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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#recolor">‑recolor</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#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#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#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> 157 158<p>Below is list of command-line options recognized by the ImageMagick <a href="/www/command-line-tools.html">command-line tools</a>. If you want a description of a particular option, click on the option name in the navigation bar above and you will go right to it. Unless otherwise noted, each option is recognized by the commands 159<a href="/www/convert.html">convert</a>, <a href="/www/mogrify.html">mogrify</a>, and .... </p> 160 161<div style="margin: auto;"> 162 <h4><a name="adaptive-blur" id="adaptive-blur"></a>-adaptive-blur <em class="arg">radius</em>[x<em class="arg">sigma</em>]</h4> 163</div> 164 165<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> 166 167<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> 168 169<div style="margin: auto;"> 170 <h4><a name="adaptive-resize" id="adaptive-resize"></a>-adaptive-resize <em class="arg">geometry</em></h4> 171</div> 172 173<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> 174 175<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> 176 177<div style="margin: auto;"> 178 <h4><a name="adaptive-sharpen" id="adaptive-sharpen"></a>-adaptive-sharpen <em class="arg">radius</em>[x<em class="arg">sigma</em>]</h4> 179</div> 180 181<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> 182 183<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> 184 185<div style="margin: auto;"> 186 <h4><a name="adjoin" id="adjoin"></a>-adjoin</h4> 187</div> 188 189<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> 190 191<p>This option is enabled by default. An attempt is made to save all 192images of an image sequence into the given output file. 193However, some formats, such as JPEG and PNG, do not support more than one 194image per file, and in that case ImageMagick is forced to write each image as a separate file. As 195such, if more than one image needs to be written, the filename given is 196modified by adding a <a href="#scene">-scene</a> number before the 197suffix, in order to make distinct names for each image. </p> 198 199<p>Use <a href="#adjoin">+adjoin</a> to force each image to be written 200to separate files, whether or not the file format allows multiple images 201per file (for example, GIF, MIFF, and TIFF). </p> 202 203<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> 204 205<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert logo: rose: -morph 15 my%02dmorph.jpg</span></p> 206<p>will create a sequence of 17 images named my00morph.jpg, my01morph.jpg, my02morph.jpg, ..., my16morph.jpg. 207</p> 208 209<p>In summary, ImageMagick tries to write all images to one file, but will use 210multiple files if either (1) the output image's file format does not allow multi-image files, 211(2) the <a href="#adjoin">+adjoin</a> option is given, or (3) a C-style integer format string is 212present in the output filename. </p> 213 214 215<div style="margin: auto;"> 216 <h4><a name="affine" 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/> 217 -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> 218</div> 219 220<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> 221 222<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> 223 224<p>The matrix entries are entered as comma-separated numeric values <i>with no spaces</i>. </p> 225 226<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> 227 228<div class="eqn"> 229<img alt="affine transformation" src="/images/affine.png"/> 230</div> 231 232<p> 233The 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> 234 235<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> 236 237<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> 238 239<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> 240 241<p class="crtsnip"> 242 -affine <em class="arg">s<sub>x</sub></em>,0,0,<em class="arg">s<sub>y</sub></em> 243</p> 244 245<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> 246 247<p class="crtsnip"> 248 -affine 1,0,0,1,<em class="arg">t<sub>x</sub></em>,<em class="arg">t<sub>y</sub></em> 249</p> 250 251<p>Rotate clockwise about the origin (the upper left-hand corner) by an angle <em>a</em> by letting 252<em>c</em> = cos(<em>a</em>), <em>s</em> = sin(<em>a</em>), and using the following.</p> 253 254<p class="crtsnip"> 255 -affine <em>c</em>,<em>s</em>,-<em>s</em>,<em>c</em> 256</p> 257 258<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> 259 260<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> 261 262<div style="margin: auto;"> 263 <h4><a name="alpha" id="alpha"></a>-alpha <em class="arg">type</em></h4> 264</div> 265 266<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> 267 268<p>Used to set a flag on an image indicating whether or not to use existing alpha 269channel 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> 270 271 272<table class="doc"> 273 <tbody> 274 <tr valign="top"> 275 <th align="left" style="width: 8%">type</th> 276 <th align="left">Description</th> 277 </tr> 278 279 <tr valign="top"> 280 <td valign="top"><kbd>Off</kbd> or 281 <kbd>Deactivate</kbd></td> 282 <td valign="top"> 283 Disables the image's transparency channel. Does not delete or change the 284 existing data, just turns off the use of that data. This is the same as 285 the older <a href="#matte" >+matte</a> operator. </td></tr> 286 287 <tr valign="top"> 288 <td valign="top"><kbd>On</kbd> or 289 <kbd>Activate</kbd></td> 290 <td valign="top"> 291 Enables the image's use of transparency. If transparency data does not 292 already exist, allocates the data and sets it to opaque. If the image has 293 transparency data, the channel is enabled and the transparency data is not changed or modified in any way. This is NOT 294 the same as the older <a href="#matte" >-matte</a> operator. </td></tr> 295 296 <tr valign="top"> 297 <td valign="top"><kbd>Set</kbd></td> 298 <td valign="top"> 299 Turns '<kbd>On</kbd>' the alpha/matte channel and if it was previously 300 turned off resets the channel to opaque. If the image already had the 301 alpha channel turned on, it will have no effect. This is the same as the older <a href="#matte">-matte</a> operator. </td></tr> 302 303 <tr valign="top"> 304 <td valign="top"><kbd>Opaque</kbd></td> 305 <td valign="top"> 306 Turns '<kbd>On</kbd>' the alpha/matte channel and forces it to be fully 307 opaque. </td></tr> 308 309 <tr valign="top"> 310 <td valign="top"><kbd>Transparent</kbd></td> 311 <td valign="top"> 312 Turns '<kbd>On</kbd>' the alpha/matte channel and forces it to be fully 313 transparent. This effectively creates a fully transparent image the same 314 size as the original and with all its original RGB data still intact. </td></tr> 315 316 <tr valign="top"> 317 <td valign="top"><kbd>Extract</kbd></td> 318 <td valign="top"> 319 Copies the alpha channel values into all the color channels and turns 320 '<kbd>Off</kbd>' the the image's transparency, so as to generate a 321 gray-scale mask of the image's shape. This is the inverse of 322 '<kbd>Copy</kbd>'. </td></tr> 323 324 <tr valign="top"> 325 <td valign="top"><kbd>Copy</kbd></td> 326 <td valign="top"> 327 Turns '<kbd>On</kbd>' the alpha/matte channel, then copies the 328 gray-scale intensity of the image, as an alpha mask, into the alpha 329 channel, converting a gray-scale mask into a transparent shaped image 330 ready to be colored appropriately. The color channels are not modified. 331 </td></tr> 332 333 <tr valign="top"> 334 <td valign="top"><kbd>Shape</kbd></td> 335 <td valign="top"> 336 As per '<kbd>Copy</kbd>' but also colors the resulting shape mask with 337 the current background color. 338 </td></tr> 339 340 <tr valign="top"> 341 <td valign="top"><kbd>Background</kbd></td> 342 <td valign="top"> 343 Set any fully-transparent pixel to the background color. 344 </td></tr> 345 </tbody> 346</table> 347 348<p>Note that while the <a href="#matte" >+matte</a> operation is the same as 349"<kbd><a href="#alpha" >-alpha</a> off</kbd>", the <a href="#matte" 350>-matte</a> operation is the same as "<kbd><a href="#alpha" >-alpha</a> set</kbd>" and 351not "<kbd><a href="#alpha" >-alpha</a> on</kbd>". 352That is, "<kbd><a href="#alpha" >-alpha</a> set</kbd>" will ensure that the 353written image is opaque if the original image had no transparency 354channel enabled, regardless if transparency data is already present. </p> 355 356 357<div style="margin: auto;"> 358 <h4><a name="annotate" id="annotate"></a> 359 -annotate <em class="arg">degrees</em> <em class="arg">text</em><br /> 360 -annotate <em class="arg">Xdegrees</em>x<em class="arg">Ydegrees</em> <em class="arg">text</em><br /> 361 -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> 362</div> 363 364<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> 365 366<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> 367 368 369<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> 370 371<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> 372 373<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> 374<div class="eqn"><img alt="annotate transformation" src="/images/annotate.png"/></div> 375 376<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> 377 378<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> 379 380<div style="margin: auto;"> 381 <h4><a name="antialias" id="antialias"></a>-antialias</h4> 382</div> 383 384<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 385drawing fonts and lines.</td><td style='text-align:right;'></td></tr></table> 386 387<p>By default, objects (e.g. text, lines, polygons, etc.) are antialiased when 388drawn. Use <a href="#antialias">+antialias</a> to disable the addition of 389antialiasing edge pixels. This will then reduce the number of colors added to 390an image to just the colors being directly drawn. That is, no mixed colors 391will be added when drawing such objects. </p> 392 393<div style="margin: auto;"> 394 <h4><a name="append" id="append"></a>-append</h4> 395</div> 396 397<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> 398 399<p>This option creates a single longer image image, by joining all the current 400images in sequence top-to-bottom. Use <a href="#append">+append</a> to 401stack images left-to-right. </p> 402 403<p>If they are not of the same width, narrower images are padded with the 404current <a href="#background">-background</a> color setting, and their 405position relative to each other can be controled by the current <a 406href="#gravity">-gravity</a> setting. </p> 407 408 409<div style="margin: auto;"> 410 <h4><a name="attenuate" id="attenuate"></a>-attenuate <em class="arg">value</em></h4> 411</div> 412 413<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> 414 415 416<div style="margin: auto;"> 417 <h4><a name="authenticate" id="authenticate"></a>-authenticate <em class="arg">password</em></h4> 418</div> 419 420<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> 421 422<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> 423 424<p>For a different encryption method, see <a href="#encipher">-encipher</a> and <a href="#decipher">-decipher</a>. </p> 425 426<div style="margin: auto;"> 427 <h4><a name="auto-gamma" id="auto-gamma"></a>-auto-gamma</h4> 428</div> 429 430<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> 431 432<div style="margin: auto;"> 433 <h4><a name="auto-level" id="auto-level"></a>-auto-level</h4> 434</div> 435 436<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> 437 438<div style="margin: auto;"> 439 <h4><a name="auto-orient" id="auto-orient"></a>-auto-orient</h4> 440</div> 441 442<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> 443 444<div style="margin: auto;"> 445 <h4><a name="average" id="average"></a>-average</h4> 446</div> 447 448<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> 449 450<p>An error results if the images are not identically sized.</p> 451 452<p>The sequence of images is terminated by the appearance of any option. If the <a href="#average">-average</a> option appears after all of the input images, all images are averaged.</p> 453 454<div style="margin: auto;"> 455 <h4><a name="backdrop" id="backdrop"></a>-backdrop</h4> 456</div> 457 458<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> 459 460<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> 461 462<div style="margin: auto;"> 463 <h4><a name="background" id="background"></a>-background <em class="arg">color</em></h4> 464</div> 465 466<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> 467 468<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> 469 470<div style="margin: auto;"> 471 <h4><a name="bench" id="bench"></a>-bench <em class="arg">iterations</em></h4> 472</div> 473 474<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> 475 476<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.</p> 477 478<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert logo: -resize 1000% -bench 5 biglogo.png</span><span class='crtout'>Performance: 5i 0.0539724ips 91.750u 2:33</span></p> 479<p>In this example, 5 iterations were completed at 0.0539724 iterations per second, using 91.750 seconds of the user's allotted time, for a total elapsed time of 2 minutes and 33 seconds.</p> 480 481<div style="margin: auto;"> 482 <h4><a name="bias" id="bias"></a>-bias <em class="arg">value</em>{<em class="arg">%</em>}</h4> 483</div> 484 485<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> 486 487<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> 488 489<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> 490 491<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 492negative results without clipping to the color value range 493(0..QuantumRange).</p> 494 495<p>See the discussion on HDRI implementations of ImageMagick on the page 496<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. 497</p> 498 499<div style="margin: auto;"> 500 <h4><a name="black-point-compensation" id="black-point-compensation"></a>-black-point-compensation</h4> 501</div> 502 503<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> 504 505<div style="margin: auto;"> 506 <h4><a name="black-threshold" id="black-threshold"></a>-black-threshold <em class="arg">value</em>{<em class="arg">%</em>}</h4> 507</div> 508 509<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> 510 511<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. 512</p> 513 514 515<div style="margin: auto;"> 516 <h4><a name="blend" id="blend"></a>-blend <em class="arg">percent</em></h4> 517</div> 518 519<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 percent.</td><td style='text-align:right;'>[<a href="/www/composite.html">composite</a>]</td></tr></table> 520 521<p>Blend will average the images together ('plus') according to the 522percentages given and each pixels transparency. If only a single percentage 523value is given it sets the weight of the composite or 'source' image, while 524the background image is weighted by the exact opposite amount. That is a 525<kbd>-blend 30</kbd> merges 30% of the 'source' image with 70% of the 526'destination' image. Thus it is equivalent to <kbd>-blend 30x70</kbd>.</p> 527 528 529<div style="margin: auto;"> 530 <h4><a name="blue-primary" id="blue-primary"></a>-blue-primary <em class="arg">x</em>,<em class="arg">y</em></h4> 531</div> 532 533<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> 534 535<div style="margin: auto;"> 536 <h4><a name="blue-shift" id="blue-shift"></a>-blue-shift <em class="arg">factor</em></h4> 537</div> 538 539<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> 540 541<div style="margin: auto;"> 542 543<div style="margin: auto;"> 544 <h4><a name="blur" id="blur"></a>-blur <em class="arg">radius</em><br />-blur <em class="arg">radius</em>x<em class="arg">sigma</em></h4> 545</div> 546 547<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> 548 549<p>Convolve the image with a Gaussian or normal distribution. The formula is:</p> 550 551<div class="eqn"><img alt="gaussian distribution" width="243px" height="42px" src="/images/gaussian-blur.png"/> 552</div> 553 554<p>Where <i>r</i> is the blur radius (<i>r</i><sup>2</sup> = <i>u</i><sup>2</sup> + <i>v</i><sup>2</sup>), and σ is the standard deviation of the Gaussian distribution. As a guideline, set <i>r</i> to approximately 3σ. If a radius of 0 is specified, ImageMagick selects a suitable radius for you.</p> 555 556<p>This option differs from <a href="#gaussian-blur">-gaussian-blur</a> simply by taking advantage of the separability properties of the distribution. Here we apply a single-dimensional Gaussian matrix in the horizontal direction, then repeat the process in the vertical direction.</p> 557 558<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how 559pixels which are outside the image proper are blurred into the final result. 560</p> 561 562 563<div style="margin: auto;"> 564 <h4><a name="blur-composite" id="blur"></a>-blur <em class="arg">Width</em>[x<em class="arg">Height</em>[+<em class="arg">Angle</em>]]</h4> 565</div> 566 567<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> 568 569<p>Each pixel in the overlaid region is replaced with an Elliptical Weighted 570Average (EWA) of the source image, scaled according to the grayscale 571mapping. </p> 572 573<p>The ellipse is weighted with sigma set to the given <em class="arg" 574>Width</em> and <em class="arg" >Height</em>. The <em class="arg" >Height</em> 575defaults to the <em class="arg" >Width</em> for a normal circular Guassian 576weighting. The <em class="arg" >Angle</em> will rotate the ellipse from 577horizontal clock-wise. </p> 578 579<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how 580pixels which are outside the image proper are blurred into the final result. 581</p> 582 583 584<div style="margin: auto;"> 585 <h4><a name="border" id="border"></a>-border <em class="arg">geometry</em></h4> 586</div> 587 588<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> 589 590<p>Set the width and height using the <em class="arg">size</em> portion of the <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 ignored. </p> 591 592<p>Set the border color by preceding with the <a href="#bordercolor">-bordercolor</a> setting.</p> 593 594<p>See also the <a href="#frame">-frame</a> option, which has more functionality.</p> 595 596<div style="margin: auto;"> 597 <h4><a name="bordercolor" id="bordercolor"></a>-bordercolor <em class="arg">color</em></h4> 598</div> 599 600<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> 601 602<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p> 603 604<p>The default border color is <kbd>#DFDFDF</kbd>, <span style="background-color: #dfdfdf;">this shade of gray</span>.</p> 605 606<div style="margin: auto;"> 607 <h4><a name="borderwidth" id="borderwidth"></a>-borderwidth <em class="arg">geometry</em> </h4> 608</div> 609 610<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> 611 612<div style="margin: auto;"> 613 <h4><a name="cache" id="cache"></a>-cache <em class="arg">threshold</em></h4> 614</div> 615 616<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> 617 618<div style="margin: auto;"> 619 <h4><a name="caption" id="caption"></a>-caption <em class="arg">string</em></h4> 620</div> 621 622<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> 623 624<div style="margin: auto;"> 625 <h4><a name="cdl" id="cdl"></a>-cdl <em class="arg">filename</em></h4> 626</div> 627 628<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> 629 630<p>Here is an example color correction collection:</p> 631 632<pre class="text"> 633<?xml version="1.0" encoding="UTF-8"?> 634<ColorCorrectionCollection xmlns="urn:ASC:CDL:v1.2"> 635 <ColorCorrection id="cc06668"> 636 <SOPNode> 637 <Slope> 0.9 1.2 0.5 </Slope> 638 <Offset> 0.4 -0.5 0.6 </Offset> 639 <Power> 1.0 0.8 1.5 </Power> 640 </SOPNode> 641 <SATNode> 642 <Saturation> 0.85 </Saturation> 643 </SATNode> 644 </ColorCorrection> 645</ColorCorrectionCollection> 646</pre> 647 648<div style="margin: auto;"> 649 <h4><a name="channel" id="channel"></a>-channel <em class="arg">type</em></h4> 650</div> 651 652<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> 653 654<p>Choose from: <kbd>Red</kbd>, <kbd>Green</kbd>, <kbd>Blue</kbd>, <kbd>Alpha</kbd>, <kbd>Cyan</kbd>, <kbd>Magenta</kbd>, <kbd>Yellow</kbd>, <kbd>Black</kbd>, <kbd>Opacity</kbd>, <kbd>Index</kbd>, <kbd>RGB</kbd>, <kbd>RGBA</kbd>, <kbd>CMYK</kbd>, or <kbd>CMYKA</kbd>.</p> 655 656<p>To print a complete list of channel types, use <a href="#list">-list channel</a>.</p> 657 658<p>The channels above can be specified as a comma-separated list or can be abbreviated as a 659concatenation of the letters '<kbd>R</kbd>', '<kbd>G</kbd>', '<kbd>B</kbd>', 660'<kbd>A</kbd>', '<kbd>O</kbd>', '<kbd>C</kbd>', '<kbd>M</kbd>', '<kbd>Y</kbd>', 661'<kbd>K</kbd>'. 662 663For example, to negate only the alpha channel of an image, use</p> 664<p class="crtsnip"> 665 -channel Alpha -negate 666</p> 667 668<p>By default, ImageMagick sets <a href="#channel">-channel</a> to the value 669'<kbd>RGB</kbd>', which specifies that operators act on all channels except 670the opacity channel. Using the option <a href="#channel" >+channel</a> will reset the value back to this default. </p> 671 672<p>Options that are affected by the <a href="#channel" >-channel</a> setting include the following. 673<a href="#black-threshold">-black-threshold</a>, 674<a href="#blur">-blur</a>, 675<a href="#clamp">-clamp</a>, 676<a href="#clut">-clut</a>, 677<a href="#combine">-combine</a>, 678<a href="#contrast-stretch">-contrast-stretch</a>, 679<a href="#evaluate">-evaluate</a>, 680<a href="#function">-function</a>, 681<a href="#fx">-fx</a>, 682<a href="#hald-clut">-hald-clut</a>, 683<a href="#gaussian-blur">-gaussian-blur</a>, 684<a href="#motion-blur">-motion-blur</a>, 685<a href="#negate">-negate</a>, 686<a href="#normalize">-normalize</a>, 687<a href="#ordered-dither">-ordered-dither</a>, 688<a href="#radial-blur">-radial-blur</a>, 689<a href="#random-threshold">-random-threshold</a>, 690<a href="#separate">-separate</a>, and 691<a href="#white-threshold">-white-threshold</a>. 692</p> 693 694 695<div style="margin: auto;"> 696 <h4><a name="clamp" id="clamp"></a>-clamp</h4> 697</div> 698 699<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> 700 701<div style="margin: auto;"> 702 <h4><a name="charcoal" id="charcoal"></a>-charcoal <em class="arg">factor</em></h4> 703</div> 704 705<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> 706 707<div style="margin: auto;"> 708 <h4><a name="chop" id="chop"></a>-chop <em class="arg">geometry</em></h4> 709</div> 710 711<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> 712 713<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> and <em class="arg">height</em> given in the of the <em class="arg">size</em> portion of the <em class="arg">geometry</em> argument give the number of columns and rows to remove. The <em class="arg">offset</em> portion of the <em class="arg">geometry</em> argument is influenced by a <a href="#gravity">-gravity</a> setting, if present.</p> 714 715<p>The <a href="#chop">-chop</a> option removes entire rows and columns, and moves the remaining corner blocks leftward and upward to close the gaps.</p> 716 717<div style="margin: auto;"> 718 <h4><a name="clip" id="clip"></a>-clip</h4> 719</div> 720 721<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> 722 723<p>If a clipping path is present, it is applied to subsequent operations.</p> 724 725<p>For example, in the command</p> 726 727<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert -clip -negate cockatoo.tif negated.tif</span></p> 728<p>only the pixels within the clipping path are negated.</p> 729 730<p>The <a href="#clip">-clip</a> feature requires the XML library. If the XML library is not present, the option is ignored.</p> 731 732<div style="margin: auto;"> 733 <h4><a name="clip-mask" id="clip-mask"></a>-clip-mask</h4> 734</div> 735 736<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> 737 738<div style="margin: auto;"> 739 <h4><a name="clip-path" id="clip-path"></a>-clip-path <em class="arg">id</em></h4> 740</div> 741 742<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> 743 744<div style="margin: auto;"> 745 <h4><a name="clone" id="clone"></a>-clone <em class="arg">index(s)</em></h4> 746</div> 747 748<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> 749 750<p>Specify the image by its index in the sequence. The first image is index 7510. Negative indexes are relative to the end of the sequence; for example, −1 752represents the last image of the sequence. Specify a range of images with a 753dash (e.g. 0−4). Separate multiple indexes with commas but no spaces (e.g. 0,2,5). Use <a 754href="#clone">+clone</a> make a copy of the last image in the image 755sequence.</p> 756 757<div style="margin: auto;"> 758 <h4><a name="clut" id="clut"></a>-clut</h4> 759</div> 760 761<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 762corresponding channel in the second image as a <b>c</b>olor 763<b>l</b>ook<b>u</b>p <b>t</b>able.</td><td style='text-align:right;'></td></tr></table> 764 765<p>The second (LUT) image is ordinarily a gradient image containing the 766histogram mapping of how each channel should be modified. Typically it is a 767either a single row or column image of replacement color values. If larger 768than a single row or column, values are taken from a diagonal line from 769top-left to bottom-right corners.</p> 770 771<p>The lookup is further controlled by the <a 772href="#interpolate">-interpolate</a> setting, which is especially handy for an 773LUT which is not the full length needed by the ImageMagick installed Quality 774(Q) level. Good settings for this are the '<kbd>bilinear</kbd>' and 775'<kbd>bicubic</kbd>' interpolation settings, which give smooth color 776gradients, and the '<kbd>integer</kbd>' setting for a direct, unsmoothed 777lookup of color values. </p> 778 779<p>This operator is especially suited to replacing a grayscale image with a 780specific color gradient from the CLUT image. </p> 781 782<p>Only the channel values defined by the <a href="#channel">-channel</a> 783setting will have their values replaced. In particular, since the default <a 784href="#channel">-channel</a> setting is <kbd>RGB</kbd>, this means that 785transparency (alpha/matte channel) is not affected, unless the <a 786href="#channel">-channel</a> setting is modified. When the alpha channel is 787set, it is treated by the <a href="#clut" >-clut</a> operator in the same way 788as the other channels, implying that alpha/matte values are replaced using the 789alpha/matte values of the original image. </p> 790 791<p>If either the image being modified, or the lookup image, conatins no 792transparency (i.e. <a href="#alpha" >-alpha</a> is turned 'off') but the <a 793href="#channel">-channel</a> setting includes alpha replacement, then it is 794assumed that image represents a gray-scale graident which will be used for the 795replacement alpha values. That is you can use a gray-scale CLUT image to 796adjust a existing images alpha channel, or you can color a gray-scale image 797using colors form CLUT containing the desired colors, including transparency. 798</p> 799 800<p>See also <a href="#hald-clut" >-hald-clut</a> which replaces colors according 801the lookup of the full color RGB value from a 2D representation of a 3D color 802cube. </p> 803 804 805<div style="margin: auto;"> 806 <h4><a name="coalesce" id="coalesce"></a>-coalesce</h4> 807</div> 808 809<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> 810 811<p>Overlay each image in an image sequence according to its <a href="#dispose">-dispose</a> meta-data, to reproduce the look of an animation at each point in the animation sequence. All images should be the same size, and are assigned appropriate GIF disposal settings for the animation to continue working as expected as a GIF animation. Such frames are more easilly viewed and processed than the highly optimized GIF overlay images. </p> 812 813<p>The animation can be re-optimized after processing using the <a href="#layers">-layers</a> method '<kbd>optimize</kbd>', though there is no guarantee that the restored GIF animation optimization is better than the original. </p> 814 815 816<div style="margin: auto;"> 817 <h4><a name="colorize" id="colorize"></a>-colorize <em class="arg">value</em></h4> 818</div> 819 820<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> 821 822<p>Specify the amount of colorization as a percentage. Separate colorization values can be applied to the red, green, and blue channels of the image with a comma-delimited list of colorization values (e.g., <kbd>-colorize 0,0,50</kbd>).</p> 823 824<div style="margin: auto;"> 825 <h4><a name="colormap" id="colormap"></a>-colormap <em class="arg">type</em></h4> 826</div> 827 828<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> 829 830<p>The <em class="arg">type</em> can be <kbd>shared</kbd> or <kbd>private</kbd>.