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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>
cristy045bd902010-01-30 18:56:24 +00001848<dt>dcm:display-range=reset</dt>
1849 <dd>Set the display range to the minimum and maximum pixel values for the DCM image format.</dd><br />
1850<dt>dot:layout-engine=<em class="arg">value</em></dt>
1851 <dd>Set the specify the layout engine for the DOT image format (e.g. <kbd>neato</kbd>).</dd><br />
1852<dt>jpeg:extent=<em class="arg">value</em></dt>
cristy7396d882010-01-27 02:37:56 +00001853 <dd>Restrict the maximum JPEG file size, for example <kbd>-define jpeg:extent=400kb</kbd>.</dd><br />
cristy045bd902010-01-30 18:56:24 +00001854<dt>jpeg:size=<em class="arg">geometry</em></dt>
cristy48dd1af2009-10-02 01:21:56 +00001855 <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 />
cristy045bd902010-01-30 18:56:24 +00001856<dt>jp2:rate=<em class="arg">value</em></dt>
cristy3ed852e2009-09-05 21:47:34 +00001857 <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 />
1858<dt>mng:need-cacheoff</dt>
1859 <dd>turn playback caching off for streaming MNG.</dd><br />
cristy045bd902010-01-30 18:56:24 +00001860<dt>png:bit-depth=<em class="arg">value</em></dt>
1861<dt>png:color-type=<em class="arg">value</em></dt>
cristy3ed852e2009-09-05 21:47:34 +00001862 <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 />
1863<dt>ps:imagemask</dt>
cristy045bd902010-01-30 18:56:24 +00001864 <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><br />
1865<dt>quantum:format=<em class="arg">type</em></dt>
1866 <dd>Set the type to <kbd>floating-point</kbd> to specify a single precision floating-point format for raw files (e.g. GRAY:).</dd>
cristy3ed852e2009-09-05 21:47:34 +00001867</ul>
1868
1869<p>For example, to create a postscript file that will render only the black pixels of a bilevel image, use:</p>
1870
1871<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert bilevel.tif -define ps:imagemask eps3:stencil.ps</span></p>
1872<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>
1873
1874<p class="crtsnip">
1875-define registry:temporary-path=/data/tmp
1876</p>
1877
1878<div style="margin: auto;">
1879 <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>
1880</div>
1881
1882<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>
1883
1884<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>
1885
1886<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>
1887
1888
1889<div style="margin: auto;">
1890 <h4><a name="delete" id="delete"></a>-delete <em class="arg">index</em></h4>
1891</div>
1892
1893<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>
1894
1895<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>
1896
1897
1898<div style="margin: auto;">
1899 <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>
1900</div>
1901
1902<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>
1903
1904<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>
1905
1906<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>
1907
1908<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>
1909
1910<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>
1911
1912<div style="margin: auto;">
1913 <h4><a name="depth" id="depth"></a>-depth <em class="arg">value</em></h4>
1914</div>
1915
1916<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>
1917
1918<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>
1919
1920<div style="margin: auto;">
1921 <h4><a name="descend" id="descend"></a>-descend</h4>
1922</div>
1923
1924<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>
1925
1926<div style="margin: auto;">
1927 <h4><a name="deskew" id="deskew"></a>-deskew <em class="arg">threshold</em></h4>
1928</div>
1929
1930<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>
1931
1932<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>
1933
1934<div style="margin: auto;">
1935 <h4><a name="despeckle" id="despeckle"></a>-despeckle</h4>
1936</div>
1937
1938<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>
1939
1940<div style="margin: auto;">
1941 <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>
1942</div>
1943
1944<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>
1945
1946<p>With this option, the 'overlay' image, and optionally the 'mask' image,
1947will be used as a displacement map, which is used to displace the lookup of
1948what part of the 'background' image is seen at each point of the overlaid
1949area. Much like the displacement map is a 'lens' that redirects light shining
1950through it so as to present a distorted view the original 'background' image
1951behind it. </p>
1952
1953<p>Any perfect grey areas of the displacement map produce a zero
1954displacement of the image. Black areas produce the given maximum negative
1955displacement of the lookup point, while white produce a maximum positive
1956displacement of the lookup. </p>
1957
1958<p>Note that it is the lookup of the 'background' that is displaced, not a
1959displacement of the image itself. As such an area of the displacement map
1960containing 'white' will have the lookup point 'shifted' by a positive amount,
1961and thus generating a copy of the destination image to the right/downward from
1962the correct position. That is the image will look like it may have been
1963'shifted' in a negative left/upward direction. Understanding this is a very
1964important in understanding how displacement maps work. </p>
1965
1966<p>The given arguments define the maximum amount of displacement in pixels
1967that a particular map can produce. If the displacement scale is large enough
1968it is also posible to lookup parts of the 'background' image that lie well
1969outside the bounds of the displacement map itself. That is you could very
1970easilly copy a section of the original image from outside the overlay area
1971into the overlay area. </p>
1972
1973<p>The '%' flag makes the displacement scale relative to the size of the
1974overlay image (100% = half width/height of image). Using '!' switches
1975percentage arguments to refer to the destination image size instead.
1976these flags were added as of IM v6.5.3-5.</p>
1977
1978<p>Normally a single grayscale displacement map is provided, which with the
1979given scaling values will determine a single direction (vector) in which
1980displacements can occur (positivally or negativally). However, if you also
1981specify a third image which is normally used as a <em class="arg">mask</em>,
1982then the <em class="arg">composite image</em> will be used for horizontal X
1983displacement, while the <em class="arg">mask image</em> is used for vertical Y
1984displacement. This allows you to define completely different displacement
1985values for the X and Y directions, and allowing you to lookup any point within
1986the <em class="arg">scale</em> bounds. In other words each pixel can lookup
1987any other nearby pixel, producing complex 2 dimentional displacements, rather
1988than a simple 1 dimentional vector displacements. </p>
1989
1990<p>Alternativally rather than suppling two separate images, as of IM v6.4.4-0,
1991you can use the 'red' channel of the overlay image to specify the horizontal
1992or X displacement, and the 'green' channel for the vertical or Y displacement.
