reduce contrast. Here, A=(white-black)/100 and B=black/100.)</td> 3150 </tr> 3151</table> 3152 3153<p>The <kbd>Polynomial</kbd> function gives great versatility, since polynomials can be used to fit any continuous curve to any degree of accuracy desired.</p> 3154</dd> 3155 3156<dt><kbd>Sinusoid</kbd></dt> 3157<dd> 3158<p>The <kbd>Sinusoid</kbd> function can be used to vary the channel values sinusoidally by setting frequency, phase shift, amplitude, and a bias. These values are given as one to four parameters, as follows,</p> 3159 3160<div style="text-align: center"> 3161 -function <kbd>Sinusoid</kbd> <em class="arg">freq</em>,[<em class="arg">phase</em>,[<em class="arg">amp</em>,[<em class="arg">bias</em>]]] 3162</div> 3163 3164<p>where <em>phase</em> is in degrees. (The domain [0,1] of the function corresponds to 0 through <em class="arg">freq</em>×360 degrees.) The result is that if a pixel's normalized channel value is originally <b><em>u</em></b>, its resulting normalized value is given by </p> 3165 3166<div style="text-align: center"> 3167<em class="arg">amp</em> * sin(2*π* (<em class="arg">freq</em> * <b><em>u</em></b> + <em class="arg">phase</em> / 360)) + <em class="arg">bias</em> 3168</div> 3169 3170<p> For example, the following generates a curve that starts and ends at 0.9 (when <b><em>u</em></b>=0 and 1, resp.), oscillating three times between .7−.2=.5 and .7+.2=.9. </p> 3171 3172<p class="crtsnip"> 3173 -function Sinusoid 3,-90,.2,.7 3174</p> 3175 3176<p>The default values of <em class="arg">amp</em> and <em class="arg">bias</em> are both .5. The default for <em class="arg">phase</em> is 0.</p> 3177 3178<p>The <kbd>Sinusoid</kbd> function generalizes <kbd>Sin</kbd> and <kbd>Cos</kbd> of the <a href="#evaluate">-evaluate</a> operator by allowing varying amplitude, phase and bias. The correspondence is as follows.</p> 3179 3180<table class="doc"> 3181 <tr> 3182 <td>-evaluate Sin <em class="arg">freq</em> </td> 3183 <td>-function Sinusoid <em class="arg">freq</em>,0 </td> 3184 </tr> 3185 <tr> 3186 <td>-evaluate Cos <em class="arg">freq</em> </td> 3187 <td>-function Sinusoid <em class="arg">freq</em>,90 </td> 3188 </tr> 3189</table> 3190</dd> 3191 3192<dt><kbd>ArcSin</kbd></dt> 3193<dd> 3194<p>The <kbd>ArcSin</kbd> function generates the inverse curve of a Sinusoid, 3195and can be used to generate cylindrical distortion and displacement maps. 3196The curve can be adjusted relative to both the input values and output range 3197of values.</p> 3198 3199<p style="text-align: center"> 3200 -function <kbd>ArcSin</kbd> <em class="arg">width</em>,[<em class="arg">center</em>,[<em class="arg">range</em>,[<em class="arg">bias</em>]]] 3201</p> 3202 3203<p>with all values given in terms of noramlize color values (0.0 for black, 32041.0 for white). Defaulting to values covering the full range from 0.0 to 1.0 3205for bout input (<em class="arg">width</em>), and output (<em 3206class="arg">width</em>) values. '<code>1.0,0.5,1.0,0.5</code>' </p> 3207 3208<p style="text-align: center"> 3209<em class="arg">range</em>/π * asin( 2/<em class="arg">width</em> * ( <b><em>u</em></b> - <em class="arg">center</em> ) ) + <em class="arg">bias</em> 3210</p> 3211 3212</dd> 3213 3214<dt><kbd>ArcTan</kbd></dt> 3215<dd> 3216<p>The <kbd>ArcTan</kbd> function generates a curve that smooth crosses from 3217limit values at infinities, though a center using the given slope value. 3218All these values can be adjusted via the arguments.</p> 3219 3220<p style="text-align: center"> 3221 -function <kbd>ArcTan</kbd> <em class="arg">slope</em>,[<em class="arg">center</em>,[<em class="arg">range</em>,[<em class="arg">bias</em>]]] 3222</p> 3223 3224<p>Defaulting to '<code>1.0,0.5,1.0,0.5</code>'. 3225</p> 3226 3227<p style="text-align: center"> 3228<em class="arg">range</em>/π * atan( <em class="arg">slope</em>*π * ( <b><em>u</em></b> - <em class="arg">center</em> ) ) + <em class="arg">bias</em> 3229</p> 3230 3231</dd> 3232 3233</dl> 3234 3235 3236<div style="margin: auto;"> 3237 <h4><a id="fuzz"></a>-fuzz <em class="arg">distance</em>{<em class="arg">%</em>}</h4> 3238</div> 3239 3240<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Colors within this <em class="arg">distance</em> are considered equal.</td><td style='text-align:right;'></td></tr></table> 3241 3242<p>A number of algorithms search for a target color. By default the color must be exact. Use this option to match colors that are close to the target color in RGB space. For example, if you want to automagically trim the edges of an image with <a href="#trim">-trim</a> but the image was scanned and the target background color may differ by a small amount. This option can account for these differences.</p> 3243 3244<p>The <em class="arg">distance</em> can be in absolute intensity units or, by appending <kbd>%</kbd> as a percentage of the maximum possible intensity (255, 65535, or 4294967295).</p> 3245 3246 3247<div style="margin: auto;"> 3248 <h4><a id="fx"></a>-fx <em class="arg">expression</em></h4> 3249</div> 3250 3251<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>apply a mathematical expression to an image or image channels.</td><td style='text-align:right;'></td></tr></table> 3252 3253<p>If the first character of <em class="arg">expression</em> is <kbd>@</kbd>, the expression is read from a file titled by the remaining characters in the string.</p> 3254 3255<p>See <a href="/www/fx.html">FX, The Special Effects Image Operator</a> for a detailed discussion of this option.</p> 3256 3257 3258<div style="margin: auto;"> 3259 <h4><a id="gamma"></a>-gamma <em class="arg">value</em></h4> 3260</div> 3261 3262<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>level of gamma correction.</td><td style='text-align:right;'></td></tr></table> 3263 3264<p>The same color image displayed on two different workstations may look different due to differences in the display monitor. Use gamma correction to adjust for this color difference. Reasonable values extend from <kbd>0.8</kbd> to <kbd>2.3</kbd>. Gamma less than 1.0 darkens the image and gamma greater than 1.0 lightens it. Large adjustments to image gamma may result in the loss of some image information if the pixel quantum size is only eight bits (quantum range 0 to 255).</p> 3265 3266<p>Gamma adjusts the image's channel values pixel-by-pixel according to a power law, namely, pow(pixel,1/gamma) or pixel^(1/gamma), where pixel is the normalized or 0 to 1 color value. For example, using a value of gamma=2 is the same as taking the square root of the image.</p> 3267 3268<p>You can apply separate gamma values to the red, green, and blue channels of the image with a gamma value list delimited with commas (e.g., <kbd>1.7,2.3,1.2</kbd>).</p> 3269 3270<p>Use <a href="#gamma">+gamma <em class="arg">value</em></a> to set the image gamma level without actually adjusting the image pixels. This option is useful if the image is of a known gamma but not set as an image attribute (e.g. PNG images).</p> 3271 3272<p>Note that gamma adjustments are also available via the <a href="#level">-level</a> operator.</p> 3273 3274<div style="margin: auto;"> 3275 <h4><a id="gaussian-blur"></a>-gaussian-blur <em class="arg">radius</em><br />-gaussian-blur <em class="arg">radius</em>x<em class="arg">sigma</em></h4> 3276</div> 3277 3278<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Blur the image with a Gaussian operator.</td><td style='text-align:right;'></td></tr></table> 3279 3280<p>Convolve the image with a Gaussian or normal distribution using the given 3281<em class="arg" >Sigma</em> value. The formula is:</p> 3282 3283<div class="eqn"><img alt="gaussian distribution" width="243px" height="42px" src="/images/gaussian-blur.png"/> 3284</div> 3285 3286<p>The <em class="arg" >Sigma</em> value is the important argument, and 3287determines the actual amount of blurring that will take place. </p> 3288 3289<p>The <em class="arg" >Radius</em> is only used to determine the size of the 3290array which will hold the calculated Gaussian distribution. It should be an 3291integer. If not given, or set to zero, IM will calculate the largest possible 3292radius that will provide meaningful results for the Gaussian distribution. 3293</p> 3294 3295<p>The larger the <em class="arg" >Radius</em> the radius the slower the 3296operation is. However too small a <em class="arg" >Radius</em>, and sever 3297aliasing effects may result. As a guideline, <em class="arg" >Radius</em> 3298should be at least twice the <em class="arg" >Sigma</em> value, though three 3299times will produce a more accurite result. </p> 3300 3301<p>This differs from the faster <a href="#blur">-blur</a> operator in that a 3302full 2-dimensional convolution is used to generate the weighted average of the 3303neighboring pixels. </p> 3304 3305<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how 3306pixels which are outside the image proper are blurred into the final result. 3307</p> 3308 3309 3310<div style="margin: auto;"> 3311 <h4><a id="geometry"></a>-geometry <em class="arg">geometry</em></h4> 3312</div> 3313 3314<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the preferred size and location of the image.</td><td style='text-align:right;'></td></tr></table> 3315 3316<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 3317 3318<div style="margin: auto;"> 3319 <h4><a id="gravity"></a>-gravity <em class="arg">type</em></h4> 3320</div> 3321 3322<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Sets the current gravity suggestion for various other settings and options.</td><td style='text-align:right;'></td></tr></table> 3323 3324<p>Choices include: <kbd>NorthWest</kbd>, <kbd>North</kbd>, <kbd>NorthEast</kbd>, 3325<kbd>West</kbd>, <kbd>Center</kbd>, <kbd>East</kbd>, <kbd>SouthWest</kbd>, 3326<kbd>South</kbd>, <kbd>SouthEast</kbd>. Use <a href="#list">-list gravity</a> to get a complete 3327list of <a href="#gravity">-gravity</a> settings available in your ImageMagick 3328installation.</p> 3329 3330<p>The direction you choose specifies where to position text or subimages. For example, a gravity of <kbd>Center</kbd> forces the text to be centered within the image. By default, the image gravity is <kbd>NorthWest</kbd>. See <a href="#draw">-draw</a> for more details about graphic primitives. Only the text primitive of <a href="#draw">-draw</a> affected by the <a href="#gravity">-gravity</a> option.</p> 3331 3332<p>The <a href="#gravity">-gravity</a> option is also used in concert with the <a href="#geometry">-geometry</a> setting and other settings or options that take <em class="arg">geometry</em> as an argument, such as the <a href="#crop">-crop</a> option. </p> 3333 3334<p>If a <a href="#gravity">-gravity</a> setting occurs before another option or setting having a <em class="arg">geometry</em> argument that specifies an offset, the offset is usually applied to the point within the image suggested by the <a href="#gravity">-gravity</a> argument. Thus, in the following command, for example, suppose the file <kbd>image.png</kbd> has dimensions 200x100. The offset specified by the argument to <a href="#region">-region</a> is (−40,+20). The argument to <a href="#gravity">-gravity</a> is <kbd>Center</kbd>, which suggests the midpoint of the image, at the point (100,50). The offset (−40,20) is applied to that point, giving (100−40,50+20)=(60,70), so the specified 10x10 region is located at that point. (In addition, the <a href="#gravity">-gravity</a> affects the region itself, which is <em>centered</em> at the pixel coordinate (60,70). (See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.)</p> 3335 3336<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert image.png -gravity Center -region 10x10-40+20 \ <br/> -negate output.png</span></p> 3337<p>When used as an option to <a href="/www/composite.html">composite</a>, <a href="#gravity">-gravity</a> gives the direction that the image gravitates within the composite.</p> 3338 3339<p>When used as an option to <a href="/www/montage.html">montage</a>, <a href="#gravity">-gravity</a> gives the direction that an image gravitates within a tile. The default gravity is <kbd>Center</kbd> for this purpose.</p> 3340 3341 3342<div style="margin: auto;"> 3343 <h4><a id="green-primary"></a>-green-primary <em class="arg">x,y</em></h4> 3344</div> 3345 3346<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>green chromaticity primary point.</td><td style='text-align:right;'></td></tr></table> 3347 3348 3349<div style="margin: auto;"> 3350 <h4><a id="hald-clut"></a>-hald-clut</h4> 3351</div> 3352 3353<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>apply a Hald color lookup table to the image.</td><td style='text-align:right;'></td></tr></table> 3354 3355<p>A Hald color lookup table is a 3-dimensional color cube mapped to 2 3356dimensions. Create it with the <kbd>HALD:</kbd> prefix (e.g. HALD:8). You 3357can apply any color transformation to the Hald image and then use this option 3358to apply the transform to the image. </p> 3359 3360<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert image.png hald.png -hald-clut transform.png</span></p> 3361<p>This option provides a convenient method for you to use Gimp or Photoshop 3362to make color corrections to the Hald CLUT image and subsequently apply them 3363to multiple images using an ImageMagick script. </p> 3364 3365<p>Note that the representation is only of the normal RGB color space and that 3366the whole color value triplet is used for the interpolated lookup of the 3367represented Hald color cube image. Because of this the operation is not <a 3368href="#channel" >-channel</a> setting effected, nor can it adjust or modify an 3369images transparency or alpha/matte channel.</p> 3370 3371<p>See also <a href="#clut" >-clut</a> which provides color value replacement 3372of the individual color channels, usally involving a simplier gray-scale 3373image. E.g: gray-scale to color replacement, or modification by a histogram 3374mapping. </p> 3375 3376 3377<div style="margin: auto;"> 3378 <h4><a id="help"></a>-help</h4> 3379</div> 3380 3381<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>print usage instructions.</td><td style='text-align:right;'></td></tr></table> 3382 3383<div style="margin: auto;"> 3384 <h4><a id="highlight-color"></a>-highlight-color <em class="arg">color</em></h4> 3385</div> 3386 3387<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>when comparing images, emphasize pixel differences with this color.</td><td style='text-align:right;'></td></tr></table> 3388 3389<div style="margin: auto;"> 3390 <h4><a id="iconGeometry"></a>-iconGeometry <em class="arg">geometry</em></h4> 3391</div> 3392 3393<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>specify the icon geometry.</td><td style='text-align:right;'></td></tr></table> 3394 3395<p>Offsets, if present in the geometry specification, are handled in the same manner as the <a href="#geometry">-geometry</a> option, using X11 style to handle negative offsets.</p> 3396 3397<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 3398 3399<div style="margin: auto;"> 3400 <h4><a id="iconic"></a>-iconic</h4> 3401</div> 3402 3403<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>iconic animation.</td><td style='text-align:right;'></td></tr></table> 3404 3405<div style="margin: auto;"> 3406 <h4><a id="identify"></a>-identify</h4> 3407</div> 3408 3409<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>identify the format and characteristics of the image.</td><td style='text-align:right;'></td></tr></table> 3410 3411<p>This information is printed: image scene number; image name; image size; the image class (<em class="arg">DirectClass</em> or <em class="arg">PseudoClass</em>); the total number of unique colors; and the number of seconds to read and transform the image. Refer to <a href="/www/miff.html">MIFF</a> for a description of the image class.</p> 3412 3413<p>If <a href="#colors">-colors</a> is also specified, the total unique colors in the image and color reduction error values are printed. Refer to <a href="/www/quantize.html">color reduction algorithm</a> for a description of these values.</p> 3414 3415<p>If <a href="#verbose">-verbose</a> precedes this option, copious 3416amounts of image properties are displayed including image statistics, profiles, 3417image histogram, and others.</p> 3418 3419<div style="margin: auto;"> 3420 <h4><a id="ift"></a>-ift</h4> 3421</div> 3422 3423<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>implements the inverse discrete Fourier transform (DFT).</td><td style='text-align:right;'></td></tr></table> 3424 3425<p>This option is new as of ImageMagick 6.5.4-3 (and now working for Windows users in ImageMagick 6.6.0-9). It transforms a pair of magnitude and phase images from the frequency domain to a single image in the normal or spatial domain. See for example, <a href="http://en.wikipedia.org/wiki/Fourier_transform">Fourier Transform</a>, <a href="http://en.wikipedia.org/wiki/DFT">Discrete Fourier Transform</a> and <a href="http://en.wikipedia.org/wiki/FFT">Fast Fourier Transform</a>.</p> 3426 3427<p>For example, depending upon the image format used to store the result of the <a href="#fft">-fft</a>, one would use either</p> 3428 3429<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert fft_image.miff -ift fft_image_ift.png</span></p> 3430<p>or</p> 3431 3432<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert fft_image-0.png fft_image-1.png -ift fft_image_ift.png</span></p> 3433 3434<p>The resulting image may need to be cropped due to padding introduced when the original image, prior to the <a href="#fft">-fft</a> or <a href="#fft">+fft</a>, was not square or even dimensioned. Any padding is at the right and/or bottom sides of the image.</p> 3435 3436<p>The <a href="http://www.fftw.org/">FFTW</a> delegate library is required to use <a href="#ift">-ift</a>.</p> 3437 3438<p>Use <a href="#ift">+ift</a> (with HDRI enabled) to transform a pair of real and imaginary images from the frequency domain to a single image in the normal (spatial) domain.</p> 3439 3440<div style="margin: auto;"> 3441 <h4><a id="immutable"></a>-immutable</h4> 3442</div> 3443 3444<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>make image immutable.</td><td style='text-align:right;'></td></tr></table> 3445 3446<div style="margin: auto;"> 3447 <h4><a id="implode"></a>-implode <em class="arg">factor</em></h4> 3448</div> 3449 3450<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>implode image pixels about the center.</td><td style='text-align:right;'></td></tr></table> 3451 3452<div style="margin: auto;"> 3453 <h4><a id="insert"></a>-insert <em class="arg">index</em></h4> 3454</div> 3455 3456<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>insert the last image into the image sequence.</td><td style='text-align:right;'></td></tr></table> 3457 3458<p>This option takes last image in the current image sequence and inserts it at the given index. If a negative index is used, the insert position is calculated before the last image is removed from the sequence. As such <kbd>-insert -1</kbd> will result in no change to the image sequence.</p> 3459 3460<p>The <kbd>+insert</kbd> option is equivalent to <kbd>-insert -1</kbd>. In other words, insert the last image, at the end of the current image sequence. Consequently this has no effect on the image sequence order.</p> 3461 3462<div style="margin: auto;"> 3463 <h4><a id="intent"></a>-intent <em class="arg">type</em></h4> 3464</div> 3465 3466<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>use this type of rendering intent when managing the image color.</td><td style='text-align:right;'></td></tr></table> 3467 3468<p>Use this option to affect the color management operation of an image (see <a href="#profile">-profile</a>). Choose from these intents: <kbd>Absolute, Perceptual, Relative, Saturation</kbd>.</p> 3469 3470<p>The default intent is undefined.</p> 3471 3472<p>To print a complete list of rendering intents, use <a href="#list">-list intent</a>.