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cristy3ed852e2009-09-05 21:47:34 +0000164
165<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
166<a href="../www/convert.html">convert</a>, <a href="../www/mogrify.html">mogrify</a>, and .... </p>
167
168<div style="margin: auto;">
169 <h4><a name="adaptive-blur" id="adaptive-blur"></a>-adaptive-blur <em class="arg">radius</em>[x<em class="arg">sigma</em>]</h4>
170</div>
171
172<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>
173
174<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>
175
176<div style="margin: auto;">
177 <h4><a name="adaptive-resize" id="adaptive-resize"></a>-adaptive-resize <em class="arg">geometry</em></h4>
178</div>
179
180<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>
181
182<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>
183
184<div style="margin: auto;">
185 <h4><a name="adaptive-sharpen" id="adaptive-sharpen"></a>-adaptive-sharpen <em class="arg">radius</em>[x<em class="arg">sigma</em>]</h4>
186</div>
187
188<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>
189
190<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>
191
192<div style="margin: auto;">
193 <h4><a name="adjoin" id="adjoin"></a>-adjoin</h4>
194</div>
195
196<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>
197
198<p>This option is enabled by default. An attempt is made to save all
199images of an image sequence into the given output file.
200However, some formats, such as JPEG and PNG, do not support more than one
201image per file, and in that case ImageMagick is forced to write each image as a separate file. As
202such, if more than one image needs to be written, the filename given is
203modified by adding a <a href="#scene">-scene</a> number before the
204suffix, in order to make distinct names for each image. </p>
205
206<p>Use <a href="#adjoin">+adjoin</a> to force each image to be written
207to separate files, whether or not the file format allows multiple images
208per file (for example, GIF, MIFF, and TIFF). </p>
209
210<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>
211
212<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert logo: rose: -morph 15 my%02dmorph.jpg</span></p>
213<p>will create a sequence of 17 images named my00morph.jpg, my01morph.jpg, my02morph.jpg, ..., my16morph.jpg.
214</p>
215
216<p>In summary, ImageMagick tries to write all images to one file, but will use
217multiple files if either (1) the output image's file format does not allow multi-image files,
218(2) the <a href="#adjoin">+adjoin</a> option is given, or (3) a C-style integer format string is
219present in the output filename. </p>
220
221
222<div style="margin: auto;">
223 <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/>
224 -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>
225</div>
226
227<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>
228
229<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>
230
231<p>The matrix entries are entered as comma-separated numeric values <i>with no spaces</i>. </p>
232
233<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>
234
235<div class="eqn">
236<img alt="affine transformation" src="../images/affine.png"/>
237</div>
238
239<p>
240The 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>
241
242<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>
243
244<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>
245
246<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>
247
248<p class="crtsnip">
249 -affine <em class="arg">s<sub>x</sub></em>,0,0,<em class="arg">s<sub>y</sub></em>
250</p>
251
252<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>
253
254<p class="crtsnip">
255 -affine 1,0,0,1,<em class="arg">t<sub>x</sub></em>,<em class="arg">t<sub>y</sub></em>
256</p>
257
258<p>Rotate clockwise about the origin (the upper left-hand corner) by an angle <em>a</em> by letting
259<em>c</em> = cos(<em>a</em>), <em>s</em> = sin(<em>a</em>), and using the following.</p>
260
261<p class="crtsnip">
262 -affine <em>c</em>,<em>s</em>,-<em>s</em>,<em>c</em>
263</p>
264
265<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>
266
267<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>
268
269<div style="margin: auto;">
270 <h4><a name="alpha" id="alpha"></a>-alpha <em class="arg">type</em></h4>
271</div>
272
273<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>
274
275<p>Used to set a flag on an image indicating whether or not to use existing alpha
276channel 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>
277
278
279<table class="doc">
280 <tbody>
281 <tr valign="top">
282 <th align="left" style="width: 8%">type</th>
283 <th align="left">Description</th>
284 </tr>
285
286 <tr valign="top">
287 <td valign="top"><kbd>Off</kbd>&nbsp; or
288 <kbd>Deactivate</kbd></td>
289 <td valign="top">
290 Disables the image's transparency channel. Does not delete or change the
291 existing data, just turns off the use of that data. This is the same as
292 the older <a href="#matte" >+matte</a> operator. </td></tr>
293
294 <tr valign="top">
295 <td valign="top"><kbd>On</kbd>&nbsp; or
296 <kbd>Activate</kbd></td>
297 <td valign="top">
298 Enables the image's use of transparency. If transparency data does not
299 already exist, allocates the data and sets it to opaque. If the image has
300 transparency data, the channel is enabled and the transparency data is not changed or modified in any way. This is NOT
301 the same as the older <a href="#matte" >-matte</a> operator. </td></tr>
302
303 <tr valign="top">
304 <td valign="top"><kbd>Set</kbd></td>
305 <td valign="top">
306 Turns '<kbd>On</kbd>' the alpha/matte channel and if it was previously
307 turned off resets the channel to opaque. If the image already had the
308 alpha channel turned on, it will have no effect. This is the same as the older <a href="#matte">-matte</a> operator. </td></tr>
309
310 <tr valign="top">
311 <td valign="top"><kbd>Opaque</kbd></td>
312 <td valign="top">
313 Turns '<kbd>On</kbd>' the alpha/matte channel and forces it to be fully
314 opaque. </td></tr>
315
316 <tr valign="top">
317 <td valign="top"><kbd>Transparent</kbd></td>
318 <td valign="top">
319 Turns '<kbd>On</kbd>' the alpha/matte channel and forces it to be fully
320 transparent. This effectively creates a fully transparent image the same
321 size as the original and with all its original RGB data still intact. </td></tr>
322
323 <tr valign="top">
324 <td valign="top"><kbd>Extract</kbd></td>
325 <td valign="top">
326 Copies the alpha channel values into all the color channels and turns
327 '<kbd>Off</kbd>' the the image's transparency, so as to generate a
328 gray-scale mask of the image's shape. This is the inverse of
329 '<kbd>Copy</kbd>'. </td></tr>
330
331 <tr valign="top">
332 <td valign="top"><kbd>Copy</kbd></td>
333 <td valign="top">
334 Turns '<kbd>On</kbd>' the alpha/matte channel, then copies the
335 gray-scale intensity of the image, as an alpha mask, into the alpha
336 channel, converting a gray-scale mask into a transparent shaped image
337 ready to be colored appropriately. The color channels are not modified.
338 </td></tr>
339
340 <tr valign="top">
341 <td valign="top"><kbd>Shape</kbd></td>
342 <td valign="top">
343 As per '<kbd>Copy</kbd>' but also colors the resulting shape mask with
344 the current background color.
345 </td></tr>
346
347 <tr valign="top">
348 <td valign="top"><kbd>Background</kbd></td>
349 <td valign="top">
350 Set any fully-transparent pixel to the background color.
351 </td></tr>
352 </tbody>
353</table>
354
355<p>Note that while the <a href="#matte" >+matte</a> operation is the same as
356"<kbd><a href="#alpha" >-alpha</a> off</kbd>", the <a href="#matte"
357>-matte</a> operation is the same as "<kbd><a href="#alpha" >-alpha</a> set</kbd>" and
358not "<kbd><a href="#alpha" >-alpha</a> on</kbd>".
359That is, "<kbd><a href="#alpha" >-alpha</a> set</kbd>" will ensure that the
360written image is opaque if the original image had no transparency
361channel enabled, regardless if transparency data is already present. </p>
362
363
364<div style="margin: auto;">
365 <h4><a name="annotate" id="annotate"></a>
366 -annotate <em class="arg">degrees</em> <em class="arg">text</em><br />
367 -annotate <em class="arg">Xdegrees</em>x<em class="arg">Ydegrees</em> <em class="arg">text</em><br />
368 -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>
369</div>
370
371<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>
372
373<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>
374
375
376<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>
377
378<p>Using <a href="#annotate">-annotate</a>&nbsp;<em class="arg">degrees</em> or <a href="#annotate">-annotate</a>&nbsp;<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>&ndash;direction is conventionally considered to be <em>downward</em> for images.)</p>
379
380<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>
381<div class="eqn"><img alt="annotate transformation" src="../images/annotate.png"/></div>
382
383<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>
384
385<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>
386
387<div style="margin: auto;">
388 <h4><a name="antialias" id="antialias"></a>-antialias</h4>
389</div>
390
391<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
392drawing fonts and lines.</td><td style='text-align:right;'></td></tr></table>
393
394<p>By default, objects (e.g. text, lines, polygons, etc.) are antialiased when
395drawn. Use <a href="#antialias">+antialias</a> to disable the addition of
396antialiasing edge pixels. This will then reduce the number of colors added to
397an image to just the colors being directly drawn. That is, no mixed colors
398will be added when drawing such objects. </p>
399
400<div style="margin: auto;">
401 <h4><a name="append" id="append"></a>-append</h4>
402</div>
403
404<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>
405
406<p>This option creates a single longer image image, by joining all the current
407images in sequence top-to-bottom. Use <a href="#append">+append</a> to
408stack images left-to-right. </p>
409
410<p>If they are not of the same width, narrower images are padded with the
411current <a href="#background">-background</a> color setting, and their
412position relative to each other can be controled by the current <a
413href="#gravity">-gravity</a> setting. </p>
414
415
416<div style="margin: auto;">
417 <h4><a name="attenuate" id="attenuate"></a>-attenuate <em class="arg">value</em></h4>
418</div>
419
420<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>
421
422
423<div style="margin: auto;">
424 <h4><a name="authenticate" id="authenticate"></a>-authenticate <em class="arg">password</em></h4>
425</div>
426
427<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>
428
429<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>
430
431<p>For a different encryption method, see <a href="#encipher">-encipher</a> and <a href="#decipher">-decipher</a>. </p>
432
cristyd934d102009-10-10 12:55:13 +0000433
434
cristy3ed852e2009-09-05 21:47:34 +0000435<div style="margin: auto;">
436 <h4><a name="auto-gamma" id="auto-gamma"></a>-auto-gamma</h4>
437</div>
438
439<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>
440
cristyd934d102009-10-10 12:55:13 +0000441<p>This calculates the mean values of an image, then applies a calculated <a
442href="#gamma" >-gamma</a> adjustment so that is the mean color exists in the
443image it will get a have a value of 50%. </p>
444
445<p>This means that any solid 'gray' image will become 50% gray. </p>
446
447<p>This works well for real-life images with little or no extreme dark and
448light areas, but tend to fail for images with large amounts of bright sky or
449dark shadows. It also does not work well for diagrmas or cartoon like images.
450</p>
451
452<p>It uses the <a href="#channel" >-channel</a> setting, (including the
453'<CODE>sync</CODE>' flag for channel syncronization), to determine which color
454values will be used and modified. As the default <a href="#channel"
455>-channel</a> setting is '<CODE>RGB,sync</CODE>', channels will be modified
456together by the same gamma value, preserving colors. </p>
457
458
459
cristy3ed852e2009-09-05 21:47:34 +0000460<div style="margin: auto;">
461 <h4><a name="auto-level" id="auto-level"></a>-auto-level</h4>
462</div>
463
464<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>
465
cristyd934d102009-10-10 12:55:13 +0000466<p>This is a 'perfect' image normalization operator. It finds the exact
467mimimum and maximum color values in the image and then applies a <a
468href="#level" >-level</a> operator to stretch the values to the full range of
469values. </p>
470
cristy83543962009-10-16 19:04:28 +0000471<p>The operator is not typically used for real-life images, image scans, or
cristyd934d102009-10-10 12:55:13 +0000472JPEG format images, as a single 'out-rider' pixel can set a bad min/max values
473for the <a href="#level" >-level</a> operation. On the other hand it is the
474right operator to use for color stretching gradient images being used to
475generate Color lookup tables, distortion maps, or other 'mathematically'
476defined images. </p>
477
478<p>The operator is very similar to the <a href="#normalize">-normalize</a>, <a
479href="#contrast-stretch" >-contrast-stretch</a>, and <a href="#linear-stretch"
480>-linear-stretch</a> operators, but without 'histogram binning' or 'clipping'
481problems that these operators may have. That is <a href="#auto-level"
cristy83543962009-10-16 19:04:28 +0000482>-auto-level</a> is the perfect or ideal version these operators. </p>
cristyd934d102009-10-10 12:55:13 +0000483
484<p>It uses the <a href="#channel" >-channel</a> setting, (including the
485special '<CODE>sync</CODE>' flag for channel syncronization), to determine
486which color values will be used and modified. As the default <a
cristy83543962009-10-16 19:04:28 +0000487href="#channel" >+channel</a> setting is '<CODE>RGB,sync</CODE>', the
488'<CODE>sync</CODE>' will ensure that the color channels will be modified
489together by the same gamma value, preserving colors, and ignoring
490transparency. </p>
cristyd934d102009-10-10 12:55:13 +0000491
492
493
cristy3ed852e2009-09-05 21:47:34 +0000494<div style="margin: auto;">
495 <h4><a name="auto-orient" id="auto-orient"></a>-auto-orient</h4>
496</div>
497
498<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>
499
cristy83543962009-10-16 19:04:28 +0000500<p>This operator reads and resets the EXIF image profile setting 'Orientation'
501and then performs the appropriate 90 degree rotation on the image to orient
502the image, for correct viewing. </p>
503
504<p>This EXIF profile setting is usually set using a gravity sensor in digital
505camara, however photos taken directly downward or upward may not have an
506appropriate value. Also images that have been orientation 'corrected' without
507reseting this setting, may be 'corrected' again resulting in a incorrect
508result. If the he EXIF profile was previously stripped, the <a
509href="#auto-orient" >-auto-orient</a> operator will do nothing. </p>
510
511
cristy3ed852e2009-09-05 21:47:34 +0000512<div style="margin: auto;">
513 <h4><a name="average" id="average"></a>-average</h4>
514</div>
515
516<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>
517
518<p>An error results if the images are not identically sized.</p>
519
cristy3ed852e2009-09-05 21:47:34 +0000520
521<div style="margin: auto;">
522 <h4><a name="backdrop" id="backdrop"></a>-backdrop</h4>
523</div>
524
525<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>
526
527<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>
528
529<div style="margin: auto;">
530 <h4><a name="background" id="background"></a>-background <em class="arg">color</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 background color.</td><td style='text-align:right;'></td></tr></table>
534
535<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>
536
537<div style="margin: auto;">
538 <h4><a name="bench" id="bench"></a>-bench <em class="arg">iterations</em></h4>
539</div>
540
541<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>
542
cristye6378132009-10-26 20:05:17 +0000543<p>Repeat the entire command for the given number of <em class="arg">iterations</em> and report the user-time and elapsed time. For instance, consider the following command and its output. Modify the benchmark with the -duration to run the benchmark for a fixed number of seconds and -concurrent to run the benchmark in parallel (requires the OpenMP feature).</p>
cristy3ed852e2009-09-05 21:47:34 +0000544
cristye6378132009-10-26 20:05:17 +0000545<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert logo: -resize 1000% -bench 5 logo.png</span><span class='crtout'>Performance: 5i 0.875657ips 6.880u 0:05.710</span></p>
546<p>In this example, 5 iterations were completed at 0.875657 iterations per second, using 6.88 seconds of the user's allotted time, for a total elapsed time of 5.71 seconds.</p>
cristy3ed852e2009-09-05 21:47:34 +0000547
548<div style="margin: auto;">
549 <h4><a name="bias" id="bias"></a>-bias <em class="arg">value</em>{<em class="arg">%</em>}</h4>
550</div>
551
552<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>
553
554<p>This option shifts the output of <a href="../www/command-line-options.html#convolve">&#x2011;convolve</a> so that positive and negative results are relative to the specified bias value. </p>
555
556<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>
557
558<p>When using an ImageMagick with the HDRI compile-time setting, <a href="../www/command-line-options.html#bias">&#x2011;bias</a> is not needed, as ImageMagick is able to store/handle any
559negative results without clipping to the color value range
560(0..QuantumRange).</p>
561
562<p>See the discussion on HDRI implementations of ImageMagick on the page
563<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.
564</p>
565
566<div style="margin: auto;">
567 <h4><a name="black-point-compensation" id="black-point-compensation"></a>-black-point-compensation</h4>
568</div>
569
570<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>
571
572<div style="margin: auto;">
cristy5cadd612009-09-21 19:33:41 +0000573 <h4><a name="black-threshold" id="black-threshold"></a>-black-threshold <em class="arg">value</em>{<em class="arg">%</em>}</h4>
cristy3ed852e2009-09-05 21:47:34 +0000574</div>
575
cristy5cadd612009-09-21 19:33:41 +0000576<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>
577
578<p> The threshold value can be given as a percentage or as an absolute integer value within [0,&nbsp;<em class="QR">QuantumRange</em>] corresponding to the desired <a href="../www/command-line-options.html#channel">&#x2011;channel</a> value. See <a href="../www/command-line-options.html#threshold">&#x2011;threshold</a> for more details on thresholds and resulting values.
579</p>
cristy3ed852e2009-09-05 21:47:34 +0000580
581
582<div style="margin: auto;">
583 <h4><a name="blend" id="blend"></a>-blend <em class="arg">percent</em></h4>
584</div>
585
586<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>
587
588<p>Blend will average the images together ('plus') according to the
589percentages given and each pixels transparency. If only a single percentage
590value is given it sets the weight of the composite or 'source' image, while
591the background image is weighted by the exact opposite amount. That is a
592<kbd>-blend 30</kbd> merges 30% of the 'source' image with 70% of the
593'destination' image. Thus it is equivalent to <kbd>-blend 30x70</kbd>.</p>
594
595
596<div style="margin: auto;">
597 <h4><a name="blue-primary" id="blue-primary"></a>-blue-primary <em class="arg">x</em>,<em class="arg">y</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 blue chromaticity primary point.</td><td style='text-align:right;'></td></tr></table>
601
602<div style="margin: auto;">
603 <h4><a name="blue-shift" id="blue-shift"></a>-blue-shift <em class="arg">factor</em></h4>
604</div>
605
606<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>
607
608<div style="margin: auto;">
609
610<div style="margin: auto;">
611 <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>
612</div>
613
614<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>
615
616<p>Convolve the image with a Gaussian or normal distribution. The formula is:</p>
617
618<div class="eqn"><img alt="gaussian distribution" width="243px" height="42px" src="../images/gaussian-blur.png"/>
619</div>
620
621<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 &sigma; is the standard deviation of the Gaussian distribution. As a guideline, set <i>r</i> to approximately 3&sigma;. If a radius of 0 is specified, ImageMagick selects a suitable radius for you.</p>
622
623<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>
624
625<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how
626pixels which are outside the image proper are blurred into the final result.
627</p>
628
629
630<div style="margin: auto;">
631 <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>
632</div>
633
634<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>
635
636<p>Each pixel in the overlaid region is replaced with an Elliptical Weighted
637Average (EWA) of the source image, scaled according to the grayscale
638mapping. </p>
639
640<p>The ellipse is weighted with sigma set to the given <em class="arg"
641>Width</em> and <em class="arg" >Height</em>. The <em class="arg" >Height</em>
642defaults to the <em class="arg" >Width</em> for a normal circular Guassian
643weighting. The <em class="arg" >Angle</em> will rotate the ellipse from
644horizontal clock-wise. </p>
645
646<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how
647pixels which are outside the image proper are blurred into the final result.
648</p>
649
650
651<div style="margin: auto;">
652 <h4><a name="border" id="border"></a>-border <em class="arg">geometry</em></h4>
653</div>
654
655<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>
656
657<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>
658
659<p>Set the border color by preceding with the <a href="#bordercolor">-bordercolor</a> setting.</p>
660
661<p>See also the <a href="#frame">-frame</a> option, which has more functionality.</p>
662
663<div style="margin: auto;">
664 <h4><a name="bordercolor" id="bordercolor"></a>-bordercolor <em class="arg">color</em></h4>
665</div>
666
667<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>
668
669<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p>
670
671<p>The default border color is <kbd>#DFDFDF</kbd>, <span style="background-color: #dfdfdf;">this shade of gray</span>.</p>
672
673<div style="margin: auto;">
674 <h4><a name="borderwidth" id="borderwidth"></a>-borderwidth <em class="arg">geometry</em> </h4>
675</div>
676
677<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>
678
679<div style="margin: auto;">
cristy16ff93c2010-01-13 23:18:07 +0000680 <h4><a name="brightness-contrast" id="brightness-contrast"></a>-brightness-contrast <em class="arg">brightness</em><br />-brightness-contrast <em class="arg">brightness</em>{x<em class="arg">contrast</em>}{<em class="arg">%</em>}}</h4>
681</div>
682
683<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Adjust the brightness and/or contrast of the image.</td><td style='text-align:right;'></td></tr></table>
684
685<p>Brightness and Contrast values apply changes to the input image. They are not absolute settings. A brightness or contrast value of zero means no change. The range of values is -100 to +100 on each. Positive values increase the brightness or contrast and negative values decrease the brightness or contrast. To control only contrast, set the brightness=0. To control only brightness, set contrast=0 or just leave it off.</p>
686
687<p>You may also use <a href="#fill">-channel</a> to control which channels to apply the brightness and/or contrast change. The default is to apply the same transformation to all channels.</p>
688
689<p>Brightness and Contrast arguments are converted to offset and slope of a linear transform and applied using <a href="#fill">-function polynomial "slope,offset"</a>.</p>
690
691<p>The slope varies from 0 at contrast=-100 to almost vertical at contrast=+100. For brightness=0 and contrast=-100, the result will be totally midgray. For brightness=0 and contrast=+100, the result will approach but not quite reach a threshold at midgray; that is the linear transformation will be a a very steep vertical line at mid gray.</p>
692
693<p>Negative slopes, i.e. negating the image, are not possible with this function. All achievable slopes will be zero or positive.</p>
694
695<p>The offset varies from -0.5 at brightness=-100 to 0 at brightness=0 to +0.5 at brightness=+100. Thus, when contrast=0 and brightness=100, the result will be totally white. Similarly, when contrast=0 and brightness=-100, the result will be totally black.</p>
696
697<p>As the range of values for the arguments are -100 to +100, adding the '%' symbol will be no different than leaving it off.</p>
698
699<div style="margin: auto;">
cristy3ed852e2009-09-05 21:47:34 +0000700 <h4><a name="cache" id="cache"></a>-cache <em class="arg">threshold</em></h4>
701</div>
702
703<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>
704
705<div style="margin: auto;">
706 <h4><a name="caption" id="caption"></a>-caption <em class="arg">string</em></h4>
707</div>
708
709<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>
710
711<div style="margin: auto;">
712 <h4><a name="cdl" id="cdl"></a>-cdl <em class="arg">filename</em></h4>
713</div>
714
715<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>
716
717<p>Here is an example color correction collection:</p>
718
719<pre class="text">
720&lt;?xml version="1.0" encoding="UTF-8"?>
721&lt;ColorCorrectionCollection xmlns="urn:ASC:CDL:v1.2">
722 &lt;ColorCorrection id="cc06668">
723 &lt;SOPNode>
724 &lt;Slope> 0.9 1.2 0.5 &lt;/Slope>
725 &lt;Offset> 0.4 -0.5 0.6 &lt;/Offset>
726 &lt;Power> 1.0 0.8 1.5 &lt;/Power>
727 &lt;/SOPNode>
728 &lt;SATNode>
729 &lt;Saturation> 0.85 &lt;/Saturation>
730 &lt;/SATNode>
731 &lt;/ColorCorrection>
732&lt;/ColorCorrectionCollection>
733</pre>
734
735<div style="margin: auto;">
736 <h4><a name="channel" id="channel"></a>-channel <em class="arg">type</em></h4>
737</div>
738
739<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>
740
741<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>
742
743<p>To print a complete list of channel types, use <a href="#list">-list channel</a>.</p>
744
cristyd934d102009-10-10 12:55:13 +0000745<p>The channels above can be specified as a comma-separated list or can be
746abbreviated as a concatenation of the letters '<kbd>R</kbd>', '<kbd>G</kbd>',
747'<kbd>B</kbd>', '<kbd>A</kbd>', '<kbd>O</kbd>', '<kbd>C</kbd>',
748'<kbd>M</kbd>', '<kbd>Y</kbd>', '<kbd>K</kbd>'.
cristy3ed852e2009-09-05 21:47:34 +0000749
750For example, to negate only the alpha channel of an image, use</p>
751<p class="crtsnip">
cristyd934d102009-10-10 12:55:13 +0000752 -channel Alpha -negate
cristy3ed852e2009-09-05 21:47:34 +0000753</p>
754
cristyd934d102009-10-10 12:55:13 +0000755Some operators also allow the use of a special channel flag
756'<code>sync</code>'. If present operators that understand this flag will
757apply the exact same image modification to all the image channels in the image
758so as to ensure that colors are kept 'in-sync'. Without this flag such
759operators will apply there function to each channel separately. See <a
760href="#auto-level">-auto-level</a> and <a href="#auto-gamma">-auto-gamma</a>
761for examples of such an operator. </p>
cristy3ed852e2009-09-05 21:47:34 +0000762
cristyd934d102009-10-10 12:55:13 +0000763
764<p>By default, ImageMagick sets <a href="#channel">-channel</a> to the value
765'<kbd>RGB,sync</kbd>', which specifies that operators act on all channels
766except the opacity channel, and that all the color channels are to be modified
767in exactly the same way. The 'plus' form <a href="#channel" >+channel</a>
768will reset the value back to this default. </p>
769
770<p>Options that are affected by the <a href="#channel" >-channel</a> setting
771include the following.
772
773<a href="#auto-gamma">-auto-gamma</a>,
774<a href="#auto-level">-auto-level</a>,
cristy3ed852e2009-09-05 21:47:34 +0000775<a href="#black-threshold">-black-threshold</a>,
776<a href="#blur">-blur</a>,
cristyb4c03bb2009-09-27 13:55:46 +0000777<a href="#clamp">-clamp</a>,
cristy3ed852e2009-09-05 21:47:34 +0000778<a href="#clut">-clut</a>,
779<a href="#combine">-combine</a>,
780<a href="#contrast-stretch">-contrast-stretch</a>,
781<a href="#evaluate">-evaluate</a>,
782<a href="#function">-function</a>,
783<a href="#fx">-fx</a>,
cristy3ed852e2009-09-05 21:47:34 +0000784<a href="#gaussian-blur">-gaussian-blur</a>,
cristyd934d102009-10-10 12:55:13 +0000785<a href="#hald-clut">-hald-clut</a>,
cristy3ed852e2009-09-05 21:47:34 +0000786<a href="#motion-blur">-motion-blur</a>,
787<a href="#negate">-negate</a>,
788<a href="#normalize">-normalize</a>,
789<a href="#ordered-dither">-ordered-dither</a>,
790<a href="#radial-blur">-radial-blur</a>,
791<a href="#random-threshold">-random-threshold</a>,
792<a href="#separate">-separate</a>, and
cristyd934d102009-10-10 12:55:13 +0000793<a href="#threshold">-threshold</a>, and
cristy3ed852e2009-09-05 21:47:34 +0000794<a href="#white-threshold">-white-threshold</a>.