1993</p>
1994
1995<p>As of IM v6.5.3-5 any alpha channel in the overlay image will be used as a
1996mask the transparency of the destination image. However areas outside the
1997overlaid areas will not be effected. </p>
1998
1999
2000<div style="margin: auto;">
2001 <h4><a name="display" id="display"></a>-display <em class="arg">host:display[.screen]</em></h4>
2002</div>
2003
2004<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>
2005
2006<p>This option is used with convert for obtaining image or font from this X server. See <em class="arg">X(1)</em>.</p>
2007
2008<div style="margin: auto;">
2009 <h4><a name="dispose" id="dispose"></a>-dispose <em class="arg">method</em></h4>
2010</div>
2011
2012<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>
2013
2014<p>The layer disposal method defines the way each the displayed image is to be
2015modified after the current 'frame' of an animation has finished being
2016displayed (after its 'delay' period), but before the next frame on an
2017animation is to be overlaid onto the display. </p>
2018
2019<p>Here are the valid methods:</p>
2020
2021<pre class="text">
2022Undefined 0 No disposal specified (equivalent to '<kbd>none</kbd>').
2023None 1 Do not dispose, just overlay next frame image.
2024Background 2 Clear the frame area with the background color.
2025Previous 3 Clear to the image prior to this frames overlay.
2026</pre>
2027
2028<p>You can also use the numbers given above, which is what the GIF format
2029uses internally to represent the above settings. </p>
2030
2031<p>To print a complete list of dispose methods, use <a href="#list">-list dipose</a>.</p>
2032
2033<p>Use <a href="#dispose" >+dispose</a>, turn off the setting and prevent
2034resetting the layer disposal methods of images being read in. </p>
2035
2036<p>Use <a href="#set">-set</a> '<kbd>dispose</kbd>' method to set the image
2037disposal method for images already in memory.</p>
2038
2039<div style="margin: auto;">
2040 <h4><a name="dissimilarity-threshold" id="dissimilarity-threshold"></a>-dissimilarity-threshold <em class="arg">value</em></h4>
2041</div>
2042
2043<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>
2044
2045
2046<div style="margin: auto;">
2047 <h4><a name="dissolve" id="dissolve"></a>-dissolve <em class="arg">src_percent</em>[x<em class="arg">dst_percent</em>]</h4>
2048</div>
2049
2050<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>
2051
2052<p>The opacity of the composite image is multiplied by the given percent, then
2053it is composited 'over' the main image. If <em class="arg">src_percent</em>
2054is greater than 100, start dissolving the main image so it will become
2055transparent at a value of '<kbd class="arg">200</kbd>'. If both percentages
2056are given, each image are dissolved to the percentages given. </p>
2057
2058<p>Note that dissolve percentages do not add, two opaque images dissolved
2059'50,50', produce a 75% transparency. For a 50% + 50% blending of the two
2060images, you would need to use dissolve values of '50,100'. </p>
2061
2062<div style="margin: auto;">
2063 <h4><a name="distort" id="distort"></a>-distort <em class="arg">method arguments</em></h4>
2064</div>
2065
2066<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>
2067
2068<p>The <em class="arg">arguments</em> is a single string containing a list
2069of floating point numbers separated by commas or spaces. The number of
2070and meaning of the floating point values depends on the distortion <em
2071class="arg">method</em> being used. </p>
2072
2073<p>Choose from these distortion types:</p>
2074
2075<table class="doc">
2076 <tr valign="top">
2077 <th align="left" style="width: 8%">Method</th>
2078 <th align="left">Description</th>
2079 </tr>
2080
2081 <tr valign="top">
2082 <td valign="top"><kbd>ScaleRotateTranslate</kbd>&nbsp;&nbsp;
2083 <br/>or &nbsp; <kbd>SRT</kbd></td>
2084 <td valign="top">
2085 Distort image by first scaling and rotating about a given 'center',
2086 before translating that 'center' to the new location, in that order. It
2087 is an alternative method of specifying a '<kbd>Affine</kbd>' type of
2088 distortion, but without shearing effects. It also provides a good way
2089 of rotating and displacing a smaller image for tiling onto a larger
2090 background (IE 2-dimensional animations). <br/>
2091
2092 The number of arguments determine the specific meaning of each
2093 argument for the scales, rotation, and translation operations. <br/>
2094
2095 <table style="margin-left:auto; margin-right:auto;">
2096 <tr><td># &nbsp;</td><td>arguments meaning</td></tr>
2097 <tr><td>1:</td><td><em>Angle_of_Rotation</em></td></tr>
2098 <tr><td>2:</td><td><em>Scale &nbsp; Angle</em></td></tr>
2099 <tr><td>3:</td><td><em>ScaleX,ScaleY &nbsp; Angle</em></td></tr>
2100 <tr><td>4:</td><td><em>X,Y &nbsp; Scale &nbsp; Angle</em></td></tr>
2101 <tr><td>5:</td>
2102 <td><em>X,Y &nbsp; ScaleX,ScaleY &nbsp; Angle</em></td></tr>
2103 <tr><td>6:</td>
2104 <td><em>X,Y &nbsp; Scale &nbsp; Angle &nbsp; NewX,NewY</em></td></tr>
2105 <tr><td>7:</td>
2106 <td><em>X,Y &nbsp; ScaleX,ScaleY &nbsp; Angle
2107 &nbsp; NewX,NewY</em></td></tr>
2108 </table>
2109
2110 This is actually an alternative way of specifing a 2 dimensional linear
2111 '<kbd>Affine</kbd>' or '<kbd>AffineProjection</kbd>' distortion. </td> </tr>
2112
2113 <tr valign="top">
2114 <td valign="top"><kbd>Affine</kbd></td>
2115 <td valign="top">
2116 Distort the image linearly by moving a list of at least 3 or more sets
2117 of control points (as defined below). Idealy 3 sets or 12 floating
2118 point values are given allowing the image to be linearly scaled,
2119 rotated, sheared, and translated, according to those three points. See
2120 also the related '<kbd>AffineProjection</kbd>' and '<kbd>SRT</kbd>'
2121 distortions. <br/>
2122
2123 More than 3 sets given control point pairs (12 numbers) is least
2124 squares fitted to best match a lineary affine distortion. If only 2
2125 control point pairs (8 numbers) are given a two point image translation
2126 rotation and scaling is performed, without any posible shearing,
2127 flipping or changes in aspect ratio to the resulting image. If only one
2128 control point pair is provides the image is only translated, (which may
2129 be a floating point non-integer translation). <br/>
2130
2131 This distortion does not include any form of perspective distortion.
2132 </td>
2133
2134 </tr>
2135
2136 <tr valign="top">
2137 <td valign="top"><kbd>AffineProjection</kbd></td>
2138 <td valign="top">
2139 Linearly distort an image using the given Affine Matrix of 6
2140 pre-calculated coefficients forming a set of Affine Equations to map
2141 the source image to the destination image.