</p> 3473 3474<div style="margin: auto;"> 3475 <h4><a id="interlace"></a>-interlace <em class="arg">type</em></h4> 3476</div> 3477 3478<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>the type of interlacing scheme.</td><td style='text-align:right;'></td></tr></table> 3479 3480<p>Choose from:</p> 3481 3482<pre class="text"> 3483 none 3484 line 3485 plane 3486 partition 3487 JPEG 3488 GIF 3489 PNG 3490</pre> 3491 3492<p>This option is used to specify the type of interlacing scheme for raw image formats such as <kbd>RGB</kbd> or <kbd>YUV</kbd>.</p> 3493 3494<p><kbd>None</kbd> means do not interlace (RGBRGBRGBRGBRGBRGB...),</p> 3495 3496<p><kbd>Line</kbd> uses scanline interlacing (RRR...GGG...BBB...RRR...GGG...BBB...), and.</p> 3497 3498<p><kbd>Plane</kbd> uses plane interlacing (RRRRRR...GGGGGG...BBBBBB...).</p> 3499 3500<p><kbd>Partition</kbd> is like plane except the different planes are saved to individual files (e.g. image.R, 3501image.G, and image.B).</p> 3502 3503<p>Use <kbd>Line</kbd> or <kbd>Plane</kbd> to create an <kbd>interlaced PNG</kbd> or <kbd>GIF</kbd> or <kbd>progressive JPEG</kbd> 3504image.</p> 3505 3506<p>To print a complete list of interlacing schemes, use <a href="#list">-list interlace</a>.</p> 3507 3508<div style="margin: auto;"> 3509 <h4><a id="interpolate"></a>-interpolate <em class="arg">type</em></h4> 3510</div> 3511 3512<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the pixel color interpolation method to use when looking up a color based on a floating point or real value.</td><td style='text-align:right;'></td></tr></table> 3513 3514<p>When looking up the color of a pixel using a non-integer floating point 3515value, you typically fall in between the pixel colors defined by the source 3516image. This setting determines how the color is determined from the colors of 3517the pixels surrounding that point. That is how to determine the color of a 3518point that falls between two, or even four different colored pixels. </p> 3519 3520<pre class="text"> 3521 integer: The color of the top-left pixel (floor function) 3522 nearest-neighbor: The nearest pixel to the lookup point (rounded function) 3523 average: The average color of the surrounding four pixels 3524 bilinear A double linear interpolation of pixels (the default) 3525 mesh Divide area into two flat triangular interpolations 3526 bicubic Fitted bicubic-spines of surrounding 16 pixels 3527 spline Direct spline curves (colors are blurred) 3528 filter Use resize <a href="#filter">-filter</a> settings 3529</pre> 3530 3531<p>This most important for distortion operators such as <a href="#distort" 3532>-distort</a>, <a href="#implode" >-implode</a>, <a href="#transform" 3533>-transform</a> and <a href="#fx" >-fx</a>. </p> 3534 3535<p>To print a complete list of interpolation methods, use <a href="#list">-list interpolate</a>.</p> 3536 3537<p>See also <a href="#virtual-pixel" >-virtual-pixel</a>, for control of the 3538lookup for positions outside the boundaries of the image. </p> 3539 3540 3541<div style="margin: auto;"> 3542 <h4><a id="interline-spacing"></a>-interline-spacing <em class="arg">value</em></h4> 3543</div> 3544 3545<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>the space between two text lines.</td><td style='text-align:right;'></td></tr></table> 3546 3547<div style="margin: auto;"> 3548 <h4><a id="interword-spacing"></a>-interword-spacing <em class="arg">value</em></h4> 3549</div> 3550 3551<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>the space between two words.</td><td style='text-align:right;'></td></tr></table> 3552 3553<div style="margin: auto;"> 3554 <h4><a id="kerning"></a>-kerning <em class="arg">value</em></h4> 3555</div> 3556 3557<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>the space between two letters.</td><td style='text-align:right;'></td></tr></table> 3558 3559<div style="margin: auto;"> 3560 <h4><a id="label"></a>-label <em class="arg">name</em></h4> 3561</div> 3562 3563<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>assign a label to an image.</td><td style='text-align:right;'></td></tr></table> 3564 3565<p>Use this option to assign a specific label to the image, as it is read in 3566or created. You can use the <a href="#set" >-set</a> operation to re-assign 3567a the labels of images already read in. Image formats such as TIFF, PNG, 3568MIFF, supports saving the label information with the image.</p> 3569 3570<p>When saving an image to a <em class="arg">PostScript</em> file, any label 3571assigned to an image is used as a header string to print above the postscript 3572image. </p> 3573 3574<p>You can include the image filename, type, width, height, or other image 3575attribute by embedding special format character. See <a href="/www/escape.html">Format and Print Image 3576Properties</a> for details of the percent escape codes.</p> 3577 3578<p>For example,</p> 3579 3580<p class="crtsnip"> 3581 -label "%m:%f %wx%h" bird.miff 3582</p> 3583 3584<p>assigns an image label of <kbd>MIFF:bird.miff 512x480</kbd> to the 3585"<kbd>bird.miff</kbd>" image and whose width is 512 and height is 480, as it 3586is read in. If a <a href="#label">+label</a> option was used instead, any 3587existing label present in the image would be used. You can remove all labels 3588from an image by assigning the empty string. </p> 3589 3590<p>A label is not drawn on the image, but is embedded in the image datastream 3591via <em>Label</em> tag or similar mechanism. If you want the label to be 3592visible on the image itself, use the <a href="#draw">-draw</a> option, or 3593during the final processing in the creation of a image montage.</p> 3594 3595<p>If the first character of <em class="arg">string</em> is <em 3596class="arg">@</em>, the image label is read from a file titled by the 3597remaining characters in the string. Labels in a file are literal, no embedded 3598formatting characters are recognized.</p> 3599 3600 3601<div style="margin: auto;"> 3602 <h4><a id="lat"></a>-lat <em class="arg">width</em><br />-lat <em class="arg">width</em>x<em class="arg">height</em>{<em class="arg">+-</em>}<em class="arg">offset</em>{<em class="arg">%</em>}</h4> 3603</div> 3604 3605<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>perform local adaptive threshold.</td><td style='text-align:right;'></td></tr></table> 3606 3607<p>Adaptively threshold each pixel based on the value of pixels in a 3608surrounding window. If the current pixel is lighter than this average plus 3609the optional <kbd>offset</kbd>, then it is made white, otherwise it is made 3610black. Small variations in pixel values such as found in scanned documents 3611can be ignored if offset is positive. A negative offset will make it more 3612sensitive to those small variations. </p> 3613 3614<p>This is commonly used to threshold images with an uneven background. It is 3615based on the assumption that average color of the small window is the 3616the local background color, from which to separate the forground color. </p> 3617 3618 3619<div style="margin: auto;"> 3620 <h4><a id="layers"></a>-layers <em class="arg">method</em></h4> 3621</div> 3622 3623<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>handle multiple images forming a set of image layers or animation frames.</td><td style='text-align:right;'></td></tr></table> 3624 3625<p>Perform various image operation methods to a ordered sequence of images 3626which may represent either a set of overlaid 'image layers', a GIF disposal 3627animation, or a fully-'coalesced' animation sequence. </p> 3628 3629<table class="doc"> 3630 <tbody> 3631 <tr valign="top"> 3632 <th align="left" style="width: 8%">Method</th> 3633 <th align="left">Description</th> 3634 </tr> 3635 3636 <tr valign="top"> 3637 <td valign="top">compare-any</td> 3638 <td valign="top">Crop the second and later frames to the smallest rectangle 3639 that contains all the differences between the two images. No GIF <a 3640 href="#dispose" >-dispose</a> methods are taken into account. </td> 3641 </tr> 3642 3643 <tr><td></td><td>This exactly the same as the <a href="#deconstruct" 3644 >-deconstruct</a> operator, and does not preserve animations normal 3645 working, especially when animation used layer disposal methods such as 3646 '<kbd>Previous</kbd>' or '<kbd>Background</kbd>'. </td> 3647 </tr> 3648 3649 <tr valign="top"> 3650 <td valign="top">compare-clear</td> 3651 <td valign="top">As '<kbd>compare-any</kbd>' but crop to the bounds of any 3652 opaque pixels which become transparent in the second frame. That is the 3653 smallest image needed to mask or erase pixels for the next frame. </td> 3654 </tr> 3655 3656 <tr valign="top"> 3657 <td valign="top">compare-overlay</td> 3658 <td valign="top">As '<kbd>compare-any</kbd>' but crop to pixels that add 3659 extra color to the next image, as a result of overlaying color pixels. 3660 That is the smallest single overlaid image to add or change colors. </td> 3661 </tr> 3662 3663 <tr><td></td><td>This can be used with the <a href="#compose" >-compose</a> alpha 3664 composition method '<kbd>change-mask</kbd>', to reduce the image to 3665 just the pixels that need to be overlaid. </td> 3666 </tr> 3667 3668 <tr valign="top"> 3669 <td valign="top">coalesce</td> 3670 <td valign="top">Equivalent to a call to the <a href="#coalesce" 3671 >-coalesce</a> operator. Apply the layer disposal methods set in the 3672 current image sequence to form a fully defined animation sequence, as 3673 it should be displayed. Effectively converting a GIF animation into a 3674 'film strip'-like animation. </td> 3675 </tr> 3676 3677 <tr valign="top"> 3678 <td valign="top">composite</td> 3679 <td valign="top">Alpha Composition of two image lists, separated by a 3680 "<kbd>null:</kbd>" image, with the destination image list first, and 3681 the source images last. An image from each list are composited 3682 together until one list is finished. The separator image and source 3683 image lists are removed. </td> 3684 </tr> 3685 3686 3687 <tr><td></td> 3688 <td>The <a href="#geometry" >-geometry</a> offset is adjusted according 3689 to <a href="#gravity" >-gravity</a> in accordance of the virtual 3690 canvas size of the first image in each list. Unlike a normal <a 3691 href="#composite" >-composite</a> operation, the canvas offset is also 3692 added to the final composite positioning of each image. </td> </tr> 3693 3694 <tr><td></td> 3695 <td>If one of the image lists only contains one image, that image is 3696 applied to all the images in the other image list, regardless of which 3697 list it is. In this case it is the image meta-data of the list which 3698 preserved. </td> 3699 </tr> 3700 3701 3702 <tr valign="top"> 3703 <td valign="top">dispose</td> 3704 <td valign="top">This like '<kbd>coalesce</kbd>' but shows the look of 3705 the animation after the layer disposal method has been applied, before 3706 the next sub-frame image is overlaid. That is the 'dispose' image that 3707 results from the application of the GIF <a href="#dispose" 3708 >-dispose</a> method. This allows you to check what 3709 is going wrong with a particular animation you may be developing. 3710 </td> 3711 </tr> 3712 3713 <tr valign="top"> 3714 <td valign="top">flatten</td> 3715 <td valign="top">Create a canvas the size of the first images virtual 3716 canvas using the current <a href="#background" >-background</a> color, 3717 and <a href="#compose" >-compose</a> each image in turn onto that 3718 canvas. Images falling outside that canvas is clipped. Final 3719 image will have a zero virtual canvas offset. </td> 3720 </tr> 3721 3722 <tr><td></td> 3723 <td>This usally used as one of the final 'image layering' operations 3724 overlaying all the prepared image layers into a final image. </td> 3725 </tr> 3726 3727 <tr><td></td> 3728 <td>For a single image this method can also be used to fillout a virtual 3729 canvas with real pixels, or to underlay a opaque color to remove 3730 transparency from an image.</td> 3731 </tr> 3732 3733 3734 <tr valign="top"> 3735 <td valign="top">merge</td> 3736 <td valign="top">As 'flatten' method but merging all the given image 3737 layers into a new layer image just large enough to hold all the image 3738 without clipping or extra space. The new images virtual offset will 3739 prevere the position of the new layer, even if this offset is 3740 negative. the virtual canvas size of the first image is preserved. 3741 </td> 3742 </tr> 3743 3744 <tr><td></td><td>Caution is advised when handling image layers with negative offsets 3745 as few image file formats handle them correctly. </td> 3746 </tr> 3747 3748 <tr valign="top"> 3749 <td valign="top">mosaic</td> 3750 <td valign="top">As 'flatten' method but expanding the initial canvas size 3751 of the first image so as to hold all the image layers. However as a 3752 virtual canvas is 'locked' to the origin, by definition, image layers 3753 with a negative offsets will still be clipped by the top and left 3754 edges.</td> 3755 </tr> 3756 3757 <tr><td></td><td>This method is commonly used to layout individual image using various 3758 offset but without knowing the final canvas size. The resulting image 3759 will, like 'flatten' not have any virtual offset, so can be saved to 3760 any image file format. </td> 3761 </tr> 3762 3763 3764 <tr valign="top"> 3765 <td valign="top">optimize</td> 3766 <td valign="top">Optimize a coalesced animation, into GIF animation using 3767 a number of general techniques. This currently a short cut to 3768 apply both the '<kbd>optimize-frame</kbd>', and 3769 '<kbd>optimize-transparency</kbd>' methods but may be expanded to 3770 include other optimization methods as they are developed. </td> 3771 </tr> 3772 3773 <tr valign="top"> 3774 <td valign="top">optimize-frame</td> 3775 <td valign="top">Optimize a coalesced animation, into GIF animation by 3776 reducing the number of pixels per frame as much as possible by 3777 attempting to pick the best layer disposal method to use, while ensuring 3778 the result will continue to animate properly. </td> 3779 </tr> 3780 3781 <tr><td></td><td> There is no guarantee that the best optimization is found. But 3782 then no reasonably fast GIF optimization algorithm can do this. 3783 However this does seem to do better than most other GIF frame 3784 optimizers seen. </td> 3785 </tr> 3786 3787 <tr valign="top"> 3788 <td valign="top">optimize-plus</td> 3789 <td valign="top">As '<kbd>optimize-frame</kbd>' but attempt to improve the 3790 overall optimization by adding extra frames to the animation, without 3791 changing the final look or timing of the animation. The frames are 3792 added to attempt to separate the clearing of pixels from the 3793 overlaying of new additional pixels from one animation frame to the 3794 next. If this does not improve the optimization (for the next frame 3795 only), it will fall back to the results of the previous normal 3796 '<kbd>optimize-frame</kbd>' technique. </td> 3797 </tr> 3798 3799 <tr><td></td><td>There is the possibility that the change in the disposal style will 3800 result in a worsening in the optimization of later frames, though this 3801 is unlikely. In other words there no guarantee that it is better than 3802 the normal '<kbd>optimize-frame</kbd>' technique. For some animations 3803 however you can get a vast improvement in the final animation size. </td> 3804 </tr> 3805 3806 <tr valign="top"> 3807 <td valign="top">optimize-transparency</td> 3808 <td valign="top">Given a GIF animation, replace any pixel in the sub-frame 3809 overlay images with transparency, if it does not change the resulting 3810 animation by more than the current <a href="#fuzz" >-fuzz</a> factor. 3811 </td> 3812 </tr> 3813 3814 <tr><td></td><td>This should allow a existing frame optimized GIF animation to compress 3815 into a smaller file size due to larger areas of one (transparent) 3816 color rather than a pattern of multiple colors repeating the current 3817 disposed image of the last frame. </td> 3818 </tr> 3819 3820 <tr valign="top"> 3821 <td valign="top">remove-dups</td> 3822 <td valign="top">Remove (and merge time delays) of duplicate consecutive 3823 images, so as to simplify layer overlays of coalesced animations. 3824 </td> 3825 </tr> 3826 3827 <tr><td></td><td>Usually this a result of using a constant time delay across the 3828 whole animation, or after a larger animation was split into smaller 3829 sub-animations. The duplicate frames could also have been used as 3830 part of some frame optimization methods. </td> 3831 </tr> 3832 3833 <tr valign="top"> 3834 <td valign="top">remove-zero</td> 3835 <td valign="top">Remove any image with a zero time delay, unless ALL the 3836 images have a zero time delay (and is not a proper timed animation, a 3837 warning is then issued). </td> 3838 </tr> 3839 3840 <tr><td></td><td>In a GIF animation, such images are usually frames which provide 3841 partial intermediary updates between the frames that are actually 3842 displayed to users. These frames are usally added for improved frame 3843 optimization in GIF animations. </td> 3844 </tr> 3845 3846 <tr valign="top"> 3847 <td valign="top">trim-bounds</td> 3848 <td valign="top">Find the bounds of all the images in the current 3849 image sequence, then adjust the offsets so all images are contained on 3850 a minimal positive canvas. None of the image data is modified, only 3851 there virtual canvas size and offset. The all the image is given 3852 the same canvas size, and and will have a positive offset, but will 3853 remain in the same position relative to each other. As a result of the 3854 minimal canvas size at least one image will touch every edge of that 3855 canvas. The image data however may be transparent. 3856 </td> 3857 </tr> 3858 3859 </tbody> 3860</table> 3861 3862<p>To print a complete list of layer types, use <a href="#list">-list layers</a>.</p> 3863 3864<p>The operators <a href="#coalesce" >-coalesce</a>, <a href="#deconstruct" 3865>-deconstruct</a>, <a href="#flatten" >-flatten</a>, and <a href="#mosaic" 3866>-mosaic</a> are only aliases for the above methods. Also see <a 3867href="#page" >-page</a>, <a href="#repage" >-repage</a> operators, the <a 3868href="#compose" >-compose</a> setting, and the GIF <a href="#dispose" 3869>-dispose</a> and <a href="#delay" >-delay</a> settings. </p> 3870 3871 3872<div style="margin: auto;"> 3873 <h4><a id="level"></a>-level <em class="arg">black_point</em>{,<em class="arg">white_point</em>}{<em class="arg">%</em>}{,<em class="arg">gamma</em>}</h4> 3874</div> 3875 3876<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>adjust the level of image channels.</td><td style='text-align:right;'></td></tr></table> 3877 3878<p>Given one, two or three values delimited with commas: black-point, 3879white-point, gamma (for example: 10,250,1.0 or 2%,98%,0.5). The black and 3880white points range from 0 to <em class="QR">QuantumRange</em>, or from 0 to 100%; if the white 3881point is omitted it is set to (<em class="QR">QuantumRange</em> - black_point), so as to center 3882contrast changes. If a <kbd>%</kbd> sign is present anywhere in the string, 3883both black and white points are percentages of the full color range. Gamma 3884will do a <a href="#gamma">-gamma</a> adjustment of the values. If it is 3885omitted, the default of 1.0 (no gamma correction) is assumed.</p> 3886 3887<p>In normal usage (<kbd>-level</kbd>) the image values are stretched so that 3888the given '<kbd>black_point</kbd>' value in the original image is set to 3889zero (or black), while the given '<kbd>white_point</kbd>' value is set to 3890<em class="QR">QuantumRange</em> (or white). This provides you with direct contrast adjustments 3891to the image. The '<kbd>gamma</kbd>' of the resulting image will then be 3892adjusted. </p> 3893 3894<p>From ImageMagick v6.4.1-9 using the plus form of the operator (<kbd>+level</kbd>) or 3895adding the special '!' flag anywhere in the argument list, will cause the 3896operator to do the reverse of the level adjustment. That is a zero, or 3897<em class="QR">QuantumRange</em> value (black, and white, resp.) in the original image, is 3898adjusted to the given level values, allowing you to de-contrast, or compress 3899the channel values within the image. The '<kbd>gamma</kbd>' is adjusted before the level adjustment to de-contrast the image is made. </p> 3900 3901<p>Only the channels defined by the current <a href="#channel">-channel</a> 3902setting are adjusted (defaults to RGB color channels only), allowing you to 3903limit the effect of this operator. </p> 3904 3905<p>Please note that the transparency channel is treated as 'matte' 3906values (0 is opaque) and not as 'alpha' values (0 is transparent).