</p> 831 832<p>This option only applies when the default X server visual is <kbd>PseudoColor</kbd> or <kbd>GrayScale</kbd>. Refer to <a href="#visual">-visual</a> for more details. By default, a shared colormap is allocated. The image shares colors with other X clients. Some image colors could be approximated, therefore your image may look very different than intended. If <kbd>private</kbd> is chosen, the image colors appear exactly as they are defined. However, other clients may go <em>technicolor</em> when the image colormap is installed.</p> 833 834<div style="margin: auto;"> 835 <h4><a name="colors" id="colors"></a>-colors <em class="arg">value</em></h4> 836</div> 837 838<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> 839 840<p>The actual number of colors in the image may be less than your request, but never more. Note that this a color reduction option. Images with fewer unique colors than specified by <em class="arg">value</em> will have any duplicate or unused colors removed. The ordering of an existing color palette may be altered. When converting an image from color to grayscale, it is more efficient to convert the image to the gray colorspace before reducing the number of colors. Refer to the <a href="/www/quantize.html">color reduction algorithm</a> for more details.</p> 841 842<div style="margin: auto;"> 843 <h4><a name="colorspace" id="colorspace"></a>-colorspace <em class="arg">value</em></h4> 844</div> 845 846<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> 847 848<p>Choices are:</p> 849 850<pre class="text"> 851 CMY 852 CMYK 853 Gray 854 HSB 855 HSL 856 HWB 857 Lab 858 Log 859 OHTA 860 Rec601Luma 861 Rec601YCbCr 862 Rec709Luma 863 Rec709YCbCr 864 RGB 865 sRGB 866 Transparent 867 XYZ 868 YCbCr 869 YCC 870 YIQ 871 YPbPr 872 YUV 873</pre> 874 875<p>To print a complete list of colorspaces, use <a href="#list">-list colorspace</a>.</p> 876 877<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> 878 879<table class="doc"> 880 <caption>Conversion Of RGB To Other Color Spaces</caption> 881 <tr><th align="left" valign="middle">CMY</th></tr> 882 <tr><td align="left" valign="middle">C=<em class="QR">QuantumRange</em>−R</td></tr> 883 <tr><td align="left" valign="middle">M=<em class="QR">QuantumRange</em>−G</td></tr> 884 <tr><td align="left" valign="middle">Y=<em class="QR">QuantumRange</em>−B</td></tr> 885 <tr><th align="left" valign="middle">CMYK — starts with CMY from above</th></tr> 886 <tr><td align="left" valign="middle">K=min(C,Y,M)</td></tr> 887 <tr><td align="left" valign="middle">C=<em class="QR">QuantumRange</em>*(C−K)/(<em class="QR">QuantumRange</em>−K)</td></tr> 888 <tr><td align="left" valign="middle">M=<em class="QR">QuantumRange</em>*(M−K)/(<em class="QR">QuantumRange</em>−K)</td></tr> 889 <tr><td align="left" valign="middle">Y=<em class="QR">QuantumRange</em>*(Y−K)/(<em class="QR">QuantumRange</em>−K)</td></tr> 890 891 <tr><th align="left" valign="middle">Gray</th></tr> 892 <tr><td align="left" valign="middle">Gray = 0.29900*R+0.58700*G+0.11400*B</td></tr> 893 894 <tr><th align="left" valign="middle">HSB — Hue, Saturation, Brightness; like a cone peak downward</th></tr> 895 <tr><td align="left" valign="middle">H=angle around perimeter (0 to 360 deg); H=0 is red; increasing angles toward green</td></tr> 896 <tr><td align="left" valign="middle">S=distance from axis outward</td></tr> 897 <tr><td align="left" valign="middle">B=distance along axis from bottom upward; B=max(R,G,B); <em>intensity-like</em></td></tr> 898 899 <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> 900 <tr><td align="left" valign="middle">H=angle around perimeter (0 to 360 deg); H=0 is red; increasing angles toward green</td></tr> 901 <tr><td align="left" valign="middle">S=distance from axis outward</td></tr> 902 <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> 903 904 <tr><th align="left" valign="middle">HWB — Hue, Whiteness, Blackness</th></tr> 905 <tr><td align="left" valign="middle">Hue (complicated equation)</td></tr> 906 <tr><td align="left" valign="middle">Whiteness (complicated equation)</td></tr> 907 <tr><td align="left" valign="middle">Blackness (complicated equation)</td></tr> 908 909 <tr><th align="left" valign="middle">LAB</th></tr> 910 <tr><td align="left" valign="middle">L (complicated equation relating X,Y,Z)</td></tr> 911 <tr><td align="left" valign="middle">A (complicated equation relating X,Y,Z)</td></tr> 912 <tr><td align="left" valign="middle">B (complicated equation relating X,Y,Z)</td></tr> 913 914 <tr><th align="left" valign="middle">LOG</th></tr> 915 <tr><td align="left" valign="middle">I1 (complicated equation involving logarithm of R)</td></tr> 916 <tr><td align="left" valign="middle">I2 (complicated equation involving logarithm of G)</td></tr> 917 <tr><td align="left" valign="middle">I3 (complicated equation involving logarithm of B)</td></tr> 918 919 <tr><th align="left" valign="middle">OHTA — approximates principal components transformation</th></tr> 920 <tr><td align="left" valign="middle">I1=0.33333*R+0.33334*G+0.33333*B; <em>intensity-like</em></td></tr> 921 <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> 922 <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> 923 924 <tr><th align="left" valign="middle">Rec601Luma</th></tr> 925 <tr><td align="left" valign="middle">Gray = 0.29900*R+0.58700*G+0.11400*B</td></tr> 926 927 <tr><th align="left" valign="middle">Rec601YCbCr</th></tr> 928 <tr><td align="left" valign="middle">Y=0.299000*R+0.587000*G+0.114000*B; <em>intensity-like</em></td></tr> 929 <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> 930 <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> 931 932 <tr><th align="left" valign="middle">Rec709Luma</th></tr> 933 <tr><td align="left" valign="middle">Gray=0.21260*R+0.71520*G+0.07220*B</td></tr> 934 935 <tr><th align="left" valign="middle">Rec709YCbCr</th></tr> 936 <tr><td align="left" valign="middle">Y=0.212600*R+0.715200*G+0.072200*B; <em>intensity-like</em></td></tr> 937 <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> 938 <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> 939 940 <tr><th align="left" valign="middle">sRGB</th></tr> 941 <tr><td align="left" valign="middle">if Rs ≤ .03928 then Rs=R/12.92 else Rs=((R+.055)/1.055)^2.4</td></tr> 942 <tr><td align="left" valign="middle">if Gs ≤ .03928 then Gs=B/12.92 else Gs=((G+.055)/1.055)^2.4</td></tr> 943 <tr><td align="left" valign="middle">if Bs ≤ .03928 then Bs=B/12.92 else Bs=((B+.055)/1.055)^2.4</td></tr> 944 945 <tr><th align="left" valign="middle">XYZ</th></tr> 946 <tr><td align="left" valign="middle">X=0.4124240*R+0.3575790*G+0.1804640*B</td></tr> 947 <tr><td align="left" valign="middle">Y=0.2126560*R+0.7151580*G+0.0721856*B</td></tr> 948 <tr><td align="left" valign="middle">Z=0.0193324*R+0.1191930*G+0.9504440*B</td></tr> 949 950 <tr><th align="left" valign="middle">YCC</th></tr> 951 <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> 952 <tr><td align="left" valign="middle">C1=(−0.29900*R−0.58700*G+0.88600*B) (with complicated scaling)</td></tr> 953 <tr><td align="left" valign="middle">C2=(0.70100*R−0.58700*G−0.11400*B) (with complicated scaling)</td></tr> 954 955 <tr><th align="left" valign="middle">YCbCr</th></tr> 956 <tr><td align="left" valign="middle">Y=0.299000*R+0.587000*G+0.114000*B; <em>intensity-like</em></td></tr> 957 <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> 958 <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> 959 960 <tr><th align="left" valign="middle">YIQ</th></tr> 961 <tr><td align="left" valign="middle">Y=0.29900*R+0.58700*G+0.11400*B; <em>intensity-like</em></td></tr> 962 <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> 963 <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> 964 965 <tr><th align="left" valign="middle">YPbPr</th></tr> 966 <tr><td align="left" valign="middle">Y=0.299000*R+0.587000*G+0.114000*B; <em>intensity-like</em></td></tr> 967 <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> 968 <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> 969 970 <tr><th align="left" valign="middle">YUV</th></tr> 971 <tr><td align="left" valign="middle">Y=0.29900*R+0.58700*G+0.11400*B; <em>intensity-like</em></td></tr> 972 <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> 973 <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> 974</table> 975 976<div style="margin: auto;"> 977 <h4><a name="combine" id="combine"></a>-combine</h4> 978</div> 979 980<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> 981 982<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> 983 984<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. 985</p> 986 987<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 -combine imagecopy.png</span></p> 988<div style="margin: auto;"> 989 <h4><a name="comment" id="comment"></a>-comment <em class="arg">string</em></h4> 990</div> 991 992<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> 993 994<p>This option places comments in a non-pixel portion of the image file. For a comment to be visibly written on the image itself, use the <a href="#annotate">-annotate</a> or <a href="#draw">-draw</a> options.</p> 995 996<p>Use this option to assign a specific comment to the image, when writing to an image format that supports comments. You can include the image filename, type, width, height, or other image attribute by embedding special format characters listed under the <a href="#format">-format</a> option. The comment is not drawn on the image, but is embedded in the image datastream via "Comment" tag or similar mechanism. </p> 997 998<p>For example,</p> 999 1000<p class="crtsnip"> 1001 -comment "%m:%f %wx%h" 1002</p> 1003 1004<p>produces an image comment 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> 1005 1006<p>If the first character of <em class="arg">string</em> is <em class="arg">@</em>, the image comment is read from a file titled by the remaining characters in the string. Comments in a file are literal; no embedded formatting characters are recognized.</p> 1007 1008<div style="margin: auto;"> 1009 <h4><a name="compose" id="compose"></a>-compose <em class="arg">operator</em></h4> 1010</div> 1011 1012<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> 1013 1014<p>The description of composition uses abstract terminology in order to allow 1015the description to be more precise, while avoiding constant values which are 1016specific to a particular build configuration. Each image pixel is represented 1017by red, green, and blue levels (which are equal for a gray pixel). The 1018build-dependent value <em class="QR">QuantumRange</em> is the maximum integral 1019value which may be stored, per pixel, in the red, green, or blue channels of 1020the image. Each image pixel may also optionally (if the image matte channel is 1021enabled) have an associated level of opacity, ranging from <em>opaque</em> to 1022<em>transparent</em>, which may be used to determine the influence of the pixel 1023color when compositing the pixel with another image pixel. If the image matte 1024channel is disabled, then all pixels in the image are treated as opaque. The 1025color of an opaque pixel is fully visible while the color of a transparent 1026pixel color is entirely absent (pixel color is ignored).</p> 1027 1028<p>By definition, raster images have a rectangular shape. All image rows are of 1029equal length, as are all image columns. By treating the alpha channel as a 1030visual "mask" the rectangular image may be given a "shape" by treating the 1031alpha channel as a cookie-cutter for the image. This is done by setting the 1032pixels within the shape to be opaque, with pixels outside the shape set as 1033transparent. Pixels on the boundary of the shape may be between opaque and 1034transparent in order to provide antialiasing (visually smooth edges). The 1035description of the composition operators use this concept of image "shape" in 1036order to make the description of the operators easier to understand. While it 1037is convenient to describe the operators in terms of "shapes" they are by no 1038means limited to mask-style operations since they are based on continuous 1039floating-point mathematics rather than simple boolean operations.</p> 1040 1041<p>The following alpha blending (Duff-Porter) compose methods are available:</p> 1042 1043<table class="doc"> 1044 <tbody> 1045 <tr valign="top"> 1046 <th align="left" style="width: 8%">Method</th> 1047 <th align="left">Description</th> 1048 </tr> 1049 1050 <tr valign="top"> 1051 <td valign="top">clear</td> 1052 <td valign="top">Both the color and the alpha of the destination are 1053 cleared. Neither the source nor the destination are used (except for 1054 destinations size and other meta-data which is always preserved.</td> 1055 </tr> 1056 1057 <tr valign="top"> 1058 <td valign="top">src</td> 1059 <td valign="top">The source is copied to the destination. The destination 1060 is not used as input, though it is cleared.</td> 1061 </tr> 1062 1063 <tr valign="top"> 1064 <td valign="top">dst</td> 1065 <td valign="top">The destination is left untouched. The source image is 1066 completely ignored.</td> 1067 </tr> 1068 1069 <tr valign="top"> 1070 <td valign="top">src-over</td> 1071 <td valign="top">The source is composited over the destination. this is 1072 the default alpha blending compose method, when neither the compose 1073 setting is set, nor is set in the image meta-data.</td> 1074 </tr> 1075 1076 <tr valign="top"> 1077 <td valign="top">dst-over</td> 1078 <td valign="top">The destination is composited over the source and the 1079 result replaces the destination.</td> 1080 </tr> 1081 1082 <tr valign="top"> 1083 <td valign="top">src-in</td> 1084 <td valign="top">The part of the source lying inside of the destination 1085 replaces the destination.</td> 1086 </tr> 1087 1088 <tr valign="top"> 1089 <td valign="top">dst-in</td> 1090 <td valign="top">The part of the destination lying inside of the source 1091 replaces the destination. Areas not overlaid are cleared.</td> 1092 </tr> 1093 1094 <tr valign="top"> 1095 <td valign="top">src-out</td> 1096 <td valign="top">The part of the source lying outside of the destination 1097 replaces the destination.</td> 1098 </tr> 1099 1100 <tr valign="top"> 1101 <td valign="top">dst-out</td> 1102 <td valign="top">The part of the destination lying outside of the source 1103 replaces the destination.</td> 1104 </tr> 1105 1106 <tr valign="top"> 1107 <td valign="top">src-atop</td> 1108 <td valign="top">The part of the source lying inside of the destination is 1109 composited onto the destination.</td> 1110 </tr> 1111 1112 <tr valign="top"> 1113 <td valign="top">dst-atop</td> 1114 <td valign="top">The part of the destination lying inside of the source is 1115 composited over the source and replaces the destination. Areas not 1116 overlaid are cleared. </td> 1117 </tr> 1118 1119 <tr valign="top"> 1120 <td valign="top">xor</td> 1121 <td valign="top">The part of the source that lies outside of the 1122 destination is combined with the part of the destination that lies 1123 outside of the source. Source or Destination, but not both. </td> 1124 </tr> 1125 1126 </tbody> 1127</table> 1128 1129<p>Any of the 'Src-*' methods can also be specified without the 'Src-' part. 1130For example the defaul compose method can be specified as just 'Over'.</p> 1131 1132 1133<p>The following mathemathical composition methods are also available. </p> 1134 1135<p>Typically these use the default 'Over' alpha blending when transparencies 1136are also involved, except for 'Plus', 'Minus', 'Add', and 'Subtract', which 1137also composes the alpha channel using the same process as the color channels. 1138This allows them to be used for special image masking techniques. </p> 1139 1140<table class="doc"> 1141 <tbody> 1142 <tr valign="top"> 1143 <th align="left" style="width: 8%">Method</th> 1144 <th align="left">Description</th> 1145 </tr> 1146 1147 <tr valign="top"> 1148 <td valign="top">multiply</td> 1149 <td valign="top">The source is multiplied by the destination and replaces the destination. The resultant color is always at least as dark as either of the two constituent colors. Multiplying any color with black produces black. Multiplying any color with white leaves the original color unchanged.</td> 1150 </tr> 1151 1152 <tr valign="top"> 1153 <td valign="top">screen</td> 1154 <td valign="top">The source and destination are complemented and then multiplied and then replace the destination. The resultant color is always at least as light as either of the two constituent colors. Screening any color with white produces white. Screening any color with black leaves the original color unchanged.</td> 1155 </tr> 1156 1157 <tr valign="top"> 1158 <td valign="top">plus</td> 1159 <td valign="top">The source is added to the destination and replaces the 1160 destination. This operator is useful for averaging or a controled 1161 merger of two images, rather than a direct overlay.</td> 1162 </tr> 1163 1164 <tr valign="top"> 1165 <td valign="top">add</td> 1166 <td valign="top">As per 'plus' but transparency data is treated as matte 1167 values. As such any transparent areas in either image remain 1168 transparent. </td> 1169 </tr> 1170 1171 <tr valign="top"> 1172 <td valign="top">minus</td> 1173 <td valign="top">Subtract the colors in the source image from the 1174 destination image. When transparency is involved, opaque areas is 1175 subtracted from any destination opaque areas. </td> 1176 </tr> 1177 1178 <tr valign="top"> 1179 <td valign="top">subtract</td> 1180 <td valign="top">Subtract the colors in the source image from the 1181 destination image. When transparency is involved transparent areas are 1182 subtracted, so only the opaque areas in the source remain opaque in 1183 the destination image. </td> 1184 </tr> 1185 1186 <tr valign="top"> 1187 <td valign="top">difference</td> 1188 <td valign="top">Subtracts the darker of the two constituent colors from 1189 the lighter. Painting with white inverts the destination color. 1190 Painting with black produces no change.</td> 1191 </tr> 1192 1193 <tr valign="top"> 1194 <td valign="top">exclusion</td> 1195 <td valign="top">Produces an effect similar to that of 'difference', but 1196 appears as lower contrast. Painting with white inverts the 1197 destination color. Painting with black produces no change.</td> 1198 </tr> 1199 1200 <tr valign="top"> 1201 <td valign="top">darken</td> 1202 <td valign="top">Selects the darker of the destination and source colors. 1203 The destination is replaced with the source when the source is darker, 1204 otherwise it is left unchanged.</td> 1205 </tr> 1206 1207 <tr valign="top"> 1208 <td valign="top">lighten</td> 1209 <td valign="top">Selects the lighter of the destination and source colors. 1210 The destination is replaced with the source when the source is 1211 lighter, otherwise it is left unchanged. </td> 1212 </tr> 1213 1214 <tr valign="top"> 1215 <td valign="top">linear-dodge</td> 1216 <td valign="top">This is equivelent to 'Plus' in that the color channels 1217 are simply added, however it does not 'Plus' the alpha channel, but 1218 uses the normal 'Over' alpha blending, which transparencies are 1219 involved. Produces a sort of additive multiply-like result. Added 1220 ImageMagick version 6.5.4-3. </td> 1221 </tr> 1222 1223 <tr valign="top"> 1224 <td valign="top">linear-burn</td> 1225 <td valign="top">As 'Linear-Dodge', but also subtract one from the result. 1226 Sort of a additive 'Screen' of the images. Added ImageMagick version 1227 6.5.4-3. </td> 1228 </tr> 1229 1230 <tr valign="top"> 1231 <td valign="top">color-dodge</td> 1232 <td valign="top">Brightens the destination color to reflect the source 1233 color. Painting with black produces no change.</td> 1234 </tr> 1235 1236 <tr valign="top"> 1237 <td valign="top">color-burn</td> 1238 <td valign="top">Darkens the destination color to reflect the source 1239 color. Painting with white produces no change. Fixed in ImageMagick 1240 version 6.5.4-3. </td> 1241 </tr> 1242 1243 <tr valign="top"> 1244 <td valign="top">overlay</td> 1245 <td valign="top">Multiplies or screens the colors, dependent on the 1246 destination color. Source colors overlay the destination whilst 1247 preserving its highlights and shadows. The destination color is not 1248 replaced, but is mixed with the source color to reflect the lightness 1249 or darkness of the destination.</td> 1250 </tr> 1251 1252 <tr valign="top"> 1253 <td valign="top">hard-light</td> 1254 <td valign="top">Multiplies or screens the colors, dependent on the source 1255 color value. If the source color is lighter than 0.5, the destination 1256 is lightened as if it were screened. If the source color is darker 1257 than 0.5, the destination is darkened, as if it were multiplied. The 1258 degree of lightening or darkening is proportional to the difference 1259 between the source color and 0.5. If it is equal to 0.5 the 1260 destination is unchanged. Painting with pure black or white produces 1261 black or white.</td> 1262 </tr> 1263 1264 1265 <tr valign="top"> 1266 <td valign="top">linear-light</td> 1267 <td valign="top">Like 'Hard-Light' but using linear-dodge and linear-burn 1268 instead. Increases contrast slightly with an impact on the 1269 foreground's tonal values.</td> 1270 </tr> 1271 1272 <tr valign="top"> 1273 <td valign="top">soft-light</td> 1274 <td valign="top">Darkens or lightens the colors, dependent on the source 1275 color value. If the source color is lighter than 0.5, the destination 1276 is lightened. If the source color is darker than 0.5, the destination 1277 is darkened, as if it were burned in. The degree of darkening or 1278 lightening is proportional to the difference between the source color 1279 and 0.5. If it is equal to 0.5, the destination is unchanged. Painting 1280 with pure black or white produces a distinctly darker or lighter area, 1281 but does not result in pure black or white. Fixed in ImageMagick 1282 version 6.5.4-3. </td> 1283 </tr> 1284 1285 <tr valign="top"> 1286 <td valign="top">pegtop-light</td> 1287 <td valign="top">Almost equivelent to 'Soft-Light', but using a 1288 continuious mathematical formula rather than two conditionally 1289 selected formulae. Added ImageMagick version 6.5.4-3. </td> 1290 </tr> 1291 1292 <tr valign="top"> 1293 <td valign="top">vivid-light</td> 1294 <td valign="top">A modified 'Linear-Light' designed to preserve very stong 1295 primary and secondary colors in the image. Added ImageMagick version 1296 6.5.4-3. </td> 1297 </tr> 1298 1299 <tr valign="top"> 1300 <td valign="top">pin-light</td> 1301 <td valign="top">Similar to 'Hard-Light', but using sharp linear shadings, 1302 to similate the effects of a strong 'pinhole' light source. Added 1303 ImageMagick version 6.5.4-3. </td> 1304 </tr> 1305 1306 </tbody> 1307</table> 1308 1309 1310<p>Also included are these special purpose compose methods:</p> 1311 1312<table class="doc"> 1313 <tbody> 1314 <tr valign="top"> 1315 <th align="left" style="width: 8%">Method</th> 1316 <th align="left">Description</th> 1317 </tr> 1318 1319 <tr valign="top"> 1320 <td valign="top">copy-*</td> 1321 <td valign="top">Copy the specified channel (Red, Green, Blue, Cyan, 1322 Magenta, Yellow, Black, or Opacity) in the source image to the 1323 same channel in the destination image. If the channel specified 1324 does not exist in the source image, (which can only happen for methods, 1325 '<kbd>copy-opacity</kbd>' or '<kbd>copy-black</kbd>') then it is 1326 assumed that the source image is a special grayscale channel image 1327 of the values to be copied. </td> 1328 </tr> 1329 1330 <tr valign="top"> 1331 <td valign="top">change-mask</td> 1332 <td valign="top">Replace any destination pixel that is the similar to the source images pixel (as defined by the current <a href="#fuzz">-fuzz</a> factor), with transparency. </td> 1333 </tr> 1334 </tbody> 1335</table> 1336 1337<p>On top of these composed methods are a few special ones that not only require 1338the two images that are being merged or overlaid, but have some extra numerical 1339arguments, which are tabled below. </p> 1340 1341<p>In the "<code>composite</code>" command these composition methods are 1342selected using special options with the arguments needed. They are usually, 1343but not always, the same name as the composte 'method' they use, and replaces 1344the normal use of the <a href="#compose" >-compose</a> setting in the 1345"<code>composite</code>" command. For example... </p> 1346 1347<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>composite ... -blend 50x50 ...</span></p> 1348<p>As of IM v6.5.3-4 the "<code>convert</code>" command can now also supply 1349these extra arguments to its <a href="#composite" >-composite</a> operator, 1350using the special <a href="#set">-set</a> attribute of '<kbd class="arg">option:compose:args</kbd>'. This means you can now make use of 1351these special argumented <a href="#compose" >-compose</a> methods, those the 1352argument and the method both need to be set separatally. For example... </p> 1353 1354<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert ... -compose blend -set option:compose:args 50x50 -composite ...</span></p> 1355<p>The following is a table of these special 'argumented' compose methods, 1356with a brief summary of what they do. For more details see the equivalent 1357"composite" command option name. </p> 1358 1359<table class="doc"> 1360 <tbody> 1361 <tr valign="top"> 1362 <th align="left" style="width: 8%">Method</th> 1363 <th align="left">Description</th> 1364 </tr> 1365 1366 <tr valign="top"> 1367 <td valign="top">dissolve</td> 1368 <td valign="top">Arguments: 1369 <em class="arg">src_percent</em>[x<em class="arg">dst_percent</em>] 1370 <br>Equivalent to "<code>composite</code>" <a href="#dissolve">-dissolve</a> 1371 <br>Dissolve the 'source' image by the percentage given before overlaying 1372 'over' the 'destination' image. If <em class="arg">src_percent</em> is 1373 greater than 100, it starts dissolving the main image so it will 1374 become transparent at a value of '<kbd class="arg">200</kbd>'. If 1375 both percentages are given, each image are dissolved to the 1376 percentages given. 1377 </td> 1378 </tr> 1379 1380 <tr valign="top"> 1381 <td valign="top">blend</td> 1382 <td valign="top">Arguments: 1383 <em class="arg">src_percent</em>[x<em class="arg">dst_percent</em>] 1384 <br>Equivalent to "<code>composite</code>" <a href="#blend">-blend</a> 1385 <br>Average the images together ('plus') according to the percentages 1386 given and each pixels transparency. If only a single percentage value 1387 is given it sets the weight of the composite or 'source' image, while 1388 the background image is weighted by the exact opposite amount. That is 1389 a <kbd>-blend 30</kbd> merges 30% of the 'source' image with 70% of 1390 the 'destination' image. Thus it is equivalent to <kbd>-blend 1391 30x70</kbd>. 1392 </td> 1393 </tr> 1394 1395 <tr valign="top"> 1396 <td valign="top">mathematics</td> 1397 <td valign="top">Arguments: <em class="arg">A, B, C, D</em> 1398 <br>Not available in "<code>composite</code>" at this time. 1399 <br>Merge the source and destination images according to the formula 1400 <br> <code>A*Sc*Dc + B*Sc + C*Dc + D</code> 1401 <br>Can be used to generate a custom composition method that would 1402 otherwise need to be implemented using the slow <a href="#fx">-fx</a> 1403 DIY image operator. Added to ImageMagick version 6.5.4-3. 1404 </td> 1405 </tr> 1406 1407 <tr valign="top"> 1408 <td valign="top">modulate</td> 1409 <td valign="top">Arguments: 1410 <em class="arg">brightness</em>[x<em class="arg">saturation</em>] 1411 <br>Equivalent to "<code>composite</code>" <a href="#watermark">-watermark</a> 1412 <br>Take a grayscale image (with alpha mask) and modify the destination 1413 image's brightness according to watermark image's grayscale value and 1414 the <em class="arg">brightness</em> percentage. The destinations 1415 color saturation attribute is just direct modified by the <em 1416 class="arg">saturation</em> percentage, which defaults to 100 percent 1417 (no color change). 1418 1419 </td> 1420 </tr> 1421 1422 <tr valign="top"> 1423 <td valign="top">displace</td> 1424 <td valign="top">Arguments: 1425 <em class="arg">X-scale</em>[x<em class="arg">Y-scale</em>][!][%] 1426 <br>Equivalent to "<code>composite</code>" <a href="#displace">-displace</a> 1427 <br>With this option, the 'overlay' image, and optionally the 'mask' 1428 image, is used as a relative displacement map, which is used to 1429 displace the lookup of what part of the destination image is seen at 1430 each point of the overlaid area. Much like the displacement map is a 1431 'lens' that distorts the original 'background' image behind it. 1432 <br><br> 1433 The X-scale is modilated by the 'red' channel of the overlay image 1434 while the Y-scale is modulated by the green channel, (the mask image 1435 if given is rolled into green channel of the overlay image. This 1436 separation allows you to modulate the X and Y lookup displacement 1437 separatally allowing you to di 2 dimentional displacements, rather 1438 than 1 dimentional verctored displacements (using grayscale image). 