2142
2143 <div style="text-align: center"><em>
2144 s<sub>x</sub>, r<sub>x</sub>,
2145 r<sub>y</sub>, s<sub>y</sub>,
2146 t<sub>x</sub>, t<sub>y</sub>
2147 </em></div>
2148
2149 See <a href="#affine" >-affine</a> setting for more detail, and
2150 meanings of these coefficients. <br/>
2151
2152 The distortions '<kbd>Affine</kbd>' and '<kbd>SRT</kbd>' provide
2153 alternative methods of defining this distortion, with ImageMagick doing the
2154 calculations needed to generate the required coefficients. You can see
2155 the internally generated coefficients, by using a <a href="#verbose"
2156 >-verbose</a> setting. </td>
2157
2158 </tr>
2159
2160<!-- still under development, do not display - Anthony
2161 <tr valign="top">
2162 <td valign="top"><kbd>Bilinear</kbd></td>
2163 <td valign="top">
2164 Bilinear (reversed) Distortion, given a minimum of 4 sets of
2165 coordinate pairs, or 16 values (see below). Not that lines may not
2166 appear straight after distortion, though the distance between
2167 coordinates will remain consistant. </td>
2168 </tr>
2169-->
2170
2171 <tr valign="top">
2172 <td valign="top"><kbd>Perspective</kbd></td>
2173 <td valign="top">
2174 Perspective distort the images, using a list of 4 or more sets of
2175 control points (as defined below). More that 4 sets (16 numbers) of
2176 control points provide least squares fitting for more accurate
2177 distortions (for the purposes of image registration and panarama
2178 effects). Less than 4 sets will fall back to a '<kbd>Affine</kbd>'
2179 linear distortion. <br/>
2180
2181 Perspective Distorted images ensures that straight lines remain
2182 straight, but the scale of the distorted image will vary. The horizon
2183 is anti-aliased, and the 'sky' color may be set using the
2184 <a href="#mattecolor" >-mattecolor</a> setting. </td>
2185 </tr>
2186
2187 <tr valign="top">
2188 <td valign="top"><kbd>PerspectiveProjection</kbd>&nbsp;&nbsp;</td>
2189 <td valign="top">
2190 Do a '<kbd>Perspective</kbd>' distortion basied on a set of 8
2191 pre-calculated coefficients. You can get these coefficients by looking
2192 at the <a href="#verbose" >-verbose</a> output of a
2193 '<kbd>Prespective</kbd>' distortion, or by calculating them yourself.
2194 If the last two perspective scaling coefficients are zero, the
2195 remaining 6 represents a transposed 'Affine Matrix'. </td>
2196
2197 </tr>
2198
2199 <tr valign="top">
2200 <td valign="top"><kbd>Arc</kbd></td>
2201 <td valign="top">
2202 Arc the image (variation of polar mapping) over the angle given around
2203 a circle. <br/>
2204 <table width="90%" style = "margin-left: auto; margin-right: auto;">
2205 <tr valign="top"><td>Argument</td>
2206 <td>Meaning</td></tr>
2207 <tr valign="top"><td><em>arc_angle</em></td>
2208 <td>The angle over which to arc the image side-to-side</td></tr>
2209 <tr valign="top"><td><em>rotate_angle</em></td>
2210 <td>Angle to rotate resulting image from vertical center</td></tr>
2211 <tr valign="top"><td><em>top_radius</em></td>
2212 <td>Set top edge of source image at this radius</td></tr>
2213 <tr valign="top"><td><em>bottom_radius</em>&nbsp;</td>
2214 <td>Set bottom edge to this radius (radial scaling)</td></tr>
2215 </table>
2216
2217 The resulting image is always resized to best fit the resulting image,
2218 (as if using <a href="#distort" >+distort</a>) while attempting to
2219 preserve scale and aspect ratio of the original image as much as
2220 possible with the arguments given by the user. All four arguments will
2221 be needed to change the overall aspect ratio of an 'Arc'ed image. <br/>
2222
2223 This a variation of a polar distortion designed to try to preserve the
2224 aspect ratio of the image rather than direct Cartesian to Polar
2225 conversion. </td>
2226 </tr>
2227
2228 <tr valign="top">
2229 <td valign="top"><kbd>Polar</kbd></td>
2230 <td valign="top">
2231 Like '<kbd>Arc</kbd>' but do a complete Cartesian to Polar mapping of
2232 the image. that is the height of the input image is mapped to the
2233 radius limits, while the width is wrapped around between the
2234 angle limits. <br/>
2235
2236 Arguments: <em>Rmax,Rmin CenterX,CenterY, start,end_angle</em> <br/>
2237
2238 All arguments are optional. With <em>Rmin</em> defaulting to zero, the
2239 center to the center of the image, and the angles going from -180 (top)
2240 to +180 (top). If <em>Rmax</em> is given the special value of
2241 '<code>0</code>', the the distance from the center to the nearest edge
2242 is used for the radius of the output image, which will ensure the whole
2243 image is visible (though scaled smaller). However a special value of
2244 '<code>-1</code>' will use the distance from the center to the furthest
2245 corner, This may 'clip' the corners from the input rectangular image,
2246 but will generate the exact reverse of a '<kbd>DePolar</kbd>' with
2247 the same arguments. <br/>
2248
2249 If the plus form of distort (<a href="#distort" >+distort</a>) is used
2250 output image center will default to <code>0,0</code> of the virtual
2251 canvas, and the image size adjusted to ensure the whole input image is
2252 made visible in the output image on the virtual canvas. </td>
2253
2254 </tr>
2255
2256 <tr valign="top">
2257 <td valign="top"><kbd>DePolar</kbd></td>
2258 <td valign="top">
2259 Uses the same arguments and meanings as a '<kbd>Polar</kbd>' distortion
2260 but generates the reverse Polar to Cartesian distortion. <br/>
2261
2262 The special <em>Rmax</em> setting of '<code>0</code>' may however clip
2263 the corners of the input image. However using the special
2264 <em>Rmax</em> setting of '<code>-1</code>' (maximum center to corner
2265 distance) will ensure the whole distorted image is preserved in the
2266 generated result, so that the same argument to '<kbd>Polar</kbd>' will
2267 reverse the distortion re-producing the original.