</p> 3907 3908 3909<div style="margin: auto;"> 3910 <h4><a id="level-colors"></a>-level-colors {<em 3911 class="arg">black_color</em>}{,}{<em class="arg">white_color</em>}</h4> 3912</div> 3913 3914<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>adjust the level of an image using the provided dash separated colors.</td><td style='text-align:right;'></td></tr></table> 3915 3916<p>This function is exactly like <a href="#level">-level</a>, except that the 3917value value for each color channel is determined by the 3918'<kbd>black_color</kbd>' and '<kbd>white_color</kbd>' colors given (as 3919described under the <a href="#fill">-fill</a> option). </p> 3920 3921<p>This effectually means the colors provided to <kbd>-level-colors</kbd> 3922is mapped to become 'black' and 'white' respectively, with all the other 3923colors linearly adjusted (or clipped) to match that change. Each channel is 3924adjusted separately using the channel values of the colors specified. </p> 3925 3926<p>On the other hand the plus form of the operator (<kbd>+level-colors</kbd>) 3927will map the image color 'black' and 'white' to the given colors 3928respectively, resulting in a gradient (de-contrasting) tint of the image to 3929those colors. This can also be used to convert a plain gray-scale image into a 3930one using the gradient of colors specified. </p> 3931 3932<p>By supplying a single color with a comma separator either before or after 3933that color, will just replace the respective 'black' or 'white' point 3934respectively. But if no comma separator is provided, the given color is 3935used for both the black and white color points, making the operator either 3936threshold the images around that color (- form) or set all colors to that 3937color (+ form). </p> 3938 3939 3940<div style="margin: auto;"> 3941 <h4><a id="limit"></a>-limit <em class="arg">type value</em></h4> 3942</div> 3943 3944<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the pixel cache resource limit.</td><td style='text-align:right;'></td></tr></table> 3945 3946<p>Choose from: <kbd>area</kbd>, <kbd>disk</kbd>, <kbd>file</kbd>, <kbd>map</kbd>, <kbd>memory</kbd>, <kbd>threads</kbd>, or <kbd>time</kbd>.</p> 3947 3948<p>The value for <kbd>file</kbd> is in number of files. The other limits are in bytes. By default the limits are 768 files, 2GB of image area, 1.5GiB memory, 8GiB memory map, and 18.45EB of disk. These limits are adjusted relative to the available resources on your computer if this information is available. When any limit is reached, ImageMagick fails in some fashion but attempts to take compensating actions, if possible. For example, the following limits memory:</p> 3949 3950<p class="crtsnip"> 3951 -limit memory 32MiB -limit map 64MiB 3952</p> 3953 3954<p>Use <a href="#list">-list resource</a> to list the current limits. For example, our system shows these limits:</p> 3955 3956<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>identify -list resource</span><span class='crtout'></span></p><pre class="text"> 3957File Area Memory Map Disk Thread Time 3958------------------------------------------------------------------------------ 3959 768 12.404GB 8.6642GiB 23.104GiB 18.446744EB 8 unlimited 3960</pre> 3961 3962<p>Requests for pixel storage to keep intermediate images are satisfied by one of three resource categories: in-memory pool, memory-mapped files pool, and disk pool (in that order) depending on the <a href="/www/command-line-options.html#limit">‑limit</a> settings and whether the system honors a resource request. If the total size of allocated pixel storage in the given pool reaches the corresponding limit, the request is passed to the next pool. Additionally, requests that exceed the <kbd>area</kbd> limit automagically are allocated on disk.</p> 3963 3964<p>To illustrate how ImageMagick utilizes resource limits, consider a typical image resource request. First, ImageMagick tries to allocate the pixels in memory. The request might be denied if the resource request exceeds the <kbd>memory</kbd> limit or if the system does not honor the request. If a memory request is not honored, the pixels are allocated to disk and the file is memory-mapped. However, if the allocation request exceeds the <kbd>map</kbd> limit, the resource allocation goes to disk. In all cases, if the resource request exceeds the <kbd>area</kbd> limit, the pixels are automagically cached to disk. If the disk has a hard limit, the program fails.</p> 3965 3966<p>In most cases you simply do not need to concern yourself with resource limits. ImageMagick chooses reasonable defaults and most images do not tax your computer resources. Where limits do come in handy is when you process images that are large or on shared systems where ImageMagick can consume all or most of the available memory. In this case, the ImageMagick workflow slows other processes or, in extreme cases, brings the system to a halt. Under these circumstances, setting limits give some assurances that the ImageMagick workflow will not interfere with other concurrent uses of the computer. For example, assume you have a web interface that processes images uploaded from the Internet. To assure ImageMagick does not exceed 10mb of memory you can simply set the area limit to 10mb:</p> 3967 3968<p class="crtsnip"> 3969-limit area 10mb 3970</p> 3971 3972<p>Now whenever a large image is processed, the pixels are automagically cached to disk instead of memory. This of course implies that large images typically process very slowly, simply because pixel processing in memory can be an order of magnitude faster than on disk. Because your web site users might inadvertently upload a huge image to process, you should set a disk limit as well:</p> 3973 3974<p class="crtsnip"> 3975-limit area 10mb -limit disk 500mb 3976</p> 3977 3978<p>Here ImageMagick stops processing if an image requires more than 500MB of disk storage.</p> 3979 3980<p>In addition to command-line resource limit option, resources can be set with <a href="/www/resources.html#environment">environment variables</a>. Set the environment variables <kbd>MAGICK_AREA_LIMIT</kbd>, <kbd>MAGICK_DISK_LIMIT</kbd>, <kbd>MAGICK_FILE_LIMIT</kbd>, <kbd>MAGICK_MEMORY_LIMIT</kbd>, <kbd>MAGICK_MAP_LIMIT</kbd>, <kbd>MAGICK_THREAD_LIMIT</kbd>, <kbd>MAGICK_TIME_LIMIT</kbd> for limits of image area, disk space, open files, heap memory, memory map, number of threads of execution, and maximum elapsed time in seconds respectively.</p> 3981 3982<p> Inquisitive users can try adding <a href="#debug">-debug cache</a> to their commands and then scouring the generated output for references to the pixel cache, in order to determine how the pixel cache was allocated and how resources were consumed. Advanced Unix/Linux users can pipe that output through <kbd>grep memory|open|destroy|disk</kbd> for more readable sifting. 3983</p> 3984 3985<p>For more about ImageMagick's use of resources, see the section <b>Cache Storage and Resource Requirements</b> on the <a href="/www/architecture.html#cache">Architecture</a> page. 3986</p> 3987 3988<div style="margin: auto;"> 3989 <h4><a id="linear-stretch"></a>-linear-stretch <em class="arg">black-point</em><br />-linear-stretch <em class="arg">black-point</em>{x<em class="arg">white-point</em>}{<em class="arg">%</em>}}</h4> 3990</div> 3991 3992<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Linear with saturation stretch.</td><td style='text-align:right;'></td></tr></table> 3993 3994<p>This is very similar to <a href="#contrast-stretch" >-contrast-stretch</a>, 3995and uses a 'histogram bin' to determine the range of color values that needs to 3996be stretched. However it then stretchs those colors using the <a 3997href="#level" >-level</a> operator.</p> 3998 3999<p>As such while the initial determination may have 'binning' round off 4000effects, the image colors are stretched mathematically, rather than using the 4001histogram bins. This makes the operator more accurate. </p> 4002 4003<p>note however that a <a href="#linear-stretch" >-linear-stretch</a> of 4004'<kbd>0</kbd>' does nothing, while a value of '<kbd>1</kbd>' does a near 4005perfect stretch of the color range. </p> 4006 4007<p>See also <a href="#auto-level" >-auto-level</a> for a 'perfect' 4008normalization of mathematical images. </p> 4009 4010<p>This operator is under review for re-development. </p> 4011 4012 4013<div style="margin: auto;"> 4014 <h4><a id="linewidth"></a>-linewidth</h4> 4015</div> 4016 4017<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>the line width for subsequent draw operations.</td><td style='text-align:right;'></td></tr></table> 4018 4019<div style="margin: auto;"> 4020 <h4><a id="liquid-rescale"></a>-liquid-rescale <em class="arg">geometry</em></h4> 4021</div> 4022 4023<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>rescale image with seam-carving.</td><td style='text-align:right;'></td></tr></table> 4024 4025<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 4026 4027<div style="margin: auto;"> 4028 <h4><a id="list"></a>-list <em class="arg">type</em></h4> 4029</div> 4030 4031<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Print a list of supported arguments for various options or settings. Choose from these list types:</td><td style='text-align:right;'></td></tr></table> 4032 4033<pre class="text"> 4034 Align 4035 Alpha 4036 Boolean 4037 Channel 4038 Class 4039 ClipPath 4040 Coder 4041 Color 4042 Colorspace 4043 Command 4044 Compose 4045 Compress 4046 Configure 4047 DataType 4048 Debug 4049 Decoration 4050 Delegate 4051 Direction 4052 Dispose 4053 Distort 4054 Dither 4055 Endian 4056 Evaluate 4057 FillRule 4058 Filter 4059 Font 4060 Format 4061 Function 4062 Gravity 4063 ImageList 4064 Intent 4065 Interlace 4066 Interpolate 4067 Kernel 4068 Layers 4069 LineCap 4070 LineJoin 4071 List 4072 Locale 4073 LogEvent 4074 Log 4075 Magic 4076 Method 4077 Metric 4078 Mime 4079 Mode 4080 Morphology 4081 Module 4082 Noise 4083 Orientation 4084 Policy 4085 PolicyDomain 4086 PolicyRights 4087 Preview 4088 Primitive 4089 QuantumFormat 4090 Resource 4091 SparseColor 4092 Storage 4093 Stretch 4094 Style 4095 Threshold 4096 Type 4097 Units 4098 Validate 4099 VirtualPixel 4100</pre> 4101 4102<p>These lists vary depending on your version of ImageMagick. Use "<kbd>-list 4103list</kbd>" to get a complete listing of all the "<kbd>-list</kbd>" arguments 4104available:</p> 4105 4106<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>identify -list list</span></p> 4107<div style="margin: auto;"> 4108 <h4><a id="log"></a>-log <em class="arg">string</em></h4> 4109</div> 4110 4111<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Specify format for debug log.</td><td style='text-align:right;'></td></tr></table> 4112 4113<p>This option specifies the format for the log printed when the <a 4114href="#debug">-debug</a> option is active.</p> 4115 4116<p>You can display the following components by embedding special format 4117characters:</p> 4118 4119<pre class="text"> 4120 %d domain 4121 %e event 4122 %f function 4123 %l line 4124 %m module 4125 %p process ID 4126 %r real CPU time 4127 %t wall clock time 4128 %u user CPU time 4129 %% percent sign 4130 \n newline 4131 \r carriage return 4132</pre> 4133 4134<p>For example:</p> 4135 4136<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert -debug coders -log "%u %m:%l %e" in.gif out.png</span></p> 4137<p>The default behavior is to print all of the components.</p> 4138 4139<div style="margin: auto;"> 4140 <h4><a id="loop"></a>-loop <em class="arg">iterations</em></h4> 4141</div> 4142 4143<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>add Netscape loop extension to your GIF animation.</td><td style='text-align:right;'></td></tr></table> 4144 4145<p>Set iterations to zero to repeat the animation an infinite number of times, 4146otherwise the animation repeats itself up to <em class="arg">iterations</em> 4147times.</p> 4148 4149<div style="margin: auto;"> 4150 <h4><a id="lowlight-color"></a>-lowlight-color <em class="arg">color</em></h4> 4151</div> 4152 4153<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>when comparing images, de-emphasize pixel differences with this color.</td><td style='text-align:right;'></td></tr></table> 4154 4155<div style="margin: auto;"> 4156 <h4><a id="magnify"></a>-magnify <em class="arg">factor</em></h4> 4157</div> 4158 4159<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>magnify the image.</td><td style='text-align:right;'></td></tr></table> 4160 4161 4162<div style="margin: auto;"> 4163 <h4><a id="map"></a>-map <em class="arg">type</em></h4> 4164</div> 4165 4166<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Display image using this <em class="arg">type</em>.</td><td style='text-align:right;'>[<a href="/www/animate.html">animate</a>, <a href="/www/display.html">display</a>]</td></tr></table> 4167 4168<p>Choose from these <em class="arg">Standard Colormap</em> types:</p> 4169 4170<pre class="text"> 4171 best 4172 default 4173 gray 4174 red 4175 green 4176 blue 4177</pre> 4178 4179<p>The <em class="arg">X server</em> must support the <em class="arg">Standard 4180Colormap</em> you choose, otherwise an error occurs. Use <kbd>list</kbd> as 4181the type and <kbd>display</kbd> searches the list of colormap types in 4182<kbd>top-to-bottom</kbd> order until one is located. See <em 4183class="arg">xstdcmap(1)</em> for one way of creating Standard Colormaps.</p> 4184 4185 4186<div style="margin: auto;"> 4187 <h4><a id="map_stream_"></a>-map <em class="arg">components</em></h4> 4188</div> 4189 4190<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>pixel map.</td><td style='text-align:right;'>[<a href="/www/stream.html">stream</a>]</td></tr></table> 4191 4192<p>Here are the valid components of a map:</p> 4193 4194<pre class="text"> 4195 r red pixel component 4196 g green pixel component 4197 b blue pixel component 4198 a alpha pixel component (0 is transparent) 4199 o opacity pixel component (0 is opaque) 4200 i grayscale intensity pixel component 4201 c cyan pixel component 4202 m magenta pixel component 4203 y yellow pixel component 4204 k black pixel component 4205 p pad component (always 0) 4206</pre> 4207 4208<p>You can specify as many of these components as needed in any order (e.g. 4209bgr). The components can repeat as well (e.g. rgbr).</p> 4210 4211 4212<div style="margin: auto;"> 4213 <h4><a id="mask"></a>-mask 4214<em class="arg">filename</em></h4> 4215</div> 4216 4217<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Composite the image pixels as defined by the mask.</td><td style='text-align:right;'></td></tr></table> 4218 4219<p>Use <a href="#mask">+mask</a> to remove the image mask.</p> 4220 4221<div style="margin: auto;"> 4222 <h4><a id="mattecolor"></a>-mattecolor <em class="arg">color</em></h4> 4223</div> 4224 4225<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Specify the color to be used with the <a href="#frame">-frame</a> option.</td><td style='text-align:right;'></td></tr></table> 4226 4227<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p> 4228 4229<p>The default matte color is <kbd>#BDBDBD</kbd>, <span 4230style="background-color: #bdbdbd;">this shade of gray</span>.</p> 4231 4232<div style="margin: auto;"> 4233 <h4><a id="maximum"></a>-maximum</h4> 4234</div> 4235 4236<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>return the maximum intensity of an image sequence.</td><td style='text-align:right;'></td></tr></table> 4237 4238<div style="margin: auto;"> 4239 <h4><a id="median"></a>-median <em class="arg">radius</em></h4> 4240</div> 4241 4242<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>apply a median filter to the image.</td><td style='text-align:right;'></td></tr></table> 4243 4244<div style="margin: auto;"> 4245 <h4><a id="metric"></a>-metric <em class="arg">type</em></h4> 4246</div> 4247 4248<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Output to STDERR a measure of the differences between images according to the <em class="arg">type</em> given metric.</td><td style='text-align:right;'></td></tr></table> 4249 4250<p>Choose from:</p> 4251 4252<pre class="text"> 4253 AE absolute error count, number of different pixels (-fuzz effected) 4254 FUZZ mean color distance 4255 MAE mean absolute error (normalized), average channel error distance 4256 MEPP mean error per pixel (normalized mean error, normalized peak error) 4257 MSE mean error squared, average of the channel error squared 4258 NCC normalized cross correlation 4259 PAE peak absolute (normalize peak absolute) 4260 PSNR peak signal to noise ratio 4261 RMSE root mean squared (normalized root mean squared) 4262</pre> 4263 4264<p>Control the '<kbd>AE</kbd>', or absolute count of pixels that are different, 4265with the <a href="#fuzz" >-fuzz</a> factor (ignore pixels which 4266only changed by a small amount). Use '<kbd>PAE</kbd>' to find the 4267size of the <a href="#fuzz" >-fuzz</a> factor needed to make all pixels 4268'similar', while '<kbd>MAE</kbd>' dtermines the factor needed 4269for about half the pixels to be similar. </p> 4270 4271<p>The '<kbd>MEPP</kbd>' metric returns three different metrics 4272('<kbd>MAE</kbd>', '<kbd>MAE</kbd>' normalized, and '<kbd>PAE</kbd>' 4273normalized) from a single comparison run. </p> 4274 4275<p>To print a complete list of metrics, use the <a href="#list">-list 4276metrics</a> option.</p> 4277 4278 4279<div style="margin: auto;"> 4280 <h4><a id="minimum"></a>-minimum</h4> 4281</div> 4282 4283<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>return the minimum intensity of an image sequence.</td><td style='text-align:right;'></td></tr></table> 4284 4285 4286<div style="margin: auto;"> 4287 <h4><a id="mode"></a>-mode <em class="arg">value</em></h4> 4288</div> 4289 4290<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Mode of operation.</td><td style='text-align:right;'>[<a href="/www/montage.html">montage</a>]</td></tr></table> 4291 4292<p>Choose the <em class="arg">value</em> from these styles: <kbd>Frame, 4293Unframe, or Concatenate</kbd></p> 4294 4295<p>Use the <a href="#list" >-list</a> option with a '<kbd>Mode</kbd>' argument 4296for a list of <a href="#mode" >-mode</a> arguments available in your 4297ImageMagick installation.</p> 4298 4299 4300<div style="margin: auto;"> 4301 <h4><a id="modulate"></a>-modulate <em class="arg">brightness</em>[,<em class="arg">saturation</em>,<em class="arg">hue</em>]</h4> 4302</div> 4303 4304<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Vary the <em class="arg">brightness</em>, <em 4305class="arg">saturation</em>, and <em class="arg">hue</em> of an image.</td><td style='text-align:right;'></td></tr></table> 4306 4307<p>The arguments are given as a percentages of variation. A value of 100 means 4308no change, and any missing values are taken to mean 100.</p> 4309 4310<p>The <em class="arg">brightness</em> is a multiplier of the overall 4311brightness of the image, so 0 means pure black, 50 is half as bright, 200 is 4312twice as bright. To invert its meaning <a href="#negate">-negate</a> the image 4313before and after. </p> 4314 4315<p>The <em class="arg">saturation</em> controls the amount of color in an 4316image. For example, 0 produce a grayscale image, while a large value such as 4317200 produce a very colorful, 'cartoonish' color.