795</p>
796
cristyd934d102009-10-10 12:55:13 +0000797<p>Warning, some operators behave differentally when the <a href="#channel"
798>+channel</a> default setting is in effect, verses ANY user defined <a
799href="#channel" >-channel</a> setting (including the equivelent of the
800default). For example <a href="#threshold">-threshold</a> will by default
801gray-scale the image before thresholding, if no <a href="#channel"
802>-channel</a> setting has been defined. </p>
803
804<p>Also some operators such as <a href="#blur">-blur</a>, <a
805href="#gaussian-blur">-gaussian-blur</a>, will modify their handling of the
806color channels if the '<kbd>alpha</kbd>' channel is also enabled by <a
807href="#channel" >-channel</a>. Generally this done to ensure that
808fully-transparent colors are treated as being fully-transparent, and thus any
809underlying 'hidden' color has no effect on the final results. Typically
810resulting in 'halo' effects. </p>
811
812<p>As a alpha channel is optional within images some operators will read the
813color channels of an image as a greyscale alpha mask, when the image has no
814alpha channel present, but the <a href="#channel" >-channel</a> setting tells
815the operator to apply the alpha channel. The <a href="#clut">-clut</a>
816operator is a good example of this. </p>
817
cristy3ed852e2009-09-05 21:47:34 +0000818
819<div style="margin: auto;">
cristyb4c03bb2009-09-27 13:55:46 +0000820 <h4><a name="clamp" id="clamp"></a>-clamp</h4>
821</div>
822
823<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>
824
825<div style="margin: auto;">
cristy3ed852e2009-09-05 21:47:34 +0000826 <h4><a name="charcoal" id="charcoal"></a>-charcoal <em class="arg">factor</em></h4>
827</div>
828
829<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>
830
831<div style="margin: auto;">
832 <h4><a name="chop" id="chop"></a>-chop <em class="arg">geometry</em></h4>
833</div>
834
835<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>
836
837<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>
838
839<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>
840
841<div style="margin: auto;">
842 <h4><a name="clip" id="clip"></a>-clip</h4>
843</div>
844
845<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>
846
847<p>If a clipping path is present, it is applied to subsequent operations.</p>
848
849<p>For example, in the command</p>
850
851<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert -clip -negate cockatoo.tif negated.tif</span></p>
852<p>only the pixels within the clipping path are negated.</p>
853
854<p>The <a href="#clip">-clip</a> feature requires the XML library. If the XML library is not present, the option is ignored.</p>
855
856<div style="margin: auto;">
857 <h4><a name="clip-mask" id="clip-mask"></a>-clip-mask</h4>
858</div>
859
860<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>
861
862<div style="margin: auto;">
863 <h4><a name="clip-path" id="clip-path"></a>-clip-path <em class="arg">id</em></h4>
864</div>
865
866<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>
867
868<div style="margin: auto;">
869 <h4><a name="clone" id="clone"></a>-clone <em class="arg">index(s)</em></h4>
870</div>
871
872<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>
873
874<p>Specify the image by its index in the sequence. The first image is index
8750. Negative indexes are relative to the end of the sequence; for example, &minus;1
876represents the last image of the sequence. Specify a range of images with a
877dash (e.g. 0&minus;4). Separate multiple indexes with commas but no spaces (e.g. 0,2,5). Use <a
878href="#clone">+clone</a> make a copy of the last image in the image
879sequence.</p>
880
881<div style="margin: auto;">
882 <h4><a name="clut" id="clut"></a>-clut</h4>
883</div>
884
885<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
886corresponding channel in the second image as a <b>c</b>olor
887<b>l</b>ook<b>u</b>p <b>t</b>able.</td><td style='text-align:right;'></td></tr></table>
888
889<p>The second (LUT) image is ordinarily a gradient image containing the
890histogram mapping of how each channel should be modified. Typically it is a
891either a single row or column image of replacement color values. If larger
892than a single row or column, values are taken from a diagonal line from
893top-left to bottom-right corners.</p>
894
895<p>The lookup is further controlled by the <a
896href="#interpolate">-interpolate</a> setting, which is especially handy for an
897LUT which is not the full length needed by the ImageMagick installed Quality
898(Q) level. Good settings for this are the '<kbd>bilinear</kbd>' and
899'<kbd>bicubic</kbd>' interpolation settings, which give smooth color
900gradients, and the '<kbd>integer</kbd>' setting for a direct, unsmoothed
901lookup of color values. </p>
902
903<p>This operator is especially suited to replacing a grayscale image with a
904specific color gradient from the CLUT image. </p>
905
906<p>Only the channel values defined by the <a href="#channel">-channel</a>
907setting will have their values replaced. In particular, since the default <a
908href="#channel">-channel</a> setting is <kbd>RGB</kbd>, this means that
909transparency (alpha/matte channel) is not affected, unless the <a
910href="#channel">-channel</a> setting is modified. When the alpha channel is
911set, it is treated by the <a href="#clut" >-clut</a> operator in the same way
912as the other channels, implying that alpha/matte values are replaced using the
913alpha/matte values of the original image. </p>
914
915<p>If either the image being modified, or the lookup image, conatins no
916transparency (i.e. <a href="#alpha" >-alpha</a> is turned 'off') but the <a
917href="#channel">-channel</a> setting includes alpha replacement, then it is
918assumed that image represents a gray-scale graident which will be used for the
919replacement alpha values. That is you can use a gray-scale CLUT image to
920adjust a existing images alpha channel, or you can color a gray-scale image
921using colors form CLUT containing the desired colors, including transparency.
922</p>
923
924<p>See also <a href="#hald-clut" >-hald-clut</a> which replaces colors according
925the lookup of the full color RGB value from a 2D representation of a 3D color
926cube. </p>
927
928
929<div style="margin: auto;">
930 <h4><a name="coalesce" id="coalesce"></a>-coalesce</h4>
931</div>
932
933<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>
934
935<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>
936
937<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>
938
939
940<div style="margin: auto;">
941 <h4><a name="colorize" id="colorize"></a>-colorize <em class="arg">value</em></h4>
942</div>
943
944<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>
945
946<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>
947
948<div style="margin: auto;">
949 <h4><a name="colormap" id="colormap"></a>-colormap <em class="arg">type</em></h4>
950</div>
951
952<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>
953
954<p>The <em class="arg">type</em> can be <kbd>shared</kbd> or <kbd>private</kbd>.</p>
955
956<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>
957
958<div style="margin: auto;">
959 <h4><a name="colors" id="colors"></a>-colors <em class="arg">value</em></h4>
960</div>
961
962<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>
963
964<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>
965
966<div style="margin: auto;">
967 <h4><a name="colorspace" id="colorspace"></a>-colorspace <em class="arg">value</em></h4>
968</div>
969
970<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>
971
972<p>Choices are:</p>
973
974<pre class="text">
975 CMY
976 CMYK
977 Gray
978 HSB
979 HSL
980 HWB
981 Lab
982 Log
983 OHTA
984 Rec601Luma
985 Rec601YCbCr
986 Rec709Luma
987 Rec709YCbCr
988 RGB
989 sRGB
990 Transparent
991 XYZ
992 YCbCr
993 YCC
994 YIQ
995 YPbPr
996 YUV
997</pre>
998
999<p>To print a complete list of colorspaces, use <a href="#list">-list colorspace</a>.</p>
1000
1001<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>
1002
1003<table class="doc">
1004 <caption>Conversion Of RGB To Other Color Spaces</caption>
1005 <tr><th align="left" valign="middle">CMY</th></tr>
1006 <tr><td align="left" valign="middle">C=<em class="QR">QuantumRange</em>&minus;R</td></tr>
1007 <tr><td align="left" valign="middle">M=<em class="QR">QuantumRange</em>&minus;G</td></tr>
1008 <tr><td align="left" valign="middle">Y=<em class="QR">QuantumRange</em>&minus;B</td></tr>
1009 <tr><th align="left" valign="middle">CMYK &mdash; starts with CMY from above</th></tr>
1010 <tr><td align="left" valign="middle">K=min(C,Y,M)</td></tr>
1011 <tr><td align="left" valign="middle">C=<em class="QR">QuantumRange</em>*(C&minus;K)/(<em class="QR">QuantumRange</em>&minus;K)</td></tr>
1012 <tr><td align="left" valign="middle">M=<em class="QR">QuantumRange</em>*(M&minus;K)/(<em class="QR">QuantumRange</em>&minus;K)</td></tr>
1013 <tr><td align="left" valign="middle">Y=<em class="QR">QuantumRange</em>*(Y&minus;K)/(<em class="QR">QuantumRange</em>&minus;K)</td></tr>
1014
1015 <tr><th align="left" valign="middle">Gray</th></tr>
1016 <tr><td align="left" valign="middle">Gray = 0.29900*R+0.58700*G+0.11400*B</td></tr>
1017
1018 <tr><th align="left" valign="middle">HSB &mdash; Hue, Saturation, Brightness; like a cone peak downward</th></tr>
1019 <tr><td align="left" valign="middle">H=angle around perimeter (0 to 360 deg); H=0 is red; increasing angles toward green</td></tr>
1020 <tr><td align="left" valign="middle">S=distance from axis outward</td></tr>
1021 <tr><td align="left" valign="middle">B=distance along axis from bottom upward; B=max(R,G,B); <em>intensity-like</em></td></tr>
1022
1023 <tr><th align="left" valign="middle">HSL &mdash; Hue, Saturation, Lightness; like a double cone end-to-end with peaks at very top and bottom</th></tr>
1024 <tr><td align="left" valign="middle">H=angle around perimeter (0 to 360 deg); H=0 is red; increasing angles toward green</td></tr>
1025 <tr><td align="left" valign="middle">S=distance from axis outward</td></tr>
1026 <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>
1027
1028 <tr><th align="left" valign="middle">HWB &mdash; Hue, Whiteness, Blackness</th></tr>
1029 <tr><td align="left" valign="middle">Hue (complicated equation)</td></tr>
1030 <tr><td align="left" valign="middle">Whiteness (complicated equation)</td></tr>
1031 <tr><td align="left" valign="middle">Blackness (complicated equation)</td></tr>
1032
1033 <tr><th align="left" valign="middle">LAB</th></tr>
1034 <tr><td align="left" valign="middle">L (complicated equation relating X,Y,Z)</td></tr>
1035 <tr><td align="left" valign="middle">A (complicated equation relating X,Y,Z)</td></tr>
1036 <tr><td align="left" valign="middle">B (complicated equation relating X,Y,Z)</td></tr>
1037
1038 <tr><th align="left" valign="middle">LOG</th></tr>
1039 <tr><td align="left" valign="middle">I1 (complicated equation involving logarithm of R)</td></tr>
1040 <tr><td align="left" valign="middle">I2 (complicated equation involving logarithm of G)</td></tr>
1041 <tr><td align="left" valign="middle">I3 (complicated equation involving logarithm of B)</td></tr>
1042
1043 <tr><th align="left" valign="middle">OHTA &mdash; approximates principal components transformation</th></tr>
1044 <tr><td align="left" valign="middle">I1=0.33333*R+0.33334*G+0.33333*B; <em>intensity-like</em></td></tr>
1045 <tr><td align="left" valign="middle">I2=(0.50000*R+0.00000*G&minus;0.50000*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr>
1046 <tr><td align="left" valign="middle">I3=(&minus;0.25000*R+0.50000*G&minus;0.25000*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr>
1047
1048 <tr><th align="left" valign="middle">Rec601Luma</th></tr>
1049 <tr><td align="left" valign="middle">Gray = 0.29900*R+0.58700*G+0.11400*B</td></tr>
1050
1051 <tr><th align="left" valign="middle">Rec601YCbCr</th></tr>
1052 <tr><td align="left" valign="middle">Y=0.299000*R+0.587000*G+0.114000*B; <em>intensity-like</em></td></tr>
1053 <tr><td align="left" valign="middle">Cb=(&minus;0.168736*R-0.331264*G+0.500000*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr>
1054 <tr><td align="left" valign="middle">Cr=(0.500000*R&minus;0.418688*G&minus;0.081312*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr>
1055
1056 <tr><th align="left" valign="middle">Rec709Luma</th></tr>
1057 <tr><td align="left" valign="middle">Gray=0.21260*R+0.71520*G+0.07220*B</td></tr>
1058
1059 <tr><th align="left" valign="middle">Rec709YCbCr</th></tr>
1060 <tr><td align="left" valign="middle">Y=0.212600*R+0.715200*G+0.072200*B; <em>intensity-like</em></td></tr>
1061 <tr><td align="left" valign="middle">Cb=(&minus;0.114572*R&minus;0.385428*G+0.500000*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr>
1062 <tr><td align="left" valign="middle">Cr=(0.500000*R&minus;0.454153*G&minus;0.045847*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr>
1063
1064 <tr><th align="left" valign="middle">sRGB</th></tr>
1065 <tr><td align="left" valign="middle">if Rs &le; .03928 then Rs=R/12.92 else Rs=((R+.055)/1.055)^2.4</td></tr>
1066 <tr><td align="left" valign="middle">if Gs &le; .03928 then Gs=B/12.92 else Gs=((G+.055)/1.055)^2.4</td></tr>
1067 <tr><td align="left" valign="middle">if Bs &le; .03928 then Bs=B/12.92 else Bs=((B+.055)/1.055)^2.4</td></tr>
1068
1069 <tr><th align="left" valign="middle">XYZ</th></tr>
1070 <tr><td align="left" valign="middle">X=0.4124240*R+0.3575790*G+0.1804640*B</td></tr>
1071 <tr><td align="left" valign="middle">Y=0.2126560*R+0.7151580*G+0.0721856*B</td></tr>
1072 <tr><td align="left" valign="middle">Z=0.0193324*R+0.1191930*G+0.9504440*B</td></tr>
1073
1074 <tr><th align="left" valign="middle">YCC</th></tr>
1075 <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>
1076 <tr><td align="left" valign="middle">C1=(&minus;0.29900*R&minus;0.58700*G+0.88600*B) (with complicated scaling)</td></tr>
1077 <tr><td align="left" valign="middle">C2=(0.70100*R&minus;0.58700*G&minus;0.11400*B) (with complicated scaling)</td></tr>
1078
1079 <tr><th align="left" valign="middle">YCbCr</th></tr>
1080 <tr><td align="left" valign="middle">Y=0.299000*R+0.587000*G+0.114000*B; <em>intensity-like</em></td></tr>
1081 <tr><td align="left" valign="middle">Cb=(&minus;0.168736*R&minus;0.331264*G+0.500000*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr>
1082 <tr><td align="left" valign="middle">Cr=(0.500000*R&minus;0.418688*G&minus;0.081312*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr>
1083
1084 <tr><th align="left" valign="middle">YIQ</th></tr>
1085 <tr><td align="left" valign="middle">Y=0.29900*R+0.58700*G+0.11400*B; <em>intensity-like</em></td></tr>
1086 <tr><td align="left" valign="middle">I=(0.59600*R&minus;0.27400*G&minus;0.32200*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr>
1087 <tr><td align="left" valign="middle">Q=(0.21100*R&minus;0.52300*G+0.31200*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr>
1088
1089 <tr><th align="left" valign="middle">YPbPr</th></tr>
1090 <tr><td align="left" valign="middle">Y=0.299000*R+0.587000*G+0.114000*B; <em>intensity-like</em></td></tr>
1091 <tr><td align="left" valign="middle">Pb=(&minus;0.168736*R&minus;0.331264*G+0.500000*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr>
1092 <tr><td align="left" valign="middle">Pr=(0.500000*R&minus;0.418688*G&minus;0.081312*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr>
1093
1094 <tr><th align="left" valign="middle">YUV</th></tr>
1095 <tr><td align="left" valign="middle">Y=0.29900*R+0.58700*G+0.11400*B; <em>intensity-like</em></td></tr>
1096 <tr><td align="left" valign="middle">U=(&minus;0.14740*R&minus;0.28950*G+0.43690*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr>
1097 <tr><td align="left" valign="middle">V=(0.61500*R&minus;0.51500*G&minus;0.10000*B)*(<em class="QR">QuantumRange</em>+1)/2</td></tr>
1098</table>
1099
1100<div style="margin: auto;">
1101 <h4><a name="combine" id="combine"></a>-combine</h4>
1102</div>
1103
1104<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>
1105
1106<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>
1107
1108<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.
1109</p>
1110
1111<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert original.png -channel RGB -separate sepimage.png</span><span class='crtout'></span><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert sepimage-0.png sepimage-1.png sepimage-2.png -channel RGB -combine imagecopy.png</span></p>
1112<div style="margin: auto;">
1113 <h4><a name="comment" id="comment"></a>-comment <em class="arg">string</em></h4>
1114</div>
1115
1116<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>
1117
1118<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>
1119
1120<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>
1121
1122<p>For example,</p>
1123
1124<p class="crtsnip">
1125 -comment "%m:%f %wx%h"
1126</p>
1127
1128<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>
1129
1130<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>
1131
1132<div style="margin: auto;">
1133 <h4><a name="compose" id="compose"></a>-compose <em class="arg">operator</em></h4>
1134</div>
1135
1136<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>
1137
1138<p>The description of composition uses abstract terminology in order to allow
1139the description to be more precise, while avoiding constant values which are
1140specific to a particular build configuration. Each image pixel is represented
1141by red, green, and blue levels (which are equal for a gray pixel). The
1142build-dependent value <em class="QR">QuantumRange</em> is the maximum integral
1143value which may be stored, per pixel, in the red, green, or blue channels of
1144the image. Each image pixel may also optionally (if the image matte channel is
1145enabled) have an associated level of opacity, ranging from <em>opaque</em> to
1146<em>transparent</em>, which may be used to determine the influence of the pixel
1147color when compositing the pixel with another image pixel. If the image matte
1148channel is disabled, then all pixels in the image are treated as opaque. The
1149color of an opaque pixel is fully visible while the color of a transparent
1150pixel color is entirely absent (pixel color is ignored).</p>
1151
1152<p>By definition, raster images have a rectangular shape. All image rows are of
1153equal length, as are all image columns. By treating the alpha channel as a
1154visual "mask" the rectangular image may be given a "shape" by treating the
1155alpha channel as a cookie-cutter for the image. This is done by setting the
1156pixels within the shape to be opaque, with pixels outside the shape set as
1157transparent. Pixels on the boundary of the shape may be between opaque and
1158transparent in order to provide antialiasing (visually smooth edges). The
1159description of the composition operators use this concept of image "shape" in
1160order to make the description of the operators easier to understand. While it
1161is convenient to describe the operators in terms of "shapes" they are by no
1162means limited to mask-style operations since they are based on continuous
1163floating-point mathematics rather than simple boolean operations.</p>
1164
1165<p>The following alpha blending (Duff-Porter) compose methods are available:</p>
1166
1167<table class="doc">
1168 <tbody>
1169 <tr valign="top">
1170 <th align="left" style="width: 8%">Method</th>
1171 <th align="left">Description</th>
1172 </tr>
1173
1174 <tr valign="top">
1175 <td valign="top">clear</td>
1176 <td valign="top">Both the color and the alpha of the destination are
1177 cleared. Neither the source nor the destination are used (except for
1178 destinations size and other meta-data which is always preserved.</td>
1179 </tr>
1180
1181 <tr valign="top">
1182 <td valign="top">src</td>
1183 <td valign="top">The source is copied to the destination. The destination
1184 is not used as input, though it is cleared.</td>
1185 </tr>
1186
1187 <tr valign="top">
1188 <td valign="top">dst</td>
1189 <td valign="top">The destination is left untouched. The source image is
1190 completely ignored.</td>
1191 </tr>
1192
1193 <tr valign="top">
1194 <td valign="top">src-over</td>
1195 <td valign="top">The source is composited over the destination. this is
1196 the default alpha blending compose method, when neither the compose
1197 setting is set, nor is set in the image meta-data.</td>
1198 </tr>
1199
1200 <tr valign="top">
1201 <td valign="top">dst-over</td>
1202 <td valign="top">The destination is composited over the source and the
1203 result replaces the destination.</td>
1204 </tr>
1205
1206 <tr valign="top">
1207 <td valign="top">src-in</td>
1208 <td valign="top">The part of the source lying inside of the destination
1209 replaces the destination.</td>
1210 </tr>
1211
1212 <tr valign="top">
1213 <td valign="top">dst-in</td>
1214 <td valign="top">The part of the destination lying inside of the source
1215 replaces the destination. Areas not overlaid are cleared.</td>
1216 </tr>
1217
1218 <tr valign="top">
1219 <td valign="top">src-out</td>
1220 <td valign="top">The part of the source lying outside of the destination
1221 replaces the destination.</td>
1222 </tr>
1223
1224 <tr valign="top">
1225 <td valign="top">dst-out</td>
1226 <td valign="top">The part of the destination lying outside of the source
1227 replaces the destination.</td>
1228 </tr>
1229
1230 <tr valign="top">
1231 <td valign="top">src-atop</td>
1232 <td valign="top">The part of the source lying inside of the destination is
1233 composited onto the destination.</td>
1234 </tr>
1235
1236 <tr valign="top">
1237 <td valign="top">dst-atop</td>
1238 <td valign="top">The part of the destination lying inside of the source is
1239 composited over the source and replaces the destination. Areas not
1240 overlaid are cleared. </td>
1241 </tr>
1242
1243 <tr valign="top">
1244 <td valign="top">xor</td>
1245 <td valign="top">The part of the source that lies outside of the
1246 destination is combined with the part of the destination that lies
1247 outside of the source. Source or Destination, but not both. </td>
1248 </tr>
1249
1250 </tbody>
1251</table>
1252
1253<p>Any of the 'Src-*' methods can also be specified without the 'Src-' part.
1254For example the defaul compose method can be specified as just 'Over'.</p>
1255
1256
1257<p>The following mathemathical composition methods are also available. </p>
1258
1259<p>Typically these use the default 'Over' alpha blending when transparencies
1260are also involved, except for 'Plus', 'Minus', 'Add', and 'Subtract', which
1261also composes the alpha channel using the same process as the color channels.
1262This allows them to be used for special image masking techniques. </p>
1263
1264<table class="doc">
1265 <tbody>
1266 <tr valign="top">
1267 <th align="left" style="width: 8%">Method</th>
1268 <th align="left">Description</th>
1269 </tr>
1270
1271 <tr valign="top">
1272 <td valign="top">multiply</td>
1273 <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>
1274 </tr>
1275
1276 <tr valign="top">
1277 <td valign="top">screen</td>
1278 <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>
1279 </tr>
1280
1281 <tr valign="top">
1282 <td valign="top">plus</td>
1283 <td valign="top">The source is added to the destination and replaces the
1284 destination. This operator is useful for averaging or a controled
1285 merger of two images, rather than a direct overlay.</td>
1286 </tr>
1287
1288 <tr valign="top">
1289 <td valign="top">add</td>
1290 <td valign="top">As per 'plus' but transparency data is treated as matte
1291 values. As such any transparent areas in either image remain
1292 transparent. </td>
1293 </tr>
1294
1295 <tr valign="top">
1296 <td valign="top">minus</td>
1297 <td valign="top">Subtract the colors in the source image from the
1298 destination image. When transparency is involved, opaque areas is
1299 subtracted from any destination opaque areas. </td>
1300 </tr>
1301
1302 <tr valign="top">
1303 <td valign="top">subtract</td>
1304 <td valign="top">Subtract the colors in the source image from the
1305 destination image. When transparency is involved transparent areas are
1306 subtracted, so only the opaque areas in the source remain opaque in
1307 the destination image. </td>
1308 </tr>
1309
1310 <tr valign="top">
1311 <td valign="top">difference</td>
1312 <td valign="top">Subtracts the darker of the two constituent colors from
1313 the lighter. Painting with white inverts the destination color.
1314 Painting with black produces no change.</td>
1315 </tr>
1316
1317 <tr valign="top">
1318 <td valign="top">exclusion</td>
1319 <td valign="top">Produces an effect similar to that of 'difference', but
1320 appears as lower contrast. Painting with white inverts the
1321 destination color. Painting with black produces no change.</td>
1322 </tr>
1323
1324 <tr valign="top">
1325 <td valign="top">darken</td>
1326 <td valign="top">Selects the darker of the destination and source colors.
1327 The destination is replaced with the source when the source is darker,
1328 otherwise it is left unchanged.</td>
1329 </tr>
1330
1331 <tr valign="top">
1332 <td valign="top">lighten</td>
1333 <td valign="top">Selects the lighter of the destination and source colors.
1334 The destination is replaced with the source when the source is
1335 lighter, otherwise it is left unchanged. </td>
1336 </tr>
1337
1338 <tr valign="top">
1339 <td valign="top">linear-dodge</td>
1340 <td valign="top">This is equivelent to 'Plus' in that the color channels
1341 are simply added, however it does not 'Plus' the alpha channel, but
1342 uses the normal 'Over' alpha blending, which transparencies are
1343 involved. Produces a sort of additive multiply-like result. Added
1344 ImageMagick version 6.5.4-3. </td>
1345 </tr>
1346
1347 <tr valign="top">
1348 <td valign="top">linear-burn</td>
1349 <td valign="top">As 'Linear-Dodge', but also subtract one from the result.
1350 Sort of a additive 'Screen' of the images. Added ImageMagick version
1351 6.5.4-3. </td>
1352 </tr>
1353
1354 <tr valign="top">
1355 <td valign="top">color-dodge</td>
1356 <td valign="top">Brightens the destination color to reflect the source
1357 color. Painting with black produces no change.</td>
1358 </tr>
1359
1360 <tr valign="top">
1361 <td valign="top">color-burn</td>
1362 <td valign="top">Darkens the destination color to reflect the source
1363 color. Painting with white produces no change. Fixed in ImageMagick
1364 version 6.5.4-3. </td>
1365 </tr>
1366
1367 <tr valign="top">
1368 <td valign="top">overlay</td>
1369 <td valign="top">Multiplies or screens the colors, dependent on the
1370 destination color. Source colors overlay the destination whilst
1371 preserving its highlights and shadows. The destination color is not
1372 replaced, but is mixed with the source color to reflect the lightness
1373 or darkness of the destination.</td>
1374 </tr>
1375
1376 <tr valign="top">
1377 <td valign="top">hard-light</td>
1378 <td valign="top">Multiplies or screens the colors, dependent on the source
1379 color value. If the source color is lighter than 0.5, the destination
1380 is lightened as if it were screened. If the source color is darker
1381 than 0.5, the destination is darkened, as if it were multiplied. The
1382 degree of lightening or darkening is proportional to the difference
1383 between the source color and 0.5. If it is equal to 0.5 the
1384 destination is unchanged. Painting with pure black or white produces
1385 black or white.</td>
1386 </tr>
1387
1388
1389 <tr valign="top">
1390 <td valign="top">linear-light</td>
1391 <td valign="top">Like 'Hard-Light' but using linear-dodge and linear-burn
1392 instead. Increases contrast slightly with an impact on the
1393 foreground's tonal values.</td>
1394 </tr>
1395
1396 <tr valign="top">
1397 <td valign="top">soft-light</td>
1398 <td valign="top">Darkens or lightens the colors, dependent on the source
1399 color value. If the source color is lighter than 0.5, the destination
1400 is lightened. If the source color is darker than 0.5, the destination
1401 is darkened, as if it were burned in. The degree of darkening or
1402 lightening is proportional to the difference between the source color
1403 and 0.5. If it is equal to 0.5, the destination is unchanged. Painting
1404 with pure black or white produces a distinctly darker or lighter area,
1405 but does not result in pure black or white. Fixed in ImageMagick
1406 version 6.5.4-3. </td>
1407 </tr>
1408
1409 <tr valign="top">
1410 <td valign="top">pegtop-light</td>
1411 <td valign="top">Almost equivelent to 'Soft-Light', but using a
1412 continuious mathematical formula rather than two conditionally
1413 selected formulae. Added ImageMagick version 6.5.4-3. </td>
1414 </tr>
1415
1416 <tr valign="top">
1417 <td valign="top">vivid-light</td>
1418 <td valign="top">A modified 'Linear-Light' designed to preserve very stong
1419 primary and secondary colors in the image. Added ImageMagick version
1420 6.5.4-3. </td>
1421 </tr>
1422
1423 <tr valign="top">
1424 <td valign="top">pin-light</td>
1425 <td valign="top">Similar to 'Hard-Light', but using sharp linear shadings,
1426 to similate the effects of a strong 'pinhole' light source. Added
1427 ImageMagick version 6.5.4-3. </td>
1428 </tr>
1429
1430 </tbody>
1431</table>
1432
1433
1434<p>Also included are these special purpose compose methods:</p>
1435
1436<table class="doc">
1437 <tbody>
1438 <tr valign="top">
1439 <th align="left" style="width: 8%">Method</th>
1440 <th align="left">Description</th>
1441 </tr>
1442
1443 <tr valign="top">
1444 <td valign="top">copy-*</td>
1445 <td valign="top">Copy the specified channel (Red, Green, Blue, Cyan,
1446 Magenta, Yellow, Black, or Opacity) in the source image to the
1447 same channel in the destination image. If the channel specified
1448 does not exist in the source image, (which can only happen for methods,
1449 '<kbd>copy-opacity</kbd>' or '<kbd>copy-black</kbd>') then it is
1450 assumed that the source image is a special grayscale channel image
1451 of the values to be copied. </td>
1452 </tr>
1453
1454 <tr valign="top">
1455 <td valign="top">change-mask</td>
1456 <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>
1457 </tr>
1458 </tbody>
1459</table>
1460
1461<p>On top of these composed methods are a few special ones that not only require
1462the two images that are being merged or overlaid, but have some extra numerical
1463arguments, which are tabled below. </p>
1464
1465<p>In the "<code>composite</code>" command these composition methods are
1466selected using special options with the arguments needed. They are usually,
1467but not always, the same name as the composte 'method' they use, and replaces
1468the normal use of the <a href="#compose" >-compose</a> setting in the
1469"<code>composite</code>" command. For example... </p>
1470
1471<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>composite ... -blend 50x50 ...</span></p>
1472<p>As of IM v6.5.3-4 the "<code>convert</code>" command can now also supply
1473these extra arguments to its <a href="#composite" >-composite</a> operator,
1474using the special <a href="#set">-set</a> attribute of '<kbd class="arg">option:compose:args</kbd>'. This means you can now make use of
1475these special argumented <a href="#compose" >-compose</a> methods, those the
1476argument and the method both need to be set separatally. For example... </p>
1477
1478<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert ... -compose blend -set option:compose:args 50x50 -composite ...</span></p>
1479<p>The following is a table of these special 'argumented' compose methods,
1480with a brief summary of what they do. For more details see the equivalent
1481"composite" command option name. </p>
1482
1483<table class="doc">
1484 <tbody>
1485 <tr valign="top">
1486 <th align="left" style="width: 8%">Method</th>
1487 <th align="left">Description</th>
1488 </tr>
1489
1490 <tr valign="top">
1491 <td valign="top">dissolve</td>
1492 <td valign="top">Arguments:
1493 <em class="arg">src_percent</em>[x<em class="arg">dst_percent</em>]
1494 <br>Equivalent to "<code>composite</code>" <a href="#dissolve">-dissolve</a>
1495 <br>Dissolve the 'source' image by the percentage given before overlaying
1496 'over' the 'destination' image. If <em class="arg">src_percent</em> is
1497 greater than 100, it starts dissolving the main image so it will
1498 become transparent at a value of '<kbd class="arg">200</kbd>'. If
1499 both percentages are given, each image are dissolved to the
1500 percentages given.