1439 <br><br> 1440 If the overlay image contains transparency this is used as a mask 1441 of the resulting image to remove 'invalid' pixels. 1442 <br><br> 1443 The '%' flag makes the displacement scale relative to the size of the 1444 overlay image (100% = half width/height of image). Using '!' switches 1445 percentage arguments to refer to the destination image size instead. 1446 <br><br> 1447 Special flags were added Added to ImageMagick version 6.5.3-5. 1448 </td> 1449 </tr> 1450 1451 <tr valign="top"> 1452 <td valign="top">distort</td> 1453 <td valign="top">Arguments: 1454 <em class="arg">X-scale</em>[x<em class="arg">Y-scale</em 1455 >[+<em class="arg">X-center</em>+<em class="arg">Y-center</em>]][!][%] 1456 <br>Not available in "<code>composite</code>" at this time. 1457 <br>Exactly as per 'Displace' (above), but using absolute coordinates, 1458 relative to the center of the overlay (or that given). Basically 1459 allows you to generate absolute distortion maps where 'black' will 1460 look up the left/top edge, and 'white' looks up the bottom/right 1461 edge of the destination image, according to the scale given. 1462 <br><br> 1463 The '!' flag not only switches percentage scaling, to use the 1464 destination image, but also the image the center offset of the lookup. 1465 This means the overlay can lookup a completely different region of the 1466 destination image. 1467 <br><br> 1468 Added to ImageMagick version 6.5.3-5. 1469 </td> 1470 </tr> 1471 1472 <tr valign="top"> 1473 <td valign="top">blur</td> 1474 <td valign="top">Arguments: 1475 <em class="arg">Width</em>[x<em class="arg">Height</em 1476 >[+<em class="arg">Angle</em>]] 1477 <br>Equivalent to "<code>composite</code>" 1478 <a href="#blur-composite">-blur</a> 1479 <br>A Variable Blur Mapping Composition method, where each pixel in the 1480 overlaid region is replaced with an Elliptical Weighted Average (EWA), 1481 with an ellipse (typically a circle) of the given sigma size, scaled 1482 according to overlay (source image) grayscale mapping. 1483 <br><br> 1484 As per 'Displace' and 'Distort', the red channel will modulate the 1485 width of the ellipse, while the green channel will modulate the height 1486 of the ellipse. However at this time the ellipse angle is not 1487 modulated though this may be a future posibility (perhaps with a 1488 special flag to enable use of blur channel for this purpose). 1489 <br><br> 1490 Added to ImageMagick version 6.5.4-0. 1491 </td> 1492 </tr> 1493 1494 </tbody> 1495</table> 1496 1497<p>To print a complete list of all the available compose operators, use <a href="#list">-list compose</a>.</p> 1498 1499 1500<div style="margin: auto;"> 1501 <h4><a name="composite" id="composite"></a>-composite</h4> 1502</div> 1503 1504<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Perform alpha composition on the current image sequence.</td><td style='text-align:right;'></td></tr></table> 1505 1506<p>Take the first image 'destination' and overlay the second 'source' image 1507according to the current <a href="#compose">-compose</a> setting. The location 1508of the 'source' or 'overlay' image is controlled according to <a 1509href="#geometry" >-geometry</a>, and <a href="#geometry" >-geometry</a> 1510settings. </p> 1511 1512<p>If a third image is given this is treated as a gray-scale 'mask' image 1513relative to the first 'destination' image. This mask will limit what parts of 1514the destination can be modified by the image composition. However for the 1515'<kbd>displace</kbd>' compose method, the mask is used to provide a separate 1516Y-displacement image instead. </p> 1517 1518<p>If a <a href="#compose">-compose</a> method requires extra numerical 1519arguments or flags these can be provided by setting the <a 1520href="#set">-set</a> '<kbd class="arg">option:compose:args</kbd>' 1521appropriatally for the compose method. </p> 1522 1523<p>Some <a href="#compose">-compose</a> methods can modify the 'destination' 1524image outside the overlay area. You can disable this by setting the special <a 1525href="#set">-set</a> '<kbd class="arg">option:compose:outside-overlay</kbd>' 1526to '<kbd>false</kbd>'. </p> 1527 1528 1529<div style="margin: auto;"> 1530 <h4><a name="compress" id="compress"></a>-compress <em class="arg">type</em></h4> 1531</div> 1532 1533<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> 1534 1535<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> 1536 1537<p>To print a complete list of compression types, use <a href="#list">-list compress</a>.</p> 1538 1539<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> 1540 1541<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> 1542 1543<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> 1544 1545<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> 1546 1547<div style="margin: auto;"> 1548 <h4><a name="contrast" id="contrast"></a>-contrast</h4> 1549</div> 1550 1551<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> 1552 1553<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> 1554 1555<p>For a more pronounced effect you can repeat the option:</p> 1556 1557<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert rose: -contrast -contrast rose_c2.png</span></p> 1558<div style="margin: auto;"> 1559 <h4><a name="contrast-stretch" 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> 1560</div> 1561 1562<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> 1563 1564<p>While performing the stretch, black-out at most <em class="arg">black-point</em> pixels and white-out at most <em class="arg">white-point</em> pixels. Or, if percent is used, black-out at most <em class="arg">black-point %</em> pixels and white-out at most <em class="arg">white-point %</em> pixels.</p> 1565 1566<p>Prior to ImageMagick 6.4.7-0, <a href="#contrast-stretch">-contrast-stretch</a> will black-out at most <em class="arg">black-point</em> pixels and white-out at most <em class="arg">total pixels minus white-point</em> pixels. Or, if percent is used, black-out at most <em class="arg">black-point %</em> pixels and white-out at most <em class="arg">100% minus white-point %</em> pixels.</p> 1567 1568<p>Note that <kbd>-contrast-stretch 0</kbd> will modify the image such that the image's 1569min and max values are stretched to 0 and <em class="QR">QuantumRange</em>, respectively, without any loss of data due to burn-out at either end. This is not the same as <a href="#normalize">-normalize</a>, which is equivalent to <kbd>-contrast-stretch 2%x1%</kbd> (or prior to ImageMagick 6.4.7-0, <kbd>-contrast-stretch 2%x99%</kbd>).</p> 1570 1571<p>The channels are stretched in concert. Specify <a href="#channel">-channel</a> to normalize the RGB channels individually.</p> 1572 1573 1574<div style="margin: auto;"> 1575 <h4><a name="convolve" id="convolve"></a>-convolve <em class="arg">kernel</em></h4> 1576</div> 1577 1578<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> 1579 1580<p>The <em class="arg">kernel</em> is a square matrix specified as a comma-separated list of integers (with no spaces), ordered left-to right, starting with the top row. Presently, only odd-dimensioned kernels are supported, and therefore the number of entries in the specified <em class="arg">kernel</em> must be 3<sup>2</sup>=9, 5<sup>2</sup>=25, 7<sup>2</sup>=49, etc. </p> 1581 1582<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 positive and negative results are relative to a user-specified bias value. 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 is clipped at zero. 1583</p> 1584 1585<p>When using an ImageMagick with the HDRI compile-time setting, <a href="/www/command-line-options.html#bias">‑bias</a> is not needed, 1586as ImageMagick is able to store/handle any negative results without 1587clipping to the color value range (0..QuantumRange).</p> 1588 1589<p>See the discussion on HDRI implementations of ImageMagick on the page 1590<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. 1591</p> 1592 1593<div style="margin: auto;"> 1594 <h4><a name="crop" id="crop"></a>-crop <em class="arg">geometry</em></h4> 1595</div> 1596 1597<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> 1598 1599<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> 1600 1601<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> 1602 1603<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> 1604 1605<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> 1606 1607<p>By adding a exclamation character flag to the geometry argument, the 1608cropped images virtual canvas page size and offset is set as if the 1609geometry argument was a viewport or window. This means the canvas page size 1610is set to exactly the same size you specified, the image offset set 1611relative top left corner of the region cropped. </p> 1612 1613<p>If the cropped image 'missed' the actual image on its virtual canvas, a 1614special single pixel transparent 'missed' image is returned, and a 'crop 1615missed' warning given. </p> 1616 1617 1618<div style="margin: auto;"> 1619 <h4><a name="cycle" id="cycle"></a>-cycle <em class="arg">amount</em></h4> 1620</div> 1621 1622<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> 1623 1624<p><em class="arg">Amount</em> defines the number of positions each 1625colormap entry is shifted.</p> 1626 1627 1628<div style="margin: auto;"> 1629 <h4><a name="debug" id="debug"></a>-debug <em class="arg">events</em></h4> 1630</div> 1631 1632<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> 1633 1634<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> 1635 1636 1637<p>For example, to log cache and blob events, use.</p> 1638 1639<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert -debug "Cache,Blob" rose: rose.png</span></p> 1640<p>The <kbd>User</kbd> domain is normally empty, but developers can log user events in their private copy of ImageMagick.</p> 1641 1642<p>To print the complete list of debug methods, use <a href="#list">-list debug</a>.</p> 1643 1644<p>Use the <a href="#log">-log</a> option to specify the format for debugging output.</p> 1645 1646<p>Use <a href="#debug">+debug</a> to turn off all logging.</p> 1647 1648<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> 1649 1650 1651<div style="margin: auto;"> 1652 <h4><a name="decipher" id="decipher"></a>-decipher <em class="arg">filename</em></h4> 1653</div> 1654 1655<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> 1656 1657<p>Get the passphrase from the file specified by <em class="arg">filename</em>.</p> 1658 1659<p>For more information, see the webpage, <a href="http://www.imagemagick.org/www/cipher.html">ImageMagick: Encipher or Decipher an Image</a>.</p> 1660 1661 1662<div style="margin: auto;"> 1663 <h4><a name="deconstruct" id="deconstruct"></a>-deconstruct</h4> 1664</div> 1665 1666<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> 1667 1668<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> 1669 1670<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> 1671 1672<p>This option is actually equivalent to the <a href="#layers">-layers</a> method '<kbd>compare-any</kbd>'. </p> 1673 1674 1675<div style="margin: auto;"> 1676 <h4><a name="define" id="define"></a>-define <em class="arg">key</em>{<em class="arg">=value</em>}<em class="arg">...</em></h4> 1677</div> 1678 1679<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>add coder/decoder specific options.</td><td style='text-align:right;'></td></tr></table> 1680 1681<p>This option creates one or more definitions for coders and decoders to use while reading and writing image data. Definitions may be passed to coders and decoders to control options that are specific to certain image formats. If <em class="arg">value</em> is missing for a definition, an empty-valued definition of a flag is created with that name. This used to control on/off options. Use <a href="#define">+define key</a> to remove definitions previously created. Use <a href="#define">+define "*"</a> to remove all existing definitions.</p> 1682 1683<p>The following definitions may be created:</p> 1684 1685<ul> 1686<dt>jp2:rate=value</dt> 1687 <dd>Specify the compression factor to use while writing JPEG-2000 files. The compression factor is the reciprocal of the compression ratio. The valid range is 0.0 to 1.0, with 1.0 indicating lossless compression. If defined, this value overrides the -quality setting. A quality setting of 75 results in a rate value of 0.06641.</dd><br /> 1688<dt>mng:need-cacheoff</dt> 1689 <dd>turn playback caching off for streaming MNG.</dd><br /> 1690<dt>png:bit-depth=value</dt> 1691<dt>png:color-type=value</dt> 1692 <dd>desired bit-depth and color-type for PNG output. You can force the PNG encoder to use a different bit-depth and color-type than it would have normally selected, but only if this does not cause any loss of image quality. Any attempt to reduce image quality is treated as an error and no PNG file is written. E.g., if you have a 1-bit black-and-white image, you can use these "defines" to cause it to be written as an 8-bit grayscale, indexed, or even a 64-bit RGBA. But if you have a 16-million color image, you cannot force it to be written as a grayscale or indexed PNG. If you wish to do this, you must use the appropriate <a href="#depth">-depth</a>, <a href="#colors">-colors</a>, or <a href="#type">-type</a> directives to reduce the image quality prior to using the PNG encoder. Note that in indexed PNG files, "bit-depth" refers to the number of bits per index, which can range from 1 to 8. In such files, the color samples always have 8-bit depth.</dd><br /> 1693<dt>ps:imagemask</dt> 1694 <dd>If the ps:imagemask flag is defined, the PS3 and EPS3 coders will create Postscript files that render bilevel images with the Postscript imagemask operator instead of the image operator.</dd> 1695</ul> 1696 1697<p>For example, to create a postscript file that will render only the black pixels of a bilevel image, use:</p> 1698 1699<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert bilevel.tif -define ps:imagemask eps3:stencil.ps</span></p> 1700<p>Set attributes of the image registry by prefixing the value with <kbd>registry:</kbd>. For example, to set a temporary path to put work files, use:</p> 1701 1702<p class="crtsnip"> 1703-define registry:temporary-path=/data/tmp 1704</p> 1705 1706<div style="margin: auto;"> 1707 <h4><a name="delay" 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> 1708</div> 1709 1710<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> 1711 1712<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> 1713 1714<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> 1715 1716 1717<div style="margin: auto;"> 1718 <h4><a name="delete" id="delete"></a>-delete <em class="arg">index</em></h4> 1719</div> 1720 1721<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> 1722 1723<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> 1724 1725 1726<div style="margin: auto;"> 1727 <h4><a name="density" id="density"></a>-density <em class="arg">width</em><br />-density <em class="arg">width</em>x<em class="arg">height</em></h4> 1728</div> 1729 1730<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> 1731 1732<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> 1733 1734<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> 1735 1736<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> 1737 1738<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> 1739 1740<div style="margin: auto;"> 1741 <h4><a name="depth" id="depth"></a>-depth <em class="arg">value</em></h4> 1742</div> 1743 1744<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> 1745 1746<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> 1747 1748<div style="margin: auto;"> 1749 <h4><a name="descend" id="descend"></a>-descend</h4> 1750</div> 1751 1752<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> 1753 1754<div style="margin: auto;"> 1755 <h4><a name="deskew" id="deskew"></a>-deskew <em class="arg">threshold</em></h4> 1756</div> 1757 1758<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> 1759 1760<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> 1761 1762<div style="margin: auto;"> 1763 <h4><a name="despeckle" id="despeckle"></a>-despeckle</h4> 1764</div> 1765 1766<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> 1767 1768<div style="margin: auto;"> 1769 <h4><a name="displace" 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> 1770</div> 1771 1772<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> 1773 1774<p>With this option, the 'overlay' image, and optionally the 'mask' image, 1775will be used as a displacement map, which is used to displace the lookup of 1776what part of the 'background' image is seen at each point of the overlaid 1777area. Much like the displacement map is a 'lens' that redirects light shining 1778through it so as to present a distorted view the original 'background' image 1779behind it. </p> 1780 1781<p>Any perfect grey areas of the displacement map produce a zero 1782displacement of the image. Black areas produce the given maximum negative 1783displacement of the lookup point, while white produce a maximum positive 1784displacement of the lookup. </p> 1785 1786<p>Note that it is the lookup of the 'background' that is displaced, not a 1787displacement of the image itself. As such an area of the displacement map 1788containing 'white' will have the lookup point 'shifted' by a positive amount, 1789and thus generating a copy of the destination image to the right/downward from 1790the correct position. That is the image will look like it may have been 1791'shifted' in a negative left/upward direction. Understanding this is a very 1792important in understanding how displacement maps work. </p> 1793 1794<p>The given arguments define the maximum amount of displacement in pixels 1795that a particular map can produce. If the displacement scale is large enough 1796it is also posible to lookup parts of the 'background' image that lie well 1797outside the bounds of the displacement map itself. That is you could very 1798easilly copy a section of the original image from outside the overlay area 1799into the overlay area. </p> 1800 1801<p>The '%' flag makes the displacement scale relative to the size of the 1802overlay image (100% = half width/height of image). Using '!' switches 1803percentage arguments to refer to the destination image size instead. 1804these flags were added as of IM v6.5.3-5.</p> 1805 1806<p>Normally a single grayscale displacement map is provided, which with the 1807given scaling values will determine a single direction (vector) in which 1808displacements can occur (positivally or negativally). However, if you also 1809specify a third image which is normally used as a <em class="arg">mask</em>, 1810then the <em class="arg">composite image</em> will be used for horizontal X 1811displacement, while the <em class="arg">mask image</em> is used for vertical Y 1812displacement. This allows you to define completely different displacement 1813values for the X and Y directions, and allowing you to lookup any point within 1814the <em class="arg">scale</em> bounds. In other words each pixel can lookup 1815any other nearby pixel, producing complex 2 dimentional displacements, rather 1816than a simple 1 dimentional vector displacements. </p> 1817 1818<p>Alternativally rather than suppling two separate images, as of IM v6.4.4-0, 1819you can use the 'red' channel of the overlay image to specify the horizontal 1820or X displacement, and the 'green' channel for the vertical or Y displacement. 1821</p> 1822 1823<p>As of IM v6.5.3-5 any alpha channel in the overlay image will be used as a 1824mask the transparency of the destination image. However areas outside the 1825overlaid areas will not be effected. </p> 1826 1827 1828<div style="margin: auto;"> 1829 <h4><a name="display" id="display"></a>-display <em class="arg">host:display[.screen]</em></h4> 1830</div> 1831 1832<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> 1833 1834<p>This option is used with convert for obtaining image or font from this X server. See <em class="arg">X(1)</em>.</p> 1835 1836<div style="margin: auto;"> 1837 <h4><a name="dispose" id="dispose"></a>-dispose <em class="arg">method</em></h4> 1838</div> 1839 1840<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> 1841 1842<p>The layer disposal method defines the way each the displayed image is to be 1843modified after the current 'frame' of an animation has finished being 1844displayed (after its 'delay' period), but before the next frame on an 1845animation is to be overlaid onto the display. </p> 1846 1847<p>Here are the valid methods:</p> 1848 1849<pre class="text"> 1850Undefined 0 No disposal specified (equivalent to '<kbd>none</kbd>'). 1851None 1 Do not dispose, just overlay next frame image. 1852Background 2 Clear the frame area with the background color. 1853Previous 3 Clear to the image prior to this frames overlay. 1854</pre> 1855 1856<p>You can also use the numbers given above, which is what the GIF format 1857uses internally to represent the above settings. </p> 1858 1859<p>To print a complete list of dispose methods, use <a href="#list">-list dipose</a>.</p> 1860 1861<p>Use <a href="#dispose" >+dispose</a>, turn off the setting and prevent 1862resetting the layer disposal methods of images being read in. </p> 1863 1864<p>Use <a href="#set">-set</a> '<kbd>dispose</kbd>' method to set the image 1865disposal method for images already in memory.</p> 1866 1867<div style="margin: auto;"> 1868 <h4><a name="dissimilarity-threshold" id="dissimilarity-threshold"></a>-dissimilarity-threshold <em class="arg">value</em></h4> 1869</div> 1870 1871<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> 1872 1873 1874<div style="margin: auto;"> 1875 <h4><a name="dissolve" id="dissolve"></a>-dissolve <em class="arg">src_percent</em>[x<em class="arg">dst_percent</em>]</h4> 1876</div> 1877 1878<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> 1879 1880<p>The opacity of the composite image is multiplied by the given percent, then 1881it is composited 'over' the main image. If <em class="arg">src_percent</em> 1882is greater than 100, start dissolving the main image so it will become 1883transparent at a value of '<kbd class="arg">200</kbd>'. If both percentages 1884are given, each image are dissolved to the percentages given. </p> 1885 1886<p>Note that dissolve percentages do not add, two opaque images dissolved 1887'50,50', produce a 75% transparency. For a 50% + 50% blending of the two 1888images, you would need to use dissolve values of '50,100'. </p> 1889 1890<div style="margin: auto;"> 1891 <h4><a name="distort" id="distort"></a>-distort <em class="arg">method arguments</em></h4> 1892</div> 1893 1894<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> 1895 1896<p>The <em class="arg">arguments</em> is a single string containing a list 1897of floating point numbers separated by commas or spaces. The number of 1898and meaning of the floating point values depends on the distortion <em 1899class="arg">method</em> being used. </p> 1900 1901<p>Choose from these distortion types:</p> 1902 1903<table class="doc"> 1904 <tr valign="top"> 1905 <th align="left" style="width: 8%">Method</th> 1906 <th align="left">Description</th> 1907 </tr> 1908 1909 <tr valign="top"> 1910 <td valign="top"><kbd>ScaleRotateTranslate</kbd> 1911 <br/>or <kbd>SRT</kbd></td> 1912 <td valign="top"> 1913 Distort image by first scaling and rotating about a given 'center', 1914 before translating that 'center' to the new location, in that order. It 1915 is an alternative method of specifying a '<kbd>Affine</kbd>' type of 1916 distortion, but without shearing effects. It also provides a good way 1917 of rotating and displacing a smaller image for tiling onto a larger 1918 background (IE 2-dimensional animations). <br/> 1919 1920 The number of arguments determine the specific meaning of each 1921 argument for the scales, rotation, and translation operations. <br/> 1922 1923 <table style="margin-left:auto; margin-right:auto;"> 1924 <tr><td># </td><td>arguments meaning</td></tr> 1925 <tr><td>1:</td><td><em>Angle_of_Rotation</em></td></tr> 1926 <tr><td>2:</td><td><em>Scale Angle</em></td></tr> 1927 <tr><td>3:</td><td><em>ScaleX,ScaleY Angle</em></td></tr> 1928 <tr><td>4:</td><td><em>X,Y Scale Angle</em></td></tr> 1929 <tr><td>5:</td> 1930 <td><em>X,Y ScaleX,ScaleY Angle</em></td></tr> 1931 <tr><td>6:</td> 1932 <td><em>X,Y Scale Angle NewX,NewY</em></td></tr> 1933 <tr><td>7:</td> 1934 <td><em>X,Y ScaleX,ScaleY Angle 1935 NewX,NewY</em></td></tr> 1936 </table> 1937 1938 This is actually an alternative way of specifing a 2 dimensional linear 1939 '<kbd>Affine</kbd>' or '<kbd>AffineProjection</kbd>' distortion. </td> </tr> 1940 1941 <tr valign="top"> 1942 <td valign="top"><kbd>Affine</kbd></td> 1943 <td valign="top"> 1944 Distort the image linearly by moving a list of at least 3 or more sets 1945 of control points (as defined below). Idealy 3 sets or 12 floating 1946 point values are given allowing the image to be linearly scaled, 1947 rotated, sheared, and translated, according to those three points. See 1948 also the related '<kbd>AffineProjection</kbd>' and '<kbd>SRT</kbd>' 1949 distortions. <br/> 1950 1951 More than 3 sets given control point pairs (12 numbers) is least 1952 squares fitted to best match a lineary affine distortion. If only 2 1953 control point pairs (8 numbers) are given a two point image translation 1954 rotation and scaling is performed, without any posible shearing, 1955 flipping or changes in aspect ratio to the resulting image. If only one 1956 control point pair is provides the image is only translated, (which may 1957 be a floating point non-integer translation). <br/> 1958 1959 This distortion does not include any form of perspective distortion. 1960 </td> 1961 1962 </tr> 1963 1964 <tr valign="top"> 1965 <td valign="top"><kbd>AffineProjection</kbd></td> 1966 <td valign="top"> 1967 Linearly distort an image using the given Affine Matrix of 6 1968 pre-calculated coefficients forming a set of Affine Equations to map 1969 the source image to the destination image. 1970 1971 <div style="text-align: center"><em> 1972 s<sub>x</sub>, r<sub>x</sub>, 1973 r<sub>y</sub>, s<sub>y</sub>, 1974 t<sub>x</sub>, t<sub>y</sub> 1975 </em></div> 1976 1977 See <a href="#affine" >-affine</a> setting for more detail, and 1978 meanings of these coefficients. <br/> 1979 1980 The distortions '<kbd>Affine</kbd>' and '<kbd>SRT</kbd>' provide 1981 alternative methods of defining this distortion, with ImageMagick doing the 1982 calculations needed to generate the required coefficients. You can see 1983 the internally generated coefficients, by using a <a href="#verbose" 1984 >-verbose</a> setting. </td> 1985 1986 </tr> 1987 1988<!-- still under development, do not display - Anthony 1989 <tr valign="top"> 1990 <td valign="top"><kbd>Bilinear</kbd></td> 1991 <td valign="top"> 1992 Bilinear (reversed) Distortion, given a minimum of 4 sets of 1993 coordinate pairs, or 16 values (see below). Not that lines may not 1994 appear straight after distortion, though the distance between 1995 coordinates will remain consistant. </td> 1996 </tr> 1997--> 1998 1999 <tr valign="top"> 2000 <td valign="top"><kbd>Perspective</kbd></td> 2001 <td valign="top"> 2002 Perspective distort the images, using a list of 4 or more sets of 2003 control points (as defined below). More that 4 sets (16 numbers) of 2004 control points provide least squares fitting for more accurate 2005 distortions (for the purposes of image registration and panarama 2006 effects). Less than 4 sets will fall back to a '<kbd>Affine</kbd>' 2007 linear distortion. <br/> 2008 2009 Perspective Distorted images ensures that straight lines remain 2010 straight, but the scale of the distorted image will vary. The horizon 2011 is anti-aliased, and the 'sky' color may be set using the 2012 <a href="#mattecolor" >-mattecolor</a> setting. </td> 2013 </tr> 2014 2015 <tr valign="top"> 2016 <td valign="top"><kbd>PerspectiveProjection</kbd> </td> 2017 <td valign="top"> 2018 Do a '<kbd>Perspective</kbd>' distortion basied on a set of 8 2019 pre-calculated coefficients. You can get these coefficients by looking 2020 at the <a href="#verbose" >-verbose</a> output of a 2021 '<kbd>Prespective</kbd>' distortion, or by calculating them yourself. 