</p> 4318 4319<p>The <em class="arg">hue</em> argument causes a "rotation" of the colors 4320within the image by the amount specified. For example, 50 results in 4321a counter-clockwise rotation of 90, mapping red shades to purple, and so on. 4322A value of either 0 or 200 results in a complete 180 degree rotation of the 4323image. Using a value of 300 is a 360 degree rotation resulting in no change to 4324the original image. </p> 4325 4326<p>For example, to increase the color brightness by 20% and decrease the color 4327saturation by 10% and leave the hue unchanged, use <a 4328href="#modulate">-modulate 120,90</a>.</p> 4329 4330<p>Use <a href="#set">-set</a> attribute of '<kbd 4331class="arg">option:modulate:colorspace</kbd>' to specify which colorspace to 4332modulate. Choose from <kbd>HSB</kbd>, <kbd>HSL</kbd> (the default), or 4333<kbd>HWB</kbd>. For example,</p> 4334 4335<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert image.png -set option:modulate:colorspace hsb -modulate 120,90 modulate.png</span></p> 4336 4337<div style="margin: auto;"> 4338 <h4><a id="monitor"></a>-monitor</h4> 4339</div> 4340 4341<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>monitor progress.</td><td style='text-align:right;'></td></tr></table> 4342 4343 4344<div style="margin: auto;"> 4345 <h4><a id="monochrome"></a>-monochrome</h4> 4346</div> 4347 4348<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>transform the image to black and white.</td><td style='text-align:right;'></td></tr></table> 4349 4350 4351<div style="margin: auto;"> 4352 <h4><a id="morph"></a>-morph <em class="arg">frames</em></h4> 4353</div> 4354 4355<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>morphs an image sequence.</td><td style='text-align:right;'></td></tr></table> 4356 4357<p>Both the image pixels and size are linearly interpolated to give the 4358appearance of a meta-morphosis from one image to the next, over all the images 4359in the current image list. The added images are the equivalent of a <a 4360href="#blend">-blend</a> composition. The <em class="arg">frames</em> 4361argument determine how many images to interpolate between each image. </p> 4362 4363 4364<div style="margin: auto;"> 4365 <h4><a id="morphology"></a>-morphology</h4> 4366 <h4>-morphology <em class="arg">method</em> <em class="arg">kernel</em></h4> 4367</div> 4368 4369<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>apply a morphology method to the image.</td><td style='text-align:right;'></td></tr></table> 4370 4371<p>Until I get around to writing a option summary for this, see <a 4372href="http://www.imagemagick.org/Usage/morphology/" >IM Usage Examples, 4373Morphology</a>. </p> 4374 4375 4376<div style="margin: auto;"> 4377 <h4><a id="mosaic"></a>-mosaic</h4> 4378</div> 4379 4380<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>an simple alias for the <a href="#layers" >-layers</a> method "mosaic"</td><td style='text-align:right;'></td></tr></table> 4381 4382 4383<div style="margin: auto;"> 4384 <h4><a id="motion-blur"></a>-motion-blur <em class="arg">radius</em><br />-motion-blur <em class="arg">radius</em>x<em class="arg">sigma</em>+<em class="arg">angle</em></h4> 4385</div> 4386 4387<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>simulate motion blur.</td><td style='text-align:right;'></td></tr></table> 4388 4389<p>Blur with the given radius, standard deviation (sigma), and angle. The 4390angle given is the angle toward which the image is blurred. That is the 4391direction people would consider the object is coming from. </p> 4392 4393<p>Note that the blur is not uniform distribution, giving the motion a 4394definite sense of direction of movement. </p> 4395 4396<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how 4397pixels which are outside the image proper are blurred into the final result. 4398</p> 4399 4400<div style="margin: auto;"> 4401 <h4><a id="name"></a>-name</h4> 4402</div> 4403 4404<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>name an image.</td><td style='text-align:right;'></td></tr></table> 4405<div style="margin: auto;"> 4406 <h4><a id="negate"></a>-negate</h4> 4407</div> 4408 4409<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>replace each pixel with its complementary color.</td><td style='text-align:right;'></td></tr></table> 4410 4411<p>The red, green, and blue intensities of an image are negated. White becomes black, yellow becomes blue, etc. Use <a href="#negate">+negate</a> to only negate the grayscale pixels of the image.</p> 4412 4413<div style="margin: auto;"> 4414 <h4><a id="noise"></a>-noise <em class="arg">radius</em><br/> 4415 +noise <em class="arg">type</em></h4> 4416</div> 4417 4418<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Add or reduce noise in an image.</td><td style='text-align:right;'></td></tr></table> 4419 4420<p>The principal function of noise peak elimination filter is to smooth the objects within an image without losing edge information and without creating undesired structures. The central idea of the algorithm is to replace a pixel with its next neighbor in value within a pixel window, if this pixel has been found to be noise. A pixel is defined as noise if and only if this pixel is a maximum or minimum within the pixel window.</p> 4421 4422<p>Use <kbd><a href="#noise">-noise</a> <em class="arg">radius</em></kbd> to specify the width of the neighborhood when reducing noise.</p> 4423 4424<p>Use <a href="#noise">+noise</a> followed by a noise <em class="arg">type</em> to add noise to an image. Choose from these noise types:</p> 4425 4426<pre class="text"> 4427Gaussian 4428Impulse 4429Laplacian 4430Multiplicative 4431Poisson 4432Random 4433Uniform 4434</pre> 4435 4436<p>To print a complete list of noises, use the <a href="#list">-list noise</a> option.</p> 4437 4438<p>Also see the <a href="#evaluate">-evaluate</a> noise functions that allos 4439the use of a controlling value to specify teh amount of noise that should be 4440added to an image. </p> 4441 4442 4443<div style="margin: auto;"> 4444 <h4><a id="normalize"></a>-normalize</h4> 4445</div> 4446 4447<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Increase the contrast in an image by <em>stretching</em> the range of intensity values.</td><td style='text-align:right;'></td></tr></table> 4448 4449<p>The intensity values are stretched to cover the entire range of possible 4450values. While doing so, black-out at most <em>2%</em> of the pixels and 4451white-out at most <em>1%</em> of the pixels.</p> 4452 4453<p>Note that as of ImageMagick 6.4.7-0, <a href="#normalize" >-normalize</a> 4454is equivalent to <a href="#contrast-stretch" >-contrast-stretch 2%x1%</a>. 4455(Before this version, it was equivalent to <a href="#contrast-stretch" 4456>-contrast-stretch 2%x99%</a>).</p> 4457 4458<p>All the channels are normalized in concert by the came amount so as to 4459preserve color integrity, when the default <a href="#channel" >+channel</a> 4460setting is in use. Specifying any other <a href="#channel" >-channel</a> 4461setting will normalize the RGB channels independently.</p> 4462 4463<p>See <a href="#contrast-stretch" >-contrast-stretch</a> for more details. 4464Also see <a href="#auto-level" >-auto-level</a> for a 'perfect' normalization 4465that is better suited to mathematically generated images. </p> 4466 4467<p>This operator is under review for re-development. </p> 4468 4469 4470<div style="margin: auto;"> 4471 <h4><a id="ordered-dither"></a>-ordered-dither <em class="arg">threshold_map</em>{,<em class="arg">level</em>...}</h4> 4472</div> 4473 4474<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>dither the image using a pre-defined ordered dither <em 4475class="arg">threshold map</em> specified, and a uniform color map with the 4476given number of <em class="arg">levels</em> per color channel . </td><td style='text-align:right;'></td></tr></table> 4477 4478<p>You can choose from these standard threshold maps:</p> 4479 4480<pre class="text"> 4481threshold 1x1 Threshold 1x1 (non-dither) 4482checks 2x1 Checkerboard 2x1 (dither) 4483o2x2 2x2 Ordered 2x2 (dispersed) 4484o3x3 3x3 Ordered 3x3 (dispersed) 4485o4x4 4x4 Ordered 4x4 (dispersed) 4486o8x8 8x8 Ordered 8x8 (dispersed) 4487h4x4a 4x1 Halftone 4x4 (angled) 4488h6x6a 6x1 Halftone 6x6 (angled) 4489h8x8a 8x1 Halftone 8x8 (angled) 4490h4x4o Halftone 4x4 (orthogonal) 4491h6x6o Halftone 6x6 (orthogonal) 4492h8x8o Halftone 8x8 (orthogonal) 4493h16x16o Halftone 16x16 (orthogonal) 4494c5x5b c5x5 Circles 5x5 (black) 4495c5x5w Circles 5x5 (white) 4496c6x6b c6x6 Circles 6x6 (black) 4497c6x6w Circles 6x6 (white) 4498c7x7b c7x7 Circles 7x7 (black) 4499c7x7w Circles 7x7 (white) 4500</pre> 4501 4502<p> The <kbd>checks</kbd> pattern produces a 3 level checkerbord dither 4503pattern. Or you can define your own <em class="arg" >threshold map</em> in a 4504personal or system <kbd>thresholds.xml</kbd> XML file. </p> 4505 4506<p>To print a complete list of threshold, use the <a href="#list" >-list 4507threshold</a> option.</p> 4508 4509<p>It is recommended that the <a href="#map" >+map</a> operator be used after 4510applying <a href="#ordered-dither" >-ordered-dither</a> to reduce the number of 4511colors an animated image sequence, to less that 256 colors. This ensures that 4512a common or global color table is used when saving the result to a color 4513limited file format such as GIF. </p> 4514 4515<p>Note that at this time the exact same threshold dithering map is used for 4516all color channels, no attempt is made to offset or rotate the map for 4517different channels is made, to create an offset printing effect. (possible 4518future expansion) </p> 4519 4520 4521<div style="margin: auto;"> 4522 <h4><a id="opaque"></a>-opaque <em class="arg">color</em></h4> 4523</div> 4524 4525<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>change this color to the fill color within the image.</td><td style='text-align:right;'></td></tr></table> 4526 4527<p>The <em class="arg">color</em> argument is defined using the format 4528described under the <a href="#fill" >-fill</a> option. The <a href="#fuzz" 4529>-fuzz</a> setting can be used to match and replace colors similar to the one 4530given.</p> 4531 4532<p>Use <a href="#opaque">+opaque</a> to paint any pixel that does not match 4533the target color. </p> 4534 4535<p>The <a href="#transparent">-transparent</a> operator is exactly the same 4536as <a href="#opaque" >-opaque</a> but replaces the matching color with 4537transparency rather than the current <a href="#fill">-fill</a> color setting. 4538To ensure that it can do this it also ensures that the image has an alpha 4539channel enabled, as per "<kbd><a href="#alpha" >-alpha</a> set</kbd>", for 4540the new transparent colors, and does not require you to modify the <a 4541href="#channel">-channel</a> to enable alpha channel handling. </p> 4542 4543 4544<div style="margin: auto;"> 4545 <h4><a id="orient"></a>-orient <em class="arg">image orientation</em></h4> 4546</div> 4547 4548<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>specify orientation of a digital camera image.</td><td style='text-align:right;'></td></tr></table> 4549 4550<p>Choose from these orientations:</p> 4551 4552<pre class="text"> 4553 bottom-left 4554 bottom-right 4555 left-bottom 4556 left-top 4557 right-bottom 4558 right-top 4559 top-left 4560 top-right 4561 undefined 4562</pre> 4563 4564<p>To print a complete list of orientations, use the <a href="#list" >-list 4565orientation</a> option.</p> 4566 4567 4568<div style="margin: auto;"> 4569 <h4><a id="page"></a>-page <em class="arg">geometry</em><br/> 4570 -page <em class="arg">media</em>[<em class="arg">offset</em>][{<em class="arg">^!<></em>}]<br/> 4571 +page 4572 </h4> 4573</div> 4574 4575<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the size and location of an image on the larger virtual canvas.</td><td style='text-align:right;'></td></tr></table> 4576 4577<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 4578 4579<p>For convenience you can specify the page size using <em class="arg">media</em> (see below). Offsets can then be added as with other <em class="arg">geometry</em> arguments (e.g. <a href="#page">-page</a> <kbd>Letter+43+43</kbd>).</p> 4580 4581<p>Use <em class="arg">media</em> as shorthand to specify the dimensions (<em class="arg">width</em>x<em class="arg">height</em>) of the <em class="arg">PostScript</em> page in dots per inch or a TEXT page in pixels. The choices for a PostScript page are:</p> 4582<table id="geometryTable" cellpadding="2" cellspacing="0" border="1" width="50%" style="margin-left: auto; margin-right: auto;"> 4583<thead> 4584 <tr valign="top"> 4585 <th align="center"><em class="arg">media</em></th> 4586 <th align="center"><em class="arg">width</em></th> 4587 <th align="center"><em class="arg">height</em></th> 4588 </tr> 4589</thead> 4590<tbody> 4591<tr><td align="left"> 11x17 </td> <td align="right"> 792</td> <td align="right"> 1224</td> </tr> 4592<tr><td align="left"> Ledger </td> <td align="right"> 1224</td> <td align="right"> 792</td> </tr> 4593<tr><td align="left"> Legal </td> <td align="right"> 612</td> <td align="right"> 1008</td> </tr> 4594<tr><td align="left"> Letter </td> <td align="right"> 612</td> <td align="right"> 792</td> </tr> 4595<tr><td align="left"> LetterSmall</td> <td align="right"> 612</td> <td align="right"> 792</td> </tr> 4596<tr><td align="left"> ArchE </td> <td align="right"> 2592</td> <td align="right"> 3456</td> </tr> 4597<tr><td align="left"> ArchD </td> <td align="right"> 1728</td> <td align="right"> 2592</td> </tr> 4598<tr><td align="left"> ArchC </td> <td align="right"> 1296</td> <td align="right"> 1728</td> </tr> 4599<tr><td align="left"> ArchB </td> <td align="right"> 864</td> <td align="right"> 1296</td> </tr> 4600<tr><td align="left"> ArchA </td> <td align="right"> 648</td> <td align="right"> 864</td> </tr> 4601<tr><td align="left"> A0 </td> <td align="right"> 2380</td> <td align="right"> 3368</td> </tr> 4602<tr><td align="left"> A1 </td> <td align="right"> 1684</td> <td align="right"> 2380</td> </tr> 4603<tr><td align="left"> A2 </td> <td align="right"> 1190</td> <td align="right"> 1684</td> </tr> 4604<tr><td align="left"> A3 </td> <td align="right"> 842</td> <td align="right"> 1190</td> </tr> 4605<tr><td align="left"> A4 </td> <td align="right"> 595</td> <td align="right"> 842</td> </tr> 4606<tr><td align="left"> A4Small </td> <td align="right"> 595</td> <td align="right"> 842</td> </tr> 4607<tr><td align="left"> A5 </td> <td align="right"> 421</td> <td align="right"> 595</td> </tr> 4608<tr><td align="left"> A6 </td> <td align="right"> 297</td> <td align="right"> 421</td> </tr> 4609<tr><td align="left"> A7 </td> <td align="right"> 210</td> <td align="right"> 297</td> </tr> 4610<tr><td align="left"> A8 </td> <td align="right"> 148</td> <td align="right"> 210</td> </tr> 4611<tr><td align="left"> A9 </td> <td align="right"> 105</td> <td align="right"> 148</td> </tr> 4612<tr><td align="left"> A10 </td> <td align="right"> 74</td> <td align="right"> 105</td> </tr> 4613<tr><td align="left"> B0 </td> <td align="right"> 2836</td> <td align="right"> 4008</td> </tr> 4614<tr><td align="left"> B1 </td> <td align="right"> 2004</td> <td align="right"> 2836</td> </tr> 4615<tr><td align="left"> B2 </td> <td align="right"> 1418</td> <td align="right"> 2004</td> </tr> 4616<tr><td align="left"> B3 </td> <td align="right"> 1002</td> <td align="right"> 1418</td> </tr> 4617<tr><td align="left"> B4 </td> <td align="right"> 709</td> <td align="right"> 1002</td> </tr> 4618<tr><td align="left"> B5 </td> <td align="right"> 501</td> <td align="right"> 709</td> </tr> 4619<tr><td align="left"> C0 </td> <td align="right"> 2600</td> <td align="right"> 3677</td> </tr> 4620<tr><td align="left"> C1 </td> <td align="right"> 1837</td> <td align="right"> 2600</td> </tr> 4621<tr><td align="left"> C2 </td> <td align="right"> 1298</td> <td align="right"> 1837</td> </tr> 4622<tr><td align="left"> C3 </td> <td align="right"> 918</td> <td align="right"> 1298</td> </tr> 4623<tr><td align="left"> C4 </td> <td align="right"> 649</td> <td align="right"> 918</td> </tr> 4624<tr><td align="left"> C5 </td> <td align="right"> 459</td> <td align="right"> 649</td> </tr> 4625<tr><td align="left"> C6 </td> <td align="right"> 323</td> <td align="right"> 459</td> </tr> 4626<tr><td align="left"> Flsa </td> <td align="right"> 612</td> <td align="right"> 936</td> </tr> 4627<tr><td align="left"> Flse </td> <td align="right"> 612</td> <td align="right"> 936</td> </tr> 4628<tr><td align="left"> HalfLetter </td> <td align="right"> 396</td> <td align="right"> 612</td> </tr> 4629</tbody> 4630</table> 4631 4632 4633 4634 4635<p>This option is also used to place subimages when writing to a multi-image format that supports offsets, such as GIF89 and MNG. When used for this purpose the offsets are always measured from the top left corner of the canvas and are not affected by the <a href="#gravity">-gravity</a> option. To position a GIF or MNG image, use <a href="#page">-page</a><em class="arg">{+-}x{+-}y</em> (e.g. -page +100+200). When writing to a MNG file, a <a href="#page">-page</a> option appearing ahead of the first image in the sequence with nonzero width and height defines the width and height values that are written in the <kbd>MHDR</kbd> chunk. Otherwise, the MNG width and height are computed from the bounding box that contains all images in the sequence. When writing a GIF89 file, only the bounding box method is used to determine its dimensions.</p> 4636 4637<p>For a PostScript page, the image is sized as in <a href="#geometry">-geometry</a> but positioned relative to the <em>lower left-hand corner</em> of the page by {+-}<kbd>x</kbd><em class="arg">offset</em>{+-}<kbd>y</kbd> <em class="arg">offset</em>. Use <a href="#page">-page 612x792</a>, for example, to center the image within the page. If the image size exceeds the PostScript page, it is reduced to fit the page. The default gravity for the <a href="#page">-page</a> option is <em class="arg">NorthWest</em>, i.e., positive <kbd>x</kbd> and <kbd>y</kbd> <em class="arg">offset</em> are measured rightward and downward from the top left corner of the page, unless the <a href="#gravity">-gravity</a> option is present with a value other than <em class="arg">NorthWest</em>.</p> 4638 4639<p>The default page dimensions for a TEXT image is 612x792.</p> 4640 4641<p>This option is used in concert with <a href="#density">-density</a>.</p> 4642 4643<p>Use <a href="#page">+page</a> to remove the page settings for an image.</p> 4644 4645<div style="margin: auto;"> 4646 <h4><a id="paint"></a>-paint <em class="arg">radius</em></h4> 4647</div> 4648 4649<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>simulate an oil painting.</td><td style='text-align:right;'></td></tr></table> 4650 4651<p>Each pixel is replaced by the most frequent color in a circular neighborhood whose width is specified with <em class="arg">radius</em>.</p> 4652 4653<div style="margin: auto;"> 4654 <h4><a id="path"></a>-path <em class="arg">path</em></h4></div> 4655 4656<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>write images to this path on disk.</td><td style='text-align:right;'></td></tr></table> 4657 4658<div style="margin: auto;"> 4659 <h4><a id="pause_animate_"></a>-pause <em class="arg">seconds</em></h4> 4660</div> 4661 4662<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Pause between animation loops.</td><td style='text-align:right;'>[<a href="/www/animate.html">animate</a>]</td></tr></table> 4663 4664<p>Pause for the specified number of seconds before repeating the animation.</p> 4665 4666<div style="margin: auto;"> 4667 <h4><a id="pause_import_"></a>-pause <em class="arg">seconds</em></h4> 4668</div> 4669 4670<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Pause between snapshots.</td><td style='text-align:right;'>[<a href="/www/import.html">import</a>]</td></tr></table> 4671 4672<p>Pause for the specified number of seconds before taking the next snapshot.</p> 4673 4674<div style="margin: auto;"> 4675 <h4><a id="ping"></a>-ping</h4> 4676</div> 4677 4678<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>efficiently determine image characteristics.