1501 </td>
1502 </tr>
1503
1504 <tr valign="top">
1505 <td valign="top">blend</td>
1506 <td valign="top">Arguments:
1507 <em class="arg">src_percent</em>[x<em class="arg">dst_percent</em>]
1508 <br>Equivalent to "<code>composite</code>" <a href="#blend">-blend</a>
1509 <br>Average the images together ('plus') according to the percentages
1510 given and each pixels transparency. If only a single percentage value
1511 is given it sets the weight of the composite or 'source' image, while
1512 the background image is weighted by the exact opposite amount. That is
1513 a <kbd>-blend 30</kbd> merges 30% of the 'source' image with 70% of
1514 the 'destination' image. Thus it is equivalent to <kbd>-blend
1515 30x70</kbd>.
1516 </td>
1517 </tr>
1518
1519 <tr valign="top">
1520 <td valign="top">mathematics</td>
1521 <td valign="top">Arguments: <em class="arg">A, B, C, D</em>
1522 <br>Not available in "<code>composite</code>" at this time.
1523 <br>Merge the source and destination images according to the formula
1524 <br>&nbsp; &nbsp; &nbsp;<code>A*Sc*Dc + B*Sc + C*Dc + D</code>
1525 <br>Can be used to generate a custom composition method that would
1526 otherwise need to be implemented using the slow <a href="#fx">-fx</a>
1527 DIY image operator. Added to ImageMagick version 6.5.4-3.
1528 </td>
1529 </tr>
1530
1531 <tr valign="top">
1532 <td valign="top">modulate</td>
1533 <td valign="top">Arguments:
1534 <em class="arg">brightness</em>[x<em class="arg">saturation</em>]
1535 <br>Equivalent to "<code>composite</code>" <a href="#watermark">-watermark</a>
1536 <br>Take a grayscale image (with alpha mask) and modify the destination
1537 image's brightness according to watermark image's grayscale value and
1538 the <em class="arg">brightness</em> percentage. The destinations
1539 color saturation attribute is just direct modified by the <em
1540 class="arg">saturation</em> percentage, which defaults to 100 percent
1541 (no color change).
1542
1543 </td>
1544 </tr>
1545
1546 <tr valign="top">
1547 <td valign="top">displace</td>
1548 <td valign="top">Arguments:
1549 <em class="arg">X-scale</em>[x<em class="arg">Y-scale</em>][!][%]
1550 <br>Equivalent to "<code>composite</code>" <a href="#displace">-displace</a>
1551 <br>With this option, the 'overlay' image, and optionally the 'mask'
1552 image, is used as a relative displacement map, which is used to
1553 displace the lookup of what part of the destination image is seen at
1554 each point of the overlaid area. Much like the displacement map is a
1555 'lens' that distorts the original 'background' image behind it.
1556 <br><br>
1557 The X-scale is modilated by the 'red' channel of the overlay image
1558 while the Y-scale is modulated by the green channel, (the mask image
1559 if given is rolled into green channel of the overlay image. This
1560 separation allows you to modulate the X and Y lookup displacement
1561 separatally allowing you to di 2 dimentional displacements, rather
1562 than 1 dimentional verctored displacements (using grayscale image).
1563 <br><br>
1564 If the overlay image contains transparency this is used as a mask
1565 of the resulting image to remove 'invalid' pixels.
1566 <br><br>
1567 The '%' flag makes the displacement scale relative to the size of the
1568 overlay image (100% = half width/height of image). Using '!' switches
1569 percentage arguments to refer to the destination image size instead.
1570 <br><br>
1571 Special flags were added Added to ImageMagick version 6.5.3-5.
1572 </td>
1573 </tr>
1574
1575 <tr valign="top">
1576 <td valign="top">distort</td>
1577 <td valign="top">Arguments:
1578 <em class="arg">X-scale</em>[x<em class="arg">Y-scale</em
1579 >[+<em class="arg">X-center</em>+<em class="arg">Y-center</em>]][!][%]
1580 <br>Not available in "<code>composite</code>" at this time.
1581 <br>Exactly as per 'Displace' (above), but using absolute coordinates,
1582 relative to the center of the overlay (or that given). Basically
1583 allows you to generate absolute distortion maps where 'black' will
1584 look up the left/top edge, and 'white' looks up the bottom/right
1585 edge of the destination image, according to the scale given.
1586 <br><br>
1587 The '!' flag not only switches percentage scaling, to use the
1588 destination image, but also the image the center offset of the lookup.
1589 This means the overlay can lookup a completely different region of the
1590 destination image.
1591 <br><br>
1592 Added to ImageMagick version 6.5.3-5.
1593 </td>
1594 </tr>
1595
1596 <tr valign="top">
1597 <td valign="top">blur</td>
1598 <td valign="top">Arguments:
1599 <em class="arg">Width</em>[x<em class="arg">Height</em
1600 >[+<em class="arg">Angle</em>]]
1601 <br>Equivalent to "<code>composite</code>"
1602 <a href="#blur-composite">-blur</a>
1603 <br>A Variable Blur Mapping Composition method, where each pixel in the
1604 overlaid region is replaced with an Elliptical Weighted Average (EWA),
1605 with an ellipse (typically a circle) of the given sigma size, scaled
1606 according to overlay (source image) grayscale mapping.
1607 <br><br>
1608 As per 'Displace' and 'Distort', the red channel will modulate the
1609 width of the ellipse, while the green channel will modulate the height
1610 of the ellipse. However at this time the ellipse angle is not
1611 modulated though this may be a future posibility (perhaps with a
1612 special flag to enable use of blur channel for this purpose).
1613 <br><br>
1614 Added to ImageMagick version 6.5.4-0.
1615 </td>
1616 </tr>
1617
1618 </tbody>
1619</table>
1620
1621<p>To print a complete list of all the available compose operators, use <a href="#list">-list compose</a>.</p>
1622
1623
1624<div style="margin: auto;">
1625 <h4><a name="composite" id="composite"></a>-composite</h4>
1626</div>
1627
1628<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>
1629
1630<p>Take the first image 'destination' and overlay the second 'source' image
1631according to the current <a href="#compose">-compose</a> setting. The location
1632of the 'source' or 'overlay' image is controlled according to <a
1633href="#geometry" >-geometry</a>, and <a href="#geometry" >-geometry</a>
1634settings. </p>
1635
1636<p>If a third image is given this is treated as a gray-scale 'mask' image
1637relative to the first 'destination' image. This mask will limit what parts of
1638the destination can be modified by the image composition. However for the
1639'<kbd>displace</kbd>' compose method, the mask is used to provide a separate
1640Y-displacement image instead. </p>
1641
1642<p>If a <a href="#compose">-compose</a> method requires extra numerical
1643arguments or flags these can be provided by setting the <a
1644href="#set">-set</a> '<kbd class="arg">option:compose:args</kbd>'
1645appropriatally for the compose method. </p>
1646
1647<p>Some <a href="#compose">-compose</a> methods can modify the 'destination'
1648image outside the overlay area. You can disable this by setting the special <a
1649href="#set">-set</a> '<kbd class="arg">option:compose:outside-overlay</kbd>'
1650to '<kbd>false</kbd>'. </p>
1651
1652
1653<div style="margin: auto;">
1654 <h4><a name="compress" id="compress"></a>-compress <em class="arg">type</em></h4>
1655</div>
1656
1657<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>
1658
1659<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>
1660
1661<p>To print a complete list of compression types, use <a href="#list">-list compress</a>.</p>
1662
1663<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>
1664
1665<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>
1666
1667<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>
1668
1669<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>
1670
1671<div style="margin: auto;">
1672 <h4><a name="contrast" id="contrast"></a>-contrast</h4>
1673</div>
1674
1675<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>
1676
1677<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>
1678
1679<p>For a more pronounced effect you can repeat the option:</p>
1680
1681<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert rose: -contrast -contrast rose_c2.png</span></p>
1682<div style="margin: auto;">
1683 <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>
1684</div>
1685
1686<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>
1687
cristyd934d102009-10-10 12:55:13 +00001688<p>While performing the stretch, black-out at most <em
1689class="arg" >black-point</em> pixels and white-out at most <em
1690class="arg" >white-point</em> pixels. Or, if percent is used, black-out at most
1691<em class="arg" >black-point %</em> pixels and white-out at most <em
1692class="arg" >white-point %</em> pixels.</p>
cristy3ed852e2009-09-05 21:47:34 +00001693
cristyd934d102009-10-10 12:55:13 +00001694<p>Prior to ImageMagick 6.4.7-0, <a href="#contrast-stretch"
1695>-contrast-stretch</a> will black-out at most <em class="arg"
1696>black-point</em> pixels and white-out at most <em class="arg" >total pixels
1697minus white-point</em> pixels. Or, if percent is used, black-out at most <em
1698class="arg">black-point %</em> pixels and white-out at most <em class="arg"
1699>100% minus white-point %</em> pixels.</p>
cristy3ed852e2009-09-05 21:47:34 +00001700
cristyd934d102009-10-10 12:55:13 +00001701<p>Note that <kbd>-contrast-stretch 0</kbd> will modify the image such that
1702the image's min and max values are stretched to 0 and <em class="QR"
1703>QuantumRange</em>, respectively, without any loss of data due to burn-out or
1704clipping at either end. This is not the same as <a href="#normalize"
1705>-normalize</a>, which is equivalent to <kbd>-contrast-stretch 2%x1%</kbd> (or
1706prior to ImageMagick 6.4.7-0, <kbd>-contrast-stretch 2%x99%</kbd>).</p>
cristy3ed852e2009-09-05 21:47:34 +00001707
cristyd934d102009-10-10 12:55:13 +00001708<p>Internally operator works by creating a histogram bin, and then uses that
1709bin to modify the image. As such some colors may be merged together when they
1710originally fell into the same 'bin'. </p>
1711
1712<p>All the channels are normalized in concert by the came amount so as to
1713preserve color integrity, when the default <a href="#channel" >+channel</a>
1714setting is in use. Specifing any other <a href="#channel" >-channel</a>
1715setting will normalize the RGB channels independently.</p>
1716
1717<p>See also <a href="#auto-level" >-auto-level</a> for a 'perfect'
1718normalization of mathematical images. </p>
1719
1720<p>This operator is under review for re-development. </p>
cristy3ed852e2009-09-05 21:47:34 +00001721
1722
1723<div style="margin: auto;">
1724 <h4><a name="convolve" id="convolve"></a>-convolve <em class="arg">kernel</em></h4>
1725</div>
1726
1727<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>
1728
cristy16ff93c2010-01-13 23:18:07 +00001729<p>The <em class="arg">kernel</em> is a matrix specified as
cristyd934d102009-10-10 12:55:13 +00001730a comma-separated list of integers (with no spaces), ordered left-to right,
1731starting with the top row. Presently, only odd-dimensioned kernels are
1732supported, and therefore the number of entries in the specified <em
1733class="arg">kernel</em> must be 3<sup>2</sup>=9, 5<sup>2</sup>=25,
17347<sup>2</sup>=49, etc. </p>
cristy3ed852e2009-09-05 21:47:34 +00001735
cristyd934d102009-10-10 12:55:13 +00001736<p>Note that the <a href="../www/command-line-options.html#convolve">&#x2011;convolve</a> operator supports the <a href="../www/command-line-options.html#bias">&#x2011;bias</a> setting. This option shifts the convolution so that
1737positive and negative results are relative to a user-specified bias value.
1738This is important for non-HDRI compilations of ImageMagick when dealing with
1739convolutions that contain negative as well as positive values. This is
1740especially the case with convolutions involving high pass filters or edge
1741detection. Without an output bias, the negative values is clipped at zero.
cristy3ed852e2009-09-05 21:47:34 +00001742</p>
1743
cristyd934d102009-10-10 12:55:13 +00001744<p>When using an ImageMagick with the HDRI compile-time setting, <a href="../www/command-line-options.html#bias">&#x2011;bias</a> is not needed, as ImageMagick is able to store/handle any
1745negative results without clipping to the color value range (0..QuantumRange).
1746See the discussion on HDRI implementations of ImageMagick on the page <a
1747href="/www/high-dynamic-range.html">High
1748Dynamic-Range Images</a>. For more about HDRI go the ImageMagick <a
1749href="http://www.imagemagick.org/Usage/basics/#hdri">Usage</a> pages or this
1750<a href="http://en.wikipedia.org/wiki/High_dynamic_range_imaging">Wikipedia</a>
1751entry. </p>
cristy3ed852e2009-09-05 21:47:34 +00001752
cristy3ed852e2009-09-05 21:47:34 +00001753
1754<div style="margin: auto;">
1755 <h4><a name="crop" id="crop"></a>-crop <em class="arg">geometry</em></h4>
1756</div>
1757
1758<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>
1759
1760<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>
1761
1762<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>
1763
1764<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>
1765
1766<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>
1767
1768<p>By adding a exclamation character flag to the geometry argument, the
1769cropped images virtual canvas page size and offset is set as if the
1770geometry argument was a viewport or window. This means the canvas page size
1771is set to exactly the same size you specified, the image offset set
1772relative top left corner of the region cropped. </p>
1773
1774<p>If the cropped image 'missed' the actual image on its virtual canvas, a
1775special single pixel transparent 'missed' image is returned, and a 'crop
1776missed' warning given. </p>
1777
cristy739df912009-10-24 16:10:18 +00001778<p>It might be necessary to <a href="#repage" >+repage</a> the image prior to cropping the image to ensure the crop coordinate frame is relocated to the upper-left corner of the visible image.</p>
cristy3ed852e2009-09-05 21:47:34 +00001779
1780<div style="margin: auto;">
1781 <h4><a name="cycle" id="cycle"></a>-cycle <em class="arg">amount</em></h4>
1782</div>
1783
1784<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>
1785
1786<p><em class="arg">Amount</em> defines the number of positions each
1787colormap entry is shifted.</p>
1788
1789
1790<div style="margin: auto;">
1791 <h4><a name="debug" id="debug"></a>-debug <em class="arg">events</em></h4>
1792</div>
1793
1794<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>
1795
1796<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>
1797
1798
1799<p>For example, to log cache and blob events, use.</p>
1800
1801<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert -debug "Cache,Blob" rose: rose.png</span></p>
1802<p>The <kbd>User</kbd> domain is normally empty, but developers can log user events in their private copy of ImageMagick.</p>
1803
1804<p>To print the complete list of debug methods, use <a href="#list">-list debug</a>.</p>
1805
1806<p>Use the <a href="#log">-log</a> option to specify the format for debugging output.</p>
1807
1808<p>Use <a href="#debug">+debug</a> to turn off all logging.</p>
1809
1810<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>
1811
1812
1813<div style="margin: auto;">
1814 <h4><a name="decipher" id="decipher"></a>-decipher <em class="arg">filename</em></h4>
1815</div>
1816
1817<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>
1818
1819<p>Get the passphrase from the file specified by <em class="arg">filename</em>.</p>
1820
1821<p>For more information, see the webpage, <a href="http://www.imagemagick.org/www/cipher.html">ImageMagick: Encipher or Decipher an Image</a>.</p>
1822
1823
1824<div style="margin: auto;">
1825 <h4><a name="deconstruct" id="deconstruct"></a>-deconstruct</h4>
1826</div>
1827
1828<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>
1829
1830<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>
1831
1832<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>
1833
1834<p>This option is actually equivalent to the <a href="#layers">-layers</a> method '<kbd>compare-any</kbd>'. </p>
1835
1836
1837<div style="margin: auto;">
1838 <h4><a name="define" id="define"></a>-define <em class="arg">key</em>{<em class="arg">=value</em>}<em class="arg">...</em></h4>
1839</div>
1840
1841<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>
1842
1843<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>
1844
1845<p>The following definitions may be created:</p>
1846
1847<ul>
cristy48dd1af2009-10-02 01:21:56 +00001848<dt>jpeg:size=geometry</dt>
1849 <dd>Set the size hint of a JPEG image, for example, -define jpeg:size=128x128. It is most useful for increasing performance and reducing the memory requirements when reducing the size of a large JPEG image.</dd><br />
cristy3ed852e2009-09-05 21:47:34 +00001850<dt>jp2:rate=value</dt>
1851 <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 />
1852<dt>mng:need-cacheoff</dt>
1853 <dd>turn playback caching off for streaming MNG.</dd><br />
1854<dt>png:bit-depth=value</dt>
1855<dt>png:color-type=value</dt>
1856 <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 />
1857<dt>ps:imagemask</dt>
1858 <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>
1859</ul>
1860
1861<p>For example, to create a postscript file that will render only the black pixels of a bilevel image, use:</p>
1862
1863<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert bilevel.tif -define ps:imagemask eps3:stencil.ps</span></p>
1864<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>
1865
1866<p class="crtsnip">
1867-define registry:temporary-path=/data/tmp
1868</p>
1869
1870<div style="margin: auto;">
1871 <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">&lt;</em>} {<em class="arg">&gt;</em>}</h4>
1872</div>
1873
1874<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>
1875
1876<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>
1877
1878<p>Use <kbd>&gt;</kbd> to change the image delay <em>only</em> if its current value exceeds the given delay. <kbd>&lt;</kbd> changes the image delay <em>only</em> if current value is less than the given delay. For example, if you specify <kbd>30&gt;</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>&lt;</kbd> or <kbd>&gt;</kbd> from being interpreted by your shell as a file redirection.</p>
1879
1880
1881<div style="margin: auto;">
1882 <h4><a name="delete" id="delete"></a>-delete <em class="arg">index</em></h4>
1883</div>
1884
1885<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>
1886
1887<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>
1888
1889
1890<div style="margin: auto;">
1891 <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>
1892</div>
1893
1894<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>
1895
1896<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>
1897
1898<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>
1899
1900<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>
1901
1902<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>
1903
1904<div style="margin: auto;">
1905 <h4><a name="depth" id="depth"></a>-depth <em class="arg">value</em></h4>
1906</div>
1907
1908<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>
1909
1910<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>
1911
1912<div style="margin: auto;">
1913 <h4><a name="descend" id="descend"></a>-descend</h4>
1914</div>
1915
1916<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>
1917
1918<div style="margin: auto;">
1919 <h4><a name="deskew" id="deskew"></a>-deskew <em class="arg">threshold</em></h4>
1920</div>
1921
1922<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>
1923
1924<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>
1925
1926<div style="margin: auto;">
1927 <h4><a name="despeckle" id="despeckle"></a>-despeckle</h4>
1928</div>
1929
1930<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>
1931
1932<div style="margin: auto;">
1933 <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>
1934</div>
1935
1936<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>
1937
1938<p>With this option, the 'overlay' image, and optionally the 'mask' image,
1939will be used as a displacement map, which is used to displace the lookup of
1940what part of the 'background' image is seen at each point of the overlaid
1941area. Much like the displacement map is a 'lens' that redirects light shining
1942through it so as to present a distorted view the original 'background' image
1943behind it. </p>
1944
1945<p>Any perfect grey areas of the displacement map produce a zero
1946displacement of the image. Black areas produce the given maximum negative
1947displacement of the lookup point, while white produce a maximum positive
1948displacement of the lookup. </p>
1949
1950<p>Note that it is the lookup of the 'background' that is displaced, not a
1951displacement of the image itself. As such an area of the displacement map
1952containing 'white' will have the lookup point 'shifted' by a positive amount,
1953and thus generating a copy of the destination image to the right/downward from
1954the correct position. That is the image will look like it may have been
1955'shifted' in a negative left/upward direction. Understanding this is a very
1956important in understanding how displacement maps work. </p>
1957
1958<p>The given arguments define the maximum amount of displacement in pixels
1959that a particular map can produce. If the displacement scale is large enough
1960it is also posible to lookup parts of the 'background' image that lie well
1961outside the bounds of the displacement map itself. That is you could very
1962easilly copy a section of the original image from outside the overlay area
1963into the overlay area. </p>
1964
1965<p>The '%' flag makes the displacement scale relative to the size of the
1966overlay image (100% = half width/height of image). Using '!' switches
1967percentage arguments to refer to the destination image size instead.
1968these flags were added as of IM v6.5.3-5.</p>
1969
1970<p>Normally a single grayscale displacement map is provided, which with the
1971given scaling values will determine a single direction (vector) in which
1972displacements can occur (positivally or negativally). However, if you also
1973specify a third image which is normally used as a <em class="arg">mask</em>,
1974then the <em class="arg">composite image</em> will be used for horizontal X
1975displacement, while the <em class="arg">mask image</em> is used for vertical Y
1976displacement. This allows you to define completely different displacement
1977values for the X and Y directions, and allowing you to lookup any point within
1978the <em class="arg">scale</em> bounds. In other words each pixel can lookup
1979any other nearby pixel, producing complex 2 dimentional displacements, rather
1980than a simple 1 dimentional vector displacements. </p>
1981
1982<p>Alternativally rather than suppling two separate images, as of IM v6.4.4-0,
1983you can use the 'red' channel of the overlay image to specify the horizontal
1984or X displacement, and the 'green' channel for the vertical or Y displacement.
1985</p>
1986
1987<p>As of IM v6.5.3-5 any alpha channel in the overlay image will be used as a
1988mask the transparency of the destination image. However areas outside the
1989overlaid areas will not be effected. </p>
1990
1991
1992<div style="margin: auto;">
1993 <h4><a name="display" id="display"></a>-display <em class="arg">host:display[.screen]</em></h4>
1994</div>
1995
1996<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>
1997
1998<p>This option is used with convert for obtaining image or font from this X server. See <em class="arg">X(1)</em>.</p>
1999
2000<div style="margin: auto;">
2001 <h4><a name="dispose" id="dispose"></a>-dispose <em class="arg">method</em></h4>
2002</div>
2003
2004<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>
2005
2006<p>The layer disposal method defines the way each the displayed image is to be
2007modified after the current 'frame' of an animation has finished being
2008displayed (after its 'delay' period), but before the next frame on an
2009animation is to be overlaid onto the display. </p>
2010
2011<p>Here are the valid methods:</p>
2012
2013<pre class="text">
2014Undefined 0 No disposal specified (equivalent to '<kbd>none</kbd>').
2015None 1 Do not dispose, just overlay next frame image.
2016Background 2 Clear the frame area with the background color.
2017Previous 3 Clear to the image prior to this frames overlay.