2268
2269 Note that as this distortion requires the area resampling of a circular
2270 arc, which can not be handled by the builtin EWA resampling function.
2271 As such the normal EWA filters are turned off. It is recomended some
2272 form of 'super-sampling' image processing technique be used to produce
2273 a high quality result. </td>
2274
2275 </tr>
2276
2277 <tr valign="top">
2278 <td valign="top"><kbd>Barrel</kbd></td>
2279 <td valign="top">
2280 Given the four coefficients (A,B,C,D) as defined by <a
2281 href="http://www.all-in-one.ee/~dersch/barrel/barrel.html" >Helmut
2282 Dersch</a>, perform a barrell or pincussion distortion appropriate to
2283 correct radial lens distortions. That is in photographs, make straight
2284 lines straight again. <br/>
2285
2286 Arguments: <em>A &nbsp; B &nbsp; C</em> &nbsp; [ <em>D</em> &nbsp; [
2287 <em>X</em> , <em>Y</em> ] ] <br/>
2288 or <em>A<sub>x</sub> B<sub>x</sub> C<sub>x</sub> D<sub>x</sub> &nbsp;
2289 A<sub>y</sub> B<sub>y</sub> C<sub>y</sub> D<sub>y</sub></em> &nbsp;
2290 [ <em>X</em> , <em>Y</em> ] <br/>
2291 So that it forms the function <br/>
2292 Rsrc = r * ( <em>A</em>*r<sup>3</sup> + <em>B</em>*r<sup>2</sup> +
2293 <em>C</em>*r + <em>D</em> )<br/>
2294
2295 Where <em>X</em>,<em>Y</em> is the optional center of the distortion
2296 (defaulting to the center of the image). <br/>
2297 The second form is typically used to distort images, rather than
2298 correct lens distortions. <br/>
2299 </td>
2300
2301 </tr>
2302
2303 <tr valign="top">
2304 <td valign="top"><kbd>BarrelInverse</kbd></td>
2305 <td valign="top">
2306 This is very simular to '<kbd>Barrel</kbd>' with the same set of
2307 arguments, and argument handling. However it uses the inverse
2308 of the radial polynomial,
2309 so that it forms the function <br/>
2310 Rsrc = r / ( <em>A</em>*r<sup>3</sup> + <em>B</em>*r<sup>2</sup> +
2311 <em>C</em>*r + <em>D</em> )
2312 </td>
2313 </tr>
2314
2315 <tr valign="top">
2316 <td valign="top"><kbd>Shepards</kbd></td>
2317 <td valign="top">
2318 Distort the given list control points (any number) using an Inverse
2319 Squared Distance Interpolation Method (<a
2320 href="http://www.ems-i.com/smshelp/Data_Module/Interpolation/Inverse_Distance_Weighted.htm"
2321 >Shepards Method</a>). The control points in effect do 'localized'
2322 distortions of the image around the given control point. For best
2323 results extra control points should be added to 'lock' the positions of
2324 the corners and other unchanging parts of the image. <br/>
2325
2326 The distortion has been likened to 'taffy pulling' using nails, pins or
2327 sticks. It basically uses the <a href="#sparse-color"
2328 >-sparse-color</a> method of the same name to generate separate X and Y
2329 displacement maps (see <a href="#displace" >-displace</a>) for source
2330 image color look-up. </td>
2331
2332 </tr>
2333
2334</table>
2335
2336<p>To print a complete list of distortion methods, use <a href="#list">-list distort</a>.</p>
2337
2338<p>Many of the above distortion methods such as '<kbd>Affine</kbd>',
2339'<kbd>Perspective</kbd>', and '<kbd>Shepards</kbd>' use a list control points
2340defining how these points in the given image should be distorted in the
2341destination image. Each set of four floating point values represent a source
2342image coordinate, followed immediately by the destination image coordinate.
2343This produces a list of values such as...</p>
2344<div style="text-align: center"><em>
2345 U<sub>1</sub>,V<sub>1</sub> X<sub>1</sub>,Y<sub>1</sub> &nbsp;
2346 U<sub>2</sub>,V<sub>2</sub> X<sub>2</sub>,Y<sub>2</sub> &nbsp;
2347 U<sub>3</sub>,V<sub>3</sub> X<sub>3</sub>,Y<sub>3</sub> &nbsp;
2348 ... &nbsp;
2349 U<sub>n</sub>,V<sub>n</sub> X<sub>n</sub>,Y<sub>n</sub> &nbsp;
2350</em></div>
2351<p>where <em>U,V</em> on the source image is mapped to <em>X,Y</em> on the
2352destination image. </p>
2353
2354<p>For example, to warp an image using '<kbd>perspective</kbd>' distortion,
2355needs a list of at least 4 sets of coordinates, or 16 numbers. Here is the
2356perspective distortion of the built-in "rose:" image. Note how spaces were
2357used to group the 4 sets of coordinate pairs, to make it easier to read and
2358understand.</p>
2359
2360<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>
2361 convert rose: -virtual-pixel black \ <br/>
2362 -distort Perspective '0,0,0,0 0,45,0,45 69,0,60,10 69,45,60,35' \ <br/>
2363 rose_3d_rotated.gif</span></p>
2364<p>If more that the required number of coordinate pairs are given for a
2365distortion, the distortion method is 'least squares' fitted to
2366produce the best result for all the coordinate pairs given. If less than the
2367ideal number of points are given, the distort will generally fall back to a
2368simpler form of distortion that can handles the smaller number of coordinates
2369(usally a linear '<kbd>Affine</kbd>' distortion). </p>
2370
2371<p>By using more coodinates you can make use of image registration tool to
2372find matching coordinate pairs in overlaping images, so as to improve the 'fit'
2373of the distortion. Of course a bad coordinate pair can also make the 'fit'
2374worse. Caution is always advised. </p>
2375
2376<p>Colors are acquired from the source image according to the <a
2377href="#interpolate" >-interpolate</a> color lookup setting, when the image is
2378magnified. However if the viewed image is minified (image becomes smaller), a
2379special area resampling function (added ImageMagick v6.3.5-9), is used to
2380produce a higher quality image. For example you can use a
2381'<kbd>perspective</kbd>' distortion to view a infinitely tiled 'plane' all the
2382way to the horizon. </p>
2383
2384<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert -size 90x90 pattern:checkerboard -normalize -virtual-pixel tile \ <br/>