2022 If the last two perspective scaling coefficients are zero, the 2023 remaining 6 represents a transposed 'Affine Matrix'. </td> 2024 2025 </tr> 2026 2027 <tr valign="top"> 2028 <td valign="top"><kbd>Arc</kbd></td> 2029 <td valign="top"> 2030 Arc the image (variation of polar mapping) over the angle given around 2031 a circle. <br/> 2032 <table width="90%" style = "margin-left: auto; margin-right: auto;"> 2033 <tr valign="top"><td>Argument</td> 2034 <td>Meaning</td></tr> 2035 <tr valign="top"><td><em>arc_angle</em></td> 2036 <td>The angle over which to arc the image side-to-side</td></tr> 2037 <tr valign="top"><td><em>rotate_angle</em></td> 2038 <td>Angle to rotate resulting image from vertical center</td></tr> 2039 <tr valign="top"><td><em>top_radius</em></td> 2040 <td>Set top edge of source image at this radius</td></tr> 2041 <tr valign="top"><td><em>bottom_radius</em> </td> 2042 <td>Set bottom edge to this radius (radial scaling)</td></tr> 2043 </table> 2044 2045 The resulting image is always resized to best fit the resulting image, 2046 (as if using <a href="#distort" >+distort</a>) while attempting to 2047 preserve scale and aspect ratio of the original image as much as 2048 possible with the arguments given by the user. All four arguments will 2049 be needed to change the overall aspect ratio of an 'Arc'ed image. <br/> 2050 2051 This a variation of a polar distortion designed to try to preserve the 2052 aspect ratio of the image rather than direct Cartesian to Polar 2053 conversion. </td> 2054 </tr> 2055 2056 <tr valign="top"> 2057 <td valign="top"><kbd>Polar</kbd></td> 2058 <td valign="top"> 2059 Like '<kbd>Arc</kbd>' but do a complete Cartesian to Polar mapping of 2060 the image. that is the height of the input image is mapped to the 2061 radius limits, while the width is wrapped around between the 2062 angle limits. <br/> 2063 2064 Arguments: <em>Rmax,Rmin CenterX,CenterY, start,end_angle</em> <br/> 2065 2066 All arguments are optional. With <em>Rmin</em> defaulting to zero, the 2067 center to the center of the image, and the angles going from -180 (top) 2068 to +180 (top). If <em>Rmax</em> is given the special value of 2069 '<code>0</code>', the the distance from the center to the nearest edge 2070 is used for the radius of the output image, which will ensure the whole 2071 image is visible (though scaled smaller). However a special value of 2072 '<code>-1</code>' will use the distance from the center to the furthest 2073 corner, This may 'clip' the corners from the input rectangular image, 2074 but will generate the exact reverse of a '<kbd>DePolar</kbd>' with 2075 the same arguments. <br/> 2076 2077 If the plus form of distort (<a href="#distort" >+distort</a>) is used 2078 output image center will default to <code>0,0</code> of the virtual 2079 canvas, and the image size adjusted to ensure the whole input image is 2080 made visible in the output image on the virtual canvas. </td> 2081 2082 </tr> 2083 2084 <tr valign="top"> 2085 <td valign="top"><kbd>DePolar</kbd></td> 2086 <td valign="top"> 2087 Uses the same arguments and meanings as a '<kbd>Polar</kbd>' distortion 2088 but generates the reverse Polar to Cartesian distortion. <br/> 2089 2090 The special <em>Rmax</em> setting of '<code>0</code>' may however clip 2091 the corners of the input image. However using the special 2092 <em>Rmax</em> setting of '<code>-1</code>' (maximum center to corner 2093 distance) will ensure the whole distorted image is preserved in the 2094 generated result, so that the same argument to '<kbd>Polar</kbd>' will 2095 reverse the distortion re-producing the original. 2096 2097 Note that as this distortion requires the area resampling of a circular 2098 arc, which can not be handled by the builtin EWA resampling function. 2099 As such the normal EWA filters are turned off. It is recomended some 2100 form of 'super-sampling' image processing technique be used to produce 2101 a high quality result. </td> 2102 2103 </tr> 2104 2105 <tr valign="top"> 2106 <td valign="top"><kbd>Barrel</kbd></td> 2107 <td valign="top"> 2108 Given the four coefficients (A,B,C,D) as defined by <a 2109 href="http://www.all-in-one.ee/~dersch/barrel/barrel.html" >Helmut 2110 Dersch</a>, perform a barrell or pincussion distortion appropriate to 2111 correct radial lens distortions. That is in photographs, make straight 2112 lines straight again. <br/> 2113 2114 Arguments: <em>A B C</em> [ <em>D</em> [ 2115 <em>X</em> , <em>Y</em> ] ] <br/> 2116 or <em>A<sub>x</sub> B<sub>x</sub> C<sub>x</sub> D<sub>x</sub> 2117 A<sub>y</sub> B<sub>y</sub> C<sub>y</sub> D<sub>y</sub></em> 2118 [ <em>X</em> , <em>Y</em> ] <br/> 2119 So that it forms the function <br/> 2120 Rsrc = r * ( <em>A</em>*r<sup>3</sup> + <em>B</em>*r<sup>2</sup> + 2121 <em>C</em>*r + <em>D</em> )<br/> 2122 2123 Where <em>X</em>,<em>Y</em> is the optional center of the distortion 2124 (defaulting to the center of the image). <br/> 2125 The second form is typically used to distort images, rather than 2126 correct lens distortions. <br/> 2127 </td> 2128 2129 </tr> 2130 2131 <tr valign="top"> 2132 <td valign="top"><kbd>BarrelInverse</kbd></td> 2133 <td valign="top"> 2134 This is very simular to '<kbd>Barrel</kbd>' with the same set of 2135 arguments, and argument handling. However it uses the inverse 2136 of the radial polynomial, 2137 so that it forms the function <br/> 2138 Rsrc = r / ( <em>A</em>*r<sup>3</sup> + <em>B</em>*r<sup>2</sup> + 2139 <em>C</em>*r + <em>D</em> ) 2140 </td> 2141 </tr> 2142 2143 <tr valign="top"> 2144 <td valign="top"><kbd>Shepards</kbd></td> 2145 <td valign="top"> 2146 Distort the given list control points (any number) using an Inverse 2147 Squared Distance Interpolation Method (<a 2148 href="http://www.ems-i.com/smshelp/Data_Module/Interpolation/Inverse_Distance_Weighted.htm" 2149 >Shepards Method</a>). The control points in effect do 'localized' 2150 distortions of the image around the given control point. For best 2151 results extra control points should be added to 'lock' the positions of 2152 the corners and other unchanging parts of the image. <br/> 2153 2154 The distortion has been likened to 'taffy pulling' using nails, pins or 2155 sticks. It basically uses the <a href="#sparse-color" 2156 >-sparse-color</a> method of the same name to generate separate X and Y 2157 displacement maps (see <a href="#displace" >-displace</a>) for source 2158 image color look-up. </td> 2159 2160 </tr> 2161 2162</table> 2163 2164<p>To print a complete list of distortion methods, use <a href="#list">-list distort</a>.</p> 2165 2166<p>Many of the above distortion methods such as '<kbd>Affine</kbd>', 2167'<kbd>Perspective</kbd>', and '<kbd>Shepards</kbd>' use a list control points 2168defining how these points in the given image should be distorted in the 2169destination image. Each set of four floating point values represent a source 2170image coordinate, followed immediately by the destination image coordinate. 2171This produces a list of values such as...</p> 2172<div style="text-align: center"><em> 2173 U<sub>1</sub>,V<sub>1</sub> X<sub>1</sub>,Y<sub>1</sub> 2174 U<sub>2</sub>,V<sub>2</sub> X<sub>2</sub>,Y<sub>2</sub> 2175 U<sub>3</sub>,V<sub>3</sub> X<sub>3</sub>,Y<sub>3</sub> 2176 ... 2177 U<sub>n</sub>,V<sub>n</sub> X<sub>n</sub>,Y<sub>n</sub> 2178</em></div> 2179<p>where <em>U,V</em> on the source image is mapped to <em>X,Y</em> on the 2180destination image. </p> 2181 2182<p>For example, to warp an image using '<kbd>perspective</kbd>' distortion, 2183needs a list of at least 4 sets of coordinates, or 16 numbers. Here is the 2184perspective distortion of the built-in "rose:" image. Note how spaces were 2185used to group the 4 sets of coordinate pairs, to make it easier to read and 2186understand.</p> 2187 2188<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'> 2189 convert rose: -virtual-pixel black \ <br/> 2190 -distort Perspective '0,0,0,0 0,45,0,45 69,0,60,10 69,45,60,35' \ <br/> 2191 rose_3d_rotated.gif</span></p> 2192<p>If more that the required number of coordinate pairs are given for a 2193distortion, the distortion method is 'least squares' fitted to 2194produce the best result for all the coordinate pairs given. If less than the 2195ideal number of points are given, the distort will generally fall back to a 2196simpler form of distortion that can handles the smaller number of coordinates 2197(usally a linear '<kbd>Affine</kbd>' distortion). </p> 2198 2199<p>By using more coodinates you can make use of image registration tool to 2200find matching coordinate pairs in overlaping images, so as to improve the 'fit' 2201of the distortion. Of course a bad coordinate pair can also make the 'fit' 2202worse. Caution is always advised. </p> 2203 2204<p>Colors are acquired from the source image according to the <a 2205href="#interpolate" >-interpolate</a> color lookup setting, when the image is 2206magnified. However if the viewed image is minified (image becomes smaller), a 2207special area resampling function (added ImageMagick v6.3.5-9), is used to 2208produce a higher quality image. For example you can use a 2209'<kbd>perspective</kbd>' distortion to view a infinitely tiled 'plane' all the 2210way to the horizon. </p> 2211 2212<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert -size 90x90 pattern:checkerboard -normalize -virtual-pixel tile \ <br/> 2213 -distort perspective '0,0,5,45 89,0,45,46 0,89,0,89 89,89,89,89' \ <br/> 2214 checks_tiled.jpg</span></p> 2215<p>Note that a infinitely tiled perspective images involving the horizon can 2216be very slow to generate due to the use of the high quality 'area resampling' 2217function (added ImageMagick v6.3.5-9). You can turn off 'area resampling' 2218using a <a href="#filter" >-filter</a> setting of '<kbd>point</kbd>' 2219(recommended if you plan to use super-sampling instead). </p> 2220 2221<p>If an image generates <i>invalid pixels</i>, such as the 'sky' in the last 2222'<kbd>perspective</kbd>' distortion example, <a href="#distort" >-distort</a> 2223will use the current <a href="#mattecolor" >-mattecolor</a> setting for these 2224pixels. If you do not what these pixels to be visible, set the color to match 2225the rest of the ground. </p> 2226 2227<p>The output image size will by default be the same as the input image. This 2228means that if the part of the distorted image falls outside the viewed area of 2229the 'distorted space', those parts is clipped and lost. However if you 2230use the plus form of the operator (<a href="#distort" >+distort</a>) the 2231operator will attempt (if posible) to show the whole of the distorted image, 2232while retaining a correct 'virtual canvas' offset, for image layering. This 2233offset may need to be removed using <a href="#repage" >+repage</a>, to remove 2234if it is unwanted. </p> 2235 2236<p>You can alternatively specify a special "<kbd><a href="#set" >-set</a> 2237option:distort:viewport {geometry_string}</kbd>" setting which will specify 2238the size and the offset of the generated 'viewport' image of the distorted 2239image space.</p> 2240 2241<p>Adding a "<kbd><a href="#set" >-set</a> option:distort:scale 2242{scale_factor}</kbd>" will scale the output image (viewport or otherwise) by 2243that factor without changing the viewed contents of the distorted image. This 2244can be used either for 'super-sampling' the image for a higher quality result, 2245or for panning and zooming around the image (with appropriate viewport 2246changes, or post-distort cropping and resizing). </p> 2247 2248<p>Setting <a href="#verbose" >-verbose</a> setting, will cause <a 2249href="#distort" >-distort</a> to attempt to output the internal coefficients, 2250and the <a href="#fx" >-fx</a> equivalent to the distortion, for expert study, 2251and debugging purposes. This many not be available for all distorts. </p> 2252 2253<p>Affine rotations and shears (such as '<kbd>SRT</kbd>' distortion), tend to 2254produce a cleaner result that the equivalent <a href="#rotate" >-rotate</a> 2255and/or <a href="#shear" >-shear</a> operation, with more control of due to the 2256above settings. It is algorithmically slower, though in ImageMagick it may be faster. 2257</p> 2258 2259 2260<div style="margin: auto;"> 2261 <h4><a name="dither" id="dither"></a>-dither <em class="arg">method</em></h4> 2262</div> 2263 2264<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> 2265 2266<p>Dithering places two or more colors in neighbouring 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> 2267 2268<p>Dithering is turned on by default, to turn it off use the plus form of the 2269setting, <a href="#dither">+dither</a>. This will also also render PostScript 2270without text or graphic aliasing. Disabling dithering often (but not always) 2271leads to faster process, a smaller number of colors, but more cartoon like 2272image coloring. Generally resulting in 'color banding' effects in areas with 2273color gradients. </p> 2274 2275<p>The color reduction operators <a href="#colors">-colors</a>, <a 2276href="#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> 2277 2278<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> 2279 2280 2281<div style="margin: auto;"> 2282 <h4><a name="draw" id="draw"></a>-draw <em class="arg">string</em></h4> 2283</div> 2284 2285<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> 2286 2287<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> 2288 2289<p>The shape primitives:</p> 2290 2291<pre class="text"> 2292 point x,y 2293 line x0,y0 x1,y1 2294 rectangle x0,y0 x1,y1 2295 roundRectangle x0,y0 x1,y1 wc,hc 2296 arc x0,y0 x1,y1 a0,a1 2297 ellipse x0,y0 rx,ry a0,a1 2298 circle x0,y0 x1,y1 2299 polyline x0,y0 ... xn,yn 2300 polygon x0,y0 ... xn,yn 2301 bezier x0,y0 ... xn,yn 2302 path path specification 2303 image operator x0,y0 w,h filename 2304</pre> 2305 2306<p>The text primitive:</p> 2307 2308<pre class="text"> 2309 text x0,y0 string 2310</pre> 2311<p>The text gravity primitive:</p> 2312 2313<pre class="text"> 2314 gravity NorthWest, North, NorthEast, West, Center, 2315 East, SouthWest, South, or SouthEast 2316</pre> 2317 2318<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> 2319 2320<p>The transformation primitives:</p> 2321 2322<pre class="text"> 2323 rotate degrees 2324 translate dx,dy 2325 scale sx,sy 2326 skewX degrees 2327 skewY degrees 2328</pre> 2329 2330<p>The pixel operation primitives:</p> 2331 2332<pre class="text"> 2333 color x0,y0 method 2334 matte x0,y0 method 2335</pre> 2336 2337<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> 2338 2339<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> 2340 2341<p>A <kbd>line</kbd> primitive requires a start point and end point.</p> 2342 2343<p>A <kbd>rectangle</kbd> primitive is specified by the pair of points at the upper left and lower right corners.</p> 2344 2345<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> 2346 2347<p>The <kbd>circle</kbd> primitive makes a disk (filled) or circle (unfilled). Give the center and any point on the perimeter (boundary).</p> 2348 2349<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> 2350 2351<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> 2352 2353<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>. 2354</p> 2355 2356<p>A <em>coordinate</em> is a pair of integers separated by a space or optional comma. </p> 2357 2358<p>As an example, to define a circle centered at 100,100 that extends to 150,150 use:</p> 2359 2360<p class="crtsnip"> 2361 -draw 'circle 100,100 150,150' 2362</p> 2363 2364<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 2365draw 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> 2366 2367<p class="crtsnip"> 2368 -draw 'bezier 20,50 45,100 45,0 70,50' 2369</p> 2370<p class="crtsnip"> 2371 -draw 'bezier 70,50 95,100 95,0 120,50' 2372</p> 2373 2374 2375<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> 2376 2377<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> 2378 2379<p class="crtsnip"> 2380 -draw 'image SrcOver 100,100 225,225 image.jpg' 2381</p> 2382 2383<p>You can use 0,0 for the image size, which means to use the actual dimensions found in the image header. Otherwise, it is scaled to the given dimensions. See <a href="#compose">-compose</a> for a description of the composite operators.</p> 2384 2385<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> 2386 2387<p>For example, the following annotates the image with <kbd>Works like magick!</kbd> for an image titled <kbd>bird.miff</kbd>. </p> 2388 2389<p class="crtsnip"> 2390 -draw 'text 100,100 "Works like magick!"' 2391</p> 2392 2393<p>See the <a href="#annotate">-annotate</a> option for another convenient way to annotate an image with text.</p> 2394 2395<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> 2396 2397<p>The <kbd>translate</kbd> primitive translates subsequent shape and text primitives.</p> 2398 2399<p>The <kbd>scale</kbd> primitive scales them.</p> 2400 2401<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> 2402 2403<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 2404matrix.</p> 2405 2406<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> 2407 2408<pre class="text"> 2409 point 2410 replace 2411 floodfill 2412 filltoborder 2413 reset 2414</pre> 2415 2416<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> 2417 2418<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> 2419 2420<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> 2421 2422<p>Strings that begin with a number must be quoted (e.g. use '1.png' rather than 1.png).</p> 2423 2424<p>Drawing primitives conform to the <a href="/www/magick-vector-graphics.html">Magick Vector Graphics</a> format.</p> 2425 2426 2427<div style="margin: auto;"> 2428 <h4><a name="edge" id="edge"></a>-edge <em class="arg">radius</em></h4> 2429</div> 2430 2431<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> 2432 2433<div style="margin: auto;"> 2434 <h4><a name="emboss" id="emboss"></a>-emboss <em class="arg">radius</em></h4> 2435</div> 2436 2437<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> 2438 2439<div style="margin: auto;"> 2440 <h4><a name="encipher" id="encipher"></a>-encipher <em class="arg">filename</em></h4> 2441</div> 2442 2443<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> 2444 2445<p>Get the passphrase from the file specified by <em class="arg">filename</em>.</p> 2446 2447<p>For more information, see the webpage, <a href="http://www.imagemagick.org/www/cipher.html">ImageMagick: Encipher or Decipher an Image</a>.</p> 2448 2449<div style="margin: auto;"> 2450 <h4><a name="encoding" id="encoding"></a>-encoding <em class="arg">type</em></h4> 2451</div> 2452 2453<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> 2454 2455<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> 2456 2457<div style="margin: auto;"> 2458 <h4><a name="endian" id="endian"></a>-endian <em class="arg">type</em></h4> 2459</div> 2460 2461<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> 2462 2463<p>To print a complete list of endian types, use the <a href="#list">-list endian</a> option.</p> 2464 2465<p>Use <a href="#endian">+endian</a> to revert to unspecified endianness.</p> 2466 2467 2468<div style="margin: auto;"> 2469 <h4><a name="enhance" id="enhance"></a>-enhance</h4> 2470</div> 2471 2472<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> 2473 2474 2475<div style="margin: auto;"> 2476 <h4><a name="equalize" id="equalize"></a>-equalize</h4> 2477</div> 2478 2479<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> 2480 2481<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> 2482 2483<p>For example using HSL, we have: ... <kbd>-colorspace HSL -channel lightness -equalize -colorspace RGB</kbd> ...</p> 2484 2485<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> 2486 2487<div style="margin: auto;"> 2488 <h4><a name="evaluate" id="evaluate"></a>-evaluate <em class="arg">operator value</em></h4> 2489</div> 2490 2491<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> 2492 2493<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> 2494 2495<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> 2496 2497<table class="doc"> 2498 <col width="25%" /> 2499 <col width="75%" /> 2500 <thead> 2501 <tr> 2502 <th><em class="arg">operator</em></th> 2503 <th>Summary (see further below for details)</th> 2504 </tr> 2505 </thead> 2506 <tbody> 2507 2508 <tr><td>Add </td> <td>Add <em class="arg">value</em> to pixels. </td></tr> 2509 <tr><td>AddModulus </td> <td>Add <em class="arg">value</em> to pixels modulo <em class="QR">QuantumRange</em>.</td></tr> 2510 <tr><td>And </td> <td>Binary AND of pixels with <em class="arg">value</em>.</td></tr> 2511 <tr><td>Cos, Cosine </td> <td>Apply cosine to pixels with frequency <em class="arg">value</em> with 50% bias added.</td></tr> 2512 <tr><td>Divide </td> <td>Divide pixels by <em class="arg">value</em>.</td></tr> 2513 <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> 2514 <tr><td>Log </td> <td>Apply scaled logarithm to normalized pixels.</td></tr> 2515 <tr><td>Max </td> <td>Clip pixels at lower bound <em class="arg">value</em>.</td></tr> 2516 <tr><td>Min </td> <td>Clip pixels at upper bound <em class="arg">value</em>.</td></tr> 2517 <tr><td>Multiply </td> <td>Multiply pixels by <em class="arg">value</em>.</td></tr> 2518 <tr><td>Or </td> <td>Binary OR of pixels with <em class="arg">value</em>.</td></tr> 2519 <tr><td>Pow </td> <td>Raise normalized pixels to the power <em class="arg">value</em>.</td></tr> 2520 <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> 2521 <tr><td>Set </td> <td>Set pixel equal to <em class="arg">value</em>.</td></tr> 2522 <tr><td>Sin, Sine </td> <td>Apply sine to pixels with frequency <em class="arg">value</em> with 50% bias added.</td></tr> 2523 <tr><td>Subtract </td> <td>Subtract <em class="arg">value</em> from pixels.</td></tr> 2524 <tr><td>Xor </td> <td>Binary XOR of pixels with <em class="arg">value.</em></td></tr> 2525 2526 <tr><td> </td></tr> 2527 2528 <tr><td>Gaussian-noise</td></tr> 2529 <tr><td>Impulse-noise</td></tr> 2530 <tr><td>Laplacian-noise</td></tr> 2531 <tr><td>Multiplicative-noise</td> <td>(These are equivalent to the corresponding <a href="#noise" >-noise</a> operators.)</td></tr> 2532 <tr><td>PoissonNoise</td></tr> 2533 <tr><td>Uniform-noise</td></tr> 2534 2535 <tr><td> </td></tr> 2536 2537 <tr><td>Threshold </td> <td>Threshold pixels larger than <em class="arg">value</em>.</td></tr> 2538 <tr><td>ThresholdBlack </td> <td>Threshold pixels to zero values equal to or below <em class="arg">value</em>.</td></tr> 2539 <tr><td>ThresholdWhite </td> <td>Threshold pixels to maximum values above <em class="arg">value</em>. </td></tr> 2540 </tbody> 2541 </table> 2542 2543<p>The specified functions are applied only to each previously set <a 2544href="#channel" >-channel</a> in the image. If necessary, the results of the 2545calculations are truncated (clipped) to fit in the interval [0, <em 2546class="QR">QuantumRange</em>]. The transparency channel of the image is 2547represented as a 'alpha' values (0 = fully transparent), so, for example, a 2548<kbd>Divide</kbd> by 2 of the alpha channel will make the image 2549semi-transparent. Append the percent symbol '<kbd>%</kbd>' to specify a value 2550as a percentage of the <em class="QR">QuantumRange</em>.</p> 2551 2552<p>To print a complete list of <a href="#evaluate">-evaluate</a> operators, use 2553<a href="#list">-list evaluate</a>.</p> 2554 2555<p>The results of the <kbd>Add</kbd>, <kbd>Subtract</kbd> and 2556<kbd>Multiply</kbd> methods can also be achieved using either the <a 2557href="#level" >-level</a> or the <a href="#level" >+level</a> operator, with 2558appropriate argument, to linearly modify the overall range of color values. 2559Please note, however, that <a href="#level" >-level</a> treats transparency as 2560'matte' values (0 = opaque), while <a href="#level" >-evaluate</a> works with 2561'alpha' values.</p> 2562 2563<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> 2564 2565<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> 2566 2567 <div style="text-align:center;"> 2568 log(<em class="arg">value</em> × <b><em>u</em></b> + 1) / log(<em class="arg">value</em> + 1) 2569 </div> 2570 2571<p><kbd>Pow</kbd> has been added as of ImageMagick 6.4.1-9, and works on 2572normalized pixel values. Note that <kbd>Pow</kbd> is related to the <a 2573href="#gamma" >-gamma</a> operator. For example, <b>-gamma 2</b> is equivalent 2574to <b>-evaluate pow 0.5</b>, i.e., a 'square root' function. The value used 2575with <a href="#gamma" >-gamma</a> is simply the reciprocal of the value used 2576with <kbd>Pow</kbd>.</p> 2577 2578<p><kbd>Cosine</kbd> and <kbd>Sine</kbd> was added as of IM v6.4.8-8 and 2579converts the image values into a value according to a (co)sine wave function. 2580The synonyms <kbd>Cos</kbd> and <kbd>Sin</kbd> may also be used. The output 2581is biased 50% and normalized by 50% so as to fit in the respective color value 2582range. The <em class="arg">value</em> scaling of the <em>period</em> of the 2583function (its frequency), and thus determines the number of 'waves' that will 2584be generated over the input color range. For example, if the <em 2585class="arg">value</em> is 1, the effective period is simply the <em 2586class="QR">QuantumRange</em>; but if the <em class="arg">value</em> is 2, 2587then the effective period is the <em>half</em> the <em 2588class="QR">QuantumRange</em>. 2589 2590 <div style="text-align:center;"> 2591 0.5 + 0.5 × cos(2 π <b><em>u</em></b> × <em class="arg">value</em>). 2592 </div> 2593 2594See also the <a href="#function" >-function</a> operator, which is a 2595multi-value version of evaluate. </P> 2596 2597 2598<div style="margin: auto;"> 2599 <h4><a name="extent" id="extent"></a>-extent <em class="arg">geometry</em></h4> 2600</div> 2601 2602<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> 2603 2604<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.</p> 2605 2606<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> 2607 2608<div style="margin: auto;"> 2609 <h4><a name="extract" id="extract"></a>-extract <em class="arg">geometry</em></h4> 2610</div> 2611 2612<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> 2613 2614<p>This option is most useful for extracting a subregion of a very large raw image. Note that these two commands are equivalent:</p> 2615 2616<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert -size 16000x16000 -depth 8 -extract 640x480+1280+960 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]' image.rgb image.png</span></p><p>If you omit the offsets, as in</p> 2617 2618<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert -size 16000x16000 -depth 8 -extract 640x480 image.rgb image.png</span></p> 2619<p>then the image will be <em>resized</em> to the specified dimensions instead, 2620equivalent to:</p> 2621 2622<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert -size 16000x16000 -depth 8 -resize 640x480 image.rgb image.png</span></p> 2623<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> 2624 2625<div style="margin: auto;"> 2626 <h4><a name="family" id="family"></a>-family <em class="arg">fontFamily</em></h4> 2627</div> 2628 2629<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> 2630 2631<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). 2632</p> 2633 2634<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>. 2635</p> 2636 2637<div style="margin: auto;"> 2638 <h4><a name="fft" id="fft"></a>-fft</h4> 2639</div> 2640 2641<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> 2642 2643<p>This option is new as of ImageMagick 6.5.4-3 and 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" target="_blank">Fourier Transform</a>, <a href="http://en.wikipedia.org/wiki/DFT" target="_blank">Discrete Fourier Transform</a> and <a href="http://en.wikipedia.org/wiki/FFT" target="_blank">Fast Fourier Transform</a>.</p> 2644 2645<p>A single image name is provided as output for this option. However, the output result will have two components. It will be 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" target="_blank">Complex Numbers</a>.<p> 2646 2647<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> 2648 2649<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert image.png -fft fft_image.miff</span></p> 2650<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> 2651 2652<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert image.png -fft fft_image.png</span></p> 2653<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> 2654 2655<p>The input image can be any size, but if not square and even-dimensioned, it will be 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 will be square at this size. The kind of padding relies on the <a href="#virtual-pixel">-virtual-pixel</a> setting.</p> 2656 2657<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> 2658 2659<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert fft_image.miff[0] -contrast-stretch 0 \ <br /> 2660 -evaluate log 1000 fft_image_spectrum.png</span></p> 2661<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> 2662 2663<p>The <a href="http://www.fftw.org/" target="_blank">FFTW</a> delegate library is required to use <a href="#fft">-fft</a>. 2664 2665<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> 2666 2667<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> 2668 2669<p>The real and imaginary component images resulting from <a href="#fft">+fft</a> also will be square, even dimensioned images due to the same padding that was discussed above for the magnitude and phase component images.</a> 2670 2671<p>See the discussion on HDRI implementations of ImageMagick on the page 2672<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. 