2018</pre>
2019
2020<p>You can also use the numbers given above, which is what the GIF format
2021uses internally to represent the above settings. </p>
2022
2023<p>To print a complete list of dispose methods, use <a href="#list">-list dipose</a>.</p>
2024
2025<p>Use <a href="#dispose" >+dispose</a>, turn off the setting and prevent
2026resetting the layer disposal methods of images being read in. </p>
2027
2028<p>Use <a href="#set">-set</a> '<kbd>dispose</kbd>' method to set the image
2029disposal method for images already in memory.</p>
2030
2031<div style="margin: auto;">
2032 <h4><a name="dissimilarity-threshold" id="dissimilarity-threshold"></a>-dissimilarity-threshold <em class="arg">value</em></h4>
2033</div>
2034
2035<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>
2036
2037
2038<div style="margin: auto;">
2039 <h4><a name="dissolve" id="dissolve"></a>-dissolve <em class="arg">src_percent</em>[x<em class="arg">dst_percent</em>]</h4>
2040</div>
2041
2042<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>
2043
2044<p>The opacity of the composite image is multiplied by the given percent, then
2045it is composited 'over' the main image. If <em class="arg">src_percent</em>
2046is greater than 100, start dissolving the main image so it will become
2047transparent at a value of '<kbd class="arg">200</kbd>'. If both percentages
2048are given, each image are dissolved to the percentages given. </p>
2049
2050<p>Note that dissolve percentages do not add, two opaque images dissolved
2051'50,50', produce a 75% transparency. For a 50% + 50% blending of the two
2052images, you would need to use dissolve values of '50,100'. </p>
2053
2054<div style="margin: auto;">
2055 <h4><a name="distort" id="distort"></a>-distort <em class="arg">method arguments</em></h4>
2056</div>
2057
2058<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>
2059
2060<p>The <em class="arg">arguments</em> is a single string containing a list
2061of floating point numbers separated by commas or spaces. The number of
2062and meaning of the floating point values depends on the distortion <em
2063class="arg">method</em> being used. </p>
2064
2065<p>Choose from these distortion types:</p>
2066
2067<table class="doc">
2068 <tr valign="top">
2069 <th align="left" style="width: 8%">Method</th>
2070 <th align="left">Description</th>
2071 </tr>
2072
2073 <tr valign="top">
2074 <td valign="top"><kbd>ScaleRotateTranslate</kbd>&nbsp;&nbsp;
2075 <br/>or &nbsp; <kbd>SRT</kbd></td>
2076 <td valign="top">
2077 Distort image by first scaling and rotating about a given 'center',
2078 before translating that 'center' to the new location, in that order. It
2079 is an alternative method of specifying a '<kbd>Affine</kbd>' type of
2080 distortion, but without shearing effects. It also provides a good way
2081 of rotating and displacing a smaller image for tiling onto a larger
2082 background (IE 2-dimensional animations). <br/>
2083
2084 The number of arguments determine the specific meaning of each
2085 argument for the scales, rotation, and translation operations. <br/>
2086
2087 <table style="margin-left:auto; margin-right:auto;">
2088 <tr><td># &nbsp;</td><td>arguments meaning</td></tr>
2089 <tr><td>1:</td><td><em>Angle_of_Rotation</em></td></tr>
2090 <tr><td>2:</td><td><em>Scale &nbsp; Angle</em></td></tr>
2091 <tr><td>3:</td><td><em>ScaleX,ScaleY &nbsp; Angle</em></td></tr>
2092 <tr><td>4:</td><td><em>X,Y &nbsp; Scale &nbsp; Angle</em></td></tr>
2093 <tr><td>5:</td>
2094 <td><em>X,Y &nbsp; ScaleX,ScaleY &nbsp; Angle</em></td></tr>
2095 <tr><td>6:</td>
2096 <td><em>X,Y &nbsp; Scale &nbsp; Angle &nbsp; NewX,NewY</em></td></tr>
2097 <tr><td>7:</td>
2098 <td><em>X,Y &nbsp; ScaleX,ScaleY &nbsp; Angle
2099 &nbsp; NewX,NewY</em></td></tr>
2100 </table>
2101
2102 This is actually an alternative way of specifing a 2 dimensional linear
2103 '<kbd>Affine</kbd>' or '<kbd>AffineProjection</kbd>' distortion. </td> </tr>
2104
2105 <tr valign="top">
2106 <td valign="top"><kbd>Affine</kbd></td>
2107 <td valign="top">
2108 Distort the image linearly by moving a list of at least 3 or more sets
2109 of control points (as defined below). Idealy 3 sets or 12 floating
2110 point values are given allowing the image to be linearly scaled,
2111 rotated, sheared, and translated, according to those three points. See
2112 also the related '<kbd>AffineProjection</kbd>' and '<kbd>SRT</kbd>'
2113 distortions. <br/>
2114
2115 More than 3 sets given control point pairs (12 numbers) is least
2116 squares fitted to best match a lineary affine distortion. If only 2
2117 control point pairs (8 numbers) are given a two point image translation
2118 rotation and scaling is performed, without any posible shearing,
2119 flipping or changes in aspect ratio to the resulting image. If only one
2120 control point pair is provides the image is only translated, (which may
2121 be a floating point non-integer translation). <br/>
2122
2123 This distortion does not include any form of perspective distortion.
2124 </td>
2125
2126 </tr>
2127
2128 <tr valign="top">
2129 <td valign="top"><kbd>AffineProjection</kbd></td>
2130 <td valign="top">
2131 Linearly distort an image using the given Affine Matrix of 6
2132 pre-calculated coefficients forming a set of Affine Equations to map
2133 the source image to the destination image.
2134
2135 <div style="text-align: center"><em>
2136 s<sub>x</sub>, r<sub>x</sub>,
2137 r<sub>y</sub>, s<sub>y</sub>,
2138 t<sub>x</sub>, t<sub>y</sub>
2139 </em></div>
2140
2141 See <a href="#affine" >-affine</a> setting for more detail, and
2142 meanings of these coefficients. <br/>
2143
2144 The distortions '<kbd>Affine</kbd>' and '<kbd>SRT</kbd>' provide
2145 alternative methods of defining this distortion, with ImageMagick doing the
2146 calculations needed to generate the required coefficients. You can see
2147 the internally generated coefficients, by using a <a href="#verbose"
2148 >-verbose</a> setting. </td>
2149
2150 </tr>
2151
2152<!-- still under development, do not display - Anthony
2153 <tr valign="top">
2154 <td valign="top"><kbd>Bilinear</kbd></td>
2155 <td valign="top">
2156 Bilinear (reversed) Distortion, given a minimum of 4 sets of
2157 coordinate pairs, or 16 values (see below). Not that lines may not
2158 appear straight after distortion, though the distance between
2159 coordinates will remain consistant. </td>
2160 </tr>
2161-->
2162
2163 <tr valign="top">
2164 <td valign="top"><kbd>Perspective</kbd></td>
2165 <td valign="top">
2166 Perspective distort the images, using a list of 4 or more sets of
2167 control points (as defined below). More that 4 sets (16 numbers) of
2168 control points provide least squares fitting for more accurate
2169 distortions (for the purposes of image registration and panarama
2170 effects). Less than 4 sets will fall back to a '<kbd>Affine</kbd>'
2171 linear distortion. <br/>
2172
2173 Perspective Distorted images ensures that straight lines remain
2174 straight, but the scale of the distorted image will vary. The horizon
2175 is anti-aliased, and the 'sky' color may be set using the
2176 <a href="#mattecolor" >-mattecolor</a> setting. </td>
2177 </tr>
2178
2179 <tr valign="top">
2180 <td valign="top"><kbd>PerspectiveProjection</kbd>&nbsp;&nbsp;</td>
2181 <td valign="top">
2182 Do a '<kbd>Perspective</kbd>' distortion basied on a set of 8
2183 pre-calculated coefficients. You can get these coefficients by looking
2184 at the <a href="#verbose" >-verbose</a> output of a
2185 '<kbd>Prespective</kbd>' distortion, or by calculating them yourself.
2186 If the last two perspective scaling coefficients are zero, the
2187 remaining 6 represents a transposed 'Affine Matrix'. </td>
2188
2189 </tr>
2190
2191 <tr valign="top">
2192 <td valign="top"><kbd>Arc</kbd></td>
2193 <td valign="top">
2194 Arc the image (variation of polar mapping) over the angle given around
2195 a circle. <br/>
2196 <table width="90%" style = "margin-left: auto; margin-right: auto;">
2197 <tr valign="top"><td>Argument</td>
2198 <td>Meaning</td></tr>
2199 <tr valign="top"><td><em>arc_angle</em></td>
2200 <td>The angle over which to arc the image side-to-side</td></tr>
2201 <tr valign="top"><td><em>rotate_angle</em></td>
2202 <td>Angle to rotate resulting image from vertical center</td></tr>
2203 <tr valign="top"><td><em>top_radius</em></td>
2204 <td>Set top edge of source image at this radius</td></tr>
2205 <tr valign="top"><td><em>bottom_radius</em>&nbsp;</td>
2206 <td>Set bottom edge to this radius (radial scaling)</td></tr>
2207 </table>
2208
2209 The resulting image is always resized to best fit the resulting image,
2210 (as if using <a href="#distort" >+distort</a>) while attempting to
2211 preserve scale and aspect ratio of the original image as much as
2212 possible with the arguments given by the user. All four arguments will
2213 be needed to change the overall aspect ratio of an 'Arc'ed image. <br/>
2214
2215 This a variation of a polar distortion designed to try to preserve the
2216 aspect ratio of the image rather than direct Cartesian to Polar
2217 conversion. </td>
2218 </tr>
2219
2220 <tr valign="top">
2221 <td valign="top"><kbd>Polar</kbd></td>
2222 <td valign="top">
2223 Like '<kbd>Arc</kbd>' but do a complete Cartesian to Polar mapping of
2224 the image. that is the height of the input image is mapped to the
2225 radius limits, while the width is wrapped around between the
2226 angle limits. <br/>
2227
2228 Arguments: <em>Rmax,Rmin CenterX,CenterY, start,end_angle</em> <br/>
2229
2230 All arguments are optional. With <em>Rmin</em> defaulting to zero, the
2231 center to the center of the image, and the angles going from -180 (top)
2232 to +180 (top). If <em>Rmax</em> is given the special value of
2233 '<code>0</code>', the the distance from the center to the nearest edge
2234 is used for the radius of the output image, which will ensure the whole
2235 image is visible (though scaled smaller). However a special value of
2236 '<code>-1</code>' will use the distance from the center to the furthest
2237 corner, This may 'clip' the corners from the input rectangular image,
2238 but will generate the exact reverse of a '<kbd>DePolar</kbd>' with
2239 the same arguments. <br/>
2240
2241 If the plus form of distort (<a href="#distort" >+distort</a>) is used
2242 output image center will default to <code>0,0</code> of the virtual
2243 canvas, and the image size adjusted to ensure the whole input image is
2244 made visible in the output image on the virtual canvas. </td>
2245
2246 </tr>
2247
2248 <tr valign="top">
2249 <td valign="top"><kbd>DePolar</kbd></td>
2250 <td valign="top">
2251 Uses the same arguments and meanings as a '<kbd>Polar</kbd>' distortion
2252 but generates the reverse Polar to Cartesian distortion. <br/>
2253
2254 The special <em>Rmax</em> setting of '<code>0</code>' may however clip
2255 the corners of the input image. However using the special
2256 <em>Rmax</em> setting of '<code>-1</code>' (maximum center to corner
2257 distance) will ensure the whole distorted image is preserved in the
2258 generated result, so that the same argument to '<kbd>Polar</kbd>' will
2259 reverse the distortion re-producing the original.
2260
2261 Note that as this distortion requires the area resampling of a circular
2262 arc, which can not be handled by the builtin EWA resampling function.
2263 As such the normal EWA filters are turned off. It is recomended some
2264 form of 'super-sampling' image processing technique be used to produce
2265 a high quality result. </td>
2266
2267 </tr>
2268
2269 <tr valign="top">
2270 <td valign="top"><kbd>Barrel</kbd></td>
2271 <td valign="top">
2272 Given the four coefficients (A,B,C,D) as defined by <a
2273 href="http://www.all-in-one.ee/~dersch/barrel/barrel.html" >Helmut
2274 Dersch</a>, perform a barrell or pincussion distortion appropriate to
2275 correct radial lens distortions. That is in photographs, make straight
2276 lines straight again. <br/>
2277
2278 Arguments: <em>A &nbsp; B &nbsp; C</em> &nbsp; [ <em>D</em> &nbsp; [
2279 <em>X</em> , <em>Y</em> ] ] <br/>
2280 or <em>A<sub>x</sub> B<sub>x</sub> C<sub>x</sub> D<sub>x</sub> &nbsp;
2281 A<sub>y</sub> B<sub>y</sub> C<sub>y</sub> D<sub>y</sub></em> &nbsp;
2282 [ <em>X</em> , <em>Y</em> ] <br/>
2283 So that it forms the function <br/>
2284 Rsrc = r * ( <em>A</em>*r<sup>3</sup> + <em>B</em>*r<sup>2</sup> +
2285 <em>C</em>*r + <em>D</em> )<br/>
2286
2287 Where <em>X</em>,<em>Y</em> is the optional center of the distortion
2288 (defaulting to the center of the image). <br/>
2289 The second form is typically used to distort images, rather than
2290 correct lens distortions. <br/>
2291 </td>
2292
2293 </tr>
2294
2295 <tr valign="top">
2296 <td valign="top"><kbd>BarrelInverse</kbd></td>
2297 <td valign="top">
2298 This is very simular to '<kbd>Barrel</kbd>' with the same set of
2299 arguments, and argument handling. However it uses the inverse
2300 of the radial polynomial,
2301 so that it forms the function <br/>
2302 Rsrc = r / ( <em>A</em>*r<sup>3</sup> + <em>B</em>*r<sup>2</sup> +
2303 <em>C</em>*r + <em>D</em> )
2304 </td>
2305 </tr>
2306
2307 <tr valign="top">
2308 <td valign="top"><kbd>Shepards</kbd></td>
2309 <td valign="top">
2310 Distort the given list control points (any number) using an Inverse
2311 Squared Distance Interpolation Method (<a
2312 href="http://www.ems-i.com/smshelp/Data_Module/Interpolation/Inverse_Distance_Weighted.htm"
2313 >Shepards Method</a>). The control points in effect do 'localized'
2314 distortions of the image around the given control point. For best
2315 results extra control points should be added to 'lock' the positions of
2316 the corners and other unchanging parts of the image. <br/>
2317
2318 The distortion has been likened to 'taffy pulling' using nails, pins or
2319 sticks. It basically uses the <a href="#sparse-color"
2320 >-sparse-color</a> method of the same name to generate separate X and Y
2321 displacement maps (see <a href="#displace" >-displace</a>) for source
2322 image color look-up. </td>
2323
2324 </tr>
2325
2326</table>
2327
2328<p>To print a complete list of distortion methods, use <a href="#list">-list distort</a>.</p>
2329
2330<p>Many of the above distortion methods such as '<kbd>Affine</kbd>',
2331'<kbd>Perspective</kbd>', and '<kbd>Shepards</kbd>' use a list control points
2332defining how these points in the given image should be distorted in the
2333destination image. Each set of four floating point values represent a source
2334image coordinate, followed immediately by the destination image coordinate.
2335This produces a list of values such as...</p>
2336<div style="text-align: center"><em>
2337 U<sub>1</sub>,V<sub>1</sub> X<sub>1</sub>,Y<sub>1</sub> &nbsp;
2338 U<sub>2</sub>,V<sub>2</sub> X<sub>2</sub>,Y<sub>2</sub> &nbsp;
2339 U<sub>3</sub>,V<sub>3</sub> X<sub>3</sub>,Y<sub>3</sub> &nbsp;
2340 ... &nbsp;
2341 U<sub>n</sub>,V<sub>n</sub> X<sub>n</sub>,Y<sub>n</sub> &nbsp;
2342</em></div>
2343<p>where <em>U,V</em> on the source image is mapped to <em>X,Y</em> on the
2344destination image. </p>
2345
2346<p>For example, to warp an image using '<kbd>perspective</kbd>' distortion,
2347needs a list of at least 4 sets of coordinates, or 16 numbers. Here is the
2348perspective distortion of the built-in "rose:" image. Note how spaces were
2349used to group the 4 sets of coordinate pairs, to make it easier to read and
2350understand.</p>
2351
2352<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>
2353 convert rose: -virtual-pixel black \ <br/>
2354 -distort Perspective '0,0,0,0 0,45,0,45 69,0,60,10 69,45,60,35' \ <br/>
2355 rose_3d_rotated.gif</span></p>
2356<p>If more that the required number of coordinate pairs are given for a
2357distortion, the distortion method is 'least squares' fitted to
2358produce the best result for all the coordinate pairs given. If less than the
2359ideal number of points are given, the distort will generally fall back to a
2360simpler form of distortion that can handles the smaller number of coordinates
2361(usally a linear '<kbd>Affine</kbd>' distortion). </p>
2362
2363<p>By using more coodinates you can make use of image registration tool to
2364find matching coordinate pairs in overlaping images, so as to improve the 'fit'
2365of the distortion. Of course a bad coordinate pair can also make the 'fit'
2366worse. Caution is always advised. </p>
2367
2368<p>Colors are acquired from the source image according to the <a
2369href="#interpolate" >-interpolate</a> color lookup setting, when the image is
2370magnified. However if the viewed image is minified (image becomes smaller), a
2371special area resampling function (added ImageMagick v6.3.5-9), is used to
2372produce a higher quality image. For example you can use a
2373'<kbd>perspective</kbd>' distortion to view a infinitely tiled 'plane' all the
2374way to the horizon. </p>
2375
2376<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert -size 90x90 pattern:checkerboard -normalize -virtual-pixel tile \ <br/>
2377 -distort perspective '0,0,5,45 89,0,45,46 0,89,0,89 89,89,89,89' \ <br/>
2378 checks_tiled.jpg</span></p>
2379<p>Note that a infinitely tiled perspective images involving the horizon can
2380be very slow to generate due to the use of the high quality 'area resampling'
2381function (added ImageMagick v6.3.5-9). You can turn off 'area resampling'
2382using a <a href="#filter" >-filter</a> setting of '<kbd>point</kbd>'
2383(recommended if you plan to use super-sampling instead). </p>
2384
2385<p>If an image generates <i>invalid pixels</i>, such as the 'sky' in the last
2386'<kbd>perspective</kbd>' distortion example, <a href="#distort" >-distort</a>
2387will use the current <a href="#mattecolor" >-mattecolor</a> setting for these
2388pixels. If you do not what these pixels to be visible, set the color to match
2389the rest of the ground. </p>
2390
2391<p>The output image size will by default be the same as the input image. This
2392means that if the part of the distorted image falls outside the viewed area of
2393the 'distorted space', those parts is clipped and lost. However if you
2394use the plus form of the operator (<a href="#distort" >+distort</a>) the
2395operator will attempt (if posible) to show the whole of the distorted image,
2396while retaining a correct 'virtual canvas' offset, for image layering. This
2397offset may need to be removed using <a href="#repage" >+repage</a>, to remove
2398if it is unwanted. </p>
2399
2400<p>You can alternatively specify a special "<kbd><a href="#set" >-set</a>
2401option:distort:viewport {geometry_string}</kbd>" setting which will specify
2402the size and the offset of the generated 'viewport' image of the distorted
2403image space.</p>
2404
2405<p>Adding a "<kbd><a href="#set" >-set</a> option:distort:scale
2406{scale_factor}</kbd>" will scale the output image (viewport or otherwise) by
2407that factor without changing the viewed contents of the distorted image. This
2408can be used either for 'super-sampling' the image for a higher quality result,
2409or for panning and zooming around the image (with appropriate viewport
2410changes, or post-distort cropping and resizing). </p>
2411
2412<p>Setting <a href="#verbose" >-verbose</a> setting, will cause <a
2413href="#distort" >-distort</a> to attempt to output the internal coefficients,
2414and the <a href="#fx" >-fx</a> equivalent to the distortion, for expert study,
2415and debugging purposes. This many not be available for all distorts. </p>
2416
2417<p>Affine rotations and shears (such as '<kbd>SRT</kbd>' distortion), tend to
2418produce a cleaner result that the equivalent <a href="#rotate" >-rotate</a>
2419and/or <a href="#shear" >-shear</a> operation, with more control of due to the
2420above settings. It is algorithmically slower, though in ImageMagick it may be faster.
2421</p>
2422
2423
2424<div style="margin: auto;">
2425 <h4><a name="dither" id="dither"></a>-dither <em class="arg">method</em></h4>
2426</div>
2427
2428<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>
2429
2430<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>
2431
2432<p>Dithering is turned on by default, to turn it off use the plus form of the
2433setting, <a href="#dither">+dither</a>. This will also also render PostScript
2434without text or graphic aliasing. Disabling dithering often (but not always)
2435leads to faster process, a smaller number of colors, but more cartoon like
2436image coloring. Generally resulting in 'color banding' effects in areas with
2437color gradients. </p>
2438
2439<p>The color reduction operators <a href="#colors">-colors</a>, <a
2440href="#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>
2441
2442<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>
2443
2444
2445<div style="margin: auto;">
2446 <h4><a name="draw" id="draw"></a>-draw <em class="arg">string</em></h4>
2447</div>
2448
2449<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>
2450
2451<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>
2452
2453<p>The shape primitives:</p>
2454
2455<pre class="text">
2456 point x,y
2457 line x0,y0 x1,y1
2458 rectangle x0,y0 x1,y1
2459 roundRectangle x0,y0 x1,y1 wc,hc
2460 arc x0,y0 x1,y1 a0,a1
2461 ellipse x0,y0 rx,ry a0,a1
2462 circle x0,y0 x1,y1
2463 polyline x0,y0 ... xn,yn
2464 polygon x0,y0 ... xn,yn
2465 bezier x0,y0 ... xn,yn
2466 path path specification
2467 image operator x0,y0 w,h filename
2468</pre>
2469
2470<p>The text primitive:</p>
2471
2472<pre class="text">
2473 text x0,y0 string
2474</pre>
2475<p>The text gravity primitive:</p>
2476
2477<pre class="text">
2478 gravity NorthWest, North, NorthEast, West, Center,
2479 East, SouthWest, South, or SouthEast
2480</pre>
2481
2482<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>
2483
2484<p>The transformation primitives:</p>
2485
2486<pre class="text">
2487 rotate degrees
2488 translate dx,dy
2489 scale sx,sy
2490 skewX degrees
2491 skewY degrees
2492</pre>
2493
2494<p>The pixel operation primitives:</p>
2495
2496<pre class="text">
2497 color x0,y0 method
2498 matte x0,y0 method
2499</pre>
2500
2501<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>
2502
2503<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>
2504
2505<p>A <kbd>line</kbd> primitive requires a start point and end point.</p>
2506
2507<p>A <kbd>rectangle</kbd> primitive is specified by the pair of points at the upper left and lower right corners.</p>
2508
2509<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>
2510
2511<p>The <kbd>circle</kbd> primitive makes a disk (filled) or circle (unfilled). Give the center and any point on the perimeter (boundary).</p>
2512
2513<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>
2514
2515<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>
2516
2517<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>.
2518</p>
2519
2520<p>A <em>coordinate</em> is a pair of integers separated by a space or optional comma. </p>
2521
2522<p>As an example, to define a circle centered at 100,100 that extends to 150,150 use:</p>
2523
2524<p class="crtsnip">
2525 -draw 'circle 100,100 150,150'
2526</p>
2527
2528<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
2529draw 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>
2530
2531<p class="crtsnip">
2532 -draw 'bezier 20,50 45,100 45,0 70,50'
2533</p>
2534<p class="crtsnip">
2535 -draw 'bezier 70,50 95,100 95,0 120,50'
2536</p>
2537
2538
2539<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>
2540
2541<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>
2542
2543<p class="crtsnip">
2544 -draw 'image SrcOver 100,100 225,225 image.jpg'
2545</p>
2546
2547<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>
2548
2549<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>
2550
2551<p>For example, the following annotates the image with <kbd>Works like magick!</kbd> for an image titled <kbd>bird.miff</kbd>. </p>
2552
2553<p class="crtsnip">
2554 -draw 'text 100,100 "Works like magick!"'
2555</p>
2556
2557<p>See the <a href="#annotate">-annotate</a> option for another convenient way to annotate an image with text.</p>
2558
2559<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>
2560
2561<p>The <kbd>translate</kbd> primitive translates subsequent shape and text primitives.</p>
2562
2563<p>The <kbd>scale</kbd> primitive scales them.</p>
2564
2565<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>
2566
2567<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
2568matrix.</p>
2569
2570<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>
2571
2572<pre class="text">
2573 point
2574 replace
2575 floodfill
2576 filltoborder
2577 reset
2578</pre>
2579
2580<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>
2581
2582<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>
2583
2584<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>
2585
2586<p>Strings that begin with a number must be quoted (e.g. use '1.png' rather than 1.png).</p>
2587
2588<p>Drawing primitives conform to the <a href="../www/magick-vector-graphics.html">Magick Vector Graphics</a> format.</p>
2589
2590
2591<div style="margin: auto;">
2592 <h4><a name="edge" id="edge"></a>-edge <em class="arg">radius</em></h4>
2593</div>
2594
2595<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>
2596
2597<div style="margin: auto;">
2598 <h4><a name="emboss" id="emboss"></a>-emboss <em class="arg">radius</em></h4>
2599</div>
2600
2601<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>
2602
2603<div style="margin: auto;">
2604 <h4><a name="encipher" id="encipher"></a>-encipher <em class="arg">filename</em></h4>
2605</div>
2606
2607<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>
2608
2609<p>Get the passphrase from the file specified by <em class="arg">filename</em>.</p>
2610
2611<p>For more information, see the webpage, <a href="http://www.imagemagick.org/www/cipher.html">ImageMagick: Encipher or Decipher an Image</a>.</p>
2612
2613<div style="margin: auto;">
2614 <h4><a name="encoding" id="encoding"></a>-encoding <em class="arg">type</em></h4>
2615</div>
2616
2617<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>
2618
2619<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>
2620
2621<div style="margin: auto;">
2622 <h4><a name="endian" id="endian"></a>-endian <em class="arg">type</em></h4>
2623</div>
2624
2625<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>
2626
2627<p>To print a complete list of endian types, use the <a href="#list">-list endian</a> option.</p>
2628
2629<p>Use <a href="#endian">+endian</a> to revert to unspecified endianness.</p>
2630
2631
2632<div style="margin: auto;">
2633 <h4><a name="enhance" id="enhance"></a>-enhance</h4>
2634</div>
2635
2636<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>
2637
2638
2639<div style="margin: auto;">
2640 <h4><a name="equalize" id="equalize"></a>-equalize</h4>
2641</div>
2642
2643<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>
2644
2645<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>
2646
2647<p>For example using HSL, we have: ... <kbd>-colorspace HSL -channel lightness -equalize -colorspace RGB</kbd> ...</p>
2648
2649<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>
2650
2651<div style="margin: auto;">
2652 <h4><a name="evaluate" id="evaluate"></a>-evaluate <em class="arg">operator value</em></h4>
2653</div>
2654
2655<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>
2656
2657<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>
2658
2659<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>
2660
2661<table class="doc">
2662 <col width="25%" />
2663 <col width="75%" />
2664 <thead>
2665 <tr>
2666 <th><em class="arg">operator</em></th>
2667 <th>Summary (see further below for details)</th>
2668 </tr>
2669 </thead>
2670 <tbody>
2671
2672 <tr><td>Add </td> <td>Add <em class="arg">value</em> to pixels. </td></tr>
2673 <tr><td>AddModulus </td> <td>Add <em class="arg">value</em> to pixels modulo <em class="QR">QuantumRange</em>.</td></tr>
2674 <tr><td>And </td> <td>Binary AND of pixels with <em class="arg">value</em>.</td></tr>
2675 <tr><td>Cos, Cosine </td> <td>Apply cosine to pixels with frequency <em class="arg">value</em> with 50% bias added.</td></tr>
2676 <tr><td>Divide </td> <td>Divide pixels by <em class="arg">value</em>.</td></tr>
2677 <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>
2678 <tr><td>Log </td> <td>Apply scaled logarithm to normalized pixels.</td></tr>
2679 <tr><td>Max </td> <td>Clip pixels at lower bound <em class="arg">value</em>.</td></tr>
2680 <tr><td>Min </td> <td>Clip pixels at upper bound <em class="arg">value</em>.</td></tr>
2681 <tr><td>Multiply </td> <td>Multiply pixels by <em class="arg">value</em>.</td></tr>
2682 <tr><td>Or </td> <td>Binary OR of pixels with <em class="arg">value</em>.</td></tr>
2683 <tr><td>Pow </td> <td>Raise normalized pixels to the power <em class="arg">value</em>.</td></tr>
2684 <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>
2685 <tr><td>Set </td> <td>Set pixel equal to <em class="arg">value</em>.</td></tr>
2686 <tr><td>Sin, Sine </td> <td>Apply sine to pixels with frequency <em class="arg">value</em> with 50% bias added.</td></tr>
2687 <tr><td>Subtract </td> <td>Subtract <em class="arg">value</em> from pixels.</td></tr>
2688 <tr><td>Xor </td> <td>Binary XOR of pixels with <em class="arg">value.</em></td></tr>
2689
2690 <tr><td>&nbsp;</td></tr>
2691
2692 <tr><td>Gaussian-noise</td></tr>
2693 <tr><td>Impulse-noise</td></tr>
2694 <tr><td>Laplacian-noise</td></tr>
2695 <tr><td>Multiplicative-noise</td> <td>(These are equivalent to the corresponding <a href="#noise" >-noise</a> operators.)</td></tr>
2696 <tr><td>PoissonNoise</td></tr>
2697 <tr><td>Uniform-noise</td></tr>
2698
2699 <tr><td>&nbsp;</td></tr>
2700
2701 <tr><td>Threshold </td> <td>Threshold pixels larger than <em class="arg">value</em>.</td></tr>
2702 <tr><td>ThresholdBlack </td> <td>Threshold pixels to zero values equal to or below <em class="arg">value</em>.</td></tr>
2703 <tr><td>ThresholdWhite </td> <td>Threshold pixels to maximum values above <em class="arg">value</em>. </td></tr>
2704 </tbody>
2705 </table>
2706
2707<p>The specified functions are applied only to each previously set <a
2708href="#channel" >-channel</a> in the image. If necessary, the results of the
2709calculations are truncated (clipped) to fit in the interval [0,&nbsp;<em
2710class="QR">QuantumRange</em>]. The transparency channel of the image is
2711represented as a 'alpha' values (0 = fully transparent), so, for example, a
2712<kbd>Divide</kbd> by&nbsp;2 of the alpha channel will make the image
2713semi-transparent. Append the percent symbol '<kbd>%</kbd>' to specify a value
2714as a percentage of the <em class="QR">QuantumRange</em>.</p>
2715
2716<p>To print a complete list of <a href="#evaluate">-evaluate</a> operators, use
2717<a href="#list">-list evaluate</a>.</p>
2718
2719<p>The results of the <kbd>Add</kbd>, <kbd>Subtract</kbd> and
2720<kbd>Multiply</kbd> methods can also be achieved using either the <a
2721href="#level" >-level</a> or the <a href="#level" >+level</a> operator, with
2722appropriate argument, to linearly modify the overall range of color values.