</td><td style='text-align:right;'></td></tr></table> 4679 4680<div style="margin: auto;"> 4681 <h4><a id="pointsize"></a>-pointsize <em class="arg">value</em></h4> 4682</div> 4683 4684<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>pointsize of the PostScript, OPTION1, or TrueType font.</td><td style='text-align:right;'></td></tr></table> 4685 4686<div style="margin: auto;"> 4687 <h4><a id="polaroid"></a>-polaroid <em class="arg">angle</em></h4> 4688</div> 4689 4690<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>simulate a Polaroid picture.</td><td style='text-align:right;'></td></tr></table> 4691 4692<p>Use <kbd>+polaroid</kbd> to rotate the image at a random angle between -15 and +15 degrees.</p> 4693 4694<div style="margin: auto;"> 4695 <h4><a id="posterize"></a>-posterize <em class="arg">levels</em></h4> 4696</div> 4697 4698<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>reduce the image to a limited number of color levels.</td><td style='text-align:right;'></td></tr></table> 4699 4700<div style="margin: auto;"> 4701 <h4><a id="precision"></a>-precision <em class="arg">value</em></h4> 4702</div> 4703 4704<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>set the maximum number of significant digits to be printed.</td><td style='text-align:right;'></td></tr></table> 4705 4706<div style="margin: auto;"> 4707 <h4><a id="preview"></a>-preview <em class="arg">type</em></h4> 4708</div> 4709 4710<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>image preview type.</td><td style='text-align:right;'></td></tr></table> 4711 4712<p>Use this option to affect the preview operation of an image (e.g. <kbd>convert file.png -preview Gamma Preview:gamma.png</kbd>). Choose from these previews:</p> 4713 4714<pre class="text"> 4715 Rotate 4716 Shear 4717 Roll 4718 Hue 4719 Saturation 4720 Brightness 4721 Gamma 4722 Spiff 4723 Dull 4724 Grayscale 4725 Quantize 4726 Despeckle 4727 ReduceNoise 4728 Add Noise 4729 Sharpen 4730 Blur 4731 Threshold 4732 EdgeDetect 4733 Spread 4734 Shade 4735 Raise 4736 Segment 4737 Solarize 4738 Swirl 4739 Implode 4740 Wave 4741 OilPaint 4742 CharcoalDrawing 4743 JPEG 4744</pre> 4745 4746<p>To print a complete list of previews, use the <a href="#list">-list preview</a> option.</p> 4747 4748<p>The default preview is <kbd>JPEG</kbd>.</p> 4749 4750<div style="margin: auto;"> 4751 <h4><a id="print"></a>-print <em class="arg">string</em></h4> 4752</div> 4753 4754<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>interpret string and print to console.</td><td style='text-align:right;'></td></tr></table> 4755 4756<div style="margin: auto;"> 4757 <h4><a id="process"></a>-process <em class="arg">command</em></h4> 4758</div> 4759 4760<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>process the image with a custom image filter.</td><td style='text-align:right;'></td></tr></table> 4761 4762<p>The command arguments has the form <kbd>"module arg1 arg2 arg3 ... argN"</kbd> where <kbd>module</kbd> is the name of the module to invoke (e.g. "Analyze") and arg1 arg2 arg3 ... argN are an arbitrary number of arguments to pass to the process module.</p> 4763 4764<div style="margin: auto;"> 4765 <h4><a id="profile"></a>-profile <em class="arg">filename</em><br/> 4766 +profile <em class="arg">profile_name</em></h4> 4767</div> 4768 4769<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Manage ICM, IPTC, or generic profiles in an image.</td><td style='text-align:right;'></td></tr></table> 4770 4771<p>Using <a href="#profile">-profile</a> <em class="arg">filename</em> adds an ICM (ICC color management), IPTC (newswire information), or a generic profile to the image.</p> 4772 4773<p>Use <a href="#profile">+profile <em class="arg">profile_name</em></a> to remove the indicated profile. ImageMagick uses standard filename globbing, so wildcard expressions may be used to remove more than one profile. Here we remove all profiles from the image except for the XMP profile: <kbd>+profile "!xmp,*"</kbd>. </p> 4774 4775<p>Use <kbd>identify -verbose</kbd> to find out which profiles are in the image file. Use <a href="#strip">-strip</a> to remove all profiles (and comments).</p> 4776 4777<p>To extract a profile, the <a href="#profile">-profile</a> option is not used. Instead, simply write the file to an image format such as <em class="arg">APP1, 8BImageMagick, ICM,</em> or <em class="arg">IPTC</em>.</p> 4778 4779<p>For example, to extract the Exif data (which is stored in JPEG files in the <em class="arg">APP1</em> profile), use.</p> 4780 4781<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert cockatoo.jpg profile.exif</span></p> 4782<p>It is important to note that results may depend on whether or not the original image already has an included profile. Also, keep in mind that <a href="#profile">-profile</a> is an "operator" (as opposed to a "setting") and therefore a conversion is made each time it is encountered, in order, in the command-line. For instance, in the following example, if the original image is CMYK with profile, a CMYK-CMYK-RGB conversion results.</p> 4783 4784<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert CMYK.tif -profile "CMYK.icc" -profile "RGB.icc" RGB.tiff</span></p> 4785<p>Furthermore, since ICC profiles are not necessarily symmetric, extra conversion steps can yield unwanted results. 4786CMYK profiles are often very asymmetric since they involve 3−>4 and 4−>3 channel mapping. 4787</p> 4788 4789<p>The <a href="#profile">-profile</a> option can also be used to inject 4790previously-formatted ancillary chunks into the output PNG file, using 4791the commandline option as shown below or by setting the profile via a 4792programming interface:</p> 4793 4794<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>-profile PNG-chunk-x:<filename></span></p> 4795<p>where <em>x</em> is a location flag and 4796<em class="arg">filename</em> is a file containing the chunk 4797name in the first 4 bytes, then a colon (":"), followed by the chunk data. 4798This encoder will compute the chunk length and CRC, so those must not 4799be included in the file.</p> 4800 4801<p>"x" can be "b" (before PLTE), "m" (middle, i.e., between PLTE and IDAT), 4802or "e" (end, i.e., after IDAT). If you want to write multiple chunks 4803of the same type, then add a short unique string after the "x" to prevent 4804subsequent profiles from overwriting the preceding ones, e.g.,</p> 4805 4806 4807<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>-profile PNG-chunk-b01:file01 -profile PNG-chunk-b02:file02</span></p> 4808<div style="margin: auto;"> 4809 <h4><a id="quality"></a>-quality <em class="arg">value</em></h4> 4810</div> 4811 4812<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>JPEG/MIFF/PNG compression level.</td><td style='text-align:right;'></td></tr></table> 4813 4814<p>For the JPEG and MPEG image formats, quality is 1 (lowest image quality and highest compression) to 100 (best quality but least effective compression). The default is to use the estimate quality of your input image otherwise 92. Use the <a href="#sampling-factor">-sampling-factor</a> option to specify the factors for chroma downsampling.</p> 4815 4816<p>For the MIFF image format, quality/10 is the zlib compression level, which is 0 (worst but fastest compression) to 9 (best but slowest). It has no effect on the image appearance, since the compression is always lossless.</p> 4817 4818<p>For the JPEG-2000 image format, quality is mapped using a non-linear equation to the compression ratio required by the Jasper library. This non-linear equation is intended to loosely approximate the quality provided by the JPEG v1 format. The default quality value 100, a request for non-lossy compression. A quality of 75 results in a request for 16:1 compression.</p> 4819 4820<p>For the MNG and PNG image formats, the quality value sets the zlib compression level (quality / 10) and filter-type (quality % 10). For compression level 0, the Huffman-only strategy is used, which is fastest but not necessarily the worst compression. The default PNG compression is 75.</p> 4821 4822<p>If filter-type is 4 or less, the specified filter-type is used for all scanlines:</p> 4823 4824<pre class="text"> 4825 0: none 4826 1: sub 4827 2: up 4828 3: average 4829 4: Paeth 4830</pre> 4831 4832<p>If filter-type is 5, adaptive filtering is used when quality is greater than 50 and the image does not have a color map, otherwise no filtering is used.</p> 4833 4834<p>If filter-type is 6, adaptive filtering with <em class="arg">minimum-sum-of-absolute-values</em> is used.</p> 4835 4836<p>Only if the output is MNG, if filter-type is 7, the LOCO color transformation and adaptive filtering with <em class="arg">minimum-sum-of-absolute-values</em> are used.</p> 4837 4838<p>The quality setting has no effect on the appearance of PNG and MNG images, since the compression is always lossless.</p> 4839 4840<p>For further information, see the <a href="http://www.w3.org/pub/WWW/TR">PNG</a> specification.</p> 4841 4842<div style="margin: auto;"> 4843 <h4><a id="quantize"></a>-quantize <em class="arg">colorspace</em></h4> 4844</div> 4845 4846<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>reduce colors using this colorspace.</td><td style='text-align:right;'></td></tr></table> 4847 4848<p>This setting defines the colorspace used to sort out and reduce the number 4849of colors needed by an image (for later dithering) by operators such as <a 4850href="#colors" >-colors</a>, Note that color reducion also happens 4851automatically when saving images to color-limited image file formats, such as 4852GIF, and PNG8.</p> 4853 4854 4855<div style="margin: auto;"> 4856 <h4><a id="quiet"></a>-quiet</h4> 4857</div> 4858 4859<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>suppress all warning messages. Error messages are still reported.</td><td style='text-align:right;'></td></tr></table> 4860 4861<div style="margin: auto;"> 4862 <h4><a id="radial-blur"></a>-radial-blur <em class="arg">angle</em></h4> 4863</div> 4864 4865<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Blur around the center of the image.</td><td style='text-align:right;'></td></tr></table> 4866 4867<p>Note that this is actually a rotational blur rather than a radial and as 4868such actually mis-named. </p> 4869 4870<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how 4871pixels which are outside the image proper are blurred into the final result. 4872</p> 4873 4874 4875<div style="margin: auto;"> 4876 <h4><a id="raise"></a>-raise <em class="arg">thickness</em></h4> 4877</div> 4878 4879<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Lighten or darken image edges.</td><td style='text-align:right;'></td></tr></table> 4880 4881<p>This will create a 3-D effect. Use <a href="#raise">-raise</a> to create a raised effect, otherwise use <a href="#raise">+raise</a>. 4882</p> 4883 4884<p>Unlike the similar <a href="#frame">-frame</a> option, <a href="#raise">-raise</a> does not alter the dimensions of the image.</p> 4885 4886<div style="margin: auto;"> 4887 <h4><a id="random-threshold"></a>-random-threshold <em class="arg">low</em>x<em class="arg">high</em></h4> 4888</div> 4889 4890<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Apply a random threshold to the image.</td><td style='text-align:right;'></td></tr></table> 4891 4892<div style="margin: auto;"> 4893 <h4><a id="red-primary"></a>-red-primary <em class="arg">x,y</em></h4> 4894</div> 4895 4896<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the red chromaticity primary point.</td><td style='text-align:right;'></td></tr></table> 4897 4898<div style="margin: auto;"> 4899 <h4><a id="regard-warnings"></a>-regard-warnings</h4> 4900</div> 4901 4902<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Pay attention to warning messages.</td><td style='text-align:right;'></td></tr></table> 4903 4904<div style="margin: auto;"> 4905 <h4><a id="remap"></a>-remap <em class="arg">filename</em></h4> 4906</div> 4907 4908<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Reduce the number of colors in an image to the colors used by this image.</td><td style='text-align:right;'></td></tr></table> 4909 4910<p>If the <a href="#dither">-dither</a> setting is enabled (the default) then 4911the given colors are dithered over the image as necessary, otherwise the closest 4912color (in RGB colorspace) is selected to replace that pixel in the image. </p> 4913 4914<p>As a side effect of applying a <a href="#remap">-remap</a> of colors across all 4915images in the current image sequence, all the images will have the same color 4916table. That means that when saved to a file format such as GIF, it will use 4917that color table as a single common or global color table, for all the images, 4918without requiring extra local color tables. </p> 4919 4920<p>Use <a href="#remap">+remap</a> to reduce all images in the current image 4921sequence to use a common color map over all the images. This equivalent to 4922appending all the images together (without extra background colors) and color 4923reducing those images using <a href="#colors">-colors</a> with a 256 color 4924limit, then <a href="#remap">-remap</a> those colors over the original list of 4925images. This ensures all the images follow a single color map. </p> 4926 4927<p>If the number of colors over all the images is less than 256, then <a 4928href="#remap">+remap</a> should not perform any color reduction or dithering, as 4929no color changes are needed. In that case, its only effect is to force the use 4930of a global color table. This recommended after using either <a 4931href="#colors">-colors</a> or <a href="#ordered-dither">-ordered-dither</a> to 4932reduce the number of colors in an animated image sequence. </p> 4933 4934<div style="margin: auto;"> 4935 <h4><a id="region"></a>-region <em class="arg">geometry</em></h4> 4936</div> 4937 4938<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set a region in which subsequent operations apply.</td><td style='text-align:right;'></td></tr></table> 4939 4940<p>The <em class="arg">x</em> and <em class="arg">y</em> offsets are treated in the same manner as in <a href="#crop">-crop</a>.</p> 4941 4942<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 4943 4944<div style="margin: auto;"> 4945 <h4><a id="remote"></a>-remote</h4> 4946</div> 4947 4948<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>perform a remote operation.</td><td style='text-align:right;'></td></tr></table> 4949 4950<p>The only command recognized is the name of an image file to load.</p> 4951 4952<p>If you have more than one <a href="/www/display.html">display</a> application running simultaneously, use the <a href="#window"> window</a> option to specify which application to control.</p> 4953 4954<div style="margin: auto;"> 4955 <h4><a id="render"></a>-render</h4> 4956</div> 4957 4958<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>render vector operations.</td><td style='text-align:right;'></td></tr></table> 4959 4960<p>Use <a href="#render">+render</a> to turn off rendering vector operations. This useful when saving the result to vector formats such as MVG or SVG.</p> 4961 4962<div style="margin: auto;"> 4963<h4><a id="repage"></a>-repage <em class="arg">geometry</em></h4> 4964</div> 4965 4966<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Adjust the canvas and offset information of the image.</td><td style='text-align:right;'></td></tr></table> 4967 4968<p>This option is like <a href="#page">-page</a> but acts as an image operator 4969rather than a setting. You can separately set the canvas size or the offset 4970of the image on that canvas by only providing those components. </p> 4971 4972<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 4973 4974<p>If a <kbd>!</kbd> flag is given the offset given is added to the existing 4975offset to move the image relative to its previous position. This useful for 4976animation sequences. </p> 4977 4978<p>A given a canvas size of zero such as '<kbd>0x0</kbd>' forces it to 4979recalculate the canvas size so the image (at its current offset) will appear 4980completely on that canvas (unless it has a negative offset).</p> 4981 4982<p>Use <a href="#repage">+repage</a> to completely remove/reset the virtual 4983canvas meta-data from the images. </p> 4984 4985<p>The <a href="#set">-set</a> '<kbd>page</kbd>' option can be used to 4986directly assign virtual canvas meta-data. </p> 4987 4988 4989<div style="margin: auto;"> 4990 <h4><a id="resample"></a>-resample <em class="arg">horizontal</em>x<em class="arg">vertical</em></h4> 4991</div> 4992 4993<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Resample image to specified horizontal and vertical resolution.</td><td style='text-align:right;'></td></tr></table> 4994 4995<p>Resize the image so that its rendered size remains the same as the original at the specified target resolution. For example, if a 300 DPI image renders at 3 inches by 2 inches on a 300 DPI device, when the image has been resampled to 72 DPI, it will render at 3 inches by 2 inches on a 72 DPI device. Note that only a small number of image formats (e.g. JPEG, PNG, and TIFF) are capable of storing the image resolution. For formats which do not support an image resolution, the original resolution of the image must be specified via <a href="#density">-density</a> on the command line prior to specifying the resample resolution.</p> 4996 4997<p>Note that Photoshop stores and obtains image resolution from a proprietary embedded profile. If this profile exists in the image, then Photoshop will continue to treat the image using its former resolution, ignoring the image resolution specified in the standard file header.</p> 4998 4999<div style="margin: auto;"> 5000 <h4><a id="resize"></a>-resize <em class="arg">geometry</em></h4> 5001</div> 5002 5003<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Resize an image.</td><td style='text-align:right;'></td></tr></table> 5004 5005<p>See <a href="/www/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 ignored, and the <a href="#gravity">-gravity</a> option has no effect.</p> 5006 5007<p>If the <a href="#filter">-filter</a> option precedes the <a href="#resize">-resize</a> option, the image is resized with the specified filter.</p> 5008 5009<p>Many image processing algorithms assume your image is in a linear-light coding. If your image is gamma-corrected, you can remove the nonlinear gamma correction, apply the transform, then restore it like this:</p> 5010 5011<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert portrait.jpg -gamma .45455 -resize 25% -gamma 2.2 \ <br/> -quality 92 passport.jpg</span></p> 5012<div style="margin: auto;"> 5013 <h4><a id="respect-parentheses"></a>-respect-parentheses</h4> 5014</div> 5015 5016<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>settings remain in effect until parenthesis boundary.</td><td style='text-align:right;'></td></tr></table> 5017 5018<div style="margin: auto;"> 5019 <h4><a id="reverse"></a>-reverse</h4> 5020</div> 5021 5022<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Reverse the order of images in the current image list.</td><td style='text-align:right;'></td></tr></table> 5023 5024 5025<div style="margin: auto;"> 5026 <h4><a id="roll"></a>-roll {<em class="arg">+-</em>}<em class="arg">x</em>{<em class="arg">+-</em>}<em class="arg">y</em></h4> 5027</div> 5028 5029<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>roll an image vertically or horizontally by the amount given.</td><td style='text-align:right;'></td></tr></table> 5030 5031<p>A negative <em class="arg">x</em> offset rolls the image left-to-right. A negative <em class="arg">y</em> offset rolls the image top-to-bottom.</p> 5032 5033 5034<div style="margin: auto;"> 5035 <h4><a id="rotate"></a>-rotate <em class="arg">degrees</em>{<em class="arg"><</em>}{<em class="arg">></em>}</h4> 5036</div> 5037 5038<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Apply Paeth image rotation (using shear operations) to the image.