2673</p> 2674 2675 2676<div style="margin: auto;"> 2677 <h4><a name="fill" id="fill"></a>-fill <em class="arg">color</em></h4> 2678</div> 2679 2680<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> 2681 2682<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> 2683 2684<p>Enclose the color specification in quotation marks to prevent the "#" or the parentheses from being interpreted by your shell.</p> 2685 2686<p>For example,</p> 2687 2688<p class="crtsnip"> 2689 -fill blue 2690</p> 2691<p class="crtsnip"> 2692 -fill "#ddddff" 2693</p> 2694<p class="crtsnip"> 2695 -fill "rgb(255,255,255)" 2696</p> 2697 2698<p>See <a href="#draw">-draw</a> for further details.</p> 2699 2700<p>To print a complete list of color names, use the <a href="#list">-list color</a> option.</p> 2701 2702<div style="margin: auto;"> 2703 <h4><a name="filter" id="filter"></a>-filter <em class="arg">type</em></h4> 2704</div> 2705 2706<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 an image.</td><td style='text-align:right;'></td></tr></table> 2707 2708<p>Use this option to affect the resizing operation of an image (see <a 2709href="#resize">-resize</a>). For example you can use a simple resize filter 2710such as:</p> 2711 2712<pre class="text"> 2713 Point Hermite Cubic 2714 Box Gaussian Catrom 2715 Triangle Quadratic Mitchell 2716</pre> 2717 2718<p>The <kbd>Bessel</kbd> and <kbd>Sinc</kbd> filter is also provided, but are 2719by default <kbd>blackman</kbd>-windowed. However these filters define a 2720windowing filter for the Sinc or Bessel filter function, as appropriate for 2721the scaling operator used (usally Sinc for orthogonal <a href="#resize" 2722>-resize</a>). Windowed filters include: </p> 2723 2724<pre class="text"> 2725 Lanczos Hamming Parzen 2726 Blackman Kaiser Welsh 2727 Hanning Bartlett Bohman 2728</pre> 2729 2730<p>Also one special self-windowing filter is also provided 2731<kbd>Lagrange</kbd>, which will automagically re-adjust its function depending 2732on the current 'support' or 'lobes' expert settings (see below).</p> 2733 2734<p>If you do not select a filter with this option, the filter defaults to <kbd>Mitchell</kbd> for a colormapped image, a image with a matte channel, or if the image is enlarged. Otherwise the filter default to <kbd>Lanczos</kbd>.</p> 2735 2736<p>To print a complete list of resize filters, use the <a href="#list">-list filter</a> option.</p> 2737 2738<p>You can modify how the filter behaves as it scales your image through the 2739use of these expert settings:</p> 2740 2741<dl class="doc"> 2742<dt>-set filter:blur <em>factor</em></dt> 2743<dd>Scale the X axis of the filter (and its window). Use > 1.0 for 2744 blurry or < 1.0 for sharp.</dd> 2745 2746<dt>-set filter:support <em>radius</em></dt> 2747<dd>Set the filter support radius.</dd> 2748 2749<dt>-set filter:lobes <em>count</em></dt> 2750<dd>Set the number of lobes to use for the Sinc/Bessel filter. This an 2751 alternative way of specifying the 'support' range of the filter.</dd> 2752 2753<dt>-set filter:b <em>b-spline_factor</em></dt> 2754<dt>-set filter:c <em>keys_alpha_factor</em></dt> 2755<dd>Redefine the values used for cubic filters such as <kbd>Cubic</kbd>, 2756 <kbd>Catrom</kbd>, <kbd>Mitchel</kbd>, and <kbd>Hermite</kbd>, as well as 2757 the <kbd>Parzen</kbd> Sinc windowing function. If only one of the values 2758 are defined, the other is set so as to generate a 'Keys' type cubic 2759 filter. 2760 2761<dt>-set filter:filter <em>filter</em></dt> 2762<dd>Use this function directly as the scaling filter. This will allow 2763 you to directly use a 'windowing filter' such as <kbd>blackman</kbd>, 2764 rather than as its normal usage as a windowing function for 'Sinc' or 2765 'Bessel'. If defined, no windowing function is used, unless the following 2766 expert setting is also defined.</dd> 2767 2768<dt>-set filter:window <em>filter</em></dt> 2769<dd>The IIR (infinite impulse response) filters <kbd>bessel</kbd> and 2770 <kbd>sinc</kbd> are windowed (brought down to zero over the defined 2771 support range) with the given filter. This allows you to use a filter that 2772 is not normally used as a windowing function, such as <kbd>box</kbd>, 2773 (which effectivally turns off the windowing function). </dd> 2774 2775</dl> 2776 2777<p>For example, to get a 8 lobe Lanczos-Bessel filter:</p> 2778 2779<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert image.png -filter bessel \ <br/> 2780 -set filter:window=bessel -set filter:lobes=8 \ <br/> 2781 -resize 150% image.jpg</span></p> 2782<p>Or a raw un-windowed Sinc filter with 4 lobes:</p> 2783 2784<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert image.png -set filter:filter=sinc -set filter:lobes=4 \ <br/> 2785 -resize 150% image.jpg</span></p> 2786<p>Note that the use of expert options (except for 'blur' with simple resize 2787filters), are provided for image processing experts who have studied and 2788understood how resize filters work. Without this knowledge, and an 2789understanding of the defination of the actual filters involved, using expert 2790settings are more likely to be detremental to your image resizing.</p> 2791 2792 2793<div style="margin: auto;"> 2794 <h4><a name="flatten" id="flatten"></a>-flatten</h4> 2795</div> 2796 2797<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> 2798 2799 2800<div style="margin: auto;"> 2801 <h4><a name="flip" id="flip"></a>-flip</h4> 2802</div> 2803 2804<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> 2805 2806<p>reflect the scanlines in the vertical direction.</p> 2807 2808<div style="margin: auto;"> 2809 <h4><a name="floodfill" 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> 2810</div> 2811 2812<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> 2813 2814<div style="margin: auto;"> 2815 <h4><a name="flop" id="flop"></a>-flop</h4> 2816</div> 2817 2818<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> 2819 2820<p>reflect the scanlines in the horizontal direction.</p> 2821 2822 2823<div style="margin: auto;"> 2824 <h4><a name="font" id="font"></a>-font <em class="arg">name</em></h4> 2825</div> 2826 2827<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> 2828 2829<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> 2830 2831<p>In addition to the fonts specified by the above pre-defined list, you can 2832also specify a font from a specific source. For example <kbd>Arial.ttf</kbd> 2833is a TrueType font file, <kbd>ps:helvetica</kbd> is PostScript font, and 2834<kbd>x:fixed</kbd> is X11 font.</p> 2835 2836<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> 2837 2838 2839<div style="margin: auto;"> 2840 <h4><a name="foreground" id="foreground"></a>-foreground <em class="arg">color</em></h4> 2841</div> 2842 2843<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> 2844 2845<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p> 2846 2847<p>The default foreground color is black.</p> 2848 2849<div style="margin: auto;"> 2850 <h4><a name="format" id="format"></a>-format <em class="arg">type</em></h4> 2851</div> 2852 2853<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> 2854 2855<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> 2856 2857<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> 2858 2859<div style="margin: auto;"> 2860 <h4><a name="format_identify_" id="format_identify_"></a>-format <em class="arg">string</em></h4> 2861</div> 2862 2863<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> 2864 2865<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> 2866 2867<div style="margin: auto;"> 2868 <h4><a name="frame" id="frame"></a>-frame <em class="arg">geometry</em></h4> 2869</div> 2870 2871<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> 2872 2873<p>The color of the border is specified with the <a href="#mattecolor">-mattecolor</a> command line option. </p> 2874 2875<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 class="arg">geometry</em> argument indicates the amount of extra width and height that is added to the dimensions of the image. If no offsets are given in the <em class="arg">geometry</em> argument, then the border added is a solid color. Offsets <em>x</em> and <em>y</em>, if present, specify that the width and height of the border is partitioned to form an outer bevel of thickness <em>x</em> pixels and an inner bevel of thickness <em>y</em> pixels. (Negative offsets make no sense here.) The <a href="#frame">-frame</a> option is not affected by the <a href="#gravity">-gravity</a> option.</p> 2876 2877 2878<div style="margin: auto;"> 2879 <h4><a name="frame_import_" id="frame_import_"></a>-frame</h4> 2880</div> 2881 2882<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> 2883 2884<div style="margin: auto;"> 2885 <h4><a name="function" id="function"></a>-function <em class="arg">function</em> <em class="arg">parameters</em></h4> 2886</div> 2887 2888<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> 2889 2890<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> 2891 2892<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> 2893 2894<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> 2895 2896<pre class="text"> 2897 Polynomial 2898 Sinusoid 2899 Arcsin 2900 Arctan 2901</pre> 2902 2903<p>To print a complete list of <a href="#function">-function</a> operators, use <a href="#list">-list function</a>. Descriptions follow.</p> 2904 2905<dl class="doc"> 2906<dt><kbd>Polynomial</kbd></dt> 2907<dd> 2908<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> 2909 2910<div style="text-align: center"> 2911 -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> 2912</div> 2913 2914<p>will invoke a polynomial function given by</p> 2915 2916<div style="text-align: center"> 2917 <em>a</em><sub><em>n</em></sub> <b><em>u</em></b><sup><em>n</em></sup> + 2918 <em>a</em><sub><em>n</em>-1</sub> <b><em>u</em></b><sup><em>n</em>-1</sup> + 2919 ··· <em>a</em><sub>1</sub> <b><em>u</em></b> + <em>a</em><sub>0</sub>, 2920</div> 2921 2922<p>where <b><em>u</em></b> is pixel's original normalized channel value.</p> 2923 2924<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> 2925 2926<table class="doc"> 2927 <col width="35%" /> 2928 <col width="35%" /> 2929 <col width="30%" /> 2930 <tr> 2931 <td>-evaluate Set <em class="arg">value</em> </td> 2932 <td>-function Polynomial <em class="arg">value</em></td> 2933 <td>(Constant functions; set <em class="arg">value</em>×100% gray when channels are RGB.)</td> 2934 </tr> 2935 <tr> 2936 <td>-evaluate Add <em class="arg">value</em> </td> 2937 <td>-function Polynomial 1,<em class="arg">value</em></td> 2938 </tr> 2939 <tr> 2940 <td>-evaluate Subtract <em class="arg">value</em> </td> 2941 <td>-function Polynomial 1,−<em class="arg">value</em></td> 2942 </tr> 2943 <tr> 2944 <td>-evaluate Multiply <em class="arg">value</em> </td> 2945 <td>-function Polynomial <em class="arg">value</em>,0</td> 2946 </tr> 2947 <tr> 2948 <td>+level black% x white%</td> 2949 <td>-function Polynomial A,B</td> 2950 <td>(Reduce contrast. Here, A=(white-black)/100 and B=black/100.)</td> 2951 </tr> 2952</table> 2953 2954<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> 2955</dd> 2956 2957<dt><kbd>Sinusoid</kbd></dt> 2958<dd> 2959<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> 2960 2961<div style="text-align: center"> 2962 -function <kbd>Sinusoid</kbd> <em class="arg">freq</em>,[<em class="arg">phase</em>,[<em class="arg">amp</em>,[<em class="arg">bias</em>]]] 2963</div> 2964 2965<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> 2966 2967<div style="text-align: center"> 2968<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> 2969</div> 2970 2971<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> 2972 2973<p class="crtsnip"> 2974 -function Sinusoid 3,-90,.2,.7 2975</p> 2976 2977<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> 2978 2979<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> 2980 2981<table class="doc"> 2982 <tr> 2983 <td>-evaluate Sin <em class="arg">freq</em> </td> 2984 <td>-function Sinusoid <em class="arg">freq</em>,0 </td> 2985 </tr> 2986 <tr> 2987 <td>-evaluate Cos <em class="arg">freq</em> </td> 2988 <td>-function Sinusoid <em class="arg">freq</em>,90 </td> 2989 </tr> 2990</table> 2991</dd> 2992 2993<dt><kbd>ArcSin</kbd></dt> 2994<dd> 2995<p>The <kbd>ArcSin</kbd> function generates the inverse curve of a Sinusoid, 2996and can be used to generate cylindrical distortion and displacement maps. 2997The curve can be adjusted relative to both the input values and output range 2998of values. 2999 3000<div style="text-align: center"> 3001 -function <kbd>ArcSin</kbd> <em class="arg">width</em>,[<em class="arg">center</em>,[<em class="arg">range</em>,[<em class="arg">bias</em>]]] 3002</div> 3003 3004<p>with all values given in terms of noramlize color values (0.0 for black, 30051.0 for white). Defaulting to values covering the full range from 0.0 to 1.0 3006for bout input (<em class="arg">width</em>), and output (<em 3007class="arg">width</em>) values. '<code>1.0,0.5,1.0,0.5</code>' </p> 3008 3009<div style="text-align: center"> 3010<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> 3011</div> 3012 3013</dd> 3014 3015<dt><kbd>ArcTan</kbd></dt> 3016<dd> 3017<p>The <kbd>ArcTan</kbd> function generates a curve that smooth crosses from 3018limit values at infinities, though a center using the given slope value. 3019All these values can be adjusted via the arguments. 3020 3021<div style="text-align: center"> 3022 -function <kbd>ArcTan</kbd> <em class="arg">slope</em>,[<em class="arg">center</em>,[<em class="arg">range</em>,[<em class="arg">bias</em>]]] 3023</div> 3024 3025<p>Defaulting to '<code>1.0,0.5,1.0,0.5</code>'. 3026</p> 3027 3028<div style="text-align: center"> 3029<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> 3030</div> 3031 3032</dd> 3033 3034</dl> 3035 3036 3037<div style="margin: auto;"> 3038 <h4><a name="fuzz" id="fuzz"></a>-fuzz <em class="arg">distance</em>{<em class="arg">%</em>}</h4> 3039</div> 3040 3041<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> 3042 3043<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> 3044 3045<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> 3046 3047 3048<div style="margin: auto;"> 3049 <h4><a name="fx" id="fx"></a>-fx <em class="arg">expression</em></h4> 3050</div> 3051 3052<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> 3053 3054<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> 3055 3056<p>See <a href="/www/fx.html">FX, The Special Effects Image Operator</a> for a detailed discussion of this option.</p> 3057 3058 3059<div style="margin: auto;"> 3060 <h4><a name="gamma" id="gamma"></a>-gamma <em class="arg">value</em></h4> 3061</div> 3062 3063<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> 3064 3065<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> 3066 3067<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> 3068 3069<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> 3070 3071<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> 3072 3073<p>Note that gamma adjustments are also available via the <a href="#level">-level</a> operator.</p> 3074 3075<div style="margin: auto;"> 3076 <h4><a name="gaussian-blur" 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> 3077</div> 3078 3079<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> 3080 3081<p>Convolve the image with a Gaussian or normal distribution. The formula is:</p> 3082 3083<div class="eqn"><img alt="gaussian distribution" width="243px" height="42px" src="/images/gaussian-blur.png"/> 3084</div> 3085 3086<p>where <i>r</i> is the blur radius (<i>r</i><sup>2</sup> = <i>u</i><sup>2</sup> + <i>v</i><sup>2</sup>), and σ is the standard deviation of the Gaussian distribution. As a guideline, set <i>r</i> to approximately 3σ. Specify a radius of 0 and ImageMagick selects a suitable radius for you.</p> 3087 3088<p>This differs from the faster <a href="#blur">-blur</a> operator in that a 3089full 2-dimentional convolution is used to generate the weighted average of the 3090neighbouring pixels. </p> 3091 3092<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how 3093pixels which are outside the image proper are blurred into the final result. 3094</p> 3095 3096 3097<div style="margin: auto;"> 3098 <h4><a name="geometry" id="geometry"></a>-geometry <em class="arg">geometry</em></h4> 3099</div> 3100 3101<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> 3102 3103<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> 3104 3105<div style="margin: auto;"> 3106 <h4><a name="gravity" id="gravity"></a>-gravity <em class="arg">type</em></h4> 3107</div> 3108 3109<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> 3110 3111<p>Choices include: <kbd>NorthWest</kbd>, <kbd>North</kbd>, <kbd>NorthEast</kbd>, 3112<kbd>West</kbd>, <kbd>Center</kbd>, <kbd>East</kbd>, <kbd>SouthWest</kbd>, 3113<kbd>South</kbd>, <kbd>SouthEast</kbd>. Use <a href="#list">-list gravity</a> to get a complete 3114list of <a href="#gravity">-gravity</a> settings available in your ImageMagick 3115installation.</p> 3116 3117<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> 3118 3119<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> 3120 3121<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> 3122 3123<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert image.png -gravity Center -region 10x10-40+20 -negate output.png</span></p> 3124<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> 3125 3126<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> 3127 3128 3129<div style="margin: auto;"> 3130 <h4><a name="green-primary" id="green-primary"></a>-green-primary <em class="arg">x,y</em></h4> 3131</div> 3132 3133<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> 3134 3135 3136<div style="margin: auto;"> 3137 <h4><a name="hald-clut" id="hald-clut"></a>-hald-clut</h4> 3138</div> 3139 3140<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> 3141 3142<p>A Hald color lookup table is a 3-dimensional color cube mapped to 2 3143dimensions. Create it with the <kbd>HALD:</kbd> prefix (e.g. HALD:8). You 3144can apply any color transformation to the Hald image and then use this option 3145to apply the transform to the image. </p> 3146 3147<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert image.png hald.png -hald-clut transform.png</span></p> 3148<p>This option provides a convenient method for you to use Gimp or Photoshop 3149to make color corrections to the Hald CLUT image and subsequently apply them 3150to multiple images using an ImageMagick script. </p> 3151 3152<p>Note that the representation is only of the normal RGB color space and that 3153the whole color value triplet is used for the interpolated lookup of the 3154represented Hald color cube image. Because of this the operation is not <a 3155href="#channel" >-channel</a> setting effected, nor can it adjust or modify an 3156images transparency or alpha/matte channel.</p> 3157 3158<p>See also <a href="#clut" >-clut</a> which provides color value replacement 3159of the individual color channels, usally involving a simplier gray-scale 3160image. E.g: gray-scale to color replacement, or modification by a histogram 3161mapping. </p> 3162 3163 3164<div style="margin: auto;"> 3165 <h4><a name="help" id="help"></a>-help</h4> 3166</div> 3167 3168<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> 3169 3170<div style="margin: auto;"> 3171 <h4><a name="highlight-color" id="highlight-color"></a>-highlight-color <em class="arg">color</em></h4> 3172</div> 3173 3174<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> 3175 3176<div style="margin: auto;"> 3177 <h4><a name="iconGeometry" id="iconGeometry"></a>-iconGeometry <em class="arg">geometry</em></h4> 3178</div> 3179 3180<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> 3181 3182<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> 3183 3184<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> 3185 3186<div style="margin: auto;"> 3187 <h4><a name="iconic" id="iconic"></a>-iconic</h4> 3188</div> 3189 3190<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> 3191 3192<div style="margin: auto;"> 3193 <h4><a name="identify" id="identify"></a>-identify</h4> 3194</div> 3195 3196<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> 3197 3198<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> 3199 3200<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> 3201 3202<p>If <a href="#verbose">-verbose</a> preceds this option, copious 3203amounts of image properties are displayed including image statistics, profiles, 3204image histogram, and others.</p> 3205 3206<div style="margin: auto;"> 3207 <h4><a name="ift" id="ift"></a>-ift</h4> 3208</div> 3209 3210<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> 3211 3212<p>This option is new as of ImageMagick 6.5.4-3 and 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" target="_blank">Fourier Transform</a>, <a href="http://en.wikipedia.org/wiki/DFT" target="_blank">Discrete Fourier Transform</a> and <a href="http://en.wikipedia.org/wiki/FFT" target="_blank">Fast Fourier Transform</a>.</p> 3213 3214<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> 3215 3216<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert fft_image.miff -ift fft_image_ift.png</span></p> 3217<p>or</p> 3218 3219<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> 3220 3221<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 will be at the right and/or bottom sides of the image. 3222 3223<p>The <a href="http://www.fftw.org/" target="_blank">FFTW</a> delegate library is required to use <a href="#ift">-ift</a>. 3224 3225<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. 3226 3227<div style="margin: auto;"> 3228 <h4><a name="immutable" id="immutable"></a>-immutable</h4> 3229</div> 3230 3231<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> 3232 3233<div style="margin: auto;"> 3234 <h4><a name="implode" id="implode"></a>-implode <em class="arg">factor</em></h4> 3235</div> 3236 3237<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> 3238 3239<div style="margin: auto;"> 3240 <h4><a name="insert" id="insert"></a>-insert <em class="arg">index</em></h4> 3241</div> 3242 3243<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> 3244 3245<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> 3246 3247<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> 3248 3249<div style="margin: auto;"> 3250 <h4><a name="intent" id="intent"></a>-intent <em class="arg">type</em></h4> 3251</div> 3252 3253<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> 3254 3255<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> 3256 3257<p>The default intent is undefined.</p> 3258 3259<p>To print a complete list of rendering intents, use <a href="#list">-list intent</a>.</p> 3260 3261<div style="margin: auto;"> 3262 <h4><a name="interlace" id="interlace"></a>-interlace <em class="arg">type</em></h4> 3263</div> 3264 3265<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> 3266 3267<p>Choose from:</p> 3268 3269<pre class="text"> 3270 none 3271 line 3272 plane 3273 partition 3274 JPEG 3275 GIF 3276 PNG 3277</pre> 3278 3279<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> 3280 3281<p><kbd>None</kbd> means do not interlace (RGBRGBRGBRGBRGBRGB...),</p> 3282 3283<p><kbd>Line</kbd> uses scanline interlacing (RRR...GGG...BBB...RRR...GGG...BBB...), and.</p> 3284 3285<p><kbd>Plane</kbd> uses plane interlacing (RRRRRR...GGGGGG...BBBBBB...).</p> 3286 3287<p><kbd>Partition</kbd> is like plane except the different planes are saved to individual files (e.g. image.R, 3288image.G, and image.B).</p> 3289 3290<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> 3291image.</p> 3292 3293<p>To print a complete list of interlacing schemes, use <a href="#list">-list interlace</a>.</p> 3294 3295<div style="margin: auto;"> 3296 <h4><a name="interpolate" id="interpolate"></a>-interpolate <em class="arg">type</em></h4> 3297</div> 3298 3299<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> 3300 3301<p>When looking up the color of a pixel using a non-interger floating point 3302value, you typically fall in between the pixel colors defined by the source 3303image. This setting determines how the color is determined from the colors of 3304the pixels surrounding that point. That is how to determine the color of a 3305point that falls between two, or even four different colored pixels. </p> 3306 3307<pre class="text"> 3308 integer: The color of the top-left pixel (floor function) 3309 nearest-neighbor: The nearest pixel to the lookup point (rounded function) 3310 average: The average color of the surrounding four pixels 3311 bilinear A double linear interpolation of pixels (the default) 3312 mesh Divide area into two flat triangular interpolations 3313 bicubic Fitted bicubic-spines of surrounding 16 pixels 3314 spline Direct spline curves (colors are blurred) 3315 filter Use resize <a href="#filter">-filter</a> settings 3316</pre> 3317 3318<p>This most important for distortion operators such as <a href="#distort" 3319>-distort</a>, <a href="#implode" >-implode</a>, <a href="#transform" 3320>-transform</a> and <a href="#fx" >-fx</a>. </p> 3321 3322<p>To print a complete list of interpolation methods, use <a href="#list">-list interpolate</a>.</p> 3323 3324<p>See also <a href="#virtual-pixel" >-virtual-pixel</a>, for control of the 3325lookup for positions outside the boundaries of the image. </p> 3326 3327 3328<div style="margin: auto;"> 3329 <h4><a name="interline-spacing" id="interline-spacing"></a>-interline-spacing <em class="arg">value</em></h4> 3330</div> 3331 3332<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> 3333 3334<div style="margin: auto;"> 3335 <h4><a name="interword-spacing" id="interword-spacing"></a>-interword-spacing <em class="arg">value</em></h4> 3336</div> 3337 3338<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> 3339 3340<div style="margin: auto;"> 3341 <h4><a name="kerning" id="kerning"></a>-kerning <em class="arg">value</em></h4> 3342</div> 3343 3344<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> 3345 3346<div style="margin: auto;"> 3347 <h4><a name="label" id="label"></a>-label <em class="arg">name</em></h4> 3348</div> 3349 3350<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> 3351 3352<p>Use this option to assign a specific label to the image, as it is read in or created. You can use the <a href="#set" >-set</a> operation to re-assign a the labels of images already read in. Image formats such as TIFF, PNG, MIFF, supports saving the label information with the image.</p> 3353 3354<p>When saving an image to a <em class="arg">PostScript</em> file, any label assigned to an image is used as a header string to print above the postscript image. </p> 3355 3356<p>You can include the image filename, type, width, height, or other image attribute by embedding special format character. See <a href="#format">-format</a> for details of the percent escape codes.</p> 3357 3358<p>For example,</p> 3359 3360<p class="crtsnip"> 3361 -label "%m:%f %wx%h" bird.miff 3362</p> 3363 3364<p>assigns an image label of <kbd>MIFF:bird.miff 512x480</kbd> to the "<kbd>bird.miff</kbd>" image and whose width is 512 and height is 480, as it is read in. If a <a href="#label">+label</a> option was used instead, any existing label present in the image would be used. You can remove all labels from an image by assigning the empty string. </p> 3365 3366<p>A label is not drawn on the image, but is embedded in the image datastream via <em>Label</em> tag or similar mechanism. If you want the label to be visible on the image itself, use the <a href="#draw">-draw</a> option, or during the final processing in the creation of a image montage.</p> 3367 3368<p>The label font can be specified with <a href="#font">-font</a>, and the 3369other font attribute settings.</p> 3370 3371<p>If the first character of <em class="arg">string</em> is <em class="arg">@</em>, the image label is read from a file titled by the remaining characters in the string. Labels in a file are literal, no embedded formatting characters are recognized.