2723Please note, however, that <a href="#level" >-level</a> treats transparency as
2724'matte' values (0 = opaque), while <a href="#level" >-evaluate</a> works with
2725'alpha' values.</p>
2726
2727<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,&nbsp;<em class="QR">QuantumRange</em>]. </p>
2728
2729<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>
2730
2731 <div style="text-align:center;">
2732 log(<em class="arg">value</em> &times; <b><em>u</em></b> + 1) / log(<em class="arg">value</em> + 1)
2733 </div>
2734
2735<p><kbd>Pow</kbd> has been added as of ImageMagick 6.4.1-9, and works on
2736normalized pixel values. Note that <kbd>Pow</kbd> is related to the <a
2737href="#gamma" >-gamma</a> operator. For example, <b>-gamma 2</b> is equivalent
2738to <b>-evaluate pow 0.5</b>, i.e., a 'square root' function. The value used
2739with <a href="#gamma" >-gamma</a> is simply the reciprocal of the value used
2740with <kbd>Pow</kbd>.</p>
2741
2742<p><kbd>Cosine</kbd> and <kbd>Sine</kbd> was added as of IM v6.4.8-8 and
2743converts the image values into a value according to a (co)sine wave function.
2744The synonyms <kbd>Cos</kbd> and <kbd>Sin</kbd> may also be used. The output
2745is biased 50% and normalized by 50% so as to fit in the respective color value
2746range. The <em class="arg">value</em> scaling of the <em>period</em> of the
2747function (its frequency), and thus determines the number of 'waves' that will
2748be generated over the input color range. For example, if the <em
2749class="arg">value</em> is&nbsp;1, the effective period is simply the <em
2750class="QR">QuantumRange</em>; but if the <em class="arg">value</em> is&nbsp;2,
2751then the effective period is the <em>half</em> the <em
2752class="QR">QuantumRange</em>.
2753
2754 <div style="text-align:center;">
2755 0.5 + 0.5 &times; cos(2 &pi; <b><em>u</em></b> &times; <em class="arg">value</em>).
2756 </div>
2757
2758See also the <a href="#function" >-function</a> operator, which is a
2759multi-value version of evaluate. </P>
2760
2761
2762<div style="margin: auto;">
2763 <h4><a name="extent" id="extent"></a>-extent <em class="arg">geometry</em></h4>
2764</div>
2765
2766<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>
2767
2768<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>
2769
2770<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>
2771
2772<div style="margin: auto;">
2773 <h4><a name="extract" id="extract"></a>-extract <em class="arg">geometry</em></h4>
2774</div>
2775
2776<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>
2777
2778<p>This option is most useful for extracting a subregion of a very large raw image. Note that these two commands are equivalent:</p>
2779
2780<p class='crt'><span class="crtprompt"> $magick&gt; </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&gt; </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>
2781
2782<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert -size 16000x16000 -depth 8 -extract 640x480 image.rgb image.png</span></p>
2783<p>then the image will be <em>resized</em> to the specified dimensions instead,
2784equivalent to:</p>
2785
2786<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert -size 16000x16000 -depth 8 -resize 640x480 image.rgb image.png</span></p>
2787<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>
2788
2789<div style="margin: auto;">
2790 <h4><a name="family" id="family"></a>-family <em class="arg">fontFamily</em></h4>
2791</div>
2792
2793<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>
2794
2795<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).
2796</p>
2797
2798<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>.
2799</p>
2800
2801<div style="margin: auto;">
2802 <h4><a name="fft" id="fft"></a>-fft</h4>
2803</div>
2804
2805<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>
2806
2807<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>
2808
2809<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>
2810
2811<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>
2812
2813<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert image.png -fft fft_image.miff</span></p>
2814<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>
2815
2816<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert image.png -fft fft_image.png</span></p>
2817<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>
2818
2819<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>
2820
2821<p>Both output components will have dynamic ranges that fit within [0,&nbsp;<em class="QR">QuantumRange</em>], so that HDRI need not be enabled. Phase values nominally range from 0 to 2*&pi;, 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>
2822
2823<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert fft_image.miff[0] -contrast-stretch 0 \ <br />
2824 -evaluate log 1000 fft_image_spectrum.png</span></p>
2825<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>
2826
2827<p>The <a href="http://www.fftw.org/" target="_blank">FFTW</a> delegate library is required to use <a href="#fft">-fft</a>.
2828
2829<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>
2830
2831<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>
2832
2833<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>
2834
2835<p>See the discussion on HDRI implementations of ImageMagick on the page
2836<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.
2837</p>
2838
2839
2840<div style="margin: auto;">
2841 <h4><a name="fill" id="fill"></a>-fill <em class="arg">color</em></h4>
2842</div>
2843
2844<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>
2845
2846<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>
2847
2848<p>Enclose the color specification in quotation marks to prevent the "#" or the parentheses from being interpreted by your shell.</p>
2849
2850<p>For example,</p>
2851
2852<p class="crtsnip">
2853 -fill blue
2854</p>
2855<p class="crtsnip">
2856 -fill "#ddddff"
2857</p>
2858<p class="crtsnip">
2859 -fill "rgb(255,255,255)"
2860</p>
2861
2862<p>See <a href="#draw">-draw</a> for further details.</p>
2863
2864<p>To print a complete list of color names, use the <a href="#list">-list color</a> option.</p>
2865
2866<div style="margin: auto;">
2867 <h4><a name="filter" id="filter"></a>-filter <em class="arg">type</em></h4>
2868</div>
2869
2870<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>
2871
2872<p>Use this option to affect the resizing operation of an image (see <a
2873href="#resize">-resize</a>). For example you can use a simple resize filter
2874such as:</p>
2875
2876<pre class="text">
2877 Point Hermite Cubic
2878 Box Gaussian Catrom
2879 Triangle Quadratic Mitchell
2880</pre>
2881
2882<p>The <kbd>Bessel</kbd> and <kbd>Sinc</kbd> filter is also provided, but are
2883by default <kbd>blackman</kbd>-windowed. However these filters define a
2884windowing filter for the Sinc or Bessel filter function, as appropriate for
2885the scaling operator used (usally Sinc for orthogonal <a href="#resize"
2886>-resize</a>). Windowed filters include: </p>
2887
2888<pre class="text">
2889 Lanczos Hamming Parzen
2890 Blackman Kaiser Welsh
2891 Hanning Bartlett Bohman
2892</pre>
2893
2894<p>Also one special self-windowing filter is also provided
2895<kbd>Lagrange</kbd>, which will automagically re-adjust its function depending
2896on the current 'support' or 'lobes' expert settings (see below).</p>
2897
2898<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>
2899
2900<p>To print a complete list of resize filters, use the <a href="#list">-list filter</a> option.</p>
2901
2902<p>You can modify how the filter behaves as it scales your image through the
2903use of these expert settings:</p>
2904
2905<dl class="doc">
2906<dt>-set filter:blur <em>factor</em></dt>
2907<dd>Scale the X axis of the filter (and its window). Use &gt; 1.0 for
2908 blurry or &lt; 1.0 for sharp.</dd>
2909
2910<dt>-set filter:support <em>radius</em></dt>
2911<dd>Set the filter support radius.</dd>
2912
2913<dt>-set filter:lobes <em>count</em></dt>
2914<dd>Set the number of lobes to use for the Sinc/Bessel filter. This an
2915 alternative way of specifying the 'support' range of the filter.</dd>
2916
2917<dt>-set filter:b <em>b-spline_factor</em></dt>
2918<dt>-set filter:c <em>keys_alpha_factor</em></dt>
2919<dd>Redefine the values used for cubic filters such as <kbd>Cubic</kbd>,
2920 <kbd>Catrom</kbd>, <kbd>Mitchel</kbd>, and <kbd>Hermite</kbd>, as well as
2921 the <kbd>Parzen</kbd> Sinc windowing function. If only one of the values
2922 are defined, the other is set so as to generate a 'Keys' type cubic
2923 filter.
2924
2925<dt>-set filter:filter <em>filter</em></dt>
2926<dd>Use this function directly as the scaling filter. This will allow
2927 you to directly use a 'windowing filter' such as <kbd>blackman</kbd>,
2928 rather than as its normal usage as a windowing function for 'Sinc' or
2929 'Bessel'. If defined, no windowing function is used, unless the following
2930 expert setting is also defined.</dd>
2931
2932<dt>-set filter:window <em>filter</em></dt>
2933<dd>The IIR (infinite impulse response) filters <kbd>bessel</kbd> and
2934 <kbd>sinc</kbd> are windowed (brought down to zero over the defined
2935 support range) with the given filter. This allows you to use a filter that
2936 is not normally used as a windowing function, such as <kbd>box</kbd>,
2937 (which effectivally turns off the windowing function). </dd>
2938
2939</dl>
2940
2941<p>For example, to get a 8 lobe Lanczos-Bessel filter:</p>
2942
2943<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert image.png -filter bessel \ <br/>
2944 -set filter:window=bessel -set filter:lobes=8 \ <br/>
2945 -resize 150% image.jpg</span></p>
2946<p>Or a raw un-windowed Sinc filter with 4 lobes:</p>
2947
2948<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert image.png -set filter:filter=sinc -set filter:lobes=4 \ <br/>
2949 -resize 150% image.jpg</span></p>
2950<p>Note that the use of expert options (except for 'blur' with simple resize
2951filters), are provided for image processing experts who have studied and
2952understood how resize filters work. Without this knowledge, and an
2953understanding of the defination of the actual filters involved, using expert
2954settings are more likely to be detremental to your image resizing.</p>
2955
2956
2957<div style="margin: auto;">
2958 <h4><a name="flatten" id="flatten"></a>-flatten</h4>
2959</div>
2960
2961<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>
2962
2963
2964<div style="margin: auto;">
2965 <h4><a name="flip" id="flip"></a>-flip</h4>
2966</div>
2967
2968<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>
2969
2970<p>reflect the scanlines in the vertical direction.</p>
2971
2972<div style="margin: auto;">
2973 <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>
2974</div>
2975
2976<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>
2977
2978<div style="margin: auto;">
2979 <h4><a name="flop" id="flop"></a>-flop</h4>
2980</div>
2981
2982<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>
2983
2984<p>reflect the scanlines in the horizontal direction.</p>
2985
2986
2987<div style="margin: auto;">
2988 <h4><a name="font" id="font"></a>-font <em class="arg">name</em></h4>
2989</div>
2990
2991<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>
2992
2993<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>
2994
2995<p>In addition to the fonts specified by the above pre-defined list, you can
2996also specify a font from a specific source. For example <kbd>Arial.ttf</kbd>
2997is a TrueType font file, <kbd>ps:helvetica</kbd> is PostScript font, and
2998<kbd>x:fixed</kbd> is X11 font.</p>
2999
3000<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>
3001
3002
3003<div style="margin: auto;">
3004 <h4><a name="foreground" id="foreground"></a>-foreground <em class="arg">color</em></h4>
3005</div>
3006
3007<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>
3008
3009<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p>
3010
3011<p>The default foreground color is black.</p>
3012
3013<div style="margin: auto;">
3014 <h4><a name="format" id="format"></a>-format <em class="arg">type</em></h4>
3015</div>
3016
3017<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>
3018
3019<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>
3020
3021<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>
3022
3023<div style="margin: auto;">
3024 <h4><a name="format_identify_" id="format_identify_"></a>-format <em class="arg">string</em></h4>
3025</div>
3026
3027<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>
3028
3029<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>
3030
3031<div style="margin: auto;">
3032 <h4><a name="frame" id="frame"></a>-frame <em class="arg">geometry</em></h4>
3033</div>
3034
3035<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>
3036
3037<p>The color of the border is specified with the <a href="#mattecolor">-mattecolor</a> command line option. </p>
3038
3039<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>&nbsp;pixels and an inner bevel of thickness <em>y</em>&nbsp;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>
3040
3041
3042<div style="margin: auto;">
3043 <h4><a name="frame_import_" id="frame_import_"></a>-frame</h4>
3044</div>
3045
3046<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>
3047
3048<div style="margin: auto;">
3049 <h4><a name="function" id="function"></a>-function <em class="arg">function</em> <em class="arg">parameters</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 function to channel values.</td><td style='text-align:right;'></td></tr></table>
3053
3054<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>
3055
3056<p>This is can be considered a multi-argument version of the <a href="#evaluate">-evaluate</a> operator. (Added in ImageMagick&nbsp;6.4.8&minus;8.)</p>
3057
3058<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>
3059
3060<pre class="text">
3061 Polynomial
3062 Sinusoid
3063 Arcsin
3064 Arctan
3065</pre>
3066
3067<p>To print a complete list of <a href="#function">-function</a> operators, use <a href="#list">-list function</a>. Descriptions follow.</p>
3068
3069<dl class="doc">
3070<dt><kbd>Polynomial</kbd></dt>
3071<dd>
3072<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>
3073
3074<div style="text-align: center">
3075 -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>
3076</div>
3077
3078<p>will invoke a polynomial function given by</p>
3079
3080<div style="text-align: center">
3081 <em>a</em><sub><em>n</em></sub> <b><em>u</em></b><sup><em>n</em></sup> +
3082 <em>a</em><sub><em>n</em>-1</sub> <b><em>u</em></b><sup><em>n</em>-1</sup> +
3083 &middot;&middot;&middot; <em>a</em><sub>1</sub> <b><em>u</em></b> + <em>a</em><sub>0</sub>,
3084</div>
3085
3086<p>where <b><em>u</em></b> is pixel's original normalized channel value.</p>
3087
3088<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>
3089
3090<table class="doc">
3091 <col width="35%" />
3092 <col width="35%" />
3093 <col width="30%" />
3094 <tr>
3095 <td>-evaluate Set <em class="arg">value</em> </td>
3096 <td>-function Polynomial <em class="arg">value</em></td>
3097 <td>(Constant functions; set <em class="arg">value</em>&times;100% gray when channels are RGB.)</td>
3098 </tr>
3099 <tr>
3100 <td>-evaluate Add <em class="arg">value</em> </td>
3101 <td>-function Polynomial 1,<em class="arg">value</em></td>
3102 </tr>
3103 <tr>
3104 <td>-evaluate Subtract <em class="arg">value</em> </td>
3105 <td>-function Polynomial 1,&minus;<em class="arg">value</em></td>
3106 </tr>
3107 <tr>
3108 <td>-evaluate Multiply <em class="arg">value</em> </td>
3109 <td>-function Polynomial <em class="arg">value</em>,0</td>
3110 </tr>
3111 <tr>
3112 <td>+level black% x white%</td>
3113 <td>-function Polynomial A,B</td>
3114 <td>(Reduce contrast. Here, A=(white-black)/100 and B=black/100.)</td>
3115 </tr>
3116</table>
3117
3118<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>
3119</dd>
3120
3121<dt><kbd>Sinusoid</kbd></dt>
3122<dd>
3123<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>
3124
3125<div style="text-align: center">
3126 -function <kbd>Sinusoid</kbd> <em class="arg">freq</em>,[<em class="arg">phase</em>,[<em class="arg">amp</em>,[<em class="arg">bias</em>]]]
3127</div>
3128
3129<p>where <em>phase</em> is in degrees. (The domain [0,1] of the function corresponds to 0 through <em class="arg">freq</em>&times;360&nbsp;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>
3130
3131<div style="text-align: center">
3132<em class="arg">amp</em> * sin(2*&pi;* (<em class="arg">freq</em> * <b><em>u</em></b> + <em class="arg">phase</em> / 360)) + <em class="arg">bias</em>
3133</div>
3134
3135<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&minus;.2=.5 and .7+.2=.9. </p>
3136
3137<p class="crtsnip">
3138 -function Sinusoid 3,-90,.2,.7
3139</p>
3140
3141<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>
3142
3143<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>
3144
3145<table class="doc">
3146 <tr>
3147 <td>-evaluate Sin <em class="arg">freq</em> </td>
3148 <td>-function Sinusoid <em class="arg">freq</em>,0 </td>
3149 </tr>
3150 <tr>
3151 <td>-evaluate Cos <em class="arg">freq</em> </td>
3152 <td>-function Sinusoid <em class="arg">freq</em>,90 </td>
3153 </tr>
3154</table>
3155</dd>
3156
3157<dt><kbd>ArcSin</kbd></dt>
3158<dd>
3159<p>The <kbd>ArcSin</kbd> function generates the inverse curve of a Sinusoid,
3160and can be used to generate cylindrical distortion and displacement maps.
3161The curve can be adjusted relative to both the input values and output range
3162of values.
3163
3164<div style="text-align: center">
3165 -function <kbd>ArcSin</kbd> <em class="arg">width</em>,[<em class="arg">center</em>,[<em class="arg">range</em>,[<em class="arg">bias</em>]]]
3166</div>
3167
3168<p>with all values given in terms of noramlize color values (0.0 for black,
31691.0 for white). Defaulting to values covering the full range from 0.0 to 1.0
3170for bout input (<em class="arg">width</em>), and output (<em
3171class="arg">width</em>) values. '<code>1.0,0.5,1.0,0.5</code>' </p>
3172
3173<div style="text-align: center">
3174<em class="arg">range</em>/&pi; * asin( 2/<em class="arg">width</em> * ( <b><em>u</em></b> - <em class="arg">center</em> ) ) + <em class="arg">bias</em>
3175</div>
3176
3177</dd>
3178
3179<dt><kbd>ArcTan</kbd></dt>
3180<dd>
3181<p>The <kbd>ArcTan</kbd> function generates a curve that smooth crosses from
3182limit values at infinities, though a center using the given slope value.
3183All these values can be adjusted via the arguments.
3184
3185<div style="text-align: center">
3186 -function <kbd>ArcTan</kbd> <em class="arg">slope</em>,[<em class="arg">center</em>,[<em class="arg">range</em>,[<em class="arg">bias</em>]]]
3187</div>
3188
3189<p>Defaulting to '<code>1.0,0.5,1.0,0.5</code>'.
3190</p>
3191
3192<div style="text-align: center">
3193<em class="arg">range</em>/&pi; * atan( <em class="arg">slope</em>*&pi; * ( <b><em>u</em></b> - <em class="arg">center</em> ) ) + <em class="arg">bias</em>
3194</div>
3195
3196</dd>
3197
3198</dl>
3199
3200
3201<div style="margin: auto;">
3202 <h4><a name="fuzz" id="fuzz"></a>-fuzz <em class="arg">distance</em>{<em class="arg">%</em>}</h4>
3203</div>
3204
3205<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>
3206
3207<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>
3208
3209<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>
3210
3211
3212<div style="margin: auto;">
3213 <h4><a name="fx" id="fx"></a>-fx <em class="arg">expression</em></h4>
3214</div>
3215
3216<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>
3217
3218<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>
3219
3220<p>See <a href="../www/fx.html">FX, The Special Effects Image Operator</a> for a detailed discussion of this option.</p>
3221
3222
3223<div style="margin: auto;">
3224 <h4><a name="gamma" id="gamma"></a>-gamma <em class="arg">value</em></h4>
3225</div>
3226
3227<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>
3228
3229<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>
3230
3231<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>
3232
3233<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>
3234
3235<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>
3236
3237<p>Note that gamma adjustments are also available via the <a href="#level">-level</a> operator.</p>
3238
3239<div style="margin: auto;">
3240 <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>
3241</div>
3242
3243<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>
3244
3245<p>Convolve the image with a Gaussian or normal distribution. The formula is:</p>
3246
3247<div class="eqn"><img alt="gaussian distribution" width="243px" height="42px" src="../images/gaussian-blur.png"/>
3248</div>
3249
3250<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 &sigma; is the standard deviation of the Gaussian distribution. As a guideline, set <i>r</i> to approximately 3&sigma;. Specify a radius of 0 and ImageMagick selects a suitable radius for you.</p>
3251
3252<p>This differs from the faster <a href="#blur">-blur</a> operator in that a
3253full 2-dimentional convolution is used to generate the weighted average of the
3254neighbouring pixels. </p>
3255
3256<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how
3257pixels which are outside the image proper are blurred into the final result.
3258</p>
3259
3260
3261<div style="margin: auto;">
3262 <h4><a name="geometry" id="geometry"></a>-geometry <em class="arg">geometry</em></h4>
3263</div>
3264
3265<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>
3266
3267<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>
3268
3269<div style="margin: auto;">
3270 <h4><a name="gravity" id="gravity"></a>-gravity <em class="arg">type</em></h4>
3271</div>
3272
3273<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>
3274
3275<p>Choices include: <kbd>NorthWest</kbd>, <kbd>North</kbd>, <kbd>NorthEast</kbd>,
3276<kbd>West</kbd>, <kbd>Center</kbd>, <kbd>East</kbd>, <kbd>SouthWest</kbd>,
3277<kbd>South</kbd>, <kbd>SouthEast</kbd>. Use <a href="#list">-list gravity</a> to get a complete
3278list of <a href="#gravity">-gravity</a> settings available in your ImageMagick
3279installation.</p>
3280
3281<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>
3282
3283<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>
3284
3285<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 (&minus;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 (&minus;40,20) is applied to that point, giving (100&minus;40,50+20)=(60,70), so the specified 10x10&nbsp;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&nbsp;(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>
3286
3287<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert image.png -gravity Center -region 10x10-40+20 -negate output.png</span></p>
3288<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>
3289
3290<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>
3291
3292
3293<div style="margin: auto;">
3294 <h4><a name="green-primary" id="green-primary"></a>-green-primary <em class="arg">x,y</em></h4>
3295</div>
3296
3297<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>
3298
3299
3300<div style="margin: auto;">
3301 <h4><a name="hald-clut" id="hald-clut"></a>-hald-clut</h4>
3302</div>
3303
3304<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>
3305
3306<p>A Hald color lookup table is a 3-dimensional color cube mapped to 2
3307dimensions. Create it with the <kbd>HALD:</kbd> prefix (e.g. HALD:8). You
3308can apply any color transformation to the Hald image and then use this option
3309to apply the transform to the image. </p>
3310
3311<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert image.png hald.png -hald-clut transform.png</span></p>
3312<p>This option provides a convenient method for you to use Gimp or Photoshop
3313to make color corrections to the Hald CLUT image and subsequently apply them
3314to multiple images using an ImageMagick script. </p>
3315
3316<p>Note that the representation is only of the normal RGB color space and that
3317the whole color value triplet is used for the interpolated lookup of the
3318represented Hald color cube image. Because of this the operation is not <a
3319href="#channel" >-channel</a> setting effected, nor can it adjust or modify an
3320images transparency or alpha/matte channel.</p>
3321
3322<p>See also <a href="#clut" >-clut</a> which provides color value replacement
3323of the individual color channels, usally involving a simplier gray-scale
3324image. E.g: gray-scale to color replacement, or modification by a histogram
3325mapping. </p>
3326
3327
3328<div style="margin: auto;">
3329 <h4><a name="help" id="help"></a>-help</h4>
3330</div>
3331
3332<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>
3333
3334<div style="margin: auto;">
3335 <h4><a name="highlight-color" id="highlight-color"></a>-highlight-color <em class="arg">color</em></h4>
3336</div>
3337
3338<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>
3339
3340<div style="margin: auto;">
3341 <h4><a name="iconGeometry" id="iconGeometry"></a>-iconGeometry <em class="arg">geometry</em></h4>
3342</div>
3343
3344<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>
3345
3346<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>
3347
3348<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>
3349
3350<div style="margin: auto;">
3351 <h4><a name="iconic" id="iconic"></a>-iconic</h4>
3352</div>
3353
3354<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>
3355
3356<div style="margin: auto;">
3357 <h4><a name="identify" id="identify"></a>-identify</h4>
3358</div>
3359
3360<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>
3361
3362<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>
3363
3364<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>
3365
3366<p>If <a href="#verbose">-verbose</a> preceds this option, copious
3367amounts of image properties are displayed including image statistics, profiles,
3368image histogram, and others.</p>
3369
3370<div style="margin: auto;">
3371 <h4><a name="ift" id="ift"></a>-ift</h4>
3372</div>
3373
3374<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>
3375
3376<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>
3377
3378<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>
3379
3380<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert fft_image.miff -ift fft_image_ift.png</span></p>
3381<p>or</p>
3382
3383<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert fft_image-0.png fft_image-1.png -ift fft_image_ift.png</span></p>
3384
3385<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.
3386
3387<p>The <a href="http://www.fftw.org/" target="_blank">FFTW</a> delegate library is required to use <a href="#ift">-ift</a>.
3388
3389<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.