2385 -distort perspective '0,0,5,45 89,0,45,46 0,89,0,89 89,89,89,89' \ <br/>
2386 checks_tiled.jpg</span></p>
2387<p>Note that a infinitely tiled perspective images involving the horizon can
2388be very slow to generate due to the use of the high quality 'area resampling'
2389function (added ImageMagick v6.3.5-9). You can turn off 'area resampling'
2390using a <a href="#filter" >-filter</a> setting of '<kbd>point</kbd>'
2391(recommended if you plan to use super-sampling instead). </p>
2392
2393<p>If an image generates <i>invalid pixels</i>, such as the 'sky' in the last
2394'<kbd>perspective</kbd>' distortion example, <a href="#distort" >-distort</a>
2395will use the current <a href="#mattecolor" >-mattecolor</a> setting for these
2396pixels. If you do not what these pixels to be visible, set the color to match
2397the rest of the ground. </p>
2398
2399<p>The output image size will by default be the same as the input image. This
2400means that if the part of the distorted image falls outside the viewed area of
2401the 'distorted space', those parts is clipped and lost. However if you
2402use the plus form of the operator (<a href="#distort" >+distort</a>) the
2403operator will attempt (if posible) to show the whole of the distorted image,
2404while retaining a correct 'virtual canvas' offset, for image layering. This
2405offset may need to be removed using <a href="#repage" >+repage</a>, to remove
2406if it is unwanted. </p>
2407
2408<p>You can alternatively specify a special "<kbd><a href="#set" >-set</a>
2409option:distort:viewport {geometry_string}</kbd>" setting which will specify
2410the size and the offset of the generated 'viewport' image of the distorted
2411image space.</p>
2412
2413<p>Adding a "<kbd><a href="#set" >-set</a> option:distort:scale
2414{scale_factor}</kbd>" will scale the output image (viewport or otherwise) by
2415that factor without changing the viewed contents of the distorted image. This
2416can be used either for 'super-sampling' the image for a higher quality result,
2417or for panning and zooming around the image (with appropriate viewport
2418changes, or post-distort cropping and resizing). </p>
2419
2420<p>Setting <a href="#verbose" >-verbose</a> setting, will cause <a
2421href="#distort" >-distort</a> to attempt to output the internal coefficients,
2422and the <a href="#fx" >-fx</a> equivalent to the distortion, for expert study,
2423and debugging purposes. This many not be available for all distorts. </p>
2424
2425<p>Affine rotations and shears (such as '<kbd>SRT</kbd>' distortion), tend to
2426produce a cleaner result that the equivalent <a href="#rotate" >-rotate</a>
2427and/or <a href="#shear" >-shear</a> operation, with more control of due to the
2428above settings. It is algorithmically slower, though in ImageMagick it may be faster.
2429</p>
2430
2431
2432<div style="margin: auto;">
2433 <h4><a name="dither" id="dither"></a>-dither <em class="arg">method</em></h4>
2434</div>
2435
2436<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>
2437
2438<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>
2439
2440<p>Dithering is turned on by default, to turn it off use the plus form of the
2441setting, <a href="#dither">+dither</a>. This will also also render PostScript
2442without text or graphic aliasing. Disabling dithering often (but not always)
2443leads to faster process, a smaller number of colors, but more cartoon like
2444image coloring. Generally resulting in 'color banding' effects in areas with
2445color gradients. </p>
2446
2447<p>The color reduction operators <a href="#colors">-colors</a>, <a
2448href="#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>
2449
2450<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>
2451
2452
2453<div style="margin: auto;">
2454 <h4><a name="draw" id="draw"></a>-draw <em class="arg">string</em></h4>
2455</div>
2456
2457<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>
2458
2459<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>
2460
2461<p>The shape primitives:</p>
2462
2463<pre class="text">
2464 point x,y
2465 line x0,y0 x1,y1
2466 rectangle x0,y0 x1,y1
2467 roundRectangle x0,y0 x1,y1 wc,hc
2468 arc x0,y0 x1,y1 a0,a1
2469 ellipse x0,y0 rx,ry a0,a1
2470 circle x0,y0 x1,y1
2471 polyline x0,y0 ... xn,yn
2472 polygon x0,y0 ... xn,yn
2473 bezier x0,y0 ... xn,yn
2474 path path specification
2475 image operator x0,y0 w,h filename
2476</pre>
2477
2478<p>The text primitive:</p>
2479
2480<pre class="text">
2481 text x0,y0 string
2482</pre>
2483<p>The text gravity primitive:</p>
2484
2485<pre class="text">
2486 gravity NorthWest, North, NorthEast, West, Center,
2487 East, SouthWest, South, or SouthEast
2488</pre>
2489
2490<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>
2491
2492<p>The transformation primitives:</p>
2493
2494<pre class="text">
2495 rotate degrees
2496 translate dx,dy
2497 scale sx,sy
2498 skewX degrees
2499 skewY degrees
2500</pre>
2501
2502<p>The pixel operation primitives:</p>
2503
2504<pre class="text">
2505 color x0,y0 method
2506 matte x0,y0 method
2507</pre>
2508
2509<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>
2510
2511<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>
2512
2513<p>A <kbd>line</kbd> primitive requires a start point and end point.</p>
2514
2515<p>A <kbd>rectangle</kbd> primitive is specified by the pair of points at the upper left and lower right corners.</p>
2516
2517<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>
2518
2519<p>The <kbd>circle</kbd> primitive makes a disk (filled) or circle (unfilled). Give the center and any point on the perimeter (boundary).</p>
2520
2521<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>
2522
2523<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>
2524
2525<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>.