</p> 3372 3373 3374<div style="margin: auto;"> 3375 <h4><a name="lat" 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> 3376</div> 3377 3378<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> 3379 3380<p>Adaptively threshold each pixel based on the value of pixels in a 3381surrounding window. If the current pixel is lighter than this average plus 3382the optional <kbd>offset</kbd>, then it is made white, otherwise it is made 3383black. Small variations in pixel values such as found in scanned documents 3384can be ignored if offset is positive. A negative offset will make it more 3385sensitive to those small variations. </p> 3386 3387<p>This is commonly used to threshold images with an uneven background. It is 3388based on the assumption that average color of the small window is the 3389the local background color, from which to separate the forground color. </p> 3390 3391 3392<div style="margin: auto;"> 3393 <h4><a name="layers" id="layers"></a>-layers <em class="arg">method</em></h4> 3394</div> 3395 3396<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> 3397 3398<p>Perform various image operation methods to a ordered sequence of images 3399which may represent either a set of overlaid 'image layers', a GIF disposal 3400animation, or a fully-'coalesced' animation sequence. </p> 3401 3402<table class="doc"> 3403 <tbody> 3404 <tr valign="top"> 3405 <th align="left" style="width: 8%">Method</th> 3406 <th align="left">Description</th> 3407 </tr> 3408 3409 <tr valign="top"> 3410 <td valign="top">compare-any</td> 3411 <td valign="top">Crop the second and later frames to the smallest rectangle 3412 that contains all the differences between the two images. No GIF <a 3413 href="#dispose" >-dispose</a> methods are taken into account. </td> 3414 </tr> 3415 3416 <tr><td></td><td>This exactly the same as the <a href="#deconstruct" 3417 >-deconstruct</a> operator, and does not preserve animations normal 3418 working, especially when animation used layer disposal methods such as 3419 '<kbd>Previous</kbd>' or '<kbd>Background</kbd>'. </td> 3420 </tr> 3421 3422 <tr valign="top"> 3423 <td valign="top">compare-clear</td> 3424 <td valign="top">As '<kbd>compare-any</kbd>' but crop to the bounds of any 3425 opaque pixels which become transparent in the second frame. That is the 3426 smallest image needed to mask or erase pixels for the next frame. </td> 3427 </tr> 3428 3429 <tr valign="top"> 3430 <td valign="top">compare-overlay</td> 3431 <td valign="top">As '<kbd>compare-any</kbd>' but crop to pixels that add 3432 extra color to the next image, as a result of overlaying color pixels. 3433 That is the smallest single overlaid image to add or change colors. </td> 3434 </tr> 3435 3436 <tr><td></td><td>This can be used with the <a href="#compose" >-compose</a> alpha 3437 composition method '<kbd>change-mask</kbd>', to reduce the image to 3438 just the pixels that need to be overlaid. </td> 3439 </tr> 3440 3441 <tr valign="top"> 3442 <td valign="top">coalesce</td> 3443 <td valign="top">Equivalent to a call to the <a href="#coalesce" 3444 >-coalesce</a> operator. Apply the layer disposal methods set in the 3445 current image sequence to form a fully defined animation sequence, as 3446 it should be displayed. Effectively converting a GIF animation into a 3447 'film strip'-like animation. </td> 3448 </tr> 3449 3450 <tr valign="top"> 3451 <td valign="top">composite</td> 3452 <td valign="top">Alpha Composition of two image lists, separated by a 3453 "<kbd>null:</kbd>" image, with the destination image list first, and 3454 the source images last. An image from each list are composited 3455 together until one list is finished. The separator image and source 3456 image lists are removed. </td> 3457 </tr> 3458 3459 3460 <tr><td></td><td>The <a href="#geometry" >-geometry</a> offset is adjusted according to 3461 <a href="#gravity" >-gravity</a> in accordance of the virtual canvas 3462 size of the first image in each list. Unlike a normal <a 3463 href="#composite" >-composite</a> operation, the canvas offset is also 3464 added to the final composite positioning of each image. </td> 3465 </tr> 3466 3467 <tr><td></td><td>If one of the image lists only contains one image, that image is 3468 applied to all the images in the other image list, regardless of which 3469 list it is. In this case it is the image meta-data of the list which 3470 preserved. </td> 3471 </tr> 3472 3473 3474 <tr valign="top"> 3475 <td valign="top">dispose</td> 3476 <td valign="top">This like '<kbd>coalesce</kbd>' but shows the look of 3477 the animation after the layer disposal method has been applied, before 3478 the next sub-frame image is overlaid. That is the 'dispose' image that 3479 results from the application of the GIF <a href="#dispose" 3480 >-dispose</a> method. This allows you to check what 3481 is going wrong with a particular animation you may be developing. 3482 </td> 3483 </tr> 3484 3485 <tr valign="top"> 3486 <td valign="top">flatten</td> 3487 <td valign="top">Create a canvas the size of the first images virtual 3488 canvas using the current <a href="#background" >-background</a> color, 3489 and <a href="#compose" >-compose</a> each image in turn onto that 3490 canvas. Images falling outside that canvas is clipped. Final 3491 image will have a zero virtual canvas offset. </td> 3492 </tr> 3493 3494 <tr><td></td><td>This usally used as one of the final 'image layering' operations 3495 overlaying all the prepared image layers into a final image. </td> 3496 </tr> 3497 3498 <tr><td></td><td>For a single image this method can also be used to fillout a virtual 3499 canvas with real pixels, or to underlay a opaque color to remove 3500 transparency from an image.</td> 3501 </tr> 3502 3503 3504 <tr valign="top"> 3505 <td valign="top">merge</td> 3506 <td valign="top">As 'flatten' method but merging all the given image 3507 layers into a new layer image just large enough to hold all the image 3508 without clipping or extra space. The new images virtual offset will 3509 prevere the position of the new layer, even if this offset is 3510 negative. the virtual canvas size of the first image is preserved. 3511 </td> 3512 </tr> 3513 3514 <tr><td></td><td>Caution is advised when handling image layers with negative offsets 3515 as few image file formats handle them correctly. </td> 3516 </tr> 3517 3518 <tr valign="top"> 3519 <td valign="top">mosaic</td> 3520 <td valign="top">As 'flatten' method but expanding the initial canvas size 3521 of the first image so as to hold all the image layers. However as a 3522 virtual canvas is 'locked' to the origin, by defination, image layers 3523 with a negative offsets will still be clipped by the top and left 3524 edges.</td> 3525 </tr> 3526 3527 <tr><td></td><td>This method is commonly used to layout individual image using various 3528 offset but without knowning the final canvas size. The resulting image 3529 will, like 'flatten' not have any virtual offset, so can be saved to 3530 any image file format. </td> 3531 </tr> 3532 3533 3534 <tr valign="top"> 3535 <td valign="top">optimize</td> 3536 <td valign="top">Optimize a coalesced animation, into GIF animation using 3537 a number of general techniques. This currently a short cut to 3538 apply both the '<kbd>optimize-frame</kbd>', and 3539 '<kbd>optimize-transparency</kbd>' methods but may be expanded to 3540 include other optimization methods as they are developed. </td> 3541 </tr> 3542 3543 <tr valign="top"> 3544 <td valign="top">optimize-frame</td> 3545 <td valign="top">Optimize a coalesced animation, into GIF animation by 3546 reducing the number of pixels per frame as much as possible by 3547 attempting to pick the best layer disposal method to use, while ensuring 3548 the result will continue to animate properly. </td> 3549 </tr> 3550 3551 <tr><td></td><td> There is no guarantee that the best optimization is found. But 3552 then no reasonably fast GIF optimization algorithm can do this. 3553 However this does seem to do better than most other GIF frame 3554 optimizers seen. </td> 3555 </tr> 3556 3557 <tr valign="top"> 3558 <td valign="top">optimize-plus</td> 3559 <td valign="top">As '<kbd>optimize-frame</kbd>' but attempt to improve the 3560 overall optimization by adding extra frames to the animation, without 3561 changing the final look or timing of the animation. The frames are 3562 added to attempt to separate the clearing of pixels from the 3563 overlaying of new additional pixels from one animation frame to the 3564 next. If this does not improve the optimization (for the next frame 3565 only), it will fall back to the results of the previous normal 3566 '<kbd>optimize-frame</kbd>' technique. </td> 3567 </tr> 3568 3569 <tr><td></td><td>There is the possibility that the change in the disposal style will 3570 result in a worsening in the optimization of later frames, though this 3571 is unlikely. In other words there no guarantee that it is better than 3572 the normal '<kbd>optimize-frame</kbd>' technique. For some animations 3573 however you can get a vast improvment in the final animation size. </td> 3574 </tr> 3575 3576 <tr valign="top"> 3577 <td valign="top">optimize-transparency</td> 3578 <td valign="top">Given a GIF animation, replace any pixel in the sub-frame 3579 overlay images with transparency, if it does not change the resulting 3580 animation by more than the current <a href="#fuzz" >-fuzz</a> factor. 3581 </td> 3582 </tr> 3583 3584 <tr><td></td><td>This should allow a existing frame optimized GIF animation to compress 3585 into a smaller file size due to larger areas of one (transparent) 3586 color rather than a pattern of multiple colors repeating the current 3587 disposed image of the last frame. </td> 3588 </tr> 3589 3590 <tr valign="top"> 3591 <td valign="top">remove-dups</td> 3592 <td valign="top">Remove (and merge time delays) of duplicate consecutive 3593 images, so as to simplify layer overlays of coalesced animations. 3594 </td> 3595 </tr> 3596 3597 <tr><td></td><td>Usually this a result of using a constant time delay across the 3598 whole animation, or after a larger animation was split into smaller 3599 sub-animations. The duplicate frames could also have been used as 3600 part of some frame optimization methods. </td> 3601 </tr> 3602 3603 <tr valign="top"> 3604 <td valign="top">remove-zero</td> 3605 <td valign="top">Remove any image with a zero time delay, unless ALL the 3606 images have a zero time delay (and is not a proper timed animation, a 3607 warning is then issued). </td> 3608 </tr> 3609 3610 <tr><td></td><td>In a GIF animation, such images are usually frames which provide 3611 partial intermediary updates between the frames that are actually 3612 displayed to users. These frames are usally added for improved frame 3613 optimization in GIF animations. </td> 3614 </tr> 3615 3616 <tr valign="top"> 3617 <td valign="top">trim-bounds</td> 3618 <td valign="top">Find the bounds of all the images in the current 3619 image sequence, then adjust the offsets so all images are contained on 3620 a minimal positive canvas. None of the image data is modified, only 3621 there virtual canvas size and offset. The all the image is given 3622 the same canvas size, and and will have a positive offset, but will 3623 remain in the same position relative to each other. As a result of the 3624 minimal canvas size at least one image will touch every edge of that 3625 canvas. The image data however may be transparent. 3626 </td> 3627 </tr> 3628 3629 </tbody> 3630</table> 3631 3632<p>To print a complete list of layer types, use <a href="#list">-list layers</a>.</p> 3633 3634<p>The operators <a href="#coalesce" >-coalesce</a>, <a href="#deconstruct" 3635>-deconstruct</a>, <a href="#flatten" >-flatten</a>, and <a href="#mosaic" 3636>-mosaic</a> are only aliases for the above methods. Also see <a 3637href="#page" >-page</a>, <a href="#repage" >-repage</a> operators, the <a 3638href="#compose" >-compose</a> setting, and the GIF <a href="#dispose" 3639>-dispose</a> and <a href="#delay" >-delay</a> settings. </p> 3640 3641 3642<div style="margin: auto;"> 3643 <h4><a name="level" 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> 3644</div> 3645 3646<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> 3647 3648<p>Given one, two or three values delimited with commas: black-point, 3649white-point, gamma (for example: 10,250,1.0 or 2%,98%,0.5). The black and 3650white points range from 0 to <em class="QR">QuantumRange</em>, or from 0 to 100%; if the white 3651point is omitted it is set to (<em class="QR">QuantumRange</em> - black_point), so as to center 3652contrast changes. If a <kbd>%</kbd> sign is present anywhere in the string, 3653both black and white points are percentages of the full color range. Gamma 3654will do a <a href="#gamma">-gamma</a> adjustment of the values. If it is 3655omitted, the default of 1.0 (no gamma correction) is assumed.</p> 3656 3657<p>In normal usage (<kbd>-level</kbd>) the image values are stretched so that 3658the given '<kbd>black_point</kbd>' value in the original image is set to 3659zero (or black), while the given '<kbd>white_point</kbd>' value is set to 3660<em class="QR">QuantumRange</em> (or white). This provides you with direct contrast adjustments 3661to the image. The '<kbd>gamma</kbd>' of the resulting image will then be 3662adjusted. </p> 3663 3664<p>From ImageMagick v6.4.1-9 using the plus form of the operator (<kbd>+level</kbd>) or 3665adding the special '!' flag anywhere in the argument list, will cause the 3666operator to do the reverse of the level adjustment. That is a zero, or 3667<em class="QR">QuantumRange</em> value (black, and white, resp.) in the original image, is 3668adjusted to the given level values, allowing you to de-contrast, or compress 3669the channel values within the image. The '<kbd>gamma</kbd>' is adjusted before the level adjustment to de-contrast the image is made. </p> 3670 3671<p>Only the channels defined by the current <a href="#channel">-channel</a> 3672setting are adjusted (defaults to RGB color channels only), allowing you to 3673limit the effect of this operator. </p> 3674 3675<p>Please note that the transparency channel is treated as 'matte' 3676values (0 is opaque) and not as 'alpha' values (0 is transparent).</p> 3677 3678 3679<div style="margin: auto;"> 3680 <h4><a name="level-colors" id="level-colors"></a>-level-colors {<em 3681 class="arg">black_color</em>}{,}{<em class="arg">white_color</em>}</h4> 3682</div> 3683 3684<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 seperated colors.</td><td style='text-align:right;'></td></tr></table> 3685 3686<p>This function is exactly like <a href="#level">-level</a>, except that the 3687value value for each color channel is determined by the 3688'<kbd>black_color</kbd>' and '<kbd>white_color</kbd>' colors given (as 3689described under the <a href="#fill">-fill</a> option). </p> 3690 3691<p>This effectivally means the colors provided to <kbd>-level-colors</kbd> 3692is mapped to become 'black' and 'white' respectivally, with all the other 3693colors linearly adjusted (or clipped) to match that change. Each channel is 3694adjusted separatally using the channel values of the colors specified. </p> 3695 3696<p>On the other hand the plus form of the operator (<kbd>+level-colors</kbd>) 3697will map the image color 'black' and 'white' to the given colors 3698respectivally, resulting in a gradient (de-contrasting) tint of the image to 3699those colors. This can also be used to convert a plain gray-scale image into a 3700one using the gradient of colors specified. </p> 3701 3702<p>By supplying a single color with a comma separator either before or after 3703that color, will just replace the respective 'black' or 'white' point 3704respectivally. But if no comma separator is provided, the given color is 3705used for both the black and white color points, making the operator either 3706threshold the images around that color (- form) or set all colors to that 3707color (+ form). </p> 3708 3709 3710<div style="margin: auto;"> 3711 <h4><a name="limit" id="limit"></a>-limit <em class="arg">type value</em></h4> 3712</div> 3713 3714<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> 3715 3716<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> 3717 3718<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, 1.5gb memory, 8gb memory map, and 16tb 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> 3719 3720<p class="crtsnip"> 3721 -limit memory 32mb -limit map 64mb 3722</p> 3723 3724<p>Use <a href="#list">-list resource</a> to list the current limits. For example, our system shows these limits:</p> 3725 3726<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>identify -list resource</span><span class='crtout'><pre>File Area Memory Map Disk Thread Time 3727------------------------------------------------------------------- 3728 768 3.8187gb 2.864gb 7.6375gb 16eb 2 unlimited</pre> 3729</span></p> 3730<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> 3731 3732<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> 3733 3734<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> 3735 3736<p class="crtsnip"> 3737-limit area 10mb 3738</p> 3739 3740<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 inadvertedly upload a huge image to process, you should set a disk limit as well:</p> 3741 3742<p class="crtsnip"> 3743-limit area 10mb -limit disk 500mb 3744</p> 3745 3746<p>Here ImageMagick stops processing if an image requires more than 500MB of disk storage.</p> 3747 3748<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> 3749 3750<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. 3751</p> 3752 3753<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. 3754</p> 3755 3756<div style="margin: auto;"> 3757 <h4><a name="linear-stretch" 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> 3758</div> 3759 3760<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> 3761 3762<div style="margin: auto;"> 3763 <h4><a name="linewidth" id="linewidth"></a>-linewidth</h4> 3764</div> 3765 3766<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> 3767 3768<div style="margin: auto;"> 3769 <h4><a name="liquid-rescale" id="liquid-rescale"></a>-liquid-rescale <em class="arg">geometry</em></h4> 3770</div> 3771 3772<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> 3773 3774<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> 3775 3776<div style="margin: auto;"> 3777 <h4><a name="list" id="list"></a>-list <em class="arg">type</em></h4> 3778</div> 3779 3780<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> 3781 3782<pre class="text"> 3783 coder 3784 color 3785 configure 3786 delegate 3787 font 3788 format 3789 list 3790 log 3791 magic 3792 module 3793 resource 3794 threshold 3795</pre> 3796 3797<p>The above lists are only some of the many lists available. These lists vary depending on your version of ImageMagick. For example use "<kbd>-list list</kbd>" to get a complete listing of all the "<kbd>-list</kbd>" arguments available:</p> 3798 3799<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>identify -list list</span></p> 3800<div style="margin: auto;"> 3801 <h4><a name="log" id="log"></a>-log <em class="arg">string</em></h4> 3802</div> 3803 3804<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> 3805 3806<p>This option specifies the format for the log printed when the <a href="#debug">-debug</a> option is active.</p> 3807 3808<p>You can display the following components by embedding special format characters:</p> 3809 3810<pre class="text"> 3811 %d domain 3812 %e event 3813 %f function 3814 %l line 3815 %m module 3816 %p process ID 3817 %r real CPU time 3818 %t wall clock time 3819 %u user CPU time 3820 %% percent sign 3821 \n newline 3822 \r carriage return 3823</pre> 3824 3825<p>For example:</p> 3826 3827<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> 3828<p>The default behavior is to print all of the components.</p> 3829 3830<div style="margin: auto;"> 3831 <h4><a name="loop" id="loop"></a>-loop <em class="arg">iterations</em></h4> 3832</div> 3833 3834<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> 3835 3836<p>Set iterations to zero to repeat the animation an infinite number of times, otherwise the animation repeats itself up to <em class="arg">iterations</em> times.</p> 3837 3838<div style="margin: auto;"> 3839 <h4><a name="lowlight-color" id="lowlight-color"></a>-lowlight-color <em class="arg">color</em></h4> 3840</div> 3841 3842<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> 3843 3844<div style="margin: auto;"> 3845 <h4><a name="magnify" id="magnify"></a>-magnify <em class="arg">factor</em></h4> 3846</div> 3847 3848<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> 3849 3850 3851<div style="margin: auto;"> 3852 <h4><a name="map" id="map"></a>-map <em class="arg">type</em></h4> 3853</div> 3854 3855<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> 3856 3857<p>Choose from these <em class="arg">Standard Colormap</em> types:</p> 3858 3859<pre class="text"> 3860 best 3861 default 3862 gray 3863 red 3864 green 3865 blue 3866</pre> 3867 3868<p>The <em class="arg">X server</em> must support the <em class="arg">Standard Colormap</em> you choose, otherwise an error occurs. Use <kbd>list</kbd> as the type and <kbd>display</kbd> searches the list of colormap types in <kbd>top-to-bottom</kbd> order until one is located. See <em class="arg">xstdcmap(1)</em> for one way of creating Standard Colormaps.</p> 3869 3870 3871<div style="margin: auto;"> 3872 <h4><a name="map_stream_" id="map_stream_"></a>-map <em class="arg">components</em></h4> 3873</div> 3874 3875<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> 3876 3877<p>Here are the valid components of a map:</p> 3878 3879<pre class="text"> 3880 r red pixel component 3881 g green pixel component 3882 b blue pixel component 3883 a alpha pixel component (0 is transparent) 3884 o opacity pixel component (0 is opaque) 3885 i grayscale intensity pixel component 3886 c cyan pixel component 3887 m magenta pixel component 3888 y yellow pixel component 3889 k black pixel component 3890 p pad component (always 0) 3891</pre> 3892 3893<p>You can specify as many of these components as needed in any order (e.g. bgr). The components can repeat as well (e.g. rgbr).</p> 3894 3895<div style="margin: auto;"> 3896 <h4><a name="mask" id="mask"></a>-mask 3897<em class="arg">filename</em></h4> 3898</div> 3899 3900<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> 3901 3902<p>Use <a href="#mask">+mask</a> to remove the image mask.</p> 3903 3904<div style="margin: auto;"> 3905 <h4><a name="mattecolor" id="mattecolor"></a>-mattecolor <em class="arg">color</em></h4> 3906</div> 3907 3908<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> 3909 3910<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p> 3911 3912<p>The default matte color is <kbd>#BDBDBD</kbd>, <span style="background-color: #bdbdbd;">this shade of gray</span>.</p> 3913 3914<div style="margin: auto;"> 3915 <h4><a name="median" id="median"></a>-median <em class="arg">radius</em></h4> 3916</div> 3917 3918<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> 3919 3920<div style="margin: auto;"> 3921 <h4><a name="metric" id="metric"></a>-metric <em class="arg">type</em></h4> 3922</div> 3923 3924<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> 3925 3926<p>Choose from:</p> 3927 3928<pre class="text"> 3929 AE absolute number of differnet pixels 3930 MAE mean absolute error (normalized), average channel error distance 3931 MEPP mean error per pixel (normalized mean error, normalized peak error) 3932 MSE mean error squared, average of the channel error squared 3933 PAE peak absolute (normalize peak absolute) 3934 PSNR peak signal to noise ratio 3935 RMSE root mean squared (normalized root mean squared) 3936</pre> 3937 3938<p>The '<kbd>AE</kbd>' or absolute count of pixels that are different, can be 3939controled using a <a href="#fuzz" >-fuzz</a> factor to ignore pixels which 3940only changed by a small amount. The '<kbd>PAE</kbd>' can be used to find the 3941size of the <a href="#fuzz" >-fuzz</a> factor needed to make all pixels 3942'similar'. </p> 3943 3944<p>The '<kbd>MEPP</kbd>' metric returns three different metrics 3945('<kbd>MAE</kbd>', '<kbd>MAE</kbd>' normalized, and '<kbd>PAE</kbd>' 3946normalized) from the single comparision run. </p> 3947 3948<p>To print a complete list of metrics, use the <a href="#list">-list metrics</a> option.</p> 3949 3950 3951<div style="margin: auto;"> 3952 <h4><a name="mode" id="mode"></a>-mode <em class="arg">value</em></h4> 3953</div> 3954 3955<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> 3956 3957<p>Choose the <em class="arg">value</em> from these styles: <kbd>Frame, Unframe, or Concatenate</kbd></p> 3958 3959<p>Use the <a href="#list" >-list</a> option with a '<kbd>Mode</kbd>' 3960argument for a list of <a href="#mode" >-mode</a> arguments available 3961in your ImageMagick installation.</p> 3962 3963 3964<div style="margin: auto;"> 3965 <h4><a name="modulate" id="modulate"></a>-modulate <em class="arg">brightness</em>[,<em class="arg">saturation</em>,<em class="arg">hue</em>]</h4> 3966</div> 3967 3968<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 class="arg">saturation</em>, and <em class="arg">hue</em> of an image.</td><td style='text-align:right;'></td></tr></table> 3969 3970<p>The arguments are given as a percentages of variation. A value of 100 means no change, and any 3971missing values are taken to mean 100.</p> 3972 3973<p>The <em class="arg">brightness</em> is a multiplier of the overall brightness of the image, so 0 3974means pure black, 50 is half as bright, 200 is twice as bright. To invert its 3975meaning <a href="#negate">-negate</a> the image before and after. </p> 3976 3977<p>The <em class="arg">saturation</em> controls the amount of color in an image. For example, 0 produce a grayscale image, while a large value such as 200 produce a very colorful, 'cartoonish' color.</p> 3978 3979<p>The <em class="arg">hue</em> argument causes a "rotation" of the colors within the image by the amount specified. For example, 50 results in a counter-clockwise rotation of 90, mapping red 3980shades to purple, and so on. A value of either 0 or 200 results in a complete 3981180 degree rotation of the image. Using a value of 300 is a 360 degree 3982rotation resulting in no change to the original image. </p> 3983 3984<p>For example, to increase the color brightness by 20% and decrease the color saturation by 10% and leave the hue unchanged, use <a href="#modulate">-modulate 120,90</a>.</p> 3985 3986<p>Use <a href="#set">-set</a> attribute of '<kbd class="arg">option:modulate:colorspace</kbd>' to specify which colorspace to modulate. Choose from <kbd>HSB</kbd>, <kbd>HSL</kbd> (the default), or <kbd>HWB</kbd>. For example,</p> 3987 3988<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> 3989<div style="margin: auto;"> 3990 <h4><a name="monitor" id="monitor"></a>-monitor</h4> 3991</div> 3992 3993<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> 3994 3995 3996<div style="margin: auto;"> 3997 <h4><a name="monochrome" id="monochrome"></a>-monochrome</h4> 3998</div> 3999 4000<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> 4001 4002 4003<div style="margin: auto;"> 4004 <h4><a name="morph" id="morph"></a>-morph <em class="arg">frames</em></h4> 4005</div> 4006 4007<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> 4008 4009<p>Both the image pixels and size are linearly interpolated to give the 4010appearance of a meta-morphosis from one image to the next, over all the images 4011in the current image list. The added images are the equivalent of a <a 4012href="#blend">-blend</a> composition. The <em class="arg">frames</em> 4013argument determine how many images to interpolate between each image. </p> 4014 4015 4016<div style="margin: auto;"> 4017 <h4><a name="mosaic" id="mosaic"></a>-mosaic</h4> 4018</div> 4019 4020<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> 4021 4022 4023<div style="margin: auto;"> 4024 <h4><a name="motion-blur" 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> 4025</div> 4026 4027<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> 4028 4029<p>Blur with the given radius, standard deviation (sigma), and angle. The 4030angle given is the angle toward which the image is blurred. That is the 4031direction people would consider the object is coming from. </p> 4032 4033<p>Note that the blur is not uniform distribution, giving the motion a 4034definate sense of direction of movement. </p> 4035 4036<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how 4037pixels which are outside the image proper are blurred into the final result. 4038</p> 4039 4040<div style="margin: auto;"> 4041 <h4><a name="name" id="name"></a>-name</h4> 4042</div> 4043 4044<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> 4045<div style="margin: auto;"> 4046 <h4><a name="negate" id="negate"></a>-negate</h4> 4047</div> 4048 4049<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>replace every pixel with its complementary color.</td><td style='text-align:right;'></td></tr></table> 4050 4051<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> 4052 4053<div style="margin: auto;"> 4054 <h4><a name="noise" id="noise"></a>-noise <em class="arg">radius</em><br/> 4055 +noise <em class="arg">type</em></h4> 4056</div> 4057 4058<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> 4059 4060<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> 4061 4062<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> 4063 4064<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> 4065 4066<pre class="text"> 4067Gaussian 4068Impulse 4069Laplacian 4070Multiplicative 4071Poisson 4072Random 4073Uniform 4074</pre> 4075 4076<p>To print a complete list of noises, use the <a href="#list">-list noise</a> option.</p> 4077 4078 4079<div style="margin: auto;"> 4080 <h4><a name="normalize" id="normalize"></a>-normalize</h4> 4081</div> 4082 4083<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> 4084 4085<p>The intensity values are stretched to cover the entire range of possible values. While doing so, black-out at most <em>2%</em> of the pixels and white-out at most <em>1%</em> of the pixels.