3390
3391<div style="margin: auto;">
3392 <h4><a name="immutable" id="immutable"></a>-immutable</h4>
3393</div>
3394
3395<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>
3396
3397<div style="margin: auto;">
3398 <h4><a name="implode" id="implode"></a>-implode <em class="arg">factor</em></h4>
3399</div>
3400
3401<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>
3402
3403<div style="margin: auto;">
3404 <h4><a name="insert" id="insert"></a>-insert <em class="arg">index</em></h4>
3405</div>
3406
3407<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>
3408
3409<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>
3410
3411<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>
3412
3413<div style="margin: auto;">
3414 <h4><a name="intent" id="intent"></a>-intent <em class="arg">type</em></h4>
3415</div>
3416
3417<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>
3418
3419<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>
3420
3421<p>The default intent is undefined.</p>
3422
3423<p>To print a complete list of rendering intents, use <a href="#list">-list intent</a>.</p>
3424
3425<div style="margin: auto;">
3426 <h4><a name="interlace" id="interlace"></a>-interlace <em class="arg">type</em></h4>
3427</div>
3428
3429<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>
3430
3431<p>Choose from:</p>
3432
3433<pre class="text">
3434 none
3435 line
3436 plane
3437 partition
3438 JPEG
3439 GIF
3440 PNG
3441</pre>
3442
3443<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>
3444
3445<p><kbd>None</kbd> means do not interlace (RGBRGBRGBRGBRGBRGB...),</p>
3446
3447<p><kbd>Line</kbd> uses scanline interlacing (RRR...GGG...BBB...RRR...GGG...BBB...), and.</p>
3448
3449<p><kbd>Plane</kbd> uses plane interlacing (RRRRRR...GGGGGG...BBBBBB...).</p>
3450
3451<p><kbd>Partition</kbd> is like plane except the different planes are saved to individual files (e.g. image.R,
3452image.G, and image.B).</p>
3453
3454<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>
3455image.</p>
3456
3457<p>To print a complete list of interlacing schemes, use <a href="#list">-list interlace</a>.</p>
3458
3459<div style="margin: auto;">
3460 <h4><a name="interpolate" id="interpolate"></a>-interpolate <em class="arg">type</em></h4>
3461</div>
3462
3463<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>
3464
3465<p>When looking up the color of a pixel using a non-interger floating point
3466value, you typically fall in between the pixel colors defined by the source
3467image. This setting determines how the color is determined from the colors of
3468the pixels surrounding that point. That is how to determine the color of a
3469point that falls between two, or even four different colored pixels. </p>
3470
3471<pre class="text">
3472 integer: The color of the top-left pixel (floor function)
3473 nearest-neighbor: The nearest pixel to the lookup point (rounded function)
3474 average: The average color of the surrounding four pixels
3475 bilinear A double linear interpolation of pixels (the default)
3476 mesh Divide area into two flat triangular interpolations
3477 bicubic Fitted bicubic-spines of surrounding 16 pixels
3478 spline Direct spline curves (colors are blurred)
3479 filter Use resize <a href="#filter">-filter</a> settings
3480</pre>
3481
3482<p>This most important for distortion operators such as <a href="#distort"
3483>-distort</a>, <a href="#implode" >-implode</a>, <a href="#transform"
3484>-transform</a> and <a href="#fx" >-fx</a>. </p>
3485
3486<p>To print a complete list of interpolation methods, use <a href="#list">-list interpolate</a>.</p>
3487
3488<p>See also <a href="#virtual-pixel" >-virtual-pixel</a>, for control of the
3489lookup for positions outside the boundaries of the image. </p>
3490
3491
3492<div style="margin: auto;">
cristyf3bb4782009-09-08 13:10:04 +00003493 <h4><a name="interline-spacing" id="interline-spacing"></a>-interline-spacing <em class="arg">value</em></h4>
3494</div>
3495
3496<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>
3497
3498<div style="margin: auto;">
cristy3ed852e2009-09-05 21:47:34 +00003499 <h4><a name="interword-spacing" id="interword-spacing"></a>-interword-spacing <em class="arg">value</em></h4>
3500</div>
3501
3502<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>
3503
3504<div style="margin: auto;">
3505 <h4><a name="kerning" id="kerning"></a>-kerning <em class="arg">value</em></h4>
3506</div>
3507
3508<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>
3509
3510<div style="margin: auto;">
3511 <h4><a name="label" id="label"></a>-label <em class="arg">name</em></h4>
3512</div>
3513
3514<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>
3515
3516<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>
3517
3518<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>
3519
3520<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>
3521
3522<p>For example,</p>
3523
3524<p class="crtsnip">
3525 -label "%m:%f %wx%h" bird.miff
3526</p>
3527
3528<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>
3529
3530<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>
3531
3532<p>The label font can be specified with <a href="#font">-font</a>, and the
3533other font attribute settings.</p>
3534
3535<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>
3536
3537
3538<div style="margin: auto;">
3539 <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>
3540</div>
3541
3542<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>
3543
3544<p>Adaptively threshold each pixel based on the value of pixels in a
3545surrounding window. If the current pixel is lighter than this average plus
3546the optional <kbd>offset</kbd>, then it is made white, otherwise it is made
3547black. Small variations in pixel values such as found in scanned documents
3548can be ignored if offset is positive. A negative offset will make it more
3549sensitive to those small variations. </p>
3550
3551<p>This is commonly used to threshold images with an uneven background. It is
3552based on the assumption that average color of the small window is the
3553the local background color, from which to separate the forground color. </p>
3554
3555
3556<div style="margin: auto;">
3557 <h4><a name="layers" id="layers"></a>-layers <em class="arg">method</em></h4>
3558</div>
3559
3560<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>
3561
3562<p>Perform various image operation methods to a ordered sequence of images
3563which may represent either a set of overlaid 'image layers', a GIF disposal
3564animation, or a fully-'coalesced' animation sequence. </p>
3565
3566<table class="doc">
3567 <tbody>
3568 <tr valign="top">
3569 <th align="left" style="width: 8%">Method</th>
3570 <th align="left">Description</th>
3571 </tr>
3572
3573 <tr valign="top">
3574 <td valign="top">compare-any</td>
3575 <td valign="top">Crop the second and later frames to the smallest rectangle
3576 that contains all the differences between the two images. No GIF <a
3577 href="#dispose" >-dispose</a> methods are taken into account. </td>
3578 </tr>
3579
3580 <tr><td></td><td>This exactly the same as the <a href="#deconstruct"
3581 >-deconstruct</a> operator, and does not preserve animations normal
3582 working, especially when animation used layer disposal methods such as
3583 '<kbd>Previous</kbd>' or '<kbd>Background</kbd>'. </td>
3584 </tr>
3585
3586 <tr valign="top">
3587 <td valign="top">compare-clear</td>
3588 <td valign="top">As '<kbd>compare-any</kbd>' but crop to the bounds of any
3589 opaque pixels which become transparent in the second frame. That is the
3590 smallest image needed to mask or erase pixels for the next frame. </td>
3591 </tr>
3592
3593 <tr valign="top">
3594 <td valign="top">compare-overlay</td>
3595 <td valign="top">As '<kbd>compare-any</kbd>' but crop to pixels that add
3596 extra color to the next image, as a result of overlaying color pixels.
3597 That is the smallest single overlaid image to add or change colors. </td>
3598 </tr>
3599
3600 <tr><td></td><td>This can be used with the <a href="#compose" >-compose</a> alpha
3601 composition method '<kbd>change-mask</kbd>', to reduce the image to
3602 just the pixels that need to be overlaid. </td>
3603 </tr>
3604
3605 <tr valign="top">
3606 <td valign="top">coalesce</td>
3607 <td valign="top">Equivalent to a call to the <a href="#coalesce"
3608 >-coalesce</a> operator. Apply the layer disposal methods set in the
3609 current image sequence to form a fully defined animation sequence, as
3610 it should be displayed. Effectively converting a GIF animation into a
3611 'film strip'-like animation. </td>
3612 </tr>
3613
3614 <tr valign="top">
3615 <td valign="top">composite</td>
3616 <td valign="top">Alpha Composition of two image lists, separated by a
3617 "<kbd>null:</kbd>" image, with the destination image list first, and
3618 the source images last. An image from each list are composited
3619 together until one list is finished. The separator image and source
3620 image lists are removed. </td>
3621 </tr>
3622
3623
3624 <tr><td></td><td>The <a href="#geometry" >-geometry</a> offset is adjusted according to
3625 <a href="#gravity" >-gravity</a> in accordance of the virtual canvas
3626 size of the first image in each list. Unlike a normal <a
3627 href="#composite" >-composite</a> operation, the canvas offset is also
3628 added to the final composite positioning of each image. </td>
3629 </tr>
3630
3631 <tr><td></td><td>If one of the image lists only contains one image, that image is
3632 applied to all the images in the other image list, regardless of which
3633 list it is. In this case it is the image meta-data of the list which
3634 preserved. </td>
3635 </tr>
3636
3637
3638 <tr valign="top">
3639 <td valign="top">dispose</td>
3640 <td valign="top">This like '<kbd>coalesce</kbd>' but shows the look of
3641 the animation after the layer disposal method has been applied, before
3642 the next sub-frame image is overlaid. That is the 'dispose' image that
3643 results from the application of the GIF <a href="#dispose"
3644 >-dispose</a> method. This allows you to check what
3645 is going wrong with a particular animation you may be developing.
3646 </td>
3647 </tr>
3648
3649 <tr valign="top">
3650 <td valign="top">flatten</td>
3651 <td valign="top">Create a canvas the size of the first images virtual
3652 canvas using the current <a href="#background" >-background</a> color,
3653 and <a href="#compose" >-compose</a> each image in turn onto that
3654 canvas. Images falling outside that canvas is clipped. Final
3655 image will have a zero virtual canvas offset. </td>
3656 </tr>
3657
3658 <tr><td></td><td>This usally used as one of the final 'image layering' operations
3659 overlaying all the prepared image layers into a final image. </td>
3660 </tr>
3661
3662 <tr><td></td><td>For a single image this method can also be used to fillout a virtual
3663 canvas with real pixels, or to underlay a opaque color to remove
3664 transparency from an image.</td>
3665 </tr>
3666
3667
3668 <tr valign="top">
3669 <td valign="top">merge</td>
3670 <td valign="top">As 'flatten' method but merging all the given image
3671 layers into a new layer image just large enough to hold all the image
3672 without clipping or extra space. The new images virtual offset will
3673 prevere the position of the new layer, even if this offset is
3674 negative. the virtual canvas size of the first image is preserved.
3675 </td>
3676 </tr>
3677
3678 <tr><td></td><td>Caution is advised when handling image layers with negative offsets
3679 as few image file formats handle them correctly. </td>
3680 </tr>
3681
3682 <tr valign="top">
3683 <td valign="top">mosaic</td>
3684 <td valign="top">As 'flatten' method but expanding the initial canvas size
3685 of the first image so as to hold all the image layers. However as a
3686 virtual canvas is 'locked' to the origin, by defination, image layers
3687 with a negative offsets will still be clipped by the top and left
3688 edges.</td>
3689 </tr>
3690
3691 <tr><td></td><td>This method is commonly used to layout individual image using various
3692 offset but without knowning the final canvas size. The resulting image
3693 will, like 'flatten' not have any virtual offset, so can be saved to
3694 any image file format. </td>
3695 </tr>
3696
3697
3698 <tr valign="top">
3699 <td valign="top">optimize</td>
3700 <td valign="top">Optimize a coalesced animation, into GIF animation using
3701 a number of general techniques. This currently a short cut to
3702 apply both the '<kbd>optimize-frame</kbd>', and
3703 '<kbd>optimize-transparency</kbd>' methods but may be expanded to
3704 include other optimization methods as they are developed. </td>
3705 </tr>
3706
3707 <tr valign="top">
3708 <td valign="top">optimize-frame</td>
3709 <td valign="top">Optimize a coalesced animation, into GIF animation by
3710 reducing the number of pixels per frame as much as possible by
3711 attempting to pick the best layer disposal method to use, while ensuring
3712 the result will continue to animate properly. </td>
3713 </tr>
3714
3715 <tr><td></td><td> There is no guarantee that the best optimization is found. But
3716 then no reasonably fast GIF optimization algorithm can do this.
3717 However this does seem to do better than most other GIF frame
3718 optimizers seen. </td>
3719 </tr>
3720
3721 <tr valign="top">
3722 <td valign="top">optimize-plus</td>
3723 <td valign="top">As '<kbd>optimize-frame</kbd>' but attempt to improve the
3724 overall optimization by adding extra frames to the animation, without
3725 changing the final look or timing of the animation. The frames are
3726 added to attempt to separate the clearing of pixels from the
3727 overlaying of new additional pixels from one animation frame to the
3728 next. If this does not improve the optimization (for the next frame
3729 only), it will fall back to the results of the previous normal
3730 '<kbd>optimize-frame</kbd>' technique. </td>
3731 </tr>
3732
3733 <tr><td></td><td>There is the possibility that the change in the disposal style will
3734 result in a worsening in the optimization of later frames, though this
3735 is unlikely. In other words there no guarantee that it is better than
3736 the normal '<kbd>optimize-frame</kbd>' technique. For some animations
3737 however you can get a vast improvment in the final animation size. </td>
3738 </tr>
3739
3740 <tr valign="top">
3741 <td valign="top">optimize-transparency</td>
3742 <td valign="top">Given a GIF animation, replace any pixel in the sub-frame
3743 overlay images with transparency, if it does not change the resulting
3744 animation by more than the current <a href="#fuzz" >-fuzz</a> factor.
3745 </td>
3746 </tr>
3747
3748 <tr><td></td><td>This should allow a existing frame optimized GIF animation to compress
3749 into a smaller file size due to larger areas of one (transparent)
3750 color rather than a pattern of multiple colors repeating the current
3751 disposed image of the last frame. </td>
3752 </tr>
3753
3754 <tr valign="top">
3755 <td valign="top">remove-dups</td>
3756 <td valign="top">Remove (and merge time delays) of duplicate consecutive
3757 images, so as to simplify layer overlays of coalesced animations.
3758 </td>
3759 </tr>
3760
3761 <tr><td></td><td>Usually this a result of using a constant time delay across the
3762 whole animation, or after a larger animation was split into smaller
3763 sub-animations. The duplicate frames could also have been used as
3764 part of some frame optimization methods. </td>
3765 </tr>
3766
3767 <tr valign="top">
3768 <td valign="top">remove-zero</td>
3769 <td valign="top">Remove any image with a zero time delay, unless ALL the
3770 images have a zero time delay (and is not a proper timed animation, a
3771 warning is then issued). </td>
3772 </tr>
3773
3774 <tr><td></td><td>In a GIF animation, such images are usually frames which provide
3775 partial intermediary updates between the frames that are actually
3776 displayed to users. These frames are usally added for improved frame
3777 optimization in GIF animations. </td>
3778 </tr>
3779
3780 <tr valign="top">
3781 <td valign="top">trim-bounds</td>
3782 <td valign="top">Find the bounds of all the images in the current
3783 image sequence, then adjust the offsets so all images are contained on
3784 a minimal positive canvas. None of the image data is modified, only
3785 there virtual canvas size and offset. The all the image is given
3786 the same canvas size, and and will have a positive offset, but will
3787 remain in the same position relative to each other. As a result of the
3788 minimal canvas size at least one image will touch every edge of that
3789 canvas. The image data however may be transparent.
3790 </td>
3791 </tr>
3792
3793 </tbody>
3794</table>
3795
3796<p>To print a complete list of layer types, use <a href="#list">-list layers</a>.</p>
3797
3798<p>The operators <a href="#coalesce" >-coalesce</a>, <a href="#deconstruct"
3799>-deconstruct</a>, <a href="#flatten" >-flatten</a>, and <a href="#mosaic"
3800>-mosaic</a> are only aliases for the above methods. Also see <a
3801href="#page" >-page</a>, <a href="#repage" >-repage</a> operators, the <a
3802href="#compose" >-compose</a> setting, and the GIF <a href="#dispose"
3803>-dispose</a> and <a href="#delay" >-delay</a> settings. </p>
3804
3805
3806<div style="margin: auto;">
3807 <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>
3808</div>
3809
3810<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>
3811
3812<p>Given one, two or three values delimited with commas: black-point,
3813white-point, gamma (for example: 10,250,1.0 or 2%,98%,0.5). The black and
3814white points range from 0 to <em class="QR">QuantumRange</em>, or from 0 to 100%; if the white
3815point is omitted it is set to (<em class="QR">QuantumRange</em> - black_point), so as to center
3816contrast changes. If a <kbd>%</kbd> sign is present anywhere in the string,
3817both black and white points are percentages of the full color range. Gamma
3818will do a <a href="#gamma">-gamma</a> adjustment of the values. If it is
3819omitted, the default of 1.0 (no gamma correction) is assumed.</p>
3820
3821<p>In normal usage (<kbd>-level</kbd>) the image values are stretched so that
3822the given '<kbd>black_point</kbd>' value in the original image is set to
3823zero (or black), while the given '<kbd>white_point</kbd>' value is set to
3824<em class="QR">QuantumRange</em> (or white). This provides you with direct contrast adjustments
3825to the image. The '<kbd>gamma</kbd>' of the resulting image will then be
3826adjusted. </p>
3827
3828<p>From ImageMagick v6.4.1-9 using the plus form of the operator (<kbd>+level</kbd>) or
3829adding the special '!' flag anywhere in the argument list, will cause the
3830operator to do the reverse of the level adjustment. That is a zero, or
3831<em class="QR">QuantumRange</em> value (black, and white, resp.) in the original image, is
3832adjusted to the given level values, allowing you to de-contrast, or compress
3833the channel values within the image. The '<kbd>gamma</kbd>' is adjusted before the level adjustment to de-contrast the image is made. </p>
3834
3835<p>Only the channels defined by the current <a href="#channel">-channel</a>
3836setting are adjusted (defaults to RGB color channels only), allowing you to
3837limit the effect of this operator. </p>
3838
3839<p>Please note that the transparency channel is treated as 'matte'
3840values (0 is opaque) and not as 'alpha' values (0 is transparent).</p>
3841
3842
3843<div style="margin: auto;">
3844 <h4><a name="level-colors" id="level-colors"></a>-level-colors {<em
3845 class="arg">black_color</em>}{,}{<em class="arg">white_color</em>}</h4>
3846</div>
3847
3848<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>
3849
3850<p>This function is exactly like <a href="#level">-level</a>, except that the
3851value value for each color channel is determined by the
3852'<kbd>black_color</kbd>' and '<kbd>white_color</kbd>' colors given (as
3853described under the <a href="#fill">-fill</a> option). </p>
3854
3855<p>This effectivally means the colors provided to <kbd>-level-colors</kbd>
3856is mapped to become 'black' and 'white' respectivally, with all the other
3857colors linearly adjusted (or clipped) to match that change. Each channel is
3858adjusted separatally using the channel values of the colors specified. </p>
3859
3860<p>On the other hand the plus form of the operator (<kbd>+level-colors</kbd>)
3861will map the image color 'black' and 'white' to the given colors
3862respectivally, resulting in a gradient (de-contrasting) tint of the image to
3863those colors. This can also be used to convert a plain gray-scale image into a
3864one using the gradient of colors specified. </p>
3865
3866<p>By supplying a single color with a comma separator either before or after
3867that color, will just replace the respective 'black' or 'white' point
3868respectivally. But if no comma separator is provided, the given color is
3869used for both the black and white color points, making the operator either
3870threshold the images around that color (- form) or set all colors to that
3871color (+ form). </p>
3872
3873
3874<div style="margin: auto;">
3875 <h4><a name="limit" id="limit"></a>-limit <em class="arg">type value</em></h4>
3876</div>
3877
3878<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>
3879
3880<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>
3881
cristy6b636652009-12-05 17:16:11 +00003882<p>The value for <kbd>file</kbd> is in number of files. The other limits are in bytes. By default the limits are 768 files, 2GB of image area, 1.5GiB memory, 8GiB memory map, and 18.45EB of disk. These limits are adjusted relative to the available resources on your computer if this information is available. When any limit is reached, ImageMagick fails in some fashion but attempts to take compensating actions, if possible. For example, the following limits memory:</p>
cristy3ed852e2009-09-05 21:47:34 +00003883
3884<p class="crtsnip">
cristyd934d102009-10-10 12:55:13 +00003885 -limit memory 32MiB -limit map 64MiB
cristy3ed852e2009-09-05 21:47:34 +00003886</p>
3887
3888<p>Use <a href="#list">-list resource</a> to list the current limits. For example, our system shows these limits:</p>
3889
cristy6b636652009-12-05 17:16:11 +00003890<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>identify -list resource</span><span class='crtout'><pre>File Area Memory Map Disk Thread Time
3891------------------------------------------------------------------------------
3892 768 12.404GB 8.6642GiB 23.104GiB 18.446744EB 8 unlimited</pre>
cristy3ed852e2009-09-05 21:47:34 +00003893</span></p>
3894<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">&#x2011;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>
3895
3896<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>
3897
3898<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>
3899
3900<p class="crtsnip">
3901-limit area 10mb
3902</p>
3903
3904<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>
3905
3906<p class="crtsnip">
3907-limit area 10mb -limit disk 500mb
3908</p>
3909
3910<p>Here ImageMagick stops processing if an image requires more than 500MB of disk storage.</p>
3911
3912<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>
3913
3914<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.
3915</p>
3916
3917<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.
3918</p>
3919
3920<div style="margin: auto;">
3921 <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>
3922</div>
3923
3924<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>
3925
cristyd934d102009-10-10 12:55:13 +00003926<p>This is very similar to <a href="#contrast-stretch" >-contrast-stretch</a>,
3927and uses a 'histogram bin' to determine the range of color values that needs to
3928be stretched. However it then stretchs those colors using the <a
3929href="#level" >-level</a> operator.</p>
3930
3931<p>As such while the initial determination may have 'binning' round off
3932effects, the image colors are stretched mathematically, rather than using the
3933histogram bins. This makes the operator more accurate. </p>
3934
3935<p>note however that a <a href="#linear-stretch" >-linear-stretch</a> of
3936'<kbd>0</kbd>' does nothing, while a value of '<kbd>1</kbd>' does a near
3937perfect stretch of the color range. </p>
3938
3939<p>See also <a href="#auto-level" >-auto-level</a> for a 'perfect'
3940normalization of mathematical images. </p>
3941
3942<p>This operator is under review for re-development. </p>
3943
3944
cristy3ed852e2009-09-05 21:47:34 +00003945<div style="margin: auto;">
3946 <h4><a name="linewidth" id="linewidth"></a>-linewidth</h4>
3947</div>
3948
3949<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>
3950
3951<div style="margin: auto;">
3952 <h4><a name="liquid-rescale" id="liquid-rescale"></a>-liquid-rescale <em class="arg">geometry</em></h4>
3953</div>
3954
3955<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>
3956
3957<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>
3958
3959<div style="margin: auto;">
3960 <h4><a name="list" id="list"></a>-list <em class="arg">type</em></h4>
3961</div>
3962
3963<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>
3964
3965<pre class="text">
3966 coder
3967 color
3968 configure
3969 delegate
3970 font
3971 format
3972 list
3973 log
3974 magic
3975 module
3976 resource
3977 threshold
3978</pre>
3979
3980<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>
3981
3982<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>identify -list list</span></p>
3983<div style="margin: auto;">
3984 <h4><a name="log" id="log"></a>-log <em class="arg">string</em></h4>
3985</div>
3986
3987<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>
3988
3989<p>This option specifies the format for the log printed when the <a href="#debug">-debug</a> option is active.</p>
3990
3991<p>You can display the following components by embedding special format characters:</p>
3992
3993<pre class="text">
3994 %d domain
3995 %e event
3996 %f function
3997 %l line
3998 %m module
3999 %p process ID
4000 %r real CPU time
4001 %t wall clock time
4002 %u user CPU time
4003 %% percent sign
4004 \n newline
4005 \r carriage return
4006</pre>
4007
4008<p>For example:</p>
4009
4010<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert -debug coders -log "%u %m:%l %e" in.gif out.png</span></p>
4011<p>The default behavior is to print all of the components.</p>
4012
4013<div style="margin: auto;">
4014 <h4><a name="loop" id="loop"></a>-loop <em class="arg">iterations</em></h4>
4015</div>
4016
4017<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>
4018
4019<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>
4020
4021<div style="margin: auto;">
4022 <h4><a name="lowlight-color" id="lowlight-color"></a>-lowlight-color <em class="arg">color</em></h4>
4023</div>
4024
4025<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>
4026
4027<div style="margin: auto;">
4028 <h4><a name="magnify" id="magnify"></a>-magnify <em class="arg">factor</em></h4>
4029</div>
4030
4031<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>
4032
4033
4034<div style="margin: auto;">
4035 <h4><a name="map" id="map"></a>-map <em class="arg">type</em></h4>
4036</div>
4037
4038<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>
4039
4040<p>Choose from these <em class="arg">Standard Colormap</em> types:</p>
4041
4042<pre class="text">
4043 best
4044 default
4045 gray
4046 red
4047 green
4048 blue
4049</pre>
4050
4051<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>
4052
4053
4054<div style="margin: auto;">
4055 <h4><a name="map_stream_" id="map_stream_"></a>-map <em class="arg">components</em></h4>
4056</div>
4057
4058<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>
4059
4060<p>Here are the valid components of a map:</p>
4061
4062<pre class="text">
4063 r red pixel component
4064 g green pixel component
4065 b blue pixel component
4066 a alpha pixel component (0 is transparent)
4067 o opacity pixel component (0 is opaque)
4068 i grayscale intensity pixel component
4069 c cyan pixel component
4070 m magenta pixel component
4071 y yellow pixel component
4072 k black pixel component
4073 p pad component (always 0)
4074</pre>
4075
4076<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>
4077
4078<div style="margin: auto;">
4079 <h4><a name="mask" id="mask"></a>-mask
4080<em class="arg">filename</em></h4>
4081</div>
4082
4083<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>
4084
4085<p>Use <a href="#mask">+mask</a> to remove the image mask.</p>
4086
4087<div style="margin: auto;">
4088 <h4><a name="mattecolor" id="mattecolor"></a>-mattecolor <em class="arg">color</em></h4>
4089</div>
4090
4091<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>
4092
4093<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p>
4094
4095<p>The default matte color is <kbd>#BDBDBD</kbd>, <span style="background-color: #bdbdbd;">this shade of gray</span>.</p>
4096
4097<div style="margin: auto;">
4098 <h4><a name="median" id="median"></a>-median <em class="arg">radius</em></h4>
4099</div>
4100
4101<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>
4102
4103<div style="margin: auto;">
4104 <h4><a name="metric" id="metric"></a>-metric <em class="arg">type</em></h4>
4105</div>
4106
4107<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>
4108
4109<p>Choose from:</p>
4110
4111<pre class="text">
4112 AE absolute number of differnet pixels
4113 MAE mean absolute error (normalized), average channel error distance
4114 MEPP mean error per pixel (normalized mean error, normalized peak error)
4115 MSE mean error squared, average of the channel error squared
4116 PAE peak absolute (normalize peak absolute)
4117 PSNR peak signal to noise ratio
4118 RMSE root mean squared (normalized root mean squared)
4119</pre>
4120
4121<p>The '<kbd>AE</kbd>' or absolute count of pixels that are different, can be
4122controled using a <a href="#fuzz" >-fuzz</a> factor to ignore pixels which
4123only changed by a small amount. The '<kbd>PAE</kbd>' can be used to find the
4124size of the <a href="#fuzz" >-fuzz</a> factor needed to make all pixels
4125'similar'. </p>
4126
4127<p>The '<kbd>MEPP</kbd>' metric returns three different metrics
4128('<kbd>MAE</kbd>', '<kbd>MAE</kbd>' normalized, and '<kbd>PAE</kbd>'
4129normalized) from the single comparision run. </p>
4130
4131<p>To print a complete list of metrics, use the <a href="#list">-list metrics</a> option.</p>
4132
4133
4134<div style="margin: auto;">
4135 <h4><a name="mode" id="mode"></a>-mode <em class="arg">value</em></h4>
4136</div>
4137
4138<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>
4139
4140<p>Choose the <em class="arg">value</em> from these styles: <kbd>Frame, Unframe, or Concatenate</kbd></p>
4141
4142<p>Use the <a href="#list" >-list</a> option with a '<kbd>Mode</kbd>'
4143argument for a list of <a href="#mode" >-mode</a> arguments available
4144in your ImageMagick installation.</p>
4145
4146
4147<div style="margin: auto;">
4148 <h4><a name="modulate" id="modulate"></a>-modulate <em class="arg">brightness</em>[,<em class="arg">saturation</em>,<em class="arg">hue</em>]</h4>
4149</div>
4150
4151<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>
4152
4153<p>The arguments are given as a percentages of variation. A value of 100 means no change, and any
4154missing values are taken to mean 100.</p>
4155
4156<p>The <em class="arg">brightness</em> is a multiplier of the overall brightness of the image, so 0
4157means pure black, 50 is half as bright, 200 is twice as bright. To invert its
4158meaning <a href="#negate">-negate</a> the image before and after. </p>
4159
4160<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>
4161
4162<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
4163shades to purple, and so on. A value of either 0 or 200 results in a complete
4164180 degree rotation of the image. Using a value of 300 is a 360 degree
4165rotation resulting in no change to the original image. </p>
4166
4167<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>
4168
4169<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>
4170
4171<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert image.png -set option:modulate:colorspace hsb -modulate 120,90 modulate.png</span></p>
4172<div style="margin: auto;">
4173 <h4><a name="monitor" id="monitor"></a>-monitor</h4>
4174</div>
4175
4176<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>
4177
4178
4179<div style="margin: auto;">
4180 <h4><a name="monochrome" id="monochrome"></a>-monochrome</h4>
4181</div>
4182
4183<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>
4184
4185
4186<div style="margin: auto;">
4187 <h4><a name="morph" id="morph"></a>-morph <em class="arg">frames</em></h4>
4188</div>
4189
4190<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>
4191
4192<p>Both the image pixels and size are linearly interpolated to give the
4193appearance of a meta-morphosis from one image to the next, over all the images
4194in the current image list. The added images are the equivalent of a <a
4195href="#blend">-blend</a> composition. The <em class="arg">frames</em>
4196argument determine how many images to interpolate between each image. </p>
4197
4198
4199<div style="margin: auto;">
4200 <h4><a name="mosaic" id="mosaic"></a>-mosaic</h4>
4201</div>
4202
4203<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>
4204
4205
4206<div style="margin: auto;">
4207 <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>
4208</div>
4209
4210<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>
4211
4212<p>Blur with the given radius, standard deviation (sigma), and angle. The
4213angle given is the angle toward which the image is blurred. That is the
4214direction people would consider the object is coming from. </p>
4215
4216<p>Note that the blur is not uniform distribution, giving the motion a
4217definate sense of direction of movement. </p>
4218
4219<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how
4220pixels which are outside the image proper are blurred into the final result.