2526</p>
2527
2528<p>A <em>coordinate</em> is a pair of integers separated by a space or optional comma. </p>
2529
2530<p>As an example, to define a circle centered at 100,100 that extends to 150,150 use:</p>
2531
2532<p class="crtsnip">
2533 -draw 'circle 100,100 150,150'
2534</p>
2535
2536<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
2537draw 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>
2538
2539<p class="crtsnip">
2540 -draw 'bezier 20,50 45,100 45,0 70,50'
2541</p>
2542<p class="crtsnip">
2543 -draw 'bezier 70,50 95,100 95,0 120,50'
2544</p>
2545
2546
2547<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>
2548
2549<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>
2550
2551<p class="crtsnip">
2552 -draw 'image SrcOver 100,100 225,225 image.jpg'
2553</p>
2554
2555<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>
2556
2557<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>
2558
2559<p>For example, the following annotates the image with <kbd>Works like magick!</kbd> for an image titled <kbd>bird.miff</kbd>. </p>
2560
2561<p class="crtsnip">
2562 -draw 'text 100,100 "Works like magick!"'
2563</p>
2564
2565<p>See the <a href="#annotate">-annotate</a> option for another convenient way to annotate an image with text.</p>
2566
2567<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>
2568
2569<p>The <kbd>translate</kbd> primitive translates subsequent shape and text primitives.</p>
2570
2571<p>The <kbd>scale</kbd> primitive scales them.</p>
2572
2573<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>
2574
2575<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
2576matrix.</p>
2577
2578<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>
2579
2580<pre class="text">
2581 point
2582 replace
2583 floodfill
2584 filltoborder
2585 reset
2586</pre>
2587
2588<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>
2589
2590<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>
2591
2592<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>
2593
2594<p>Strings that begin with a number must be quoted (e.g. use '1.png' rather than 1.png).</p>
2595
2596<p>Drawing primitives conform to the <a href="../www/magick-vector-graphics.html">Magick Vector Graphics</a> format.</p>
2597
2598
2599<div style="margin: auto;">
2600 <h4><a name="edge" id="edge"></a>-edge <em class="arg">radius</em></h4>
2601</div>
2602
2603<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>
2604
2605<div style="margin: auto;">
2606 <h4><a name="emboss" id="emboss"></a>-emboss <em class="arg">radius</em></h4>
2607</div>
2608
2609<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>
2610
2611<div style="margin: auto;">
2612 <h4><a name="encipher" id="encipher"></a>-encipher <em class="arg">filename</em></h4>
2613</div>
2614
2615<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>
2616
2617<p>Get the passphrase from the file specified by <em class="arg">filename</em>.</p>
2618
2619<p>For more information, see the webpage, <a href="http://www.imagemagick.org/www/cipher.html">ImageMagick: Encipher or Decipher an Image</a>.</p>
2620
2621<div style="margin: auto;">
2622 <h4><a name="encoding" id="encoding"></a>-encoding <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 the text encoding.</td><td style='text-align:right;'></td></tr></table>
2626
2627<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>
2628
2629<div style="margin: auto;">
2630 <h4><a name="endian" id="endian"></a>-endian <em class="arg">type</em></h4>
2631</div>
2632
2633<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>
2634
2635<p>To print a complete list of endian types, use the <a href="#list">-list endian</a> option.</p>
2636
2637<p>Use <a href="#endian">+endian</a> to revert to unspecified endianness.</p>
2638
2639
2640<div style="margin: auto;">
2641 <h4><a name="enhance" id="enhance"></a>-enhance</h4>
2642</div>
2643
2644<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>
2645
2646
2647<div style="margin: auto;">
2648 <h4><a name="equalize" id="equalize"></a>-equalize</h4>
2649</div>
2650
2651<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>
2652
2653<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>
2654
2655<p>For example using HSL, we have: ... <kbd>-colorspace HSL -channel lightness -equalize -colorspace RGB</kbd> ...</p>
2656
2657<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>
2658
2659<div style="margin: auto;">
2660 <h4><a name="evaluate" id="evaluate"></a>-evaluate <em class="arg">operator value</em></h4>
2661</div>
2662
2663<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>
2664
2665<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>
2666
2667<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>
2668
2669<table class="doc">
2670 <col width="25%" />
2671 <col width="75%" />
2672 <thead>
2673 <tr>
2674 <th><em class="arg">operator</em></th>
2675 <th>Summary (see further below for details)</th>
2676 </tr>
2677 </thead>
2678 <tbody>
2679
2680 <tr><td>Add </td> <td>Add <em class="arg">value</em> to pixels. </td></tr>
2681 <tr><td>AddModulus </td> <td>Add <em class="arg">value</em> to pixels modulo <em class="QR">QuantumRange</em>.</td></tr>
2682 <tr><td>And </td> <td>Binary AND of pixels with <em class="arg">value</em>.</td></tr>
2683 <tr><td>Cos, Cosine </td> <td>Apply cosine to pixels with frequency <em class="arg">value</em> with 50% bias added.</td></tr>
2684 <tr><td>Divide </td> <td>Divide pixels by <em class="arg">value</em>.</td></tr>
2685 <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>
2686 <tr><td>Log </td> <td>Apply scaled logarithm to normalized pixels.</td></tr>
2687 <tr><td>Max </td> <td>Clip pixels at lower bound <em class="arg">value</em>.</td></tr>
2688 <tr><td>Min </td> <td>Clip pixels at upper bound <em class="arg">value</em>.</td></tr>
2689 <tr><td>Multiply </td> <td>Multiply pixels by <em class="arg">value</em>.</td></tr>
2690 <tr><td>Or </td> <td>Binary OR of pixels with <em class="arg">value</em>.</td></tr>
2691 <tr><td>Pow </td> <td>Raise normalized pixels to the power <em class="arg">value</em>.</td></tr>
2692 <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>
2693 <tr><td>Set </td> <td>Set pixel equal to <em class="arg">value</em>.</td></tr>
2694 <tr><td>Sin, Sine </td> <td>Apply sine to pixels with frequency <em class="arg">value</em> with 50% bias added.</td></tr>
2695 <tr><td>Subtract </td> <td>Subtract <em class="arg">value</em> from pixels.</td></tr>
2696 <tr><td>Xor </td> <td>Binary XOR of pixels with <em class="arg">value.</em></td></tr>
2697
2698 <tr><td>&nbsp;</td></tr>
2699
2700 <tr><td>Gaussian-noise</td></tr>
2701 <tr><td>Impulse-noise</td></tr>
2702 <tr><td>Laplacian-noise</td></tr>
2703 <tr><td>Multiplicative-noise</td> <td>(These are equivalent to the corresponding <a href="#noise" >-noise</a> operators.)</td></tr>
2704 <tr><td>PoissonNoise</td></tr>
2705 <tr><td>Uniform-noise</td></tr>
2706
2707 <tr><td>&nbsp;</td></tr>
2708
2709 <tr><td>Threshold </td> <td>Threshold pixels larger than <em class="arg">value</em>.</td></tr>
2710 <tr><td>ThresholdBlack </td> <td>Threshold pixels to zero values equal to or below <em class="arg">value</em>.</td></tr>
2711 <tr><td>ThresholdWhite </td> <td>Threshold pixels to maximum values above <em class="arg">value</em>. </td></tr>
2712 </tbody>
2713 </table>
2714
2715<p>The specified functions are applied only to each previously set <a
2716href="#channel" >-channel</a> in the image. If necessary, the results of the
2717calculations are truncated (clipped) to fit in the interval [0,&nbsp;<em
2718class="QR">QuantumRange</em>]. The transparency channel of the image is
2719represented as a 'alpha' values (0 = fully transparent), so, for example, a
2720<kbd>Divide</kbd> by&nbsp;2 of the alpha channel will make the image
2721semi-transparent. Append the percent symbol '<kbd>%</kbd>' to specify a value
2722as a percentage of the <em class="QR">QuantumRange</em>.</p>
2723
2724<p>To print a complete list of <a href="#evaluate">-evaluate</a> operators, use
2725<a href="#list">-list evaluate</a>.</p>
2726
2727<p>The results of the <kbd>Add</kbd>, <kbd>Subtract</kbd> and
2728<kbd>Multiply</kbd> methods can also be achieved using either the <a
2729href="#level" >-level</a> or the <a href="#level" >+level</a> operator, with
2730appropriate argument, to linearly modify the overall range of color values.