</p> 4086 4087<p>Note that as of ImageMagick 6.4.7-0, <a href="#normalize" >-normalize</a> is equivalent to <a href="#contrast-stretch" >-contrast-stretch 2%x1%</a>. (Before this 4088version, it was equivalent to <a href="#contrast-stretch">-contrast-stretch 2%x99%)</a></p> 4089 4090<p>All the channels are normalized in concert by the came amount so as to preserve color integrity. Specify <a href="#channel">-channel</a> to normalize the RGB channels independently.</p> 4091 4092 4093<div style="margin: auto;"> 4094 <h4><a name="ordered-dither" id="ordered-dither"></a>-ordered-dither <em class="arg">threshold_map</em>{,<em class="arg">level</em>...}</h4> 4095</div> 4096 4097<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 class="arg">threshold map</em> specified, and a uniform color map with the number of <em class="arg">levels</em> per color channel . </td><td style='text-align:right;'></td></tr></table> 4098 4099<p>You can choose from these standard threshold maps:</p> 4100 4101<pre class="text"> 4102 checks 4103 o2x2 4104 o3x3 4105 o4x4 4106 o8x8 4107 h4x4a 4108 h6x6a 4109 h8x8a 4110 h4x4o 4111 h6x6o 4112 h8x8o 4113 h16x16o 4114</pre> 4115 4116<p>The '<kbd>o</kbd>' are ordered diffused pixel threshold maps, while the 4117'<kbd>h</kbd>' maps are halftone threshold maps which are either 'a' angled, 4118or 'o' orthogonal. The '<kbd>checks</kbd>' produce a 3 level checkerbord 4119dither pattern. Or you can define your own <em class="arg">threshold 4120map</em> in a personal or system "<kbd>thresholds.xml</kbd>" XML file. </p> 4121 4122<p>To print a complete list of threshold, use the <a href="#list">-list threshold</a> option.</p> 4123 4124<p>It is recommended that the <a href="#map">+map</a> operator be used after 4125applying <a href="#ordered-dither">-ordered-dither</a> to reduce the number of 4126colors an animated image sequence, to less that 256 colors. This ensures that 4127a common or global color table is used when saving the result to a color 4128limited file format such as GIF. </p> 4129 4130<p>Note that at this time the exact same map is used for all color channels, no 4131attempt is made to offset or rotate the dither map for different channels is 4132made, at this point in time. (possible future expansion) </p> 4133 4134 4135<div style="margin: auto;"> 4136 <h4><a name="opaque" id="opaque"></a>-opaque <em class="arg">color</em></h4> 4137</div> 4138 4139<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> 4140 4141<p>The <em class="arg">color</em> argument is defined using the format 4142described under the <a href="#fill">-fill</a> option. 4143The <a href="#fuzz">-fuzz</a> setting can be used to match and replace colors similar 4144to the one given.</p> 4145 4146<p>The <a href="#transparent">-transparent</a> operator is exactly the same 4147as <a href="#opaque">-opaque</a> but makes the matching color transparent, 4148rather than the same as the current <a href="#fill">-fill</a> color. </p> 4149 4150<p>Use <em class="arg">+opaque</em> to paint any pixel that does not match the target color.</p> 4151 4152<div style="margin: auto;"> 4153 <h4><a name="orient" id="orient"></a>-orient <em class="arg">image orientation</em></h4> 4154</div> 4155 4156<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> 4157 4158<p>Choose from these orientations:</p> 4159 4160<pre class="text"> 4161 bottom-left 4162 bottom-right 4163 left-bottom 4164 left-top 4165 right-bottom 4166 right-top 4167 top-left 4168 top-right 4169 undefined 4170</pre> 4171 4172<p>To print a complete list of orientations, use the <a href="#list">-list orientation</a> option.</p> 4173 4174 4175<div style="margin: auto;"> 4176 <h4><a name="page" id="page"></a>-page <em class="arg">geometry</em><br/> 4177 -page <em class="arg">media</em>[<em class="arg">offset</em>][{<em class="arg">^!<></em>}]<br/> 4178 +page 4179 </h4> 4180</div> 4181 4182<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> 4183 4184<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> 4185 4186<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> 4187 4188<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> 4189<table id="geometryTable" cellpadding="2" cellspacing="0" border="1" width="50%" style="margin-left: auto; margin-right: auto;"> 4190<thead> 4191 <tr valign="top"> 4192 <th align="center"><em class="arg">media</em></th> 4193 <th align="center"><em class="arg">width</em></th> 4194 <th align="center"><em class="arg">height</em></th> 4195 </tr> 4196</thead> 4197<tbody> 4198<tr><td align="left"> 11x17 </td> <td align="right"> 792</td> <td align="right"> 1224</td> </tr> 4199<tr><td align="left"> Ledger </td> <td align="right"> 1224</td> <td align="right"> 792</td> </tr> 4200<tr><td align="left"> Legal </td> <td align="right"> 612</td> <td align="right"> 1008</td> </tr> 4201<tr><td align="left"> Letter </td> <td align="right"> 612</td> <td align="right"> 792</td> </tr> 4202<tr><td align="left"> LetterSmall</td> <td align="right"> 612</td> <td align="right"> 792</td> </tr> 4203<tr><td align="left"> ArchE </td> <td align="right"> 2592</td> <td align="right"> 3456</td> </tr> 4204<tr><td align="left"> ArchD </td> <td align="right"> 1728</td> <td align="right"> 2592</td> </tr> 4205<tr><td align="left"> ArchC </td> <td align="right"> 1296</td> <td align="right"> 1728</td> </tr> 4206<tr><td align="left"> ArchB </td> <td align="right"> 864</td> <td align="right"> 1296</td> </tr> 4207<tr><td align="left"> ArchA </td> <td align="right"> 648</td> <td align="right"> 864</td> </tr> 4208<tr><td align="left"> A0 </td> <td align="right"> 2380</td> <td align="right"> 3368</td> </tr> 4209<tr><td align="left"> A1 </td> <td align="right"> 1684</td> <td align="right"> 2380</td> </tr> 4210<tr><td align="left"> A2 </td> <td align="right"> 1190</td> <td align="right"> 1684</td> </tr> 4211<tr><td align="left"> A3 </td> <td align="right"> 842</td> <td align="right"> 1190</td> </tr> 4212<tr><td align="left"> A4 </td> <td align="right"> 595</td> <td align="right"> 842</td> </tr> 4213<tr><td align="left"> A4Small </td> <td align="right"> 595</td> <td align="right"> 842</td> </tr> 4214<tr><td align="left"> A5 </td> <td align="right"> 421</td> <td align="right"> 595</td> </tr> 4215<tr><td align="left"> A6 </td> <td align="right"> 297</td> <td align="right"> 421</td> </tr> 4216<tr><td align="left"> A7 </td> <td align="right"> 210</td> <td align="right"> 297</td> </tr> 4217<tr><td align="left"> A8 </td> <td align="right"> 148</td> <td align="right"> 210</td> </tr> 4218<tr><td align="left"> A9 </td> <td align="right"> 105</td> <td align="right"> 148</td> </tr> 4219<tr><td align="left"> A10 </td> <td align="right"> 74</td> <td align="right"> 105</td> </tr> 4220<tr><td align="left"> B0 </td> <td align="right"> 2836</td> <td align="right"> 4008</td> </tr> 4221<tr><td align="left"> B1 </td> <td align="right"> 2004</td> <td align="right"> 2836</td> </tr> 4222<tr><td align="left"> B2 </td> <td align="right"> 1418</td> <td align="right"> 2004</td> </tr> 4223<tr><td align="left"> B3 </td> <td align="right"> 1002</td> <td align="right"> 1418</td> </tr> 4224<tr><td align="left"> B4 </td> <td align="right"> 709</td> <td align="right"> 1002</td> </tr> 4225<tr><td align="left"> B5 </td> <td align="right"> 501</td> <td align="right"> 709</td> </tr> 4226<tr><td align="left"> C0 </td> <td align="right"> 2600</td> <td align="right"> 3677</td> </tr> 4227<tr><td align="left"> C1 </td> <td align="right"> 1837</td> <td align="right"> 2600</td> </tr> 4228<tr><td align="left"> C2 </td> <td align="right"> 1298</td> <td align="right"> 1837</td> </tr> 4229<tr><td align="left"> C3 </td> <td align="right"> 918</td> <td align="right"> 1298</td> </tr> 4230<tr><td align="left"> C4 </td> <td align="right"> 649</td> <td align="right"> 918</td> </tr> 4231<tr><td align="left"> C5 </td> <td align="right"> 459</td> <td align="right"> 649</td> </tr> 4232<tr><td align="left"> C6 </td> <td align="right"> 323</td> <td align="right"> 459</td> </tr> 4233<tr><td align="left"> Flsa </td> <td align="right"> 612</td> <td align="right"> 936</td> </tr> 4234<tr><td align="left"> Flse </td> <td align="right"> 612</td> <td align="right"> 936</td> </tr> 4235<tr><td align="left"> HalfLetter </td> <td align="right"> 396</td> <td align="right"> 612</td> </tr> 4236</tbody> 4237</table> 4238 4239 4240 4241 4242<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> 4243 4244<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> 4245 4246<p>The default page dimensions for a TEXT image is 612x792.</p> 4247 4248<p>This option is used in concert with <a href="#density">-density</a>.</p> 4249 4250<p>Use <a href="#page">+page</a> to remove the page settings for an image.</p> 4251 4252<div style="margin: auto;"> 4253 <h4><a name="paint" id="paint"></a>-paint <em class="arg">radius</em></h4> 4254</div> 4255 4256<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> 4257 4258<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> 4259 4260<div style="margin: auto;"> 4261 <h4><a name="path" id="path"></a>-path <em class="arg">path</em></h4></div> 4262 4263<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> 4264 4265<div style="margin: auto;"> 4266 <h4><a name="pause_animate_" id="pause_animate_"></a>-pause <em class="arg">seconds</em></h4> 4267</div> 4268 4269<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> 4270 4271<p>Pause for the specified number of seconds before repeating the animation.</p> 4272 4273<div style="margin: auto;"> 4274 <h4><a name="pause_import_" id="pause_import_"></a>-pause <em class="arg">seconds</em></h4> 4275</div> 4276 4277<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> 4278 4279<p>Pause for the specified number of seconds before taking the next snapshot.</p> 4280 4281<div style="margin: auto;"> 4282 <h4><a name="ping" id="ping"></a>-ping</h4> 4283</div> 4284 4285<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> 4286 4287<div style="margin: auto;"> 4288 <h4><a name="pointsize" id="pointsize"></a>-pointsize <em class="arg">value</em></h4> 4289</div> 4290 4291<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> 4292 4293<div style="margin: auto;"> 4294 <h4><a name="polaroid" id="polaroid"></a>-polaroid <em class="arg">angle</em></h4> 4295</div> 4296 4297<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> 4298 4299<p>Use <kbd>+polaroid</kbd> to rotate the image at a random angle between -15 and +15 degrees.</p> 4300 4301<div style="margin: auto;"> 4302 <h4><a name="posterize" id="posterize"></a>-posterize <em class="arg">levels</em></h4> 4303</div> 4304 4305<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> 4306 4307<div style="margin: auto;"> 4308 <h4><a name="preview" id="preview"></a>-preview <em class="arg">type</em></h4> 4309</div> 4310 4311<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> 4312 4313<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> 4314 4315<pre class="text"> 4316 Rotate 4317 Shear 4318 Roll 4319 Hue 4320 Saturation 4321 Brightness 4322 Gamma 4323 Spiff 4324 Dull 4325 Grayscale 4326 Quantize 4327 Despeckle 4328 ReduceNoise 4329 Add Noise 4330 Sharpen 4331 Blur 4332 Threshold 4333 EdgeDetect 4334 Spread 4335 Shade 4336 Raise 4337 Segment 4338 Solarize 4339 Swirl 4340 Implode 4341 Wave 4342 OilPaint 4343 CharcoalDrawing 4344 JPEG 4345</pre> 4346 4347<p>To print a complete list of previews, use the <a href="#list">-list preview</a> option.</p> 4348 4349<p>The default preview is <kbd>JPEG</kbd>.</p> 4350 4351<div style="margin: auto;"> 4352 <h4><a name="print" id="print"></a>-print <em class="arg">string</em></h4> 4353</div> 4354 4355<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> 4356 4357<div style="margin: auto;"> 4358 <h4><a name="process" id="process"></a>-process <em class="arg">command</em></h4> 4359</div> 4360 4361<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> 4362 4363<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> 4364 4365<div style="margin: auto;"> 4366 <h4><a name="profile" id="profile"></a>-profile <em class="arg">filename</em><br/> 4367 +profile <em class="arg">profile_name</em></h4> 4368</div> 4369 4370<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> 4371 4372<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> 4373 4374<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> 4375 4376<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> 4377 4378<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> 4379 4380<p>For example, to extract the Exif data (which is stored in JPEG files in the <em class="arg">APP1</em> profile), use.</p> 4381 4382<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert cockatoo.jpg profile.exif</span></p> 4383<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> 4384 4385<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert CMYK.tif -profile "CMYK.icc" -profile "RGB.icc" RGB.tiff</span></p> 4386<p>Furthermore, since ICC profiles are not necessarily symmetric, extra conversion steps can yield unwanted results. 4387CMYK profiles are often very asymmetric since they involve 3−>4 and 4−>3 channel mapping. 4388</p> 4389 4390<div style="margin: auto;"> 4391 <h4><a name="quality" id="quality"></a>-quality <em class="arg">value</em></h4> 4392</div> 4393 4394<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> 4395 4396<p>For the JPEG and MPEG image formats, quality is 0 (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 85. Use the <a href="#sampling-factor">-sampling-factor</a> option to specify the factors for chroma downsampling.</p> 4397 4398<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> 4399 4400<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 85 results in a request for 16:1 compression. The quality value 100 results in a request for non-lossy compression.</p> 4401 4402<p>For the MNG and PNG image formats, the quality value sets the zlib compression level (quality / 10) and filter-type (quality % 10). Compression levels range from 0 (fastest compression) to 100 (best but slowest). For compression level 0, the Huffman-only strategy is used, which is fastest but not necessarily the worst compression.</p> 4403 4404<p>If filter-type is 4 or less, the specified filter-type is used for all scanlines:</p> 4405 4406<pre class="text"> 4407 0: none 4408 1: sub 4409 2: up 4410 3: average 4411 4: Paeth 4412</pre> 4413 4414<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> 4415 4416<p>If filter-type is 6, adaptive filtering with <em class="arg">minimum-sum-of-absolute-values</em> is used.</p> 4417 4418<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> 4419 4420<p>The default is quality is 85, which means nearly the best compression with adaptive filtering. The quality setting has no effect on the appearance of PNG and MNG images, since the compression is always lossless.</p> 4421 4422<p>For further information, see the <a href="http://www.w3.org/pub/WWW/TR">PNG</a> specification.</p> 4423 4424<p>When writing a JNG image with transparency, two quality values are required, one for the main image and one for the grayscale image that conveys the alpha channel. These are written as a single integer equal to the main image quality plus 1000 times the opacity quality. For example, if you want to use quality 85 for the main image and quality 90 to compress the opacity data, use <a href="#quality">-quality 90085</a>.</p> 4425 4426<div style="margin: auto;"> 4427 <h4><a name="quantize" id="quantize"></a>-quantize <em class="arg">colorspace</em></h4> 4428</div> 4429 4430<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>reduce colors in this colorspace.</td><td style='text-align:right;'></td></tr></table> 4431 4432<p>To print a complete list of colorspaces, use the <a href="#list">-list colorspace</a> option.</p> 4433 4434 4435<div style="margin: auto;"> 4436 <h4><a name="quiet" id="quiet"></a>-quiet</h4> 4437</div> 4438 4439<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> 4440 4441<div style="margin: auto;"> 4442 <h4><a name="radial-blur" id="radial-blur"></a>-radial-blur <em class="arg">angle</em></h4> 4443</div> 4444 4445<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> 4446 4447<p>Note that this is actually a rotational blur rather than a radial and as 4448such actually mis-named. </p> 4449 4450<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how 4451pixels which are outside the image proper are blurred into the final result. 4452</p> 4453 4454 4455<div style="margin: auto;"> 4456 <h4><a name="raise" id="raise"></a>-raise <em class="arg">thickness</em></h4> 4457</div> 4458 4459<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> 4460 4461<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>. 4462</p> 4463 4464<p>Unlike the similar <a href="#frame">-frame</a> option, <a href="#raise">-raise</a> does not alter the dimensions of the image.</p> 4465 4466<div style="margin: auto;"> 4467 <h4><a name="random-threshold" id="random-threshold"></a>-random-threshold <em class="arg">low</em>x<em class="arg">high</em></h4> 4468</div> 4469 4470<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> 4471 4472<div style="margin: auto;"> 4473 <h4><a name="recolor" id="recolor"></a>-recolor <em class="arg">matrix</em></h4> 4474</div> 4475 4476<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Translate, scale, shear, or rotate image colors.</td><td style='text-align:right;'></td></tr></table> 4477 4478<p>Although variable-sized matrices can be used, typically one uses a 5x5 matrix for an RGBA image and a 6x6 for CMYKA. Populate the last row with normalized values to translate. 4479</p> 4480 4481<div style="margin: auto;"> 4482 <h4><a name="red-primary" id="red-primary"></a>-red-primary <em class="arg">x,y</em></h4> 4483</div> 4484 4485<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> 4486 4487<div style="margin: auto;"> 4488 <h4><a name="regard-warnings" id="regard-warnings"></a>-regard-warnings</h4> 4489</div> 4490 4491<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> 4492 4493<div style="margin: auto;"> 4494 <h4><a name="remap" id="remap"></a>-remap <em class="arg">filename</em></h4> 4495</div> 4496 4497<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> 4498 4499<p>If the <a href="#dither">-dither</a> setting is enabled (the default) then 4500the given colors are dithered over the image as necessary, otherwise the closest 4501color (in RGB colorspace) is selected to replace that pixel in the image. </p> 4502 4503<p>As a side effect of applying a <a href="#remap">-remap</a> of colors across all 4504images in the current image sequence, all the images will have the same color 4505table. That means that when saved to a file format such as GIF, it will use 4506that color table as a single common or global color table, for all the images, 4507without requiring extra local color tables. </p> 4508 4509<p>Use <a href="#remap">+remap</a> to reduce all images in the current image 4510sequence to use a common color map over all the images. This equivalent to 4511appending all the images together (without extra background colors) and color 4512reducing those images using <a href="#colors">-colors</a> with a 256 color 4513limit, then <a href="#remap">-remap</a> those colors over the original list of 4514images. This ensures all the images follow a single color map. </p> 4515 4516<p>If the number of colors over all the images is less than 256, then <a 4517href="#remap">+remap</a> should not perform any color reduction or dithering, as 4518no color changes are needed. In that case, its only effect is to force the use 4519of a global color table. This recommended after using either <a 4520href="#colors">-colors</a> or <a href="#ordered-dither">-ordered-dither</a> to 4521reduce the number of colors in an animated image sequence. </p> 4522 4523<div style="margin: auto;"> 4524 <h4><a name="region" id="region"></a>-region <em class="arg">geometry</em></h4> 4525</div> 4526 4527<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> 4528 4529<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> 4530 4531<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> 4532 4533<div style="margin: auto;"> 4534 <h4><a name="remote" id="remote"></a>-remote</h4> 4535</div> 4536 4537<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> 4538 4539<p>The only command recognized is the name of an image file to load.</p> 4540 4541<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> 4542 4543<div style="margin: auto;"> 4544 <h4><a name="render" id="render"></a>-render</h4> 4545</div> 4546 4547<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> 4548 4549<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> 4550 4551<div style="margin: auto;"> 4552<h4><a name="repage" id="repage"></a>-repage <em class="arg">geometry</em></h4> 4553</div> 4554 4555<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> 4556 4557<p>This option is like <a href="#page">-page</a> but acts as an image operator 4558rather than a setting. You can separately set the canvas size or the offset 4559of the image on that canvas by only providing those components. </p> 4560 4561<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> 4562 4563<p>If a <kbd>!</kbd> flag is given the offset given is added to the existing 4564offset to move the image relative to its previous position. This useful for 4565animation sequences. </p> 4566 4567<p>A given a canvas size of zero such as '<kbd>0x0</kbd>' forces it to 4568recalculate the canvas size so the image (at its current offset) will appear 4569completely on that canvas (unless it has a negative offset).</p> 4570 4571<p>Use <a href="#repage">+repage</a> to completely remove/reset the virtual 4572canvas meta-data from the images. </p> 4573 4574<p>The <a href="#set">-set</a> '<kbd>page</kbd>' option can be used to 4575directly assign virtual canvas meta-data. </p> 4576 4577 4578<div style="margin: auto;"> 4579 <h4><a name="resample" id="resample"></a>-resample <em class="arg">horizontal</em>x<em class="arg">vertical</em></h4> 4580</div> 4581 4582<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> 4583 4584<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> 4585 4586<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> 4587 4588<div style="margin: auto;"> 4589 <h4><a name="resize" id="resize"></a>-resize <em class="arg">geometry</em></h4> 4590</div> 4591 4592<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> 4593 4594<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> 4595 4596<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> 4597 4598<div style="margin: auto;"> 4599 <h4><a name="respect-parentheses" id="respect-parentheses"></a>-respect-parentheses</h4> 4600</div> 4601 4602<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> 4603 4604<div style="margin: auto;"> 4605 <h4><a name="reverse" id="reverse"></a>-reverse</h4> 4606</div> 4607 4608<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> 4609 4610 4611<div style="margin: auto;"> 4612 <h4><a name="roll" id="roll"></a>-roll {<em class="arg">+-</em>}<em class="arg">x</em>{<em class="arg">+-</em>}<em class="arg">y</em></h4> 4613</div> 4614 4615<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> 4616 4617<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> 4618 4619 4620<div style="margin: auto;"> 4621 <h4><a name="rotate" id="rotate"></a>-rotate <em class="arg">degrees</em>{<em class="arg"><</em>}{<em class="arg">></em>}</h4> 4622</div> 4623 4624<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> 4625 4626<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> 4627 4628<p>Empty triangles in the corners, left over from rotating the image, are 4629filled with the <kbd>background</kbd> color. </p> 4630 4631<p>See also the <a href="#distort">-distort</a> operator and specifically the 4632'<kbd>ScaleRotateTranslate</kbd>' distort method. </p> 4633 4634 4635<div style="margin: auto;"> 4636 <h4><a name="sample" id="sample"></a>-sample <em class="arg">geometry</em></h4> 4637</div> 4638 4639<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>scale image using pixel sampling.</td><td style='text-align:right;'></td></tr></table> 4640 4641<p><a href="#sample">-sample</a> ignores the current <a href="#resize">-resize</a> <a href="#filter">-filter</a> setting. The results are equivalent to using <a href="#resize">-resize</a> with a <a href="#filter">-filter</a> setting of <kbd>point</kbd>, though <a href="#sample">-sample</a> is a lot faster. </p> 4642 4643<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> 4644 4645 4646<div style="margin: auto;"> 4647 <h4><a name="sampling-factor" id="sampling-factor"></a>-sampling-factor <em class="arg">horizontal-factor</em>x<em class="arg">vertical-factor</em></h4> 4648</div> 4649 4650<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> 4651 4652<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> 4653 4654<div style="margin: auto;"> 4655 <h4><a name="scale" id="scale"></a>-scale <em class="arg">geometry</em></h4> 4656</div> 4657 4658<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>scale the image.</td><td style='text-align:right;'></td></tr></table> 4659 4660<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="#scale">-scale</a> option uses a simpler, faster algorithm than <a href="#resize">-resize</a>, and it ignores the <a href="#filter">-filter</a> setting if one is present. Offsets, if present in the <em class="arg">geometry</em> string, are ignored, and the <a href="#gravity">-gravity</a> option has no effect.</p> 4661 4662<div style="margin: auto;"> 4663 <h4><a name="scene" id="scene"></a>-scene <em class="arg">value</em></h4> 4664</div> 4665 4666<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> 4667 4668<p>This option sets the scene number of an image or the first image in an image sequence.</p> 4669 4670<div style="margin: auto;"> 4671 <h4><a name="screen" id="screen"></a>-screen</h4> 4672</div> 4673 4674<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> 4675 4676<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> 4677 4678<div style="margin: auto;"> 4679 <h4><a name="seed" id="seed"></a>-seed</h4> 4680</div> 4681 4682<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> 4683 4684<div style="margin: auto;"> 4685 <h4><a name="segment" id="segment"></a>-segment <em class="arg">cluster-threshold</em>x<em class="arg">smoothing-threshold</em></h4> 4686</div> 4687 4688<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> 4689 4690<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> 4691 4692<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> 4693 4694<p>If the <a href="#verbose">-verbose</a> setting is defined, a detailed report 4695of the color clusters is returned.</p> 4696 4697 4698<div style="margin: auto;"> 4699 <h4><a name="selective-blur" id="selective-blur"></a>-selective-blur <em class="arg">geometry</em></h4> 4700</div> 4701 4702<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> 4703 4704<div style="margin: auto;"> 4705 <h4><a name="separate" id="separate"></a>-separate</h4> 4706</div> 4707 4708<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> 4709 4710<div style="margin: auto;"> 4711 <h4><a name="sepia-tone" id="sepia-tone"></a>-sepia-tone <em class="arg">threshold</em></h4> 4712</div> 4713 4714<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> 4715 4716<p>Specify <em class="arg">threshold</em> as the percent threshold of the intensity (0 - 99.9%).</p> 4717 4718<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> 4719 4720<div style="margin: auto;"> 4721 <h4><a name="set" id="set"></a>-set <em class="arg">attribute value</em></h4> 4722</div> 4723 4724<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>set an image attribute for all images in the current image sequence, after they have been created or read in. </td><td style='text-align:right;'></td></tr></table> 4725 4726<p>Attributes of interest include <a href="#comment">-comment</a>, <a href="#delay">-delay</a>, <a href="#dispose">-dispose</a>, and <a href="#page">-page</a>. For example:</p> 4727 4728<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'></span><span class="crtprompt"> $magick> </span><span class='crtin'>identify -format %c rose.png</span><span class='crtout'>Rose is a rose is a rose is a rose</span></p> 4729<p>The <a href="#repage">-repage</a> operator will also set the 4730'<kbd>page</kbd>' attribute of images already in memory, but allows you to 4731separately set the virtual canvas's size and offset components, and also allows 4732relative offset changes, and automatic canvas size re-calculating. The above 4733<a href="#set">-set</a> option is purely a direct, unmodified assignment of the 4734virtual canvas (page) meta-data. </p> 4735 4736<p>Set image options by prefixing the value with <kbd>option:</kbd>. Set attributes of the image registry by prefixing the value with <kbd>registry:</kbd>.