4221</p>
4222
4223<div style="margin: auto;">
4224 <h4><a name="name" id="name"></a>-name</h4>
4225</div>
4226
4227<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>
4228<div style="margin: auto;">
4229 <h4><a name="negate" id="negate"></a>-negate</h4>
4230</div>
4231
4232<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>
4233
4234<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>
4235
4236<div style="margin: auto;">
4237 <h4><a name="noise" id="noise"></a>-noise <em class="arg">radius</em><br/>
4238 +noise <em class="arg">type</em></h4>
4239</div>
4240
4241<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>
4242
4243<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>
4244
4245<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>
4246
4247<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>
4248
4249<pre class="text">
4250Gaussian
4251Impulse
4252Laplacian
4253Multiplicative
4254Poisson
4255Random
4256Uniform
4257</pre>
4258
4259<p>To print a complete list of noises, use the <a href="#list">-list noise</a> option.</p>
4260
cristy83543962009-10-16 19:04:28 +00004261<p>Also see the <a href="#evaluate">-evaluate</a> noise functions that allos
4262the use of a controlling value to specify teh amount of noise that should be
4263added to an image. </p>
4264
cristy3ed852e2009-09-05 21:47:34 +00004265
4266<div style="margin: auto;">
4267 <h4><a name="normalize" id="normalize"></a>-normalize</h4>
4268</div>
4269
4270<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>
4271
cristyd934d102009-10-10 12:55:13 +00004272<p>The intensity values are stretched to cover the entire range of possible
4273values. While doing so, black-out at most <em>2%</em> of the pixels and
4274white-out at most <em>1%</em> of the pixels.</p>
cristy3ed852e2009-09-05 21:47:34 +00004275
cristyd934d102009-10-10 12:55:13 +00004276<p>Note that as of ImageMagick 6.4.7-0, <a href="#normalize" >-normalize</a>
4277is equivalent to <a href="#contrast-stretch" >-contrast-stretch 2%x1%</a>.
4278(Before this version, it was equivalent to <a href="#contrast-stretch"
4279>-contrast-stretch 2%x99%</a>).</p>
cristy3ed852e2009-09-05 21:47:34 +00004280
cristyd934d102009-10-10 12:55:13 +00004281<p>All the channels are normalized in concert by the came amount so as to
4282preserve color integrity, when the default <a href="#channel" >+channel</a>
4283setting is in use. Specifing any other <a href="#channel" >-channel</a>
4284setting will normalize the RGB channels independently.</p>
4285
4286<p>See <a href="#contrast-stretch" >-contrast-stretch</A> for more details.
4287Also see <a href="#auto-level" >-auto-level</a> for a 'perfect' normalization
cristy83543962009-10-16 19:04:28 +00004288that is better suited to mathematically generated images. </p>
cristyd934d102009-10-10 12:55:13 +00004289
4290<p>This operator is under review for re-development. </p>
cristy3ed852e2009-09-05 21:47:34 +00004291
4292
4293<div style="margin: auto;">
4294 <h4><a name="ordered-dither" id="ordered-dither"></a>-ordered-dither <em class="arg">threshold_map</em>{,<em class="arg">level</em>...}</h4>
4295</div>
4296
cristyd934d102009-10-10 12:55:13 +00004297<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
4298class="arg">threshold map</em> specified, and a uniform color map with the
4299given number of <em class="arg">levels</em> per color channel . </td><td style='text-align:right;'></td></tr></table>
cristy3ed852e2009-09-05 21:47:34 +00004300
4301<p>You can choose from these standard threshold maps:</p>
4302
4303<pre class="text">
cristyd934d102009-10-10 12:55:13 +00004304 threshold
cristy3ed852e2009-09-05 21:47:34 +00004305 checks
4306 o2x2
4307 o3x3
4308 o4x4
4309 o8x8
4310 h4x4a
4311 h6x6a
4312 h8x8a
4313 h4x4o
4314 h6x6o
4315 h8x8o
4316 h16x16o
4317</pre>
4318
cristyd934d102009-10-10 12:55:13 +00004319<p>The '<kbd>o</kbd>' maps are ordered diffused pixel threshold maps, while the
4320'<kbd>h</kbd>' maps are halftone threshold maps which are either 'a' angled, or
4321'o' orthogonal. The '<kbd>checks</kbd>' produce a 3 level checkerbord dither
4322pattern. Or you can define your own <em class="arg" >threshold map</em> in a
4323personal or system "<kbd>thresholds.xml</kbd>" XML file. </p>
cristy3ed852e2009-09-05 21:47:34 +00004324
cristyd934d102009-10-10 12:55:13 +00004325<p>To print a complete list of threshold, use the <a href="#list" >-list
4326threshold</a> option.</p>
cristy3ed852e2009-09-05 21:47:34 +00004327
cristyd934d102009-10-10 12:55:13 +00004328<p>It is recommended that the <a href="#map" >+map</a> operator be used after
4329applying <a href="#ordered-dither" >-ordered-dither</a> to reduce the number of
cristy3ed852e2009-09-05 21:47:34 +00004330colors an animated image sequence, to less that 256 colors. This ensures that
4331a common or global color table is used when saving the result to a color
4332limited file format such as GIF. </p>
4333
cristyd934d102009-10-10 12:55:13 +00004334<p>Note that at this time the exact same threshold dithering map is used for
4335all color channels, no attempt is made to offset or rotate the map for
4336different channels is made, to create an offset printing effect. (possible
4337future expansion) </p>
cristy3ed852e2009-09-05 21:47:34 +00004338
4339
4340<div style="margin: auto;">
4341 <h4><a name="opaque" id="opaque"></a>-opaque <em class="arg">color</em></h4>
4342</div>
4343
4344<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>
4345
cristyc54f5d42009-11-27 21:36:31 +00004346<p>The <em class="arg">color</em> argument is defined using the format
cristyd934d102009-10-10 12:55:13 +00004347described under the <a href="#fill" >-fill</a> option. The <a href="#fuzz"
4348>-fuzz</a> setting can be used to match and replace colors similar to the one
4349given.</p>
cristy3ed852e2009-09-05 21:47:34 +00004350
cristyd934d102009-10-10 12:55:13 +00004351<p>The <a href="#transparent" >-transparent</a> operator is exactly the same
4352as <a href="#opaque" >-opaque</a> but makes the matching color transparent,
cristy3ed852e2009-09-05 21:47:34 +00004353rather than the same as the current <a href="#fill">-fill</a> color. </p>
4354
cristyc54f5d42009-11-27 21:36:31 +00004355<p>Use <a href="#opaque">+opaque</a> to paint any pixel that does not match the target color.</p>
cristyd934d102009-10-10 12:55:13 +00004356
4357
cristy3ed852e2009-09-05 21:47:34 +00004358
4359<div style="margin: auto;">
4360 <h4><a name="orient" id="orient"></a>-orient <em class="arg">image orientation</em></h4>
4361</div>
4362
4363<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>
4364
4365<p>Choose from these orientations:</p>
4366
4367<pre class="text">
4368 bottom-left
4369 bottom-right
4370 left-bottom
4371 left-top
4372 right-bottom
4373 right-top
4374 top-left
4375 top-right
4376 undefined
4377</pre>
4378
cristyd934d102009-10-10 12:55:13 +00004379<p>To print a complete list of orientations, use the <a href="#list" >-list
4380orientation</a> option.</p>
cristy3ed852e2009-09-05 21:47:34 +00004381
4382
4383<div style="margin: auto;">
4384 <h4><a name="page" id="page"></a>-page <em class="arg">geometry</em><br/>
4385 -page <em class="arg">media</em>[<em class="arg">offset</em>][{<em class="arg">^!&lt;&gt;</em>}]<br/>
4386 +page
4387 </h4>
4388</div>
4389
4390<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>
4391
4392<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>
4393
4394<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>&nbsp;<kbd>Letter+43+43</kbd>).</p>
4395
4396<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>
4397<table id="geometryTable" cellpadding="2" cellspacing="0" border="1" width="50%" style="margin-left: auto; margin-right: auto;">
4398<thead>
4399 <tr valign="top">
4400 <th align="center"><em class="arg">media</em></th>
4401 <th align="center"><em class="arg">width</em></th>
4402 <th align="center"><em class="arg">height</em></th>
4403 </tr>
4404</thead>
4405<tbody>
4406<tr><td align="left"> 11x17 </td> <td align="right"> 792</td> <td align="right"> 1224</td> </tr>
4407<tr><td align="left"> Ledger </td> <td align="right"> 1224</td> <td align="right"> 792</td> </tr>
4408<tr><td align="left"> Legal </td> <td align="right"> 612</td> <td align="right"> 1008</td> </tr>
4409<tr><td align="left"> Letter </td> <td align="right"> 612</td> <td align="right"> 792</td> </tr>
4410<tr><td align="left"> LetterSmall</td> <td align="right"> 612</td> <td align="right"> 792</td> </tr>
4411<tr><td align="left"> ArchE </td> <td align="right"> 2592</td> <td align="right"> 3456</td> </tr>
4412<tr><td align="left"> ArchD </td> <td align="right"> 1728</td> <td align="right"> 2592</td> </tr>
4413<tr><td align="left"> ArchC </td> <td align="right"> 1296</td> <td align="right"> 1728</td> </tr>
4414<tr><td align="left"> ArchB </td> <td align="right"> 864</td> <td align="right"> 1296</td> </tr>
4415<tr><td align="left"> ArchA </td> <td align="right"> 648</td> <td align="right"> 864</td> </tr>
4416<tr><td align="left"> A0 </td> <td align="right"> 2380</td> <td align="right"> 3368</td> </tr>
4417<tr><td align="left"> A1 </td> <td align="right"> 1684</td> <td align="right"> 2380</td> </tr>
4418<tr><td align="left"> A2 </td> <td align="right"> 1190</td> <td align="right"> 1684</td> </tr>
4419<tr><td align="left"> A3 </td> <td align="right"> 842</td> <td align="right"> 1190</td> </tr>
4420<tr><td align="left"> A4 </td> <td align="right"> 595</td> <td align="right"> 842</td> </tr>
4421<tr><td align="left"> A4Small </td> <td align="right"> 595</td> <td align="right"> 842</td> </tr>
4422<tr><td align="left"> A5 </td> <td align="right"> 421</td> <td align="right"> 595</td> </tr>
4423<tr><td align="left"> A6 </td> <td align="right"> 297</td> <td align="right"> 421</td> </tr>
4424<tr><td align="left"> A7 </td> <td align="right"> 210</td> <td align="right"> 297</td> </tr>
4425<tr><td align="left"> A8 </td> <td align="right"> 148</td> <td align="right"> 210</td> </tr>
4426<tr><td align="left"> A9 </td> <td align="right"> 105</td> <td align="right"> 148</td> </tr>
4427<tr><td align="left"> A10 </td> <td align="right"> 74</td> <td align="right"> 105</td> </tr>
4428<tr><td align="left"> B0 </td> <td align="right"> 2836</td> <td align="right"> 4008</td> </tr>
4429<tr><td align="left"> B1 </td> <td align="right"> 2004</td> <td align="right"> 2836</td> </tr>
4430<tr><td align="left"> B2 </td> <td align="right"> 1418</td> <td align="right"> 2004</td> </tr>
4431<tr><td align="left"> B3 </td> <td align="right"> 1002</td> <td align="right"> 1418</td> </tr>
4432<tr><td align="left"> B4 </td> <td align="right"> 709</td> <td align="right"> 1002</td> </tr>
4433<tr><td align="left"> B5 </td> <td align="right"> 501</td> <td align="right"> 709</td> </tr>
4434<tr><td align="left"> C0 </td> <td align="right"> 2600</td> <td align="right"> 3677</td> </tr>
4435<tr><td align="left"> C1 </td> <td align="right"> 1837</td> <td align="right"> 2600</td> </tr>
4436<tr><td align="left"> C2 </td> <td align="right"> 1298</td> <td align="right"> 1837</td> </tr>
4437<tr><td align="left"> C3 </td> <td align="right"> 918</td> <td align="right"> 1298</td> </tr>
4438<tr><td align="left"> C4 </td> <td align="right"> 649</td> <td align="right"> 918</td> </tr>
4439<tr><td align="left"> C5 </td> <td align="right"> 459</td> <td align="right"> 649</td> </tr>
4440<tr><td align="left"> C6 </td> <td align="right"> 323</td> <td align="right"> 459</td> </tr>
4441<tr><td align="left"> Flsa </td> <td align="right"> 612</td> <td align="right"> 936</td> </tr>
4442<tr><td align="left"> Flse </td> <td align="right"> 612</td> <td align="right"> 936</td> </tr>
4443<tr><td align="left"> HalfLetter </td> <td align="right"> 396</td> <td align="right"> 612</td> </tr>
4444</tbody>
4445</table>
4446
4447
4448
4449
4450<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>
4451
4452<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>
4453
4454<p>The default page dimensions for a TEXT image is 612x792.</p>
4455
4456<p>This option is used in concert with <a href="#density">-density</a>.</p>
4457
4458<p>Use <a href="#page">+page</a> to remove the page settings for an image.</p>
4459
4460<div style="margin: auto;">
4461 <h4><a name="paint" id="paint"></a>-paint <em class="arg">radius</em></h4>
4462</div>
4463
4464<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>
4465
4466<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>
4467
4468<div style="margin: auto;">
4469 <h4><a name="path" id="path"></a>-path <em class="arg">path</em></h4></div>
4470
4471<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>
4472
4473<div style="margin: auto;">
4474 <h4><a name="pause_animate_" id="pause_animate_"></a>-pause <em class="arg">seconds</em></h4>
4475</div>
4476
4477<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>
4478
4479<p>Pause for the specified number of seconds before repeating the animation.</p>
4480
4481<div style="margin: auto;">
4482 <h4><a name="pause_import_" id="pause_import_"></a>-pause <em class="arg">seconds</em></h4>
4483</div>
4484
4485<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>
4486
4487<p>Pause for the specified number of seconds before taking the next snapshot.</p>
4488
4489<div style="margin: auto;">
4490 <h4><a name="ping" id="ping"></a>-ping</h4>
4491</div>
4492
4493<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>
4494
4495<div style="margin: auto;">
4496 <h4><a name="pointsize" id="pointsize"></a>-pointsize <em class="arg">value</em></h4>
4497</div>
4498
4499<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>
4500
4501<div style="margin: auto;">
4502 <h4><a name="polaroid" id="polaroid"></a>-polaroid <em class="arg">angle</em></h4>
4503</div>
4504
4505<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>
4506
4507<p>Use <kbd>+polaroid</kbd> to rotate the image at a random angle between -15 and +15 degrees.</p>
4508
4509<div style="margin: auto;">
4510 <h4><a name="posterize" id="posterize"></a>-posterize <em class="arg">levels</em></h4>
4511</div>
4512
4513<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>
4514
4515<div style="margin: auto;">
cristyd43a46b2010-01-21 02:13:41 +00004516 <h4><a name="precision" id="precision"></a>-precision <em class="arg">value</em></h4>
4517</div>
4518
4519<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>set the maximum number of significant digits to be printed.</td><td style='text-align:right;'></td></tr></table>
4520
4521<div style="margin: auto;">
cristy3ed852e2009-09-05 21:47:34 +00004522 <h4><a name="preview" id="preview"></a>-preview <em class="arg">type</em></h4>
4523</div>
4524
4525<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>
4526
4527<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>
4528
4529<pre class="text">
4530 Rotate
4531 Shear
4532 Roll
4533 Hue
4534 Saturation
4535 Brightness
4536 Gamma
4537 Spiff
4538 Dull
4539 Grayscale
4540 Quantize
4541 Despeckle
4542 ReduceNoise
4543 Add Noise
4544 Sharpen
4545 Blur
4546 Threshold
4547 EdgeDetect
4548 Spread
4549 Shade
4550 Raise
4551 Segment
4552 Solarize
4553 Swirl
4554 Implode
4555 Wave
4556 OilPaint
4557 CharcoalDrawing
4558 JPEG
4559</pre>
4560
4561<p>To print a complete list of previews, use the <a href="#list">-list preview</a> option.</p>
4562
4563<p>The default preview is <kbd>JPEG</kbd>.</p>
4564
4565<div style="margin: auto;">
4566 <h4><a name="print" id="print"></a>-print <em class="arg">string</em></h4>
4567</div>
4568
4569<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>
4570
4571<div style="margin: auto;">
4572 <h4><a name="process" id="process"></a>-process <em class="arg">command</em></h4>
4573</div>
4574
4575<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>
4576
4577<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>
4578
4579<div style="margin: auto;">
4580 <h4><a name="profile" id="profile"></a>-profile <em class="arg">filename</em><br/>
4581 +profile <em class="arg">profile_name</em></h4>
4582</div>
4583
4584<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>
4585
4586<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>
4587
4588<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>
4589
4590<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>
4591
4592<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>
4593
4594<p>For example, to extract the Exif data (which is stored in JPEG files in the <em class="arg">APP1</em> profile), use.</p>
4595
4596<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert cockatoo.jpg profile.exif</span></p>
4597<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>
4598
4599<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert CMYK.tif -profile "CMYK.icc" -profile "RGB.icc" RGB.tiff</span></p>
4600<p>Furthermore, since ICC profiles are not necessarily symmetric, extra conversion steps can yield unwanted results.
4601CMYK profiles are often very asymmetric since they involve 3&minus;&gt;4 and 4&minus;&gt;3 channel mapping.
4602</p>
4603
4604<div style="margin: auto;">
4605 <h4><a name="quality" id="quality"></a>-quality <em class="arg">value</em></h4>
4606</div>
4607
4608<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>
4609
4610<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>
4611
4612<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>
4613
4614<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>
4615
4616<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>
4617
4618<p>If filter-type is 4 or less, the specified filter-type is used for all scanlines:</p>
4619
4620<pre class="text">
4621 0: none
4622 1: sub
4623 2: up
4624 3: average
4625 4: Paeth
4626</pre>
4627
4628<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>
4629
4630<p>If filter-type is 6, adaptive filtering with <em class="arg">minimum-sum-of-absolute-values</em> is used.</p>
4631
4632<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>
4633
4634<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>
4635
4636<p>For further information, see the <a href="http://www.w3.org/pub/WWW/TR">PNG</a> specification.</p>
4637
4638<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>
4639
4640<div style="margin: auto;">
4641 <h4><a name="quantize" id="quantize"></a>-quantize <em class="arg">colorspace</em></h4>
4642</div>
4643
4644<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>
4645
4646<p>To print a complete list of colorspaces, use the <a href="#list">-list colorspace</a> option.</p>
4647
4648
4649<div style="margin: auto;">
4650 <h4><a name="quiet" id="quiet"></a>-quiet</h4>
4651</div>
4652
4653<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>
4654
4655<div style="margin: auto;">
4656 <h4><a name="radial-blur" id="radial-blur"></a>-radial-blur <em class="arg">angle</em></h4>
4657</div>
4658
4659<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>
4660
4661<p>Note that this is actually a rotational blur rather than a radial and as
4662such actually mis-named. </p>
4663
4664<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how
4665pixels which are outside the image proper are blurred into the final result.
4666</p>
4667
4668
4669<div style="margin: auto;">
4670 <h4><a name="raise" id="raise"></a>-raise <em class="arg">thickness</em></h4>
4671</div>
4672
4673<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>
4674
4675<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>.
4676</p>
4677
4678<p>Unlike the similar <a href="#frame">-frame</a> option, <a href="#raise">-raise</a> does not alter the dimensions of the image.</p>
4679
4680<div style="margin: auto;">
4681 <h4><a name="random-threshold" id="random-threshold"></a>-random-threshold <em class="arg">low</em>x<em class="arg">high</em></h4>
4682</div>
4683
4684<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>
4685
4686<div style="margin: auto;">
4687 <h4><a name="recolor" id="recolor"></a>-recolor <em class="arg">matrix</em></h4>
4688</div>
4689
4690<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>
4691
cristy2744bd92009-11-08 22:57:52 +00004692<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. The translation matrix is similar to that used by Adobe
4693Flash except that the offset is scaled to 1.0 (divide Flash offset by 255).</p>
cristy3ed852e2009-09-05 21:47:34 +00004694
4695<div style="margin: auto;">
4696 <h4><a name="red-primary" id="red-primary"></a>-red-primary <em class="arg">x,y</em></h4>
4697</div>
4698
4699<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>
4700
4701<div style="margin: auto;">
4702 <h4><a name="regard-warnings" id="regard-warnings"></a>-regard-warnings</h4>
4703</div>
4704
4705<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>
4706
4707<div style="margin: auto;">
4708 <h4><a name="remap" id="remap"></a>-remap <em class="arg">filename</em></h4>
4709</div>
4710
4711<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>
4712
4713<p>If the <a href="#dither">-dither</a> setting is enabled (the default) then
4714the given colors are dithered over the image as necessary, otherwise the closest
4715color (in RGB colorspace) is selected to replace that pixel in the image. </p>
4716
4717<p>As a side effect of applying a <a href="#remap">-remap</a> of colors across all
4718images in the current image sequence, all the images will have the same color
4719table. That means that when saved to a file format such as GIF, it will use
4720that color table as a single common or global color table, for all the images,
4721without requiring extra local color tables. </p>
4722
4723<p>Use <a href="#remap">+remap</a> to reduce all images in the current image
4724sequence to use a common color map over all the images. This equivalent to
4725appending all the images together (without extra background colors) and color
4726reducing those images using <a href="#colors">-colors</a> with a 256 color
4727limit, then <a href="#remap">-remap</a> those colors over the original list of
4728images. This ensures all the images follow a single color map. </p>
4729
4730<p>If the number of colors over all the images is less than 256, then <a
4731href="#remap">+remap</a> should not perform any color reduction or dithering, as
4732no color changes are needed. In that case, its only effect is to force the use
4733of a global color table. This recommended after using either <a
4734href="#colors">-colors</a> or <a href="#ordered-dither">-ordered-dither</a> to
4735reduce the number of colors in an animated image sequence. </p>
4736
4737<div style="margin: auto;">
4738 <h4><a name="region" id="region"></a>-region <em class="arg">geometry</em></h4>
4739</div>
4740
4741<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>
4742
4743<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>
4744
4745<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>
4746
4747<div style="margin: auto;">
4748 <h4><a name="remote" id="remote"></a>-remote</h4>
4749</div>
4750
4751<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>
4752
4753<p>The only command recognized is the name of an image file to load.</p>
4754
4755<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>
4756
4757<div style="margin: auto;">
4758 <h4><a name="render" id="render"></a>-render</h4>
4759</div>
4760
4761<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>
4762
4763<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>
4764
4765<div style="margin: auto;">
4766<h4><a name="repage" id="repage"></a>-repage <em class="arg">geometry</em></h4>
4767</div>
4768
4769<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>
4770
4771<p>This option is like <a href="#page">-page</a> but acts as an image operator
4772rather than a setting. You can separately set the canvas size or the offset
4773of the image on that canvas by only providing those components. </p>
4774
4775<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>
4776
4777<p>If a <kbd>!</kbd> flag is given the offset given is added to the existing
4778offset to move the image relative to its previous position. This useful for
4779animation sequences. </p>
4780
4781<p>A given a canvas size of zero such as '<kbd>0x0</kbd>' forces it to
4782recalculate the canvas size so the image (at its current offset) will appear
4783completely on that canvas (unless it has a negative offset).</p>
4784
4785<p>Use <a href="#repage">+repage</a> to completely remove/reset the virtual
4786canvas meta-data from the images. </p>
4787
4788<p>The <a href="#set">-set</a> '<kbd>page</kbd>' option can be used to
4789directly assign virtual canvas meta-data. </p>
4790
4791
4792<div style="margin: auto;">
4793 <h4><a name="resample" id="resample"></a>-resample <em class="arg">horizontal</em>x<em class="arg">vertical</em></h4>
4794</div>
4795
4796<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>
4797
4798<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>
4799
4800<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>
4801
4802<div style="margin: auto;">
4803 <h4><a name="resize" id="resize"></a>-resize <em class="arg">geometry</em></h4>
4804</div>
4805
4806<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>
4807
4808<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>
4809
4810<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>
4811
4812<div style="margin: auto;">
4813 <h4><a name="respect-parentheses" id="respect-parentheses"></a>-respect-parentheses</h4>
4814</div>
4815
4816<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>
4817
4818<div style="margin: auto;">
4819 <h4><a name="reverse" id="reverse"></a>-reverse</h4>
4820</div>
4821
4822<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>
4823
4824
4825<div style="margin: auto;">
4826 <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>
4827</div>
4828
4829<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>
4830
4831<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>
4832
4833
4834<div style="margin: auto;">
4835 <h4><a name="rotate" id="rotate"></a>-rotate <em class="arg">degrees</em>{<em class="arg">&lt;</em>}{<em class="arg">&gt;</em>}</h4>
4836</div>
4837
4838<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>
4839
4840<p>Use <kbd>&gt;</kbd> to rotate the image only if its width exceeds the height. <kbd>&lt;</kbd> rotates the image <em>only</em> if its width is less than the height. For example, if you specify <kbd>-rotate "-90&gt;"</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>&gt;</kbd> or <kbd>&lt;</kbd>, enclose it in quotation marks to prevent it from being misinterpreted as a file redirection.</p>
4841
4842<p>Empty triangles in the corners, left over from rotating the image, are
4843filled with the <kbd>background</kbd> color. </p>
4844
4845<p>See also the <a href="#distort">-distort</a> operator and specifically the
4846'<kbd>ScaleRotateTranslate</kbd>' distort method. </p>
4847
4848
4849<div style="margin: auto;">
4850 <h4><a name="sample" id="sample"></a>-sample <em class="arg">geometry</em></h4>
4851</div>
4852
4853<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>
4854
4855<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>
4856
4857<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>
4858
4859
4860<div style="margin: auto;">
4861 <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>
4862</div>
4863
4864<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>
4865
4866<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>
4867
4868<div style="margin: auto;">
4869 <h4><a name="scale" id="scale"></a>-scale <em class="arg">geometry</em></h4>
4870</div>
4871
4872<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>
4873
4874<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>
4875
4876<div style="margin: auto;">
4877 <h4><a name="scene" id="scene"></a>-scene <em class="arg">value</em></h4>
4878</div>
4879
4880<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>
4881
4882<p>This option sets the scene number of an image or the first image in an image sequence.</p>
4883
4884<div style="margin: auto;">
4885 <h4><a name="screen" id="screen"></a>-screen</h4>
4886</div>
4887
4888<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>
4889
4890<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>
4891
4892<div style="margin: auto;">
4893 <h4><a name="seed" id="seed"></a>-seed</h4>
4894</div>
4895
4896<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>
4897
4898<div style="margin: auto;">
4899 <h4><a name="segment" id="segment"></a>-segment <em class="arg">cluster-threshold</em>x<em class="arg">smoothing-threshold</em></h4>
4900</div>
4901
4902<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>
4903
4904<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>
4905
4906<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>
4907
4908<p>If the <a href="#verbose">-verbose</a> setting is defined, a detailed report
4909of the color clusters is returned.</p>
4910
4911
4912<div style="margin: auto;">
4913 <h4><a name="selective-blur" id="selective-blur"></a>-selective-blur <em class="arg">geometry</em></h4>
4914</div>
4915
4916<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>
4917
4918<div style="margin: auto;">
4919 <h4><a name="separate" id="separate"></a>-separate</h4>
4920</div>
4921
4922<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>
4923
4924<div style="margin: auto;">
4925 <h4><a name="sepia-tone" id="sepia-tone"></a>-sepia-tone <em class="arg">threshold</em></h4>
4926</div>
4927
4928<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>
4929
4930<p>Specify <em class="arg">threshold</em> as the percent threshold of the intensity (0 - 99.9%).</p>
4931
4932<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>
4933
4934<div style="margin: auto;">
4935 <h4><a name="set" id="set"></a>-set <em class="arg">attribute value</em></h4>
4936</div>
4937
4938<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>set 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>
4939
4940<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>
4941
4942<p class='crt'><span class="crtprompt"> $magick&gt; </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&gt; </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>
4943<p>The <a href="#repage">-repage</a> operator will also set the
4944'<kbd>page</kbd>' attribute of images already in memory, but allows you to
4945separately set the virtual canvas's size and offset components, and also allows
4946relative offset changes, and automatic canvas size re-calculating. The above
4947<a href="#set">-set</a> option is purely a direct, unmodified assignment of the
4948virtual canvas (page) meta-data. </p>
4949
4950<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>
4951
4952<div style="margin: auto;">
4953 <h4><a name="shade" id="shade"></a>-shade <em class="arg">azimuth</em>x<em class="arg">elevation</em></h4>
4954</div>
4955
4956<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>
4957
4958<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>
4959
4960<div style="margin: auto;">
4961 <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>
4962</div>
4963
4964<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>
4965
4966<div style="margin: auto;">
4967 <h4><a name="shared-memory"
4968id="shared-memory"></a>-shared-memory</h4>
4969</div>
4970
4971<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>
4972
4973<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>
4974
4975<div style="margin: auto;">
4976 <h4><a name="sharpen" id="sharpen"></a>-sharpen <em class="arg">radius</em>{x<em class="arg">sigma</em>}</h4>
4977</div>
4978
4979<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>
4980
4981<p>Use a Gaussian operator of the given radius and standard deviation (sigma).</p>
4982
4983<div style="margin: auto;">
4984 <h4><a name="shave" id="shave"></a>-shave <em class="arg">geometry</em></h4>
4985</div>
4986
4987<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>
4988
4989<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>
4990
4991<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>
4992
4993<div style="margin: auto;">
4994 <h4><a name="shear" id="shear"></a>-shear <em class="arg">Xdegrees</em>[x<em class="arg">Ydegrees</em>]</h4>
4995</div>
4996
4997<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>
4998
4999<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>
5000
5001<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&deg;&lt;<em class="arg">Xdegrees</em>&lt;90&deg; and to the left when 90&deg;&lt;<em class="arg">Xdegrees</em>&lt;180&deg;. 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&deg;&lt;<em class="arg">Ydegrees</em>&lt;90&deg; and up when 90&deg;&lt;<em class="arg">Ydegrees</em>&lt;180&deg;.</p>
5002
5003<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>
5004
5005<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>
5006
5007<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert logo: -shear 20x0 -shear 0x60 logo-sheared.png</span><span class='crtout'></span><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert logo: -shear 0x60 -shear 20x0 logo-sheared.png</span></p>
5008<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>
5009
5010<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert logo: -shear 20x60 logo-sheared.png</span></p>
5011<div style="margin: auto;">
5012 <h4><a name="sigmoidal" id="sigmoidal-contrast"></a>-sigmoidal-contrast <em class="arg">contrast</em>x<em class="arg">mid-point</em></h4>
5013</div>
5014
5015<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>
5016
5017<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>
5018
5019<div style="margin: auto;">
5020 <h4><a name="silent" id="silent"></a>-silent</h4>
5021</div>
5022
5023<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>
5024
5025<div style="margin: auto;">
5026 <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>
5027</div>
5028
5029<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>
5030
5031<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>
5032
5033<p>For Photo CD images, choose from these sizes:</p>
5034
5035<pre class="text">
5036 192x128
5037 384x256
5038 768x512
5039 1536x1024
5040 3072x2048
5041</pre>
5042
cristy3ed852e2009-09-05 21:47:34 +00005043<div style="margin: auto;">
5044 <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>
5045</div>
5046
5047<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>
5048
5049<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>
5050
5051<div style="margin: auto;">
5052 <h4><a name="snaps" id="snaps"></a>-snaps <em class="arg">value</em></h4>
5053</div>
5054
5055<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>
5056
5057<p>Use this option to grab more than one image from the X server screen, to create an animation sequence.</p>
5058
5059<div style="margin: auto;">
5060 <h4><a name="solarize" id="solarize"></a>-solarize <em class="arg">threshold</em></h4>
5061</div>
5062
5063<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>
5064
5065<p>Specify <em class="arg">factor</em> as the percent threshold of the intensity (0 - 99.9%).</p>
5066
5067<p>This option produces a <em class="arg">solarization</em> effect seen when exposing a photographic film to light during the development process.</p>
5068
5069<div style="margin: auto;">
5070 <h4><a name="sparse-color" id="sparse-color"></a>-sparse-color <em
5071 class="arg">method</em> '<em class="arg">x</em>,<em class="arg">y</em> <em class="arg">color</em> ...'</h4>
5072</div>
5073
5074<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>
5075
5076
5077<table class="doc">
5078 <tbody>
5079 <tr valign="top">
5080 <th align="left" style="width: 8%">Method</th>
5081 <th align="left">Description</th>
5082 </tr>
5083
5084 <tr valign="top">
5085 <td valign="top">voronoi</td>
5086 <td valign="top">Simply map each pixel to the to nearest color point
5087 given. The result are polygonal 'cells' of solid color. </td>
5088 </tr>
5089
5090 <tr valign="top">
5091 <td valign="top">shepards</td>
5092 <td valign="top">Colors points basied on the ratio of inverse distance
5093 squared. Generating spots of color in a sea of the average of
5094 colors. </td>
5095 </tr>
5096
5097 <tr valign="top">
5098 <td valign="top">barycentric</td>
5099 <td valign="top">three point triangle of color given 3 points.