</td><td style='text-align:right;'></td></tr></table> 5039 5040<p>Use <kbd>></kbd> to rotate the image only if its width exceeds the height. <kbd><</kbd> rotates the image <em>only</em> if its width is less than the height. For example, if you specify <kbd>-rotate "-90>"</kbd> and the image size is 480x640, the image is not rotated. However, if the image is 640x480, it is rotated by -90 degrees. If you use <kbd>></kbd> or <kbd><</kbd>, enclose it in quotation marks to prevent it from being misinterpreted as a file redirection.</p> 5041 5042<p>Empty triangles in the corners, left over from rotating the image, are 5043filled with the <kbd>background</kbd> color. </p> 5044 5045<p>See also the <a href="#distort">-distort</a> operator and specifically the 5046'<kbd>ScaleRotateTranslate</kbd>' distort method. </p> 5047 5048 5049<div style="margin: auto;"> 5050 <h4><a id="sample"></a>-sample <em class="arg">geometry</em></h4> 5051</div> 5052 5053<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>minify/magnify the image using pixel subsampling and pixel replication, respectively.</td><td style='text-align:right;'></td></tr></table> 5054 5055<p>Change the image size simply by directly sampling the pixels original 5056image. When magnifying, pixels are replicated in blocks. When minifying, 5057pixels are sub-sampled (i.e., some rows and columns are skipped over). </p> 5058 5059<p>The results are thus equivalent to using <a href="#resize">-resize</a> with 5060a <a href="#filter">-filter</a> setting of <kbd>point</kbd> (nearest 5061neighbour), though <a href="#sample">-sample</a> is a lot faster, as it 5062avoids all the filter processing of the image. As such it completely ignores 5063the current <a href="#filter">-filter</a> setting. </p> 5064 5065<p>The key feature of the <a href="#sample">-sample</a> is that no new colors 5066will be added to the resulting image, though some colors may disappear. </p> 5067 5068<p>See <a href="/www/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 5069ignored, unlike <a href="#resize">-resize</a>. </p> 5070 5071 5072<div style="margin: auto;"> 5073 <h4><a id="sampling-factor"></a>-sampling-factor <em class="arg">horizontal-factor</em>x<em class="arg">vertical-factor</em></h4> 5074</div> 5075 5076<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>sampling factors used by JPEG or MPEG-2 encoder and YUV decoder/encoder.</td><td style='text-align:right;'></td></tr></table> 5077 5078<p>This option specifies the sampling factors to be used by the JPEG encoder for chroma downsampling. If this option is omitted, the JPEG library will use its own default values. When reading or writing the YUV format and when writing the M2V (MPEG-2) format, use <a href="#sampling-factor">-sampling-factor 2x1</a> or <a href="#sampling-factor">-sampling-factor 4:2:2</a> to specify the 4:2:2 downsampling method.</p> 5079 5080<div style="margin: auto;"> 5081 <h4><a id="scale"></a>-scale <em class="arg">geometry</em></h4> 5082</div> 5083 5084<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>minify/magnify the image using pixel block averaging and pixel replication, respectively.</td><td style='text-align:right;'></td></tr></table> 5085 5086<p>Change the image size simply by replacing pixels by averaging pixels 5087together when minifying, or replacing pixels when magnifing. </p> 5088 5089<p>The results are thus equivalent to using <a href="#resize">-resize</a> with 5090a <a href="#filter">-filter</a> setting of <kbd>box</kbd>. Though it is a lot 5091faster, as it avoids all the filter processing of the image. As such it 5092completely ignores the current <a href="#filter">-filter</a> setting. </p> 5093 5094<p>If when shrinking (minifying) images the original image is some integer 5095multiple of the new image size, the number of pixels avergaed together to 5096produce the new pixel color is the same across the whole image. This is 5097a special case known as 'binning' and is often used as a method of reducing 5098noise in image such as those generated by digital cameras, especially in low 5099light conditions. </p> 5100 5101 5102<div style="margin: auto;"> 5103 <h4><a id="scene"></a>-scene <em class="arg">value</em></h4> 5104</div> 5105 5106<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>set scene number.</td><td style='text-align:right;'></td></tr></table> 5107 5108<p>This option sets the scene number of an image or the first image in an image sequence.</p> 5109 5110<div style="margin: auto;"> 5111 <h4><a id="screen"></a>-screen</h4> 5112</div> 5113 5114<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>specify the screen to capture.</td><td style='text-align:right;'></td></tr></table> 5115 5116<p>This option indicates that the GetImage request used to obtain the image should be done on the root window, rather than directly on the specified window. In this way, you can obtain pieces of other windows that overlap the specified window, and more importantly, you can capture menus or other popups that are independent windows but appear over the specified window.</p> 5117 5118<div style="margin: auto;"> 5119 <h4><a id="seed"></a>-seed</h4> 5120</div> 5121 5122<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>seed a new sequence of pseudo-random numbers</td><td style='text-align:right;'></td></tr></table> 5123 5124<div style="margin: auto;"> 5125 <h4><a id="segment"></a>-segment <em class="arg">cluster-threshold</em>x<em class="arg">smoothing-threshold</em></h4> 5126</div> 5127 5128<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>segment the colors of an image.</td><td style='text-align:right;'></td></tr></table> 5129 5130<p>Segment an image by analyzing the histograms of the color components and identifying units that are homogeneous with the fuzzy c-means technique. This is part of the ImageMagick color quantization routines. </p> 5131 5132<p>Specify <em class="arg">cluster threshold</em> as the number of pixels in each cluster that must exceed the cluster threshold to be considered valid. <em class="arg">Smoothing threshold</em> eliminates noise in the second derivative of the histogram. As the value is increased, you can expect a smoother second derivative. The default is 1.5.</p> 5133 5134<p>If the <a href="#verbose">-verbose</a> setting is defined, a detailed report 5135of the color clusters is returned.</p> 5136 5137 5138<div style="margin: auto;"> 5139 <h4><a id="selective-blur"></a>-selective-blur <em class="arg">geometry</em></h4> 5140</div> 5141 5142<div style="margin: auto;"> 5143 <h4>-selective-blur <em class="arg">radius</em><br />-unsharp <em class="arg">radius</em>x<em class="arg">sigma</em>{<em class="arg">+threshold</em>}</h4> 5144</div> 5145 5146<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Selectively blur pixels within a contrast threshold.</td><td style='text-align:right;'></td></tr></table> 5147 5148<p>Blurs those pixels that are less than or equal to the threshold in contrast. The threshold may be expressed as a fraction of <em class="QR">QuantumRange</em> or as a percentage.</p> 5149 5150<div style="margin: auto;"> 5151 <h4><a id="separate"></a>-separate</h4> 5152</div> 5153 5154<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>separate an image channel into a grayscale image. Specify the channel with <a href="#channel">-channel</a>.</td><td style='text-align:right;'></td></tr></table> 5155 5156<div style="margin: auto;"> 5157 <h4><a id="sepia-tone"></a>-sepia-tone <em class="arg">threshold</em></h4> 5158</div> 5159 5160<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>simulate a sepia-toned photo.</td><td style='text-align:right;'></td></tr></table> 5161 5162<p>Specify <em class="arg">threshold</em> as the percent threshold of the intensity (0 - 99.9%).</p> 5163 5164<p>This option applies a special effect to the image, similar to the effect achieved in a photo darkroom by sepia toning. Threshold ranges from 0 to <em class="QR">QuantumRange</em> and is a measure of the extent of the sepia toning. A threshold of 80% is a good starting point for a reasonable tone.</p> 5165 5166 5167 5168<div style="margin: auto;"> 5169 <h4><a id="set"></a>-set <em class="arg">key value</em></h4> 5170 <h4>+set <em class="arg">key</em></h4> 5171</div> 5172 5173<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>sets image attributes and properties for images in the current 5174image sequence.</td><td style='text-align:right;'></td></tr></table> 5175 5176<p>This will assign (or modify) specific settings attached to all the images 5177in the current image sequence. Using the <a href="#set">+set</a> form of the 5178option will either remove, or reset that setting to a default state, as 5179appropriate. </p> 5180 5181<p>For example, it will modify specific well known image meta-data 5182'attributes' such as those normally overridden by: the options <a 5183href="#delay" >-delay</a>, <a href="#dispose" >-dispose</a>, and <a 5184href="#page" >-page</a>, <a href="#colorspace" >-colorspace</a>; generally 5185assigned before the image is read in, by using a <em class="arg">key</em> of 5186the same name. </p> 5187 5188<p>If the given <em class="arg">key</em> does not match a specific known 5189'attribute ', such as shown above, the setting is stored as a a free form 5190'properity' string. Such settings are listed in <a href="#verbose" 5191>-verbose</a> information ("<kbd>info:</kbd>" output format) as "Properties". 5192</p> 5193 5194<p>This includes string 'properities' that are set by and assigned to images 5195using the options <a href="#comment" >-comment</a>, <a href="#label" 5196>-label</a>, <a href="#caption" >-caption</a>. These options actually assign 5197a global 'artifact' which are automatically assigned (and any <a href="/www/escape.html" >Format Percent 5198Escapes</a> expanded) to images as they are read in. For example:</p> 5199 5200<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert rose: -set comment 'Rose is a rose is a rose is a rose' rose.png</span><span class='crtout'>identify -format %c rose.png</span><span class="crtprompt"> $magick> </span><span class='crtin'>Rose is a rose is a rose is a rose</span></p> 5201<p>The set value can also make use of <a href="/www/escape.html" >Format and Print Image 5202Properties</a> in the defined value. For example:</p> 5203 5204<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert rose: -set origsize '%wx%h' -resize 50% \</span><span class='crtout'> -format 'Old size = %[origsize] New size = %wx%h' info:</span><span class="crtprompt"> $magick> </span><span class='crtin'>Old size = 70x46 New size = 35x23</span></p> 5205<p>Other well known 'properities' that can be include: 5206'<kbd>date:create</kbd>' and '<kbd>date:modify</kbd>' and 5207'<kbd>signature</kbd>'. </p> 5208 5209<p>The <a href="#repage">-repage</a> operator will also allow you to modify 5210the '<kbd>page</kbd>' attribute of an image for images already in memory (also 5211see <a href="#repage">-page</a>). However it is designed to provide a finer 5212control of the sub-parts of this 'attribute'. The <a href="#set">-set page</a> 5213option will only provide a direct, unmodified assignment of '<kbd>page</kbd>' 5214attribute. </p> 5215 5216<p>This option can also associate a colorspace or profile with your image. 5217For example,</p> 5218 5219<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert image.psd -set profile ISOcoated_v2_eci.icc image-icc.psd</span></p> 5220<p>Some 'properties' must be defined in a specific way to be used. For 5221example only 'properties' prefixed with "<kbd>filename:</kbd>" can be used to 5222modify the output filename of an image. For example</p> 5223 5224<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert rose: -set filename:mysize '%wx%h' 'rose_%[filename:mysize].png'</span></p> 5225<p>If the setting value is prefixed with "<kbd>option:</kbd>" the setting will 5226be saved as a global "Artifact" exactly as if it was set using the <a 5227href="#define" >-define</a> option. As such settings are globel in scope, they 5228can be used to pass 'attributes' and 'properities' of one specific image, 5229in a way that allows you to use them in a completely different image, even if 5230the original image has long since been modified or destroyed. For example: </p> 5231 5232<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert rose: -set option:rosesize '%wx%h' -delete 0 \</span><span class='crtout'> label:'%[rosesize]' label_size_of_rose.gif</span></p> 5233<p>Note that <a href="/www/escape.html" >Format Percent Escapes</a> will only match 5234a 'artifact' if the given <em class="arg">key</em> does not match an existing 5235'attribute' or 'properity'. </p> 5236 5237<p>You can set the attributes of the image registry by prefixing the value 5238with <kbd>registry:</kbd>.</p> 5239 5240 5241 5242<div style="margin: auto;"> 5243 <h4><a id="shade"></a>-shade <em class="arg">azimuth</em>x<em class="arg">elevation</em></h4> 5244</div> 5245 5246<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>shade the image using a distant light source.</td><td style='text-align:right;'></td></tr></table> 5247 5248<p>Specify <em class="arg">azimuth</em> and <em class="arg">elevation</em> as the position of the light source. Use <a href="#shade">+shade</a> to return the shading results as a grayscale image.</p> 5249 5250<div style="margin: auto;"> 5251 <h4><a id="shadow"></a>-shadow <em class="arg">percent-opacity</em>{x<em class="arg">sigma</em>}{<em class="arg">+-</em>}<em class="arg">x</em>{<em class="arg">+-</em>}<em class="arg">y</em>{<em class="arg">%</em>}</h4> 5252</div> 5253 5254<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>simulate an image shadow.</td><td style='text-align:right;'></td></tr></table> 5255 5256<div style="margin: auto;"> 5257 <h4><a 5258id="shared-memory"></a>-shared-memory</h4> 5259</div> 5260 5261<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>use shared memory.</td><td style='text-align:right;'></td></tr></table> 5262 5263<p>This option specifies whether the utility should attempt to use shared memory for pixmaps. ImageMagick must be compiled with shared memory support, and the display must support the <em class="arg">MIT-SHM</em> extension. Otherwise, this option is ignored. The default is <kbd>True</kbd>.</p> 5264 5265<div style="margin: auto;"> 5266 <h4><a id="sharpen"></a>-sharpen <em class="arg">radius</em>{x<em class="arg">sigma</em>}</h4> 5267</div> 5268 5269<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>sharpen the image.</td><td style='text-align:right;'></td></tr></table> 5270 5271<p>Use a Gaussian operator of the given radius and standard deviation (sigma).</p> 5272 5273<div style="margin: auto;"> 5274 <h4><a id="shave"></a>-shave <em class="arg">geometry</em></h4> 5275</div> 5276 5277<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Shave pixels from the image edges.</td><td style='text-align:right;'></td></tr></table> 5278 5279<p>The <em class="arg">size</em> portion of the <em class="arg">geometry</em> argument specifies the width of the region to be removed from both sides of the image and the height of the regions to be removed from top and bottom. Offsets are ignored.</p> 5280 5281<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 5282 5283<div style="margin: auto;"> 5284 <h4><a id="shear"></a>-shear <em class="arg">Xdegrees</em>[x<em class="arg">Ydegrees</em>]</h4> 5285</div> 5286 5287<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Shear the image along the x-axis and/or y-axis.</td><td style='text-align:right;'></td></tr></table> 5288 5289<p>The shear angles may be positive, negative, or zero. When <em class="arg">Ydegrees</em> is omitted it defaults to 0. When both angles are given, the horizontal component of the shear is performed before the vertical component.</p> 5290 5291<p>Shearing slides one edge of an image along the x-axis or y-axis (i.e., horizontally or vertically, respectively),creating a parallelogram. The amount of each is controlled by the respective shear angle. For horizontal shears, <em class="arg">Xdegrees</em> is measured clockwise relative to "up" (the negative y-axis), sliding the top edge to the right when 0°<<em class="arg">Xdegrees</em><90° and to the left when 90°<<em class="arg">Xdegrees</em><180°. For vertical shears <em class="arg">Ydegrees</em> is measured clockwise relative to "right" (the positive x-axis), sliding the right edge down when 0°<<em class="arg">Ydegrees</em><90° and up when 90°<<em class="arg">Ydegrees</em><180°.</p> 5292 5293<p>Empty triangles left over from shearing the image are filled with the color defined by the <a href="#fill">-background</a> option. The color is specified using the format described under the <a href="#fill">-fill</a> option.</p> 5294 5295<p>The horizontal shear is performed before the vertical part. This is important to note, since horizontal and vertical shears do not <em>commute</em>, i.e., the order matters in a sequence of shears. For example, the following two commands are not equivalent.</p> 5296 5297<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert logo: -shear 20x0 -shear 0x60 logo-sheared.png</span><span class='crtout'></span><span class="crtprompt"> $magick> </span><span class='crtin'>convert logo: -shear 0x60 -shear 20x0 logo-sheared.png</span></p> 5298<p>The first of the two commands above is equivalent to the following, except for the amount of empty space created; the command that follows generates a smaller image, and so is a better choice in terms of time and space.</p> 5299 5300<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert logo: -shear 20x60 logo-sheared.png</span></p> 5301<div style="margin: auto;"> 5302 <h4><a id="sigmoidal-contrast"></a>-sigmoidal-contrast <em class="arg">contrast</em>x<em class="arg">mid-point</em></h4> 5303</div> 5304 5305<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>increase the contrast without saturating highlights or shadows.</td><td style='text-align:right;'></td></tr></table> 5306 5307<p>Increase the contrast of the image using a sigmoidal transfer function without saturating highlights or shadows. <em class="arg">Contrast</em> indicates how much to increase the contrast (0 is none; 3 is typical; 20 is a lot); <em class="arg">mid-point</em> indicates where midtones fall in the resultant image (0 is white; 50% is middle-gray; 100% is black). By default the image contrast is increased, use <em class="arg">+sigmoidal-contrast</em> to decrease the contrast.</p> 5308 5309<div style="margin: auto;"> 5310 <h4><a id="silent"></a>-silent</h4> 5311</div> 5312 5313<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>operate silently.</td><td style='text-align:right;'></td></tr></table> 5314 5315<div style="margin: auto;"> 5316 <h4><a id="size"></a>-size <em class="arg">width</em>[x<em class="arg">height</em>][<em class="arg">+offset</em>]</h4> 5317</div> 5318 5319<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>set the width and height of the image.</td><td style='text-align:right;'></td></tr></table> 5320 5321<p>Use this option to specify the width and height of raw images whose dimensions are unknown such as <kbd>GRAY</kbd>, <kbd>RGB</kbd>, or <kbd>CMYK</kbd>. In addition to width and height, use <a href="#size">-size</a> with an offset to skip any header information in the image or tell the number of colors in a <kbd>MAP</kbd> image file, (e.g. -size 640x512+256).</p> 5322 5323<p>For Photo CD images, choose from these sizes:</p> 5324 5325<pre class="text"> 5326 192x128 5327 384x256 5328 768x512 5329 1536x1024 5330 3072x2048 5331</pre> 5332 5333<div style="margin: auto;"> 5334 <h4><a id="sketch"></a>-sketch <em class="arg">radius</em><br />-sketch <em class="arg">radius</em>x<em class="arg">sigma</em>+<em class="arg">angle</em></h4> 5335</div> 5336 5337<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>simulate a pencil sketch.</td><td style='text-align:right;'></td></tr></table> 5338 5339<p>Sketch with the given radius, standard deviation (sigma), and angle. The angle given is the angle toward which the image is sketched. That is the direction people would consider the object is coming from. </p> 5340 5341<div style="margin: auto;"> 5342 <h4><a id="smush"></a>-smush <em class="arg">offset</em></h4> 5343</div> 5344 5345<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>smush an image sequence together.