</p> 4737 4738<div style="margin: auto;"> 4739 <h4><a name="shade" id="shade"></a>-shade <em class="arg">azimuth</em>x<em class="arg">elevation</em></h4> 4740</div> 4741 4742<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> 4743 4744<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> 4745 4746<div style="margin: auto;"> 4747 <h4><a name="shadow" 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> 4748</div> 4749 4750<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> 4751 4752<div style="margin: auto;"> 4753 <h4><a name="shared-memory" 4754id="shared-memory"></a>-shared-memory</h4> 4755</div> 4756 4757<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> 4758 4759<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> 4760 4761<div style="margin: auto;"> 4762 <h4><a name="sharpen" id="sharpen"></a>-sharpen <em class="arg">radius</em>{x<em class="arg">sigma</em>}</h4> 4763</div> 4764 4765<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> 4766 4767<p>Use a Gaussian operator of the given radius and standard deviation (sigma).</p> 4768 4769<div style="margin: auto;"> 4770 <h4><a name="shave" id="shave"></a>-shave <em class="arg">geometry</em></h4> 4771</div> 4772 4773<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> 4774 4775<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> 4776 4777<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> 4778 4779<div style="margin: auto;"> 4780 <h4><a name="shear" id="shear"></a>-shear <em class="arg">Xdegrees</em>[x<em class="arg">Ydegrees</em>]</h4> 4781</div> 4782 4783<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> 4784 4785<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> 4786 4787<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> 4788 4789<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> 4790 4791<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> 4792 4793<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> 4794<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> 4795 4796<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert logo: -shear 20x60 logo-sheared.png</span></p> 4797<div style="margin: auto;"> 4798 <h4><a name="sigmoidal" id="sigmoidal-contrast"></a>-sigmoidal-contrast <em class="arg">contrast</em>x<em class="arg">mid-point</em></h4> 4799</div> 4800 4801<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> 4802 4803<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> 4804 4805<div style="margin: auto;"> 4806 <h4><a name="silent" id="silent"></a>-silent</h4> 4807</div> 4808 4809<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> 4810 4811<div style="margin: auto;"> 4812 <h4><a name="size" id="size"></a>-size <em class="arg">width</em>[x<em class="arg">height</em>][<em class="arg">+offset</em>]</h4> 4813</div> 4814 4815<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> 4816 4817<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> 4818 4819<p>For Photo CD images, choose from these sizes:</p> 4820 4821<pre class="text"> 4822 192x128 4823 384x256 4824 768x512 4825 1536x1024 4826 3072x2048 4827</pre> 4828 4829<div style="margin: auto;"> 4830 <h4><a name="sketch" 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> 4831</div> 4832 4833<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> 4834 4835<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> 4836 4837<div style="margin: auto;"> 4838 <h4><a name="snaps" id="snaps"></a>-snaps <em class="arg">value</em></h4> 4839</div> 4840 4841<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> 4842 4843<p>Use this option to grab more than one image from the X server screen, to create an animation sequence.</p> 4844 4845<div style="margin: auto;"> 4846 <h4><a name="solarize" id="solarize"></a>-solarize <em class="arg">threshold</em></h4> 4847</div> 4848 4849<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> 4850 4851<p>Specify <em class="arg">factor</em> as the percent threshold of the intensity (0 - 99.9%).</p> 4852 4853<p>This option produces a <em class="arg">solarization</em> effect seen when exposing a photographic film to light during the development process.</p> 4854 4855<div style="margin: auto;"> 4856 <h4><a name="sparse-color" id="sparse-color"></a>-sparse-color <em 4857 class="arg">method</em> '<em class="arg">x</em>,<em class="arg">y</em> <em class="arg">color</em> ...'</h4> 4858</div> 4859 4860<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> 4861 4862 4863<table class="doc"> 4864 <tbody> 4865 <tr valign="top"> 4866 <th align="left" style="width: 8%">Method</th> 4867 <th align="left">Description</th> 4868 </tr> 4869 4870 <tr valign="top"> 4871 <td valign="top">voronoi</td> 4872 <td valign="top">Simply map each pixel to the to nearest color point 4873 given. The result are polygonal 'cells' of solid color. </td> 4874 </tr> 4875 4876 <tr valign="top"> 4877 <td valign="top">shepards</td> 4878 <td valign="top">Colors points basied on the ratio of inverse distance 4879 squared. Generating spots of color in a sea of the average of 4880 colors. </td> 4881 </tr> 4882 4883 <tr valign="top"> 4884 <td valign="top">barycentric</td> 4885 <td valign="top">three point triangle of color given 3 points. 4886 Giving only 2 points will form a linear gradient between those points. 4887 Gradient is however not restricted to just the triangle or line. </td> 4888 </tr> 4889 4890 <tr valign="top"> 4891 <td valign="top">bilinear</td> 4892 <td valign="top">Like barycentric but for 4 points. Less than 4 points 4893 fall back to barycentric. </td> 4894 </tr> 4895 4896 </tbody> 4897</table> 4898 4899<p>The points are placed according to the images location on the virtual 4900canvas (<a href="#page" >-page</a> or <a href="#repage" >-repage</a> 4901offset), and do not actually have to exist on the given image, but may be 4902some point beyond the edge of the image. All points are floating point values. 4903</p> 4904 4905<p>Only the color channels defined by the <a href="#channel" >-channel</a> are 4906modified, whcih means the matte/alpha transparency channel is not effected by 4907default. If enabled, the image also needs a the matte/alpha channel to be 4908enabled for this operator to effect an images transparency. This is typical 4909transparency handling for images. </p> 4910 4911<p>All the above methods when given a single point of color will replace all 4912the colors in the image with the color given, regardless of the point. This is 4913logical, and provides an alternative technique to recolor a image to some 4914default value. </p> 4915 4916 4917<div style="margin: auto;"> 4918 <h4><a name="splice" id="splice"></a>-splice <em class="arg">geometry</em></h4> 4919</div> 4920 4921<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> 4922 4923<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> 4924 4925<div style="margin: auto;"> 4926 <h4><a name="spread" id="spread"></a>-spread <em class="arg">amount</em></h4> 4927</div> 4928 4929<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> 4930 4931<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> 4932 4933<div style="margin: auto;"> 4934 <h4><a name="stegano" id="stegano"></a>-stegano <em class="arg">offset</em></h4> 4935</div> 4936 4937<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> 4938 4939<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> 4940 4941<div style="margin: auto;"> 4942 <h4><a name="stereo" id="stereo"></a>-stereo <em class="arg">+x</em>{<em class="arg">+y</em>}</h4> 4943</div> 4944 4945<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> 4946 4947<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> 4948 4949<div style="margin: auto;"> 4950 <h4><a name="storage-type" id="storage-type"></a>-storage-type <em class="arg">type</em></h4> 4951</div> 4952 4953<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> 4954 4955<pre class="text"> 4956 char store pixels as unsigned characters 4957 double store pixels as doubles 4958 float store pixels as floats 4959 integer store pixels as integers 4960 long store pixels as longs 4961 quantum store pixels in the native depth of your ImageMagick distribution 4962 short store pixels as unsigned shorts 4963</pre> 4964 4965<p>Float and double types are normalized from 0.0 to 1.0 otherwise the pixels 4966values range from 0 to the maximum value the storage type can support.</p> 4967 4968<div style="margin: auto;"> 4969 <h4><a name="stretch" id="stretch"></a>-stretch <em class="arg">fontStretch</em></h4> 4970</div> 4971 4972<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> 4973 4974<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> 4975 4976<pre class="text"> 4977 Any 4978 Condensed 4979 Expanded 4980 ExtraCondensed 4981 ExtraExpanded 4982 Normal 4983 SemiCondensed 4984 SemiExpanded 4985 UltraCondensed 4986 UltraExpanded 4987</pre> 4988 4989<p>To print a complete list of stretch types, use <a href="#list">-list stretch</a>.</p> 4990 4991<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> 4992 4993<div style="margin: auto;"> 4994 <h4><a name="strip" id="strip"></a>-strip</h4> 4995</div> 4996 4997<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> 4998 4999<div style="margin: auto;"> 5000 <h4><a name="stroke" id="stroke"></a>-stroke <em class="arg">color</em></h4> 5001</div> 5002 5003<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> 5004 5005<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p> 5006 5007<p>See <a href="#draw">-draw</a> for further details.</p> 5008 5009<div style="margin: auto;"> 5010 <h4><a name="strokewidth" id="strokewidth"></a>-strokewidth <em class="arg">value</em></h4> 5011</div> 5012 5013<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> 5014 5015<p>See <a href="#draw">-draw</a> for further details.</p> 5016 5017<div style="margin: auto;"> 5018 <h4><a name="style" id="style"></a>-style <em class="arg">fontStyle</em></h4> 5019</div> 5020 5021<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> 5022 5023<p>This setting suggests a font style that ImageMagick should try to apply to the currently selected font family. Select <em class="arg">fontStyle</em> from the following.</p> 5024 5025<pre class="text"> 5026 Any 5027 Italic 5028 Normal 5029 Oblique 5030</pre> 5031 5032<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> 5033 5034<div style="margin: auto;"> 5035 <h4><a name="swap" id="swap"></a>-swap <em class="arg">index,index</em></h4> 5036</div> 5037 5038<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> 5039 5040<p>For example, <a href="#swap">-swap 0,2</a> swaps the first and the third images in the current image sequence. Use <a href="#swap">+swap</a> to switch the last two images in the sequence.</p> 5041 5042<div style="margin: auto;"> 5043 <h4><a name="swirl" id="swirl"></a>-swirl <em class="arg">degrees</em></h4> 5044</div> 5045 5046<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> 5047 5048<p><em class="arg">Degrees</em> defines the tightness of the swirl.</p> 5049 5050<div style="margin: auto;"> 5051 <h4><a name="taint" id="taint"></a>-taint</h4> 5052</div> 5053 5054<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Mark the image as modified even if it isn't.</td><td style='text-align:right;'></td></tr></table> 5055 5056<div style="margin: auto;"> 5057 <h4><a name="text-font" id="text-font"></a>-text-font <em class="arg">name</em></h4> 5058</div> 5059 5060<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> 5061 5062<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> 5063 5064<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> 5065 5066<div style="margin: auto;"> 5067 <h4><a name="texture" id="texture"></a>-texture <em class="arg">filename</em></h4> 5068</div> 5069 5070<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> 5071 5072<div style="margin: auto;"> 5073 <h4><a name="threshold" id="threshold"></a>-threshold <em class="arg">value</em>{<em class="arg">%</em>}</h4> 5074</div> 5075 5076<!-- {<em class="arg">green,blue,opacity</em>} 5077<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> 5078--> 5079 5080<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> 5081 5082<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> 5083 5084<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. 5085</p> 5086 5087<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> 5088 5089<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert in.png -channel red -threshold 50% out.png</span></p> 5090<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> 5091 5092 5093<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> 5094<p>Note that the values of the transparency channel is treated as 'matte' 5095values (0 is opaque) and not as 'alpha' values (0 is transparent).</p> 5096 5097<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>. 5098</p> 5099 5100<div style="margin: auto;"> 5101 <h4><a name="thumbnail" id="thumbnail"></a>-thumbnail <em class="arg">geometry</em></h4> 5102</div> 5103 5104<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> 5105 5106<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> 5107 5108<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> 5109 5110<div style="margin: auto;"> 5111 <h4><a name="tile" id="tile"></a>-tile <em class="arg">filename</em></h4> 5112</div> 5113 5114<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> 5115 5116<div style="margin: auto;"> 5117 <h4>-tile <em class="arg">geometry</em></h4> 5118</div> 5119 5120<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> 5121 5122<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> 5123 5124<div style="margin: auto;"> 5125 <h4>-tile</h4> 5126</div> 5127 5128<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> 5129 5130<div style="margin: auto;"> 5131 <h4><a name="tile-offset" 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> 5132</div> 5133 5134<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> 5135 5136<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> 5137 5138<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> 5139 5140<div style="margin: auto;"> 5141 <h4><a name="tint" id="tint"></a>-tint <em class="arg">value</em></h4> 5142</div> 5143 5144<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> 5145 5146<p>Tint the image with the fill color.</p> 5147 5148<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> 5149 5150<div style="margin: auto;"> 5151 <h4><a name="title" id="title"></a>-title <em class="arg">string</em></h4> 5152</div> 5153 5154<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> 5155 5156<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> 5157 5158<p>For example,</p> 5159 5160<p class="crtsnip"> 5161 -title "%m:%f %wx%h" 5162</p> 5163 5164<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> 5165 5166 5167<div style="margin: auto;"> 5168 <h4><a name="transform" id="transform"></a>-transform</h4> 5169</div> 5170 5171<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> 5172 5173<p>This option applies the transformation matrix from a previous <a href="#affine">-affine</a> option.</p> 5174 5175<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> 5176<div style="margin: auto;"> 5177 <h4><a name="transparent" id="transparent"></a>-transparent <em class="arg">color</em></h4> 5178</div> 5179 5180<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> 5181 5182<p>The <em class="arg">color</em> argument is defined using the format 5183described under the <a href="#fill">-fill</a> option. The <a href="#fuzz" 5184>-fuzz</a> setting can be used to match and replace colors similar to the one 5185given. </p> 5186 5187<p>The <a href="#opaque">-opaque</a> operator is exactly the same as <a 5188href="#transparent" >-transparent</a> but replaces the matching color same as 5189the current <a href="#fill">-fill</a> color setting. </p> 5190 5191<p>This does not define the 'transparency color' used for color-mapped image 5192formats, such as GIF. For that use <a href="#transparent-color" 5193>-transparent-color</a> </p> 5194 5195<p>Use <a href="#opaque">+opaque</a> to invered the pixels matched, that is 5196paint any pixel that does not match the target color, with the fill color.</p> 5197 5198 5199<div style="margin: auto;"> 5200 <h4><a name="transparent-color" id="transparent-color"></a>-transparent-color <em class="arg">color</em></h4> 5201</div> 5202 5203<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> 5204 5205<p>Sometimes this is used for saving to image formats such as 5206GIF and PNG8 which uses this color to represent boolean transparency. This 5207does not make a color transparent, it only defines what color the transparent 5208color is in the color palette of the saved image. Use <a 5209href="#transparent">-transparent</a> to make an opaque color transparent.</p> 5210 5211<p>This option allows you to have both an opaque visible color, as well as a 5212transparent color of the same color value without conflict. That is, you can 5213use the same color for both the transparent and opaque color areas within an 5214image. This, in turn, frees to you to select a transparent color that is 5215appropriate when an image is displayed by an application that does not handle a 5216transparent color index, while allowing ImageMagick to correctly handle images of this 5217type. </p> 5218 5219<p>The default transparent color is <kbd>#00000000</kbd>, which is fully transparent black.</p> 5220 5221<div style="margin: auto;"> 5222 <h4><a name="transpose" id="transpose"></a>-transpose</h4> 5223</div> 5224 5225<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> 5226 5227<p> This option mathematically transposes the pixel array. It is equivalent to the sequence <kbd>-flip -rotate 90</kbd>. 5228</p> 5229 5230<div style="margin: auto;"> 5231 <h4><a name="transverse" id="transverse"></a>-transverse</h4> 5232</div> 5233 5234<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> 5235 5236 5237<div style="margin: auto;"> 5238 <h4><a name="treedepth" id="treedepth"></a>-treedepth <em class="arg">value</em></h4> 5239</div> 5240 5241<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> 5242 5243<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> 5244 5245<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> 5246 5247<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> 5248 5249<div style="margin: auto;"> 5250 <h4><a name="trim" id="trim"></a>-trim</h4> 5251</div> 5252 5253<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> 5254 5255<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> 5256 5257<p>The page or virtual canvas information of the image is preserved allowing 5258you to extract the result of the <a href="#trim">-trim</a> operation from the 5259image. Use a <a href="#repage">+repage</a> to remove the virtual canvas page 5260information if it is unwanted.</p> 5261 5262<p>If the trimmed image 'disappears' an warning is produced, and a special 5263single pixel transparent 'missed' image is returned, in the same way as when a 5264<a href="#crop">-crop</a> operation 'misses' the image proper. </p> 5265 5266 5267<div style="margin: auto;"> 5268 <h4><a name="type" id="type"></a>-type <em class="arg">type</em></h4> 5269</div> 5270 5271<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> 5272 <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>, <kbd>ColorSeparationMatte</kbd>, or <kbd>Optimize</kbd>.</p> 5273 5274<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> 5275 5276<p class='crt'><span class="crtprompt"> $magick> </span><span class='crtin'>convert bird.png -type TrueColor bird.jpg</span></p> 5277<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> 5278 5279<p>Use <a href="#type">-type optimize</a> to ensure the image is written in the smallest possible file size.</p> 5280 5281<div style="margin: auto;"> 5282 <h4><a name="undercolor" id="undercolor"></a>-undercolor <em class="arg">color</em></h4> 5283</div> 5284 5285<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> 5286 5287<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p> 5288 5289<p>See <a href="#draw">-draw</a> for further details.</p> 5290 5291 5292<div style="margin: auto;"> 5293 <h4><a name="update" id="update"></a>-update <em class="arg">seconds</em></h4> 5294</div> 5295 5296<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> 5297 5298<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> 5299 5300 5301<div style="margin: auto;"> 5302 <h4><a name="unique-colors" id="unique-colors"></a>-unique-colors</h4> 5303</div> 5304 5305<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> 5306 5307 5308<div style="margin: auto;"> 5309 <h4><a name="units" id="units"></a>-units <em class="arg">type</em></h4> 5310</div> 5311 5312<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> 5313 5314<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> 5315 5316 5317<div style="margin: auto;"> 5318 <h4><a name="unsharp" 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> 5319</div> 5320 5321<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> 5322 5323<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> 5324 5325<p>The parameters are:</p> 5326 5327<pre class="text"> 5328 radius: The radius of the Gaussian, in pixels, not counting the center 5329 pixel (default 0). 5330 sigma: The standard deviation of the Gaussian, in pixels (default 1.0). 5331 amount: The fraction of the difference between the original and the blur 5332 image that is added back into the original (default 1.0). 5333 threshold: The threshold, as a fraction of <em class="QR">QuantumRange</em>, needed to apply the 5334 difference amount (default 0.05). 5335</pre> 5336 5337 5338<div style="margin: auto;"> 5339 <h4><a name="verbose" id="verbose"></a>-verbose</h4> 5340</div> 5341 5342<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 preceds the <a href="#identify">-identify</a> option or <kbd>info:</kbd>.</td><td style='text-align:right;'></td></tr></table> 5343 5344 5345<div style="margin: auto;"> 5346 <h4><a name="version" id="version"></a>-version</h4> 5347</div> 5348 5349<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> 5350 5351 5352<div style="margin: auto;"> 5353 <h4><a name="view" id="view"></a>-view <em class="arg">string</em></h4> 5354</div> 5355 5356<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> 5357 5358 5359<div style="margin: auto;"> 5360 <h4><a name="vignette" 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> 5361</div> 5362 5363<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> 5364 5365 5366<div style="margin: auto;"> 5367 <h4><a name="virtual-pixel" id="virtual-pixel"></a>-virtual-pixel <em class="arg">method</em></h4> 5368</div> 5369 5370<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> 5371 5372<p>This option defines what color source should be used if and when a color 5373lookup completely 'misses' the source image. The color(s) that appear to 5374surround the source image. Generally this color is derived from the source 5375image, but could also be set to a specify background color. </p> 5376 5377<p>Choose from these methods:</p> 5378 5379<pre class="text"> 5380 background: the area surrounding the image is the background color 5381 black: the area surrounding the image is black 5382 checker-tile: alternate squares with image and background color 5383 dither: non-random 32x32 dithered pattern 5384 edge: extend the edge pixel toward infinity 5385 gray: the area surrounding the image is gray 5386 horizontal-tile: horizontally tile the image, background color above/below 5387 horizontal-tile-edge: horizontally tile the image and replicate the side edge pixels 5388 mirror: mirror tile the image 5389 random: choose a random pixel from the image 5390 tile: tile the image (default) 5391 transparent: the area surrounding the image is transparent blackness 5392 vertical-tile: vertically tile the image, sides are background color 5393 vertical-tile-edge: vertically tile the image and replicate the side edge pixels 5394 white: the area surrounding the image is white 5395</pre> 5396 5397<p>The default value is "edge".</p> 5398 5399<p>This most important for distortion operators such as <a href="#distort" 5400>-distort</a>, <a href="#implode" >-implode</a>, and <a href="#fx" >-fx</a>. 5401However it also effects operations that may access pixels just outside the 5402image proper, such as <a href="#convolve">-convolve</a>, <a 5403href="#blur">-blur</a>, and <a href="#sharpen">-sharpen</a>. </p> 5404 5405<p>To print a complete list of virtual pixel types, use the <a href="#list">-list virtual-pixel</a> option.</p> 5406 5407 5408<div style="margin: auto;"> 5409 <h4><a name="visual" id="visual"></a>-visual <em class="arg">type</em></h4> 5410</div> 5411 5412<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> 5413 5414<p>Choose from these visual classes:</p> 5415 5416<pre class="text"> 5417 StaticGray 5418 GrayScale 5419 StaticColor 5420 PseudoColor 5421 TrueColor 5422 DirectColor 5423 default 5424 visual id 5425</pre> 5426 5427<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> 5428 5429 5430<div style="margin: auto;"> 5431 <h4><a name="watermark" id="watermark"></a>-watermark <em 5432 class="arg">brightness</em>x<em class="arg">saturation</em></h4> 5433</div> 5434 5435<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 5436saturation.</td><td style='text-align:right;'>[<a href="/www/composite.html">composite</a>]</td></tr></table> 5437 5438<p>Take a grayscale image (with alpha mask) and modify the destination image's 5439brightness according to watermark image's grayscale value and the <em 5440class="arg">brightness</em> percentage. The destinations color saturation 5441attribute is just direct modified by the <em class="arg">saturation</em> 5442percentage, which defaults to 100 percent (no color change). </p> 5443 5444 5445<div style="margin: auto;"> 5446 <h4><a name="wave" id="wave"></a>-wave <em class="arg">amplitude</em><br />-wave <em class="arg">amplitude</em>x<em class="arg">wavelength</em></h4> 5447</div> 5448 5449<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> 5450 5451<p>Specify <em class="arg">amplitude</em> and <em class="arg">wavelength</em> of the wave.</p> 5452 5453<div style="margin: auto;"> 5454 <h4><a name="weight" id="weight"></a>-weight <em class="arg">fontWeight</em></h4> 5455</div> 5456 5457<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> 5458 5459<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> 5460 5461<table class="doc"> 5462 <col width="25%" /> 5463 <col width="75%" /> 5464 <thead> 5465 <tr> 5466 <th><em class="arg">fontWeight</em></th> 5467 <th>Description</th> 5468 </tr> 5469 </thead> 5470 <tbody> 5471 <tr><td>All </td> <td>No effect. </td></tr> 5472 <tr><td>Bold </td> <td>Same as <em class="arg">fontWeight</em> = 700.</td></tr> 5473 <tr><td>Bolder </td> <td>Add 100 to font weight if currently ≤ 800.</td></tr> 5474 <tr><td>Lighter </td> <td>Subtract 100 to font weight if currently ≤ 100.</td></tr> 5475 <tr><td>Normal </td> <td>Same as <em class="arg">fontWeight</em> = 400.</td></tr> 5476 </tbody> 5477 </table> 5478 5479<p>To print a complete list of weight types, use <a href="#list">-list weight</a>.</p> 5480 5481<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> 5482 5483<div style="margin: auto;"> 5484 <h4><a name="white-point" id="white-point"></a>-white-point <em class="arg">x,y</em></h4> 5485</div> 5486 5487<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> 5488 5489<div style="margin: auto;"> 5490 <h4><a name="white-threshold" id="white-threshold"></a>-white-threshold <em class="arg">value</em>{<em class="arg">%</em>}</h4> 5491</div> 5492 5493<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> 5494 5495<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. 5496</p> 5497 5498<div style="margin: auto;"> 5499 <h4><a name="window" id="window"></a>-window <em class="arg">id</em></h4> 5500</div> 5501 5502<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> 5503 5504<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> 5505 5506<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> 5507 5508<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> 5509 5510<div style="margin: auto;"> 5511 <h4><a name="window-group" id="window-group"></a>-window-group</h4> 5512</div> 5513 5514<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> 5515 5516<div style="margin: auto;"> 5517 <h4><a name="write" id="write"></a>-write <em class="arg">filename</em></h4> 5518</div> 5519 5520<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> 5521 <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> 5522 5523<p>Use <a href="#compress">-compress</a> to specify the type of image compression.</p> 5524 5525 5526</div> 5527 5528<div id="linkbar"> 5529 <!-- <span id="linkbar-west"> </span> --> 5530 <span id="linkbar-center"> 5531 <a href="http://www.imagemagick.org/discourse-server/">Discourse Server</a> • 5532 <a href="/www/mailing-list.html">Mailing Lists</a> • 5533 <a href="http://studio.webbyland.com/ImageMagick/MagickStudio/scripts/MagickStudio.cgi">Studio</a> 5534 </span> 5535 <span id="linkbar-east"> </span> 5536 </div> 5537 <div class="footer"> 5538 <span id="footer-west">© 1999-2009 ImageMagick Studio LLC</span> 5539 <span id="footer-east"> <a href="http://www.imagemagick.org/script/contact.php">Contact the Wizards</a></span> 5540 </div> 5541 <div style="clear: both; margin: 0; width: 100%; "></div> 5542</body> 5543</html> 5544