5100 Giving only 2 points will form a linear gradient between those points.
5101 Gradient is however not restricted to just the triangle or line. </td>
5102 </tr>
5103
5104 <tr valign="top">
5105 <td valign="top">bilinear</td>
5106 <td valign="top">Like barycentric but for 4 points. Less than 4 points
5107 fall back to barycentric. </td>
5108 </tr>
5109
5110 </tbody>
5111</table>
5112
5113<p>The points are placed according to the images location on the virtual
5114canvas (<a href="#page" >-page</a> or <a href="#repage" >-repage</a>
5115offset), and do not actually have to exist on the given image, but may be
5116some point beyond the edge of the image. All points are floating point values.
5117</p>
5118
5119<p>Only the color channels defined by the <a href="#channel" >-channel</a> are
5120modified, whcih means the matte/alpha transparency channel is not effected by
5121default. If enabled, the image also needs a the matte/alpha channel to be
5122enabled for this operator to effect an images transparency. This is typical
5123transparency handling for images. </p>
5124
5125<p>All the above methods when given a single point of color will replace all
5126the colors in the image with the color given, regardless of the point. This is
5127logical, and provides an alternative technique to recolor a image to some
5128default value. </p>
5129
5130
5131<div style="margin: auto;">
5132 <h4><a name="splice" id="splice"></a>-splice <em class="arg">geometry</em></h4>
5133</div>
5134
5135<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>
5136
5137<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>
5138
5139<div style="margin: auto;">
5140 <h4><a name="spread" id="spread"></a>-spread <em class="arg">amount</em></h4>
5141</div>
5142
5143<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>
5144
5145<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>
5146
5147<div style="margin: auto;">
5148 <h4><a name="stegano" id="stegano"></a>-stegano <em class="arg">offset</em></h4>
5149</div>
5150
5151<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>
5152
5153<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>
5154
5155<div style="margin: auto;">
5156 <h4><a name="stereo" id="stereo"></a>-stereo <em class="arg">+x</em>{<em class="arg">+y</em>}</h4>
5157</div>
5158
5159<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>
5160
5161<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>
5162
5163<div style="margin: auto;">
5164 <h4><a name="storage-type" id="storage-type"></a>-storage-type <em class="arg">type</em></h4>
5165</div>
5166
5167<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>
5168
5169<pre class="text">
5170 char store pixels as unsigned characters
5171 double store pixels as doubles
5172 float store pixels as floats
5173 integer store pixels as integers
5174 long store pixels as longs
5175 quantum store pixels in the native depth of your ImageMagick distribution
5176 short store pixels as unsigned shorts
5177</pre>
5178
5179<p>Float and double types are normalized from 0.0 to 1.0 otherwise the pixels
5180values range from 0 to the maximum value the storage type can support.</p>
5181
5182<div style="margin: auto;">
5183 <h4><a name="stretch" id="stretch"></a>-stretch <em class="arg">fontStretch</em></h4>
5184</div>
5185
5186<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>
5187
5188<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>
5189
5190<pre class="text">
5191 Any
5192 Condensed
5193 Expanded
5194 ExtraCondensed
5195 ExtraExpanded
5196 Normal
5197 SemiCondensed
5198 SemiExpanded
5199 UltraCondensed
5200 UltraExpanded
5201</pre>
5202
5203<p>To print a complete list of stretch types, use <a href="#list">-list stretch</a>.</p>
5204
5205<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>
5206
5207<div style="margin: auto;">
5208 <h4><a name="strip" id="strip"></a>-strip</h4>
5209</div>
5210
5211<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>
5212
5213<div style="margin: auto;">
5214 <h4><a name="stroke" id="stroke"></a>-stroke <em class="arg">color</em></h4>
5215</div>
5216
5217<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>
5218
5219<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p>
5220
5221<p>See <a href="#draw">-draw</a> for further details.</p>
5222
5223<div style="margin: auto;">
5224 <h4><a name="strokewidth" id="strokewidth"></a>-strokewidth <em class="arg">value</em></h4>
5225</div>
5226
5227<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>
5228
5229<p>See <a href="#draw">-draw</a> for further details.</p>
5230
5231<div style="margin: auto;">
5232 <h4><a name="style" id="style"></a>-style <em class="arg">fontStyle</em></h4>
5233</div>
5234
5235<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>
5236
5237<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>
5238
5239<pre class="text">
5240 Any
5241 Italic
5242 Normal
5243 Oblique
5244</pre>
5245
5246<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>
5247
5248<div style="margin: auto;">
5249 <h4><a name="swap" id="swap"></a>-swap <em class="arg">index,index</em></h4>
5250</div>
5251
5252<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>
5253
5254<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>
5255
5256<div style="margin: auto;">
5257 <h4><a name="swirl" id="swirl"></a>-swirl <em class="arg">degrees</em></h4>
5258</div>
5259
5260<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>
5261
5262<p><em class="arg">Degrees</em> defines the tightness of the swirl.</p>
5263
5264<div style="margin: auto;">
5265 <h4><a name="taint" id="taint"></a>-taint</h4>
5266</div>
5267
5268<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>
5269
5270<div style="margin: auto;">
5271 <h4><a name="text-font" id="text-font"></a>-text-font <em class="arg">name</em></h4>
5272</div>
5273
5274<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>
5275
5276<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>
5277
5278<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>
5279
5280<div style="margin: auto;">
5281 <h4><a name="texture" id="texture"></a>-texture <em class="arg">filename</em></h4>
5282</div>
5283
5284<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>
5285
5286<div style="margin: auto;">
5287 <h4><a name="threshold" id="threshold"></a>-threshold <em class="arg">value</em>{<em class="arg">%</em>}</h4>
5288</div>
5289
5290<!-- {<em class="arg">green,blue,opacity</em>}
5291<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>
5292-->
5293
5294<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>
5295
5296<p>Any pixel values (more specifically, those channels set using <a href="../www/command-line-options.html#channel">&#x2011;channel</a>) that exceed the specified threshold are reassigned the maximum channel value, while all other values are assigned the minimum.</p>
5297
5298<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.
5299</p>
5300
5301<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>
5302
5303<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert in.png -channel red -threshold 50% out.png</span></p>
5304<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>
5305
5306
5307<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert in.png -threshold 100% black.png</span><span class='crtout'></span><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert in.png -threshold -1 white.png</span></p>
5308<p>Note that the values of the transparency channel is treated as 'matte'
5309values (0 is opaque) and not as 'alpha' values (0 is transparent).</p>
5310
5311<p> See also <a href="../www/command-line-options.html#black-threshold">&#x2011;black&#x2011;threshold</a> and <a href="../www/command-line-options.html#white-threshold">&#x2011;white&#x2011;threshold</a>.
5312</p>
5313
5314<div style="margin: auto;">
5315 <h4><a name="thumbnail" id="thumbnail"></a>-thumbnail <em class="arg">geometry</em></h4>
5316</div>
5317
5318<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>
5319
5320<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>
5321
5322<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>
5323
5324<div style="margin: auto;">
5325 <h4><a name="tile" id="tile"></a>-tile <em class="arg">filename</em></h4>
5326</div>
5327
5328<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>
5329
5330<div style="margin: auto;">
5331 <h4>-tile <em class="arg">geometry</em></h4>
5332</div>
5333
5334<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>
5335
5336<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>
5337
5338<div style="margin: auto;">
5339 <h4>-tile</h4>
5340</div>
5341
5342<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>
5343
5344<div style="margin: auto;">
5345 <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>
5346</div>
5347
5348<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>
5349
5350<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>
5351
5352<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>
5353
5354<div style="margin: auto;">
5355 <h4><a name="tint" id="tint"></a>-tint <em class="arg">value</em></h4>
5356</div>
5357
5358<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>
5359
5360<p>Tint the image with the fill color.</p>
5361
5362<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>
5363
5364<div style="margin: auto;">
5365 <h4><a name="title" id="title"></a>-title <em class="arg">string</em></h4>
5366</div>
5367
5368<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>
5369
5370<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>
5371
5372<p>For example,</p>
5373
5374<p class="crtsnip">
5375 -title "%m:%f %wx%h"
5376</p>
5377
5378<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>
5379
5380
5381<div style="margin: auto;">
5382 <h4><a name="transform" id="transform"></a>-transform</h4>
5383</div>
5384
5385<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>
5386
5387<p>This option applies the transformation matrix from a previous <a href="#affine">-affine</a> option.</p>
5388
5389<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert -affine 2,2,-2,2,0,0 -transform bird.ppm bird.jpg</span></p>
5390<div style="margin: auto;">
5391 <h4><a name="transparent" id="transparent"></a>-transparent <em class="arg">color</em></h4>
5392</div>
5393
5394<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>
5395
5396<p>The <em class="arg">color</em> argument is defined using the format
5397described under the <a href="#fill">-fill</a> option. The <a href="#fuzz"
5398>-fuzz</a> setting can be used to match and replace colors similar to the one
5399given. </p>
5400
5401<p>The <a href="#opaque">-opaque</a> operator is exactly the same as <a
5402href="#transparent" >-transparent</a> but replaces the matching color same as
5403the current <a href="#fill">-fill</a> color setting. </p>
5404
5405<p>This does not define the 'transparency color' used for color-mapped image
5406formats, such as GIF. For that use <a href="#transparent-color"
5407>-transparent-color</a> </p>
5408
cristyc54f5d42009-11-27 21:36:31 +00005409<p>Use <a href="#opaque">+opaque</a> to invert the pixels matched, that is
cristy3ed852e2009-09-05 21:47:34 +00005410paint any pixel that does not match the target color, with the fill color.</p>
5411
5412
5413<div style="margin: auto;">
5414 <h4><a name="transparent-color" id="transparent-color"></a>-transparent-color <em class="arg">color</em></h4>
5415</div>
5416
5417<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>
5418
5419<p>Sometimes this is used for saving to image formats such as
5420GIF and PNG8 which uses this color to represent boolean transparency. This
5421does not make a color transparent, it only defines what color the transparent
5422color is in the color palette of the saved image. Use <a
5423href="#transparent">-transparent</a> to make an opaque color transparent.</p>
5424
5425<p>This option allows you to have both an opaque visible color, as well as a
5426transparent color of the same color value without conflict. That is, you can
5427use the same color for both the transparent and opaque color areas within an
5428image. This, in turn, frees to you to select a transparent color that is
5429appropriate when an image is displayed by an application that does not handle a
5430transparent color index, while allowing ImageMagick to correctly handle images of this
5431type. </p>
5432
5433<p>The default transparent color is <kbd>#00000000</kbd>, which is fully transparent black.</p>
5434
5435<div style="margin: auto;">
5436 <h4><a name="transpose" id="transpose"></a>-transpose</h4>
5437</div>
5438
5439<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>
5440
5441<p> This option mathematically transposes the pixel array. It is equivalent to the sequence <kbd>-flip -rotate 90</kbd>.
5442</p>
5443
5444<div style="margin: auto;">
5445 <h4><a name="transverse" id="transverse"></a>-transverse</h4>
5446</div>
5447
5448<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>
5449
5450
5451<div style="margin: auto;">
5452 <h4><a name="treedepth" id="treedepth"></a>-treedepth <em class="arg">value</em></h4>
5453</div>
5454
5455<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>
5456
5457<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>
5458
5459<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>
5460
5461<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>
5462
5463<div style="margin: auto;">
5464 <h4><a name="trim" id="trim"></a>-trim</h4>
5465</div>
5466
5467<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>
5468
5469<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>
5470
5471<p>The page or virtual canvas information of the image is preserved allowing
5472you to extract the result of the <a href="#trim">-trim</a> operation from the
5473image. Use a <a href="#repage">+repage</a> to remove the virtual canvas page
5474information if it is unwanted.</p>
5475
5476<p>If the trimmed image 'disappears' an warning is produced, and a special
5477single pixel transparent 'missed' image is returned, in the same way as when a
5478<a href="#crop">-crop</a> operation 'misses' the image proper. </p>
5479
5480
5481<div style="margin: auto;">
5482 <h4><a name="type" id="type"></a>-type <em class="arg">type</em></h4>
5483</div>
5484
5485<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>
5486 <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>
5487
5488<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>
5489
5490<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert bird.png -type TrueColor bird.jpg</span></p>
5491<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>
5492
5493<p>Use <a href="#type">-type optimize</a> to ensure the image is written in the smallest possible file size.</p>
5494
5495<div style="margin: auto;">
5496 <h4><a name="undercolor" id="undercolor"></a>-undercolor <em class="arg">color</em></h4>
5497</div>
5498
5499<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>
5500
5501<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p>
5502
5503<p>See <a href="#draw">-draw</a> for further details.</p>
5504
5505
5506<div style="margin: auto;">
5507 <h4><a name="update" id="update"></a>-update <em class="arg">seconds</em></h4>
5508</div>
5509
5510<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>
5511
5512<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>
5513
5514
5515<div style="margin: auto;">
5516 <h4><a name="unique-colors" id="unique-colors"></a>-unique-colors</h4>
5517</div>
5518
5519<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>
5520
5521
5522<div style="margin: auto;">
5523 <h4><a name="units" id="units"></a>-units <em class="arg">type</em></h4>
5524</div>
5525
5526<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>
5527
5528<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>
5529
5530
5531<div style="margin: auto;">
5532 <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>
5533</div>
5534
5535<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>
5536
5537<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>
5538
5539<p>The parameters are:</p>
5540
5541<pre class="text">
5542 radius: The radius of the Gaussian, in pixels, not counting the center
5543 pixel (default 0).
5544 sigma: The standard deviation of the Gaussian, in pixels (default 1.0).
5545 amount: The fraction of the difference between the original and the blur
5546 image that is added back into the original (default 1.0).
5547 threshold: The threshold, as a fraction of <em class="QR">QuantumRange</em>, needed to apply the
5548 difference amount (default 0.05).
5549</pre>
5550
5551
5552<div style="margin: auto;">
5553 <h4><a name="verbose" id="verbose"></a>-verbose</h4>
5554</div>
5555
5556<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>
5557
5558
5559<div style="margin: auto;">
5560 <h4><a name="version" id="version"></a>-version</h4>
5561</div>
5562
5563<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>
5564
5565
5566<div style="margin: auto;">
5567 <h4><a name="view" id="view"></a>-view <em class="arg">string</em></h4>
5568</div>
5569
5570<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>
5571
5572
5573<div style="margin: auto;">
5574 <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>
5575</div>
5576
5577<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>
5578
5579
5580<div style="margin: auto;">
5581 <h4><a name="virtual-pixel" id="virtual-pixel"></a>-virtual-pixel <em class="arg">method</em></h4>
5582</div>
5583
5584<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>
5585
5586<p>This option defines what color source should be used if and when a color
5587lookup completely 'misses' the source image. The color(s) that appear to
5588surround the source image. Generally this color is derived from the source
5589image, but could also be set to a specify background color. </p>
5590
5591<p>Choose from these methods:</p>
5592
5593<pre class="text">
5594 background: the area surrounding the image is the background color
5595 black: the area surrounding the image is black
5596 checker-tile: alternate squares with image and background color
5597 dither: non-random 32x32 dithered pattern
5598 edge: extend the edge pixel toward infinity
5599 gray: the area surrounding the image is gray
5600 horizontal-tile: horizontally tile the image, background color above/below
5601 horizontal-tile-edge: horizontally tile the image and replicate the side edge pixels
5602 mirror: mirror tile the image
5603 random: choose a random pixel from the image
5604 tile: tile the image (default)
5605 transparent: the area surrounding the image is transparent blackness
5606 vertical-tile: vertically tile the image, sides are background color
5607 vertical-tile-edge: vertically tile the image and replicate the side edge pixels
5608 white: the area surrounding the image is white
5609</pre>
5610
5611<p>The default value is "edge".</p>
5612
5613<p>This most important for distortion operators such as <a href="#distort"
5614>-distort</a>, <a href="#implode" >-implode</a>, and <a href="#fx" >-fx</a>.
5615However it also effects operations that may access pixels just outside the
5616image proper, such as <a href="#convolve">-convolve</a>, <a
5617href="#blur">-blur</a>, and <a href="#sharpen">-sharpen</a>. </p>
5618
5619<p>To print a complete list of virtual pixel types, use the <a href="#list">-list virtual-pixel</a> option.</p>
5620
5621
5622<div style="margin: auto;">
5623 <h4><a name="visual" id="visual"></a>-visual <em class="arg">type</em></h4>
5624</div>
5625
5626<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>
5627
5628<p>Choose from these visual classes:</p>
5629
5630<pre class="text">
5631 StaticGray
5632 GrayScale
5633 StaticColor
5634 PseudoColor
5635 TrueColor
5636 DirectColor
5637 default
5638 visual id
5639</pre>
5640
5641<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>
5642
5643
5644<div style="margin: auto;">
5645 <h4><a name="watermark" id="watermark"></a>-watermark <em
5646 class="arg">brightness</em>x<em class="arg">saturation</em></h4>
5647</div>
5648
5649<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
5650saturation.</td><td style='text-align:right;'>[<a href="../www/composite.html">composite</a>]</td></tr></table>
5651
5652<p>Take a grayscale image (with alpha mask) and modify the destination image's
5653brightness according to watermark image's grayscale value and the <em
5654class="arg">brightness</em> percentage. The destinations color saturation
5655attribute is just direct modified by the <em class="arg">saturation</em>
5656percentage, which defaults to 100 percent (no color change). </p>
5657
5658
5659<div style="margin: auto;">
5660 <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>
5661</div>
5662
5663<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>
5664
5665<p>Specify <em class="arg">amplitude</em> and <em class="arg">wavelength</em> of the wave.</p>
5666
5667<div style="margin: auto;">
5668 <h4><a name="weight" id="weight"></a>-weight <em class="arg">fontWeight</em></h4>
5669</div>
5670
5671<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>
5672
5673<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>
5674
5675<table class="doc">
5676 <col width="25%" />
5677 <col width="75%" />
5678 <thead>
5679 <tr>
5680 <th><em class="arg">fontWeight</em></th>
5681 <th>Description</th>
5682 </tr>
5683 </thead>
5684 <tbody>
5685 <tr><td>All </td> <td>No effect. </td></tr>
5686 <tr><td>Bold </td> <td>Same as <em class="arg">fontWeight</em> = 700.</td></tr>
5687 <tr><td>Bolder </td> <td>Add 100 to font weight if currently &le; 800.</td></tr>
5688 <tr><td>Lighter </td> <td>Subtract 100 to font weight if currently &le; 100.</td></tr>
5689 <tr><td>Normal </td> <td>Same as <em class="arg">fontWeight</em> = 400.</td></tr>
5690 </tbody>
5691 </table>
5692
5693<p>To print a complete list of weight types, use <a href="#list">-list weight</a>.</p>
5694
5695<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>
5696
5697<div style="margin: auto;">
5698 <h4><a name="white-point" id="white-point"></a>-white-point <em class="arg">x,y</em></h4>
5699</div>
5700
5701<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>
5702
5703<div style="margin: auto;">
cristy5cadd612009-09-21 19:33:41 +00005704 <h4><a name="white-threshold" id="white-threshold"></a>-white-threshold <em class="arg">value</em>{<em class="arg">%</em>}</h4>
cristy3ed852e2009-09-05 21:47:34 +00005705</div>
5706
cristy5cadd612009-09-21 19:33:41 +00005707<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>
5708
5709<p> The threshold value can be given as a percentage or as an absolute integer value within [0,&nbsp;<em class="QR">QuantumRange</em>] corresponding to the desired <a href="../www/command-line-options.html#channel">&#x2011;channel</a> value. See <a href="../www/command-line-options.html#threshold">&#x2011;threshold</a> for more details on thresholds and resulting values.
5710</p>
cristy3ed852e2009-09-05 21:47:34 +00005711
5712<div style="margin: auto;">
5713 <h4><a name="window" id="window"></a>-window <em class="arg">id</em></h4>
5714</div>
5715
5716<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>
5717
5718<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>
5719
5720<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>
5721
5722<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>
5723
5724<div style="margin: auto;">
5725 <h4><a name="window-group" id="window-group"></a>-window-group</h4>
5726</div>
5727
5728<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>
5729
5730<div style="margin: auto;">
5731 <h4><a name="write" id="write"></a>-write <em class="arg">filename</em></h4>
5732</div>
5733
5734<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>
5735 <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>
5736
5737<p>Use <a href="#compress">-compress</a> to specify the type of image compression.</p>
5738
cristyf3bb4782009-09-08 13:10:04 +00005739
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5741
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5748 <span id="linkbar-east">&nbsp;</span>
5749 </div>
5750 <div class="footer">
cristy16af1cb2009-12-11 21:38:29 +00005751 <span id="footer-west">&copy; 1999-2010 ImageMagick Studio LLC</span>
cristyf3bb4782009-09-08 13:10:04 +00005752 <span id="footer-east"> <a href="http://www.imagemagick.org/script/contact.php">Contact the Wizards</a></span>
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