</td><td style='text-align:right;'></td></tr></table> 5346 5347<div style="margin: auto;"> 5348 <h4><a id="snaps"></a>-snaps <em class="arg">value</em></h4> 5349</div> 5350 5351<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the number of screen snapshots.</td><td style='text-align:right;'>[<a href="/www/import.html">import</a>]</td></tr></table> 5352 5353<p>Use this option to grab more than one image from the X server screen, to create an animation sequence.</p> 5354 5355<div style="margin: auto;"> 5356 <h4><a id="solarize"></a>-solarize <em class="arg">threshold</em></h4> 5357</div> 5358 5359<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>negate all pixels above the threshold level.</td><td style='text-align:right;'></td></tr></table> 5360 5361<p>Specify <em class="arg">factor</em> as the percent threshold of the intensity (0 - 99.9%).</p> 5362 5363<p>This option produces a <em class="arg">solarization</em> effect seen when exposing a photographic film to light during the development process.</p> 5364 5365<div style="margin: auto;"> 5366 <h4><a id="sparse-color"></a>-sparse-color <em 5367 class="arg">method</em> '<em class="arg">x</em>,<em class="arg">y</em> <em class="arg">color</em> ...'</h4> 5368</div> 5369 5370<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'> color the given image using the specified points of color, and filling the other intervening colors using the given methods. </td><td style='text-align:right;'></td></tr></table> 5371 5372 5373<table class="doc"> 5374 <tbody> 5375 <tr valign="top"> 5376 <th align="left" style="width: 8%">Method</th> 5377 <th align="left">Description</th> 5378 </tr> 5379 5380 <tr valign="top"> 5381 <td valign="top">voronoi</td> 5382 <td valign="top">Simply map each pixel to the to nearest color point 5383 given. The result are polygonal 'cells' of solid color. </td> 5384 </tr> 5385 5386 <tr valign="top"> 5387 <td valign="top">shepards</td> 5388 <td valign="top">Colors points biased on the ratio of inverse distance 5389 squared. Generating spots of color in a sea of the average of 5390 colors. </td> 5391 </tr> 5392 5393 <tr valign="top"> 5394 <td valign="top">barycentric</td> 5395 <td valign="top">three point triangle of color given 3 points. 5396 Giving only 2 points will form a linear gradient between those points. 5397 Gradient is however not restricted to just the triangle or line. </td> 5398 </tr> 5399 5400 <tr valign="top"> 5401 <td valign="top">bilinear</td> 5402 <td valign="top">Like barycentric but for 4 points. Less than 4 points 5403 fall back to barycentric. </td> 5404 </tr> 5405 5406 </tbody> 5407</table> 5408 5409<p>The points are placed according to the images location on the virtual 5410canvas (<a href="#page" >-page</a> or <a href="#repage" >-repage</a> 5411offset), and do not actually have to exist on the given image, but may be 5412some point beyond the edge of the image. All points are floating point values. 5413</p> 5414 5415<p>Only the color channels defined by the <a href="#channel" >-channel</a> are 5416modified, whcih means the matte/alpha transparency channel is not effected by 5417default. If enabled, the image also needs a the matte/alpha channel to be 5418enabled for this operator to effect an images transparency. This is typical 5419transparency handling for images. </p> 5420 5421<p>All the above methods when given a single point of color will replace all 5422the colors in the image with the color given, regardless of the point. This is 5423logical, and provides an alternative technique to recolor a image to some 5424default value. </p> 5425 5426 5427<div style="margin: auto;"> 5428 <h4><a id="splice"></a>-splice <em class="arg">geometry</em></h4> 5429</div> 5430 5431<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Splice the current background color into the image.</td><td style='text-align:right;'></td></tr></table> 5432 5433<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. See <a href="#background">-background</a> to reset the background color.</p> 5434 5435<div style="margin: auto;"> 5436 <h4><a id="spread"></a>-spread <em class="arg">amount</em></h4> 5437</div> 5438 5439<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>displace image pixels by a random amount.</td><td style='text-align:right;'></td></tr></table> 5440 5441<p>The argument <em class="arg">amount</em> defines the size of the neighborhood around each pixel from which to choose a candidate pixel to swap.</p> 5442 5443<div style="margin: auto;"> 5444 <h4><a id="stegano"></a>-stegano <em class="arg">offset</em></h4> 5445</div> 5446 5447<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>hide watermark within an image.</td><td style='text-align:right;'></td></tr></table> 5448 5449<p>Use an offset to start the image hiding some number of pixels from the beginning of the image. Note this offset and the image size. You will need this information to recover the steganographic image (e.g. display -size 320x256+35 stegano:image.png).</p> 5450 5451<div style="margin: auto;"> 5452 <h4><a id="stereo"></a>-stereo <em class="arg">+x</em>{<em class="arg">+y</em>}</h4> 5453</div> 5454 5455<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>composite two images to create a stereo anaglyph.</td><td style='text-align:right;'>[<a href="/www/composite.html">composite</a>]</td></tr></table> 5456 5457<p>The left side of the stereo pair is saved as the red channel of the output image. The right side is saved as the green channel. Red-green stereo glasses are required to properly view the stereo image.</p> 5458 5459<div style="margin: auto;"> 5460 <h4><a id="storage-type"></a>-storage-type <em class="arg">type</em></h4> 5461</div> 5462 5463<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>pixel storage type. Here are the valid types:</td><td style='text-align:right;'></td></tr></table> 5464 5465<pre class="text"> 5466 char store pixels as unsigned characters 5467 double store pixels as doubles 5468 float store pixels as floats 5469 integer store pixels as integers 5470 long store pixels as longs 5471 quantum store pixels in the native depth of your ImageMagick distribution 5472 short store pixels as unsigned shorts 5473</pre> 5474 5475<p>Float and double types are normalized from 0.0 to 1.0 otherwise the pixels 5476values range from 0 to the maximum value the storage type can support.</p> 5477 5478<div style="margin: auto;"> 5479 <h4><a id="stretch"></a>-stretch <em class="arg">fontStretch</em></h4> 5480</div> 5481 5482<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set a type of stretch style for fonts.</td><td style='text-align:right;'></td></tr></table> 5483 5484<p>This setting suggests a type of stretch that ImageMagick should try to apply to the currently selected font family. Select <em class="arg">fontStretch</em> from the following.</p> 5485 5486<pre class="text"> 5487 Any 5488 Condensed 5489 Expanded 5490 ExtraCondensed 5491 ExtraExpanded 5492 Normal 5493 SemiCondensed 5494 SemiExpanded 5495 UltraCondensed 5496 UltraExpanded 5497</pre> 5498 5499<p>To print a complete list of stretch types, use <a href="#list">-list stretch</a>.</p> 5500 5501<p>For other settings that affect fonts, see the options <a href="#font">-font</a>, <a href="#family">-family</a>, <a href="#style">-style</a>, and <a href="#weight">-weight</a>. </p> 5502 5503<div style="margin: auto;"> 5504 <h4><a id="strip"></a>-strip</h4> 5505</div> 5506 5507<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>strip the image of any profiles or comments.</td><td style='text-align:right;'></td></tr></table> 5508 5509<div style="margin: auto;"> 5510 <h4><a id="stroke"></a>-stroke <em class="arg">color</em></h4> 5511</div> 5512 5513<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>color to use when stroking a graphic primitive.</td><td style='text-align:right;'></td></tr></table> 5514 5515<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p> 5516 5517<p>See <a href="#draw">-draw</a> for further details.</p> 5518 5519<div style="margin: auto;"> 5520 <h4><a id="strokewidth"></a>-strokewidth <em class="arg">value</em></h4> 5521</div> 5522 5523<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>set the stroke width.</td><td style='text-align:right;'></td></tr></table> 5524 5525<p>See <a href="#draw">-draw</a> for further details.</p> 5526 5527<div style="margin: auto;"> 5528 <h4><a id="style"></a>-style <em class="arg">fontStyle</em></h4> 5529</div> 5530 5531<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set a font style for text.</td><td style='text-align:right;'></td></tr></table> 5532 5533<p>This setting suggests a font style that ImageMagick should try to apply to 5534the currently selected font family. Select <em class="arg">fontStyle</em> from 5535the following.</p> 5536 5537<pre class="text"> 5538 Any 5539 Italic 5540 Normal 5541 Oblique 5542</pre> 5543 5544<p>For other settings that affect fonts, see the options <a href="#font">-font</a>, <a href="#family">-family</a>, <a href="#stretch">-stretch</a>, and <a href="#weight">-weight</a>. </p> 5545 5546<div style="margin: auto;"> 5547 <h4><a id="subimage-search"></a>-subimage-search</h4> 5548</div> 5549 5550<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>search for subimage.</td><td style='text-align:right;'>[<a href="/www/compare.html">compare</a>]</td></tr></table> 5551 5552<p>This option is required to have compare search for the best match location 5553of a small image within a larger image. This search will produce two images 5554(or two frames). The first is the "difference" image and the second will 5555be the "match score" image.</p> 5556 5557<p>The "match-score" image is smaller containing a pixel for ever possible 5558position of the top-left corner of the given sub-image. that is its size will 5559be the size of the larger_image - sub_image + 1. The brightest location in 5560this image is the location s the locate on the best match that is also 5561reported. Note that this may or may nor be a perfect match, and the actual 5562brightness will reflect this. Other bright 'peaks' can be used to locate other 5563possible matching loctions. </p> 5564 5565<p>Note that the search will try to compare teh sub-image at every possible 5566location in the larger image, as such it can be very slow. The smaller the 5567sub-image the faster this search is. </p> 5568 5569 5570<div style="margin: auto;"> 5571 <h4><a id="swap"></a>-swap <em class="arg">index,index</em></h4> 5572</div> 5573 5574<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Swap the positions of two images in the image sequence.</td><td style='text-align:right;'></td></tr></table> 5575 5576<p>For example, <a href="#swap">-swap 0,2</a> swaps the first and the third 5577images in the current image sequence. Use <a href="#swap">+swap</a> to switch 5578the last two images in the sequence.</p> 5579 5580<div style="margin: auto;"> 5581 <h4><a id="swirl"></a>-swirl <em class="arg">degrees</em></h4> 5582</div> 5583 5584<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>swirl image pixels about the center.</td><td style='text-align:right;'></td></tr></table> 5585 5586<p><em class="arg">Degrees</em> defines the tightness of the swirl.</p> 5587 5588<div style="margin: auto;"> 5589 <h4><a id="synchronize"></a>-synchronize</h4> 5590</div> 5591 5592<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>synchronize image to storage device.</td><td style='text-align:right;'></td></tr></table> 5593 5594<div style="margin: auto;"> 5595 <h4><a id="taint"></a>-taint</h4> 5596</div> 5597 5598<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Mark the image as modified.</td><td style='text-align:right;'></td></tr></table> 5599 5600<div style="margin: auto;"> 5601 <h4><a id="text-font"></a>-text-font <em class="arg">name</em></h4> 5602</div> 5603 5604<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>font for writing fixed-width text.</td><td style='text-align:right;'></td></tr></table> 5605 5606<p>Specifies the name of the preferred font to use in fixed (typewriter style) formatted text. The default is 14 point <em class="arg">Courier</em>.</p> 5607 5608<p>You can tag a font to specify whether it is a PostScript, TrueType, or OPTION1 font. For example, <kbd>Courier.ttf</kbd> is a TrueType font and <kbd>x:fixed</kbd> is OPTION1.</p> 5609 5610<div style="margin: auto;"> 5611 <h4><a id="texture"></a>-texture <em class="arg">filename</em></h4> 5612</div> 5613 5614<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>name of texture to tile onto the image background.</td><td style='text-align:right;'></td></tr></table> 5615 5616<div style="margin: auto;"> 5617 <h4><a id="threshold"></a>-threshold <em class="arg">value</em>{<em class="arg">%</em>}</h4> 5618</div> 5619 5620<!-- {<em class="arg">green,blue,opacity</em>} 5621<p>If the green or blue value is omitted, these channels use the same value as the first one provided. If all three color values are the same, the result is a bi-level image. If the opacity threshold is omitted, OpaqueOpacity is used and any partially transparent pixel becomes fully transparent.</p> 5622--> 5623 5624<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Apply simultaneous black/white threshold to the image.</td><td style='text-align:right;'></td></tr></table> 5625 5626<p>Any pixel values (more specifically, those channels set using <a href="/www/command-line-options.html#channel">‑channel</a>) that exceed the specified threshold are reassigned the maximum channel value, while all other values are assigned the minimum.</p> 5627 5628<p> The threshold value can be given as a percentage or as an absolute integer value corresponding to the desired channel value. When given as an integer, the minimum attainable value is 0 (corresponding to black when all channels are affected), but the maximum value (corresponding to white) is that of the <kbd>quantum depth</kbd> of the particular build of ImageMagick, and is therefore dependent on the installation. For that reason, a reasonable recommendation for most applications is to specify the threshold values as a percentage. 5629</p> 5630 5631<p> The following would force pixels with red values above 50% to have 100% red values, while those at or below 50% red would be set to 0 in the red channel. The green, blue, and alpha channels (if present) would be unchanged. </p> 5632 5633<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert in.png -channel red -threshold 50% out.png</span></p> 5634<p>As (possibly) impractical but instructive examples, the following would generate an all-black and an all-white image with the same dimensions as the input image.</p> 5635 5636 5637<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert in.png -threshold 100% black.png</span><span class='crtout'></span><span class="crtprompt"> $magick> </span><span class='crtin'>convert in.png -threshold -1 white.png</span></p> 5638<p>Note that the values of the transparency channel is treated as 'matte' 5639values (0 is opaque) and not as 'alpha' values (0 is transparent).</p> 5640 5641<p> See also <a href="/www/command-line-options.html#black-threshold">‑black‑threshold</a> and <a href="/www/command-line-options.html#white-threshold">‑white‑threshold</a>. 5642</p> 5643 5644<div style="margin: auto;"> 5645 <h4><a id="thumbnail"></a>-thumbnail <em class="arg">geometry</em></h4> 5646</div> 5647 5648<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Create a thumbnail of the image.</td><td style='text-align:right;'></td></tr></table> 5649 5650<p>This is similar to <a href="#resize">-resize</a>, except it is optimized for speed and any image profile, other than a color profile, is removed to reduce the thumbnail size. To strip the color profiles as well, add <a href="#strip">-strip</a> just before of after this option.</p> 5651 5652<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 5653 5654<div style="margin: auto;"> 5655 <h4><a id="tile"></a>-tile <em class="arg">filename</em></h4> 5656</div> 5657 5658<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the tile image used for filling a subsequent graphic primitive.</td><td style='text-align:right;'></td></tr></table> 5659 5660<div style="margin: auto;"> 5661 <h4>-tile <em class="arg">geometry</em></h4> 5662</div> 5663 5664<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Specify the layout of images .</td><td style='text-align:right;'>[<a href="/www/montage.html">montage</a>]</td></tr></table> 5665 5666<p>See <a href="/www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument.</p> 5667 5668<div style="margin: auto;"> 5669 <h4>-tile</h4> 5670</div> 5671 5672<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Specifies that a subsequent composite operation is repeated across and down image.</td><td style='text-align:right;'>[<a href="/www/composite.html">composite</a>]</td></tr></table> 5673 5674<div style="margin: auto;"> 5675 <h4><a id="tile-offset"></a>-tile-offset {<em class="arg">+-</em>}<em class="arg">x</em>{<em class="arg">+-</em>}<em class="arg">y</em></h4> 5676</div> 5677 5678<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Specify the offset for tile images, relative to the background image it is tiled on.</td><td style='text-align:right;'></td></tr></table> 5679 5680<p>This should be set before the tiling image is set by <a href="#tile" >-tile</a> or <a href="#texture" >-texture</a>, or directly applied for creating a tiled canvas using <kbd>TILE:</kbd> or <kbd>PATTERN:</kbd> input formats. </p> 5681 5682<p>Internally ImageMagick does a <a href="#roll" >-roll</a> of the tile image by the arguments given when the tile image is set. </p> 5683 5684<div style="margin: auto;"> 5685 <h4><a id="tint"></a>-tint <em class="arg">value</em></h4> 5686</div> 5687 5688<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Tint the image with the fill color.</td><td style='text-align:right;'></td></tr></table> 5689 5690<p>Tint the image with the fill color.</p> 5691 5692<p>Specify the amount of tinting as a percentage. Pure colors like black, white red, yellow, will not be affected by -tint. Only mid-range colors such as the various shades of grey.</p> 5693 5694<div style="margin: auto;"> 5695 <h4><a id="title"></a>-title <em class="arg">string</em></h4> 5696</div> 5697 5698<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Assign a title to displayed image.</td><td style='text-align:right;'>[<a href="/www/animate.html">animate</a>, <a href="/www/display.html">display</a>, <a href="/www/montage.html">montage</a>]</td></tr></table> 5699 5700<p>Use this option to assign a specific title to the image. This assigned to the image window and is typically displayed in the window title bar. Optionally you can include the image filename, type, width, height, Exif data, or other image attribute by embedding special format characters described under the <a href="#format">-format</a> option.</p> 5701 5702<p>For example,</p> 5703 5704<p class="crtsnip"> 5705 -title "%m:%f %wx%h" 5706</p> 5707 5708<p>produces an image title of <kbd>MIFF:bird.miff 512x480</kbd> for an image titled <kbd>bird.miff</kbd> and whose width is 512 and height is 480.</p> 5709 5710 5711<div style="margin: auto;"> 5712 <h4><a id="transform"></a>-transform</h4> 5713</div> 5714 5715<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>transform the image.</td><td style='text-align:right;'></td></tr></table> 5716 5717<p>This option applies the transformation matrix from a previous <a href="#affine">-affine</a> option.</p> 5718 5719<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert -affine 2,2,-2,2,0,0 -transform bird.ppm bird.jpg</span></p> 5720 5721<p>This operator has been now been superseded by the <a 5722href="#distort">-distort</a> '<kbd>AffineProjection</kbd>' method. </p> 5723 5724 5725<div style="margin: auto;"> 5726 <h4><a id="transparent"></a>-transparent <em class="arg">color</em></h4> 5727</div> 5728 5729<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Make this color transparent within the image.