2731Please note, however, that <a href="#level" >-level</a> treats transparency as
2732'matte' values (0 = opaque), while <a href="#level" >-evaluate</a> works with
2733'alpha' values.</p>
2734
2735<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>
2736
2737<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>
2738
2739 <div style="text-align:center;">
2740 log(<em class="arg">value</em> &times; <b><em>u</em></b> + 1) / log(<em class="arg">value</em> + 1)
2741 </div>
2742
2743<p><kbd>Pow</kbd> has been added as of ImageMagick 6.4.1-9, and works on
2744normalized pixel values. Note that <kbd>Pow</kbd> is related to the <a
2745href="#gamma" >-gamma</a> operator. For example, <b>-gamma 2</b> is equivalent
2746to <b>-evaluate pow 0.5</b>, i.e., a 'square root' function. The value used
2747with <a href="#gamma" >-gamma</a> is simply the reciprocal of the value used
2748with <kbd>Pow</kbd>.</p>
2749
2750<p><kbd>Cosine</kbd> and <kbd>Sine</kbd> was added as of IM v6.4.8-8 and
2751converts the image values into a value according to a (co)sine wave function.
2752The synonyms <kbd>Cos</kbd> and <kbd>Sin</kbd> may also be used. The output
2753is biased 50% and normalized by 50% so as to fit in the respective color value
2754range. The <em class="arg">value</em> scaling of the <em>period</em> of the
2755function (its frequency), and thus determines the number of 'waves' that will
2756be generated over the input color range. For example, if the <em
2757class="arg">value</em> is&nbsp;1, the effective period is simply the <em
2758class="QR">QuantumRange</em>; but if the <em class="arg">value</em> is&nbsp;2,
2759then the effective period is the <em>half</em> the <em
2760class="QR">QuantumRange</em>.
2761
2762 <div style="text-align:center;">
2763 0.5 + 0.5 &times; cos(2 &pi; <b><em>u</em></b> &times; <em class="arg">value</em>).
2764 </div>
2765
2766See also the <a href="#function" >-function</a> operator, which is a
2767multi-value version of evaluate. </P>
2768
2769
2770<div style="margin: auto;">
2771 <h4><a name="extent" id="extent"></a>-extent <em class="arg">geometry</em></h4>
2772</div>
2773
2774<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>
2775
cristy3e2860c2010-01-24 01:36:30 +00002776<p>If the image is enlarged, unfilled areas are set to the background color. To position the image, use offsets in the <em class="arg">geometry</em> specification or precede with a <a href="#gravity">-gravity</a> setting. To specify how to compose the image with the background, use <a href="#compose" >-compose</a>.</p>
cristy3ed852e2009-09-05 21:47:34 +00002777
2778<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>
2779
2780<div style="margin: auto;">
2781 <h4><a name="extract" id="extract"></a>-extract <em class="arg">geometry</em></h4>
2782</div>
2783
2784<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>
2785
2786<p>This option is most useful for extracting a subregion of a very large raw image. Note that these two commands are equivalent:</p>
2787
2788<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>
2789
2790<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>
2791<p>then the image will be <em>resized</em> to the specified dimensions instead,
2792equivalent to:</p>
2793
2794<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>
2795<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>
2796
2797<div style="margin: auto;">
2798 <h4><a name="family" id="family"></a>-family <em class="arg">fontFamily</em></h4>
2799</div>
2800
2801<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>
2802
2803<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).
2804</p>
2805
2806<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>.
2807</p>
2808
2809<div style="margin: auto;">
cristy7396d882010-01-27 02:37:56 +00002810 <h4><a name="features" id="features"></a>-features <em class="arg">distance</em></h4>
2811</div>
2812
2813<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>display features for each channel in the image in each of four directions (horizontal, vertical, left and right diagonals) for the specified distance.</td><td style='text-align:right;'></td></tr></table>
2814
2815<div style="margin: auto;">
cristy3ed852e2009-09-05 21:47:34 +00002816 <h4><a name="fft" id="fft"></a>-fft</h4>
2817</div>
2818
2819<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>
2820
2821<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>
2822
2823<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>
2824
2825<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>
2826
2827<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert image.png -fft fft_image.miff</span></p>
2828<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>
2829
2830<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert image.png -fft fft_image.png</span></p>
2831<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>
2832
2833<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>
2834
2835<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>
2836
2837<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert fft_image.miff[0] -contrast-stretch 0 \ <br />
2838 -evaluate log 1000 fft_image_spectrum.png</span></p>
2839<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>
2840
2841<p>The <a href="http://www.fftw.org/" target="_blank">FFTW</a> delegate library is required to use <a href="#fft">-fft</a>.