</td><td style='text-align:right;'></td></tr></table> 5730 5731<p>The <em class="arg">color</em> argument is defined using the format 5732described under the <a href="#fill">-fill</a> option. The <a href="#fuzz" 5733>-fuzz</a> setting can be used to match and replace colors similar to the one 5734given. </p> 5735 5736<p>Use <a href="#transparent" >+transparent</a> to invert the pixels matched. 5737that is make all non-matching colors transparent. </p> 5738 5739<p>The <a href="#opaque">-opaque</a> operator is exactly the same as <a 5740href="#transparent" >-transparent</a> but replaces the matching color with the 5741current <a href="#fill">-fill</a> color setting, rather than transparent. 5742However the <a href="#transparent" >-transparent</a> operator also ensures 5743that the image has an alpha channel enabled, as per "<kbd><a href="#alpha" 5744>-alpha</a> set</kbd>", and does not require you to modify the <a 5745href="#channel">-channel</a> to enable alpha channel handling. </p> 5746 5747<p>Note that this does not define the color as being the 'transparency color' 5748used for color-mapped image formats, such as GIF. For that use <a 5749href="#transparent-color" >-transparent-color</a> </p> 5750 5751 5752<div style="margin: auto;"> 5753 <h4><a id="transparent-color"></a>-transparent-color <em class="arg">color</em></h4> 5754</div> 5755 5756<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set the transparent color.</td><td style='text-align:right;'></td></tr></table> 5757 5758<p>Sometimes this is used for saving to image formats such as 5759GIF and PNG8 which uses this color to represent boolean transparency. This 5760does not make a color transparent, it only defines what color the transparent 5761color is in the color palette of the saved image. Use <a 5762href="#transparent">-transparent</a> to make an opaque color transparent.</p> 5763 5764<p>This option allows you to have both an opaque visible color, as well as a 5765transparent color of the same color value without conflict. That is, you can 5766use the same color for both the transparent and opaque color areas within an 5767image. This, in turn, frees to you to select a transparent color that is 5768appropriate when an image is displayed by an application that does not handle a 5769transparent color index, while allowing ImageMagick to correctly handle images of this 5770type. </p> 5771 5772<p>The default transparent color is <kbd>#00000000</kbd>, which is fully transparent black.</p> 5773 5774<div style="margin: auto;"> 5775 <h4><a id="transpose"></a>-transpose</h4> 5776</div> 5777 5778<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Mirror the image along the top-left to bottom-right diagonal.</td><td style='text-align:right;'></td></tr></table> 5779 5780<p> This option mathematically transposes the pixel array. It is equivalent to the sequence <kbd>-flip -rotate 90</kbd>. 5781</p> 5782 5783<div style="margin: auto;"> 5784 <h4><a id="transverse"></a>-transverse</h4> 5785</div> 5786 5787<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Mirror the image along the images bottom-left top-right diagonal. Equivalent to the operations <kbd>-flop -rotate 90</kbd>.</td><td style='text-align:right;'></td></tr></table> 5788 5789 5790<div style="margin: auto;"> 5791 <h4><a id="treedepth"></a>-treedepth <em class="arg">value</em></h4> 5792</div> 5793 5794<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>tree depth for the color reduction algorithm.</td><td style='text-align:right;'></td></tr></table> 5795 5796<p>Normally, this integer value is zero or one. A value of zero or one causes the use of an optimal tree depth for the color reduction algorithm.</p> 5797 5798<p>An optimal depth generally allows the best representation of the source image with the fastest computational speed and the least amount of memory. However, the default depth is inappropriate for some images. To assure the best representation, try values between 2 and 8 for this parameter. Refer to the <a href="/www/quantize.html">color reduction algorithm</a> for more details.</p> 5799 5800<p>The <a href="#colors">-colors</a> or <a href="#monochrome">-monochrome</a> option, or writing to an image format which requires color reduction, is required for this option to take effect.</p> 5801 5802<div style="margin: auto;"> 5803 <h4><a id="trim"></a>-trim</h4> 5804</div> 5805 5806<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>trim an image.</td><td style='text-align:right;'></td></tr></table> 5807 5808<p>This option removes any edges that are exactly the same color as the corner pixels. Use <a href="#fuzz">-fuzz</a> to make <a href="#trim">-trim</a> remove edges that are nearly the same color as the corner pixels.</p> 5809 5810<p>The page or virtual canvas information of the image is preserved allowing 5811you to extract the result of the <a href="#trim">-trim</a> operation from the 5812image. Use a <a href="#repage">+repage</a> to remove the virtual canvas page 5813information if it is unwanted.</p> 5814 5815<p>If the trimmed image 'disappears' an warning is produced, and a special 5816single pixel transparent 'missed' image is returned, in the same way as when a 5817<a href="#crop">-crop</a> operation 'misses' the image proper. </p> 5818 5819 5820<div style="margin: auto;"> 5821 <h4><a id="type"></a>-type <em class="arg">type</em></h4> 5822</div> 5823 5824<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>the image type.</td><td style='text-align:right;'></td></tr></table> 5825 <p>Choose from: <kbd>Bilevel</kbd>, <kbd>Grayscale</kbd>, <kbd>GrayscaleMatte</kbd>, <kbd>Palette</kbd>, <kbd>PaletteMatte</kbd>, <kbd>TrueColor</kbd>, <kbd>TrueColorMatte</kbd>, <kbd>ColorSeparation</kbd>, or <kbd>ColorSeparationMatte</kbd>.</p> 5826 5827<p>Normally, when a format supports different subformats such as grayscale and truecolor, the encoder will try to choose an efficient subformat. The <a href="#type">-type</a> option can be used to overrride this behavior. For example, to prevent a JPEG from being written in grayscale format even though only gray pixels are present, use.</p> 5828 5829<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert bird.png -type TrueColor bird.jpg</span></p> 5830<p>Similarly, use <a href="#type">-type TrueColorMatte</a> to force the encoder to write an alpha channel even though the image is opaque, if the output format supports transparency.</p> 5831 5832<p>Use <a href="#type">-type optimize</a> to ensure the image is written in the smallest possible file size.</p> 5833 5834<div style="margin: auto;"> 5835 <h4><a id="undercolor"></a>-undercolor <em class="arg">color</em></h4> 5836</div> 5837 5838<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>set the color of the annotation bounding box.</td><td style='text-align:right;'></td></tr></table> 5839 5840<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p> 5841 5842<p>See <a href="#draw">-draw</a> for further details.</p> 5843 5844 5845<div style="margin: auto;"> 5846 <h4><a id="update"></a>-update <em class="arg">seconds</em></h4> 5847</div> 5848 5849<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>detect when image file is modified and redisplay.</td><td style='text-align:right;'></td></tr></table> 5850 5851<p>Suppose that while you are displaying an image the file that is currently displayed is over-written. <kbd>display</kbd> will automagically detect that the input file has been changed and update the displayed image accordingly.</p> 5852 5853 5854<div style="margin: auto;"> 5855 <h4><a id="unique-colors"></a>-unique-colors</h4> 5856</div> 5857 5858<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>discard all but one of any pixel color.</td><td style='text-align:right;'></td></tr></table> 5859 5860 5861<div style="margin: auto;"> 5862 <h4><a id="units"></a>-units <em class="arg">type</em></h4> 5863</div> 5864 5865<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>the units of image resolution.</td><td style='text-align:right;'></td></tr></table> 5866 5867<p>Choose from: <kbd>Undefined</kbd>, <kbd>PixelsPerInch</kbd>, or <kbd>PixelsPerCentimeter</kbd>. This option is normally used in conjunction with the <a href="#density">-density</a> option.</p> 5868 5869 5870<div style="margin: auto;"> 5871 <h4><a id="unsharp"></a>-unsharp <em class="arg">radius</em><br />-unsharp <em class="arg">radius</em>x<em class="arg">sigma</em>{<em class="arg">+amount</em>}{<em class="arg">+threshold</em>}</h4> 5872</div> 5873 5874<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>sharpen the image with an unsharp mask operator.</td><td style='text-align:right;'></td></tr></table> 5875 5876<p>The <a href="#unsharp">-unsharp</a> option sharpens an image. The image is convolved with a Gaussian operator of the given radius and standard deviation (sigma). For reasonable results, radius should be larger than sigma. Use a radius of 0 to have the method select a suitable radius.</p> 5877 5878<p>The parameters are:</p> 5879 5880<pre class="text"> 5881 radius: The radius of the Gaussian, in pixels, not counting the center 5882 pixel (default 0). 5883 sigma: The standard deviation of the Gaussian, in pixels (default 1.0). 5884 amount: The fraction of the difference between the original and the blur 5885 image that is added back into the original (default 1.0). 5886 threshold: The threshold, as a fraction of <em class="QR">QuantumRange</em>, needed to apply the 5887 difference amount (default 0.05). 5888</pre> 5889 5890 5891<div style="margin: auto;"> 5892 <h4><a id="verbose"></a>-verbose</h4> 5893</div> 5894 5895<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>print detailed information about the image when this option precedes the <a href="#identify">-identify</a> option or <kbd>info:</kbd>.</td><td style='text-align:right;'></td></tr></table> 5896 5897 5898<div style="margin: auto;"> 5899 <h4><a id="version"></a>-version</h4> 5900</div> 5901 5902<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>print ImageMagick version string and exit.</td><td style='text-align:right;'></td></tr></table> 5903 5904 5905<div style="margin: auto;"> 5906 <h4><a id="view"></a>-view <em class="arg">string</em></h4> 5907</div> 5908 5909<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>FlashPix viewing parameters.</td><td style='text-align:right;'></td></tr></table> 5910 5911 5912<div style="margin: auto;"> 5913 <h4><a id="vignette"></a>-vignette <em class="arg">radius</em>{x<em class="arg">sigma</em>}{<em class="arg">+-</em>}<em class="arg">x</em>{<em class="arg">+-</em>}<em class="arg">y</em>{<em class="arg">%</em>}</h4> 5914</div> 5915 5916<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>soften the edges of the image in vignette style.</td><td style='text-align:right;'></td></tr></table> 5917 5918 5919<div style="margin: auto;"> 5920 <h4><a id="virtual-pixel"></a>-virtual-pixel <em class="arg">method</em></h4> 5921</div> 5922 5923<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Specify contents of <em>virtual pixels</em>.</td><td style='text-align:right;'></td></tr></table> 5924 5925<p>This option defines what color source should be used if and when a color 5926lookup completely 'misses' the source image. The color(s) that appear to 5927surround the source image. Generally this color is derived from the source 5928image, but could also be set to a specify background color. </p> 5929 5930<p>Choose from these methods:</p> 5931 5932<pre class="text"> 5933 background: the area surrounding the image is the background color 5934 black: the area surrounding the image is black 5935 checker-tile: alternate squares with image and background color 5936 dither: non-random 32x32 dithered pattern 5937 edge: extend the edge pixel toward infinity 5938 gray: the area surrounding the image is gray 5939 horizontal-tile: horizontally tile the image, background color above/below 5940 horizontal-tile-edge: horizontally tile the image and replicate the side edge pixels 5941 mirror: mirror tile the image 5942 random: choose a random pixel from the image 5943 tile: tile the image (default) 5944 transparent: the area surrounding the image is transparent blackness 5945 vertical-tile: vertically tile the image, sides are background color 5946 vertical-tile-edge: vertically tile the image and replicate the side edge pixels 5947 white: the area surrounding the image is white 5948</pre> 5949 5950<p>The default value is "edge".</p> 5951 5952<p>This most important for distortion operators such as <a href="#distort" 5953>-distort</a>, <a href="#implode" >-implode</a>, and <a href="#fx" >-fx</a>. 5954However it also effects operations that may access pixels just outside the 5955image proper, such as <a href="#convolve">-convolve</a>, <a 5956href="#blur">-blur</a>, and <a href="#sharpen">-sharpen</a>. </p> 5957 5958<p>To print a complete list of virtual pixel types, use the <a href="#list">-list virtual-pixel</a> option.</p> 5959 5960 5961<div style="margin: auto;"> 5962 <h4><a id="visual"></a>-visual <em class="arg">type</em></h4> 5963</div> 5964 5965<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Animate images using this X visual type.</td><td style='text-align:right;'>[<a href="/www/animate.html">animate</a>, <a href="/www/display.html">display</a>]</td></tr></table> 5966 5967<p>Choose from these visual classes:</p> 5968 5969<pre class="text"> 5970 StaticGray 5971 GrayScale 5972 StaticColor 5973 PseudoColor 5974 TrueColor 5975 DirectColor 5976 default 5977 visual id 5978</pre> 5979 5980<p>The X server must support the visual you choose, otherwise an error occurs. If a visual is not specified, the visual class that can display the most simultaneous colors on the default screen is chosen.</p> 5981 5982 5983<div style="margin: auto;"> 5984 <h4><a id="watermark"></a>-watermark <em 5985 class="arg">brightness</em>x<em class="arg">saturation</em></h4> 5986</div> 5987 5988<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Watermark an image using the given percentages of brightness and 5989saturation.</td><td style='text-align:right;'>[<a href="/www/composite.html">composite</a>]</td></tr></table> 5990 5991<p>Take a grayscale image (with alpha mask) and modify the destination image's 5992brightness according to watermark image's grayscale value and the <em 5993class="arg">brightness</em> percentage. The destinations color saturation 5994attribute is just direct modified by the <em class="arg">saturation</em> 5995percentage, which defaults to 100 percent (no color change). </p> 5996 5997 5998<div style="margin: auto;"> 5999 <h4><a id="wave"></a>-wave <em class="arg">amplitude</em><br />-wave <em class="arg">amplitude</em>x<em class="arg">wavelength</em></h4> 6000</div> 6001 6002<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Shear the columns of an image into a sine wave.</td><td style='text-align:right;'></td></tr></table> 6003 6004<p>Specify <em class="arg">amplitude</em> and <em class="arg">wavelength</em> of the wave.</p> 6005 6006<div style="margin: auto;"> 6007 <h4><a id="weight"></a>-weight <em class="arg">fontWeight</em></h4> 6008</div> 6009 6010<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Set a font weight for text.</td><td style='text-align:right;'></td></tr></table> 6011 6012<p>This setting suggests a font weight that ImageMagick should try to apply to the currently selected font family. Use a positive integer for <em class="arg">fontWeight</em> or select from the following.</p> 6013 6014<table class="doc"> 6015 <col width="25%" /> 6016 <col width="75%" /> 6017 <thead> 6018 <tr> 6019 <th><em class="arg">fontWeight</em></th> 6020 <th>Description</th> 6021 </tr> 6022 </thead> 6023 <tbody> 6024 <tr><td>All </td> <td>No effect. </td></tr> 6025 <tr><td>Bold </td> <td>Same as <em class="arg">fontWeight</em> = 700.</td></tr> 6026 <tr><td>Bolder </td> <td>Add 100 to font weight if currently ≤ 800.</td></tr> 6027 <tr><td>Lighter </td> <td>Subtract 100 to font weight if currently ≤ 100.</td></tr> 6028 <tr><td>Normal </td> <td>Same as <em class="arg">fontWeight</em> = 400.</td></tr> 6029 </tbody> 6030 </table> 6031 6032<p>To print a complete list of weight types, use <a href="#list">-list weight</a>.</p> 6033 6034<p>For other settings that affect fonts, see the options <a href="#font">-font</a>, <a href="#family">-family</a>, <a href="#stretch">-stretch</a>, and <a href="#style">-style</a>. </p> 6035 6036<div style="margin: auto;"> 6037 <h4><a id="white-point"></a>-white-point <em class="arg">x,y</em></h4> 6038</div> 6039 6040<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>chromaticity white point.</td><td style='text-align:right;'></td></tr></table> 6041 6042<div style="margin: auto;"> 6043 <h4><a id="white-threshold"></a>-white-threshold <em class="arg">value</em>{<em class="arg">%</em>}</h4> 6044</div> 6045 6046<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Force to white all pixels above the threshold while leaving all pixels at or below the threshold unchanged.</td><td style='text-align:right;'></td></tr></table> 6047 6048<p> The threshold value can be given as a percentage or as an absolute integer value within [0, <em class="QR">QuantumRange</em>] corresponding to the desired <a href="/www/command-line-options.html#channel">‑channel</a> value. See <a href="/www/command-line-options.html#threshold">‑threshold</a> for more details on thresholds and resulting values. 6049</p> 6050 6051<div style="margin: auto;"> 6052 <h4><a id="window"></a>-window <em class="arg">id</em></h4> 6053</div> 6054 6055<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Make the image the background of a window.</td><td style='text-align:right;'>[<a href="/www/animate.html">animate</a>, <a href="/www/display.html">display</a>]</td></tr></table> 6056 6057<p><em class="arg">id</em> can be a window id or name. Specify <kbd>root</kbd> to select X's root window as the target window.</p> 6058 6059<p>By default the image is tiled onto the background of the target window. If <kbd>backdrop</kbd> or <a href="#geometry">-resize</a> are specified, the image is surrounded by the background color. Refer to <kbd>X RESOURCES</kbd> for details.</p> 6060 6061<p>The image will not display on the root window if the image has more unique colors than the target window colormap allows. Use <a href="#colors">-colors</a> to reduce the number of colors.</p> 6062 6063<div style="margin: auto;"> 6064 <h4><a id="window-group"></a>-window-group</h4> 6065</div> 6066 6067<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>specify the window group.</td><td style='text-align:right;'></td></tr></table> 6068 6069<div style="margin: auto;"> 6070 <h4><a id="write"></a>-write <em class="arg">filename</em></h4> 6071</div> 6072 6073<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>write an image sequence.</td><td style='text-align:right;'></td></tr></table> 6074 <p>The image sequence preceding the <a href="#write">-write</a> <em class="arg">filename</em> 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="#write">+write</a> <em class="arg">filename</em> option.</p> 6075 6076<p>Use <a href="#compress">-compress</a> to specify the type of image compression.</p> 6077</div> 6078</div> 6079 6080</div> 6081 6082<div id="linkbar"> 6083 <span id="linkbar-west"> </span> 6084 <span id="linkbar-center"> 6085 <a href="http://www.imagemagick.org/discourse-server/">Discourse Server</a> • 6086 <a href="http://www.imagemagick.org/MagickStudio/scripts/MagickStudio.cgi">Studio</a> 6087 </span> 6088 <span id="linkbar-east"> </span> 6089 </div> 6090 <div class="footer"> 6091 <span id="footer-west">© 1999-2011 ImageMagick Studio LLC</span> 6092 <span id="footer-east"> <a href="http://www.imagemagick.org/script/contact.php">Contact the Wizards</a></span> 6093 </div> 6094 <div style="clear: both; margin: 0; width: 100%; "></div> 6095 <script type="text/javascript"> 6096 var _gaq = _gaq || []; 6097 _gaq.push(['_setAccount', 'UA-17690367-1']); 6098 _gaq.push(['_trackPageview']); 6099 6100 (function() { 6101 var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; 6102 ga.src = ('https:' == document.location.protocol ? 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