2842
2843<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>
2844
2845<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>
2846
2847<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>
2848
2849<p>See the discussion on HDRI implementations of ImageMagick on the page
2850<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.
2851</p>
2852
2853
2854<div style="margin: auto;">
2855 <h4><a name="fill" id="fill"></a>-fill <em class="arg">color</em></h4>
2856</div>
2857
2858<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>
2859
2860<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>
2861
2862<p>Enclose the color specification in quotation marks to prevent the "#" or the parentheses from being interpreted by your shell.</p>
2863
2864<p>For example,</p>
2865
2866<p class="crtsnip">
2867 -fill blue
2868</p>
2869<p class="crtsnip">
2870 -fill "#ddddff"
2871</p>
2872<p class="crtsnip">
2873 -fill "rgb(255,255,255)"
2874</p>
2875
2876<p>See <a href="#draw">-draw</a> for further details.</p>
2877
2878<p>To print a complete list of color names, use the <a href="#list">-list color</a> option.</p>
2879
2880<div style="margin: auto;">
2881 <h4><a name="filter" id="filter"></a>-filter <em class="arg">type</em></h4>
2882</div>
2883
2884<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>
2885
2886<p>Use this option to affect the resizing operation of an image (see <a
2887href="#resize">-resize</a>). For example you can use a simple resize filter
2888such as:</p>
2889
2890<pre class="text">
2891 Point Hermite Cubic
2892 Box Gaussian Catrom
2893 Triangle Quadratic Mitchell
2894</pre>
2895
2896<p>The <kbd>Bessel</kbd> and <kbd>Sinc</kbd> filter is also provided, but are
2897by default <kbd>blackman</kbd>-windowed. However these filters define a
2898windowing filter for the Sinc or Bessel filter function, as appropriate for
2899the scaling operator used (usally Sinc for orthogonal <a href="#resize"
2900>-resize</a>). Windowed filters include: </p>
2901
2902<pre class="text">
2903 Lanczos Hamming Parzen
2904 Blackman Kaiser Welsh
2905 Hanning Bartlett Bohman
2906</pre>
2907
2908<p>Also one special self-windowing filter is also provided
2909<kbd>Lagrange</kbd>, which will automagically re-adjust its function depending
2910on the current 'support' or 'lobes' expert settings (see below).</p>
2911
2912<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>
2913
2914<p>To print a complete list of resize filters, use the <a href="#list">-list filter</a> option.</p>
2915
2916<p>You can modify how the filter behaves as it scales your image through the
2917use of these expert settings:</p>
2918
2919<dl class="doc">
2920<dt>-set filter:blur <em>factor</em></dt>
2921<dd>Scale the X axis of the filter (and its window). Use &gt; 1.0 for
2922 blurry or &lt; 1.0 for sharp.</dd>
2923
2924<dt>-set filter:support <em>radius</em></dt>
2925<dd>Set the filter support radius.</dd>
2926
2927<dt>-set filter:lobes <em>count</em></dt>
2928<dd>Set the number of lobes to use for the Sinc/Bessel filter. This an
2929 alternative way of specifying the 'support' range of the filter.</dd>
2930
2931<dt>-set filter:b <em>b-spline_factor</em></dt>
2932<dt>-set filter:c <em>keys_alpha_factor</em></dt>
2933<dd>Redefine the values used for cubic filters such as <kbd>Cubic</kbd>,
2934 <kbd>Catrom</kbd>, <kbd>Mitchel</kbd>, and <kbd>Hermite</kbd>, as well as
2935 the <kbd>Parzen</kbd> Sinc windowing function. If only one of the values
2936 are defined, the other is set so as to generate a 'Keys' type cubic
2937 filter.
2938
2939<dt>-set filter:filter <em>filter</em></dt>
2940<dd>Use this function directly as the scaling filter. This will allow
2941 you to directly use a 'windowing filter' such as <kbd>blackman</kbd>,
2942 rather than as its normal usage as a windowing function for 'Sinc' or
2943 'Bessel'. If defined, no windowing function is used, unless the following
2944 expert setting is also defined.</dd>
2945
2946<dt>-set filter:window <em>filter</em></dt>
2947<dd>The IIR (infinite impulse response) filters <kbd>bessel</kbd> and
2948 <kbd>sinc</kbd> are windowed (brought down to zero over the defined
2949 support range) with the given filter. This allows you to use a filter that
2950 is not normally used as a windowing function, such as <kbd>box</kbd>,
2951 (which effectivally turns off the windowing function). </dd>
2952
2953</dl>
2954
2955<p>For example, to get a 8 lobe Lanczos-Bessel filter:</p>
2956
2957<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert image.png -filter bessel \ <br/>
2958 -set filter:window=bessel -set filter:lobes=8 \ <br/>
2959 -resize 150% image.jpg</span></p>
2960<p>Or a raw un-windowed Sinc filter with 4 lobes:</p>
2961
2962<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert image.png -set filter:filter=sinc -set filter:lobes=4 \ <br/>
2963 -resize 150% image.jpg</span></p>
2964<p>Note that the use of expert options (except for 'blur' with simple resize
2965filters), are provided for image processing experts who have studied and
2966understood how resize filters work. Without this knowledge, and an
2967understanding of the defination of the actual filters involved, using expert
2968settings are more likely to be detremental to your image resizing.</p>
2969
2970
2971<div style="margin: auto;">
2972 <h4><a name="flatten" id="flatten"></a>-flatten</h4>
2973</div>
2974
2975<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>
2976
2977
2978<div style="margin: auto;">
2979 <h4><a name="flip" id="flip"></a>-flip</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 vertical direction.</p>
2985
2986<div style="margin: auto;">
2987 <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>
2988</div>
2989
2990<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>
2991
2992<div style="margin: auto;">
2993 <h4><a name="flop" id="flop"></a>-flop</h4>
2994</div>
2995
2996<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>
2997
2998<p>reflect the scanlines in the horizontal direction.</p>
2999
3000
3001<div style="margin: auto;">
3002 <h4><a name="font" id="font"></a>-font <em class="arg">name</em></h4>
3003</div>
3004
3005<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>
3006
3007<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>
3008
3009<p>In addition to the fonts specified by the above pre-defined list, you can
3010also specify a font from a specific source. For example <kbd>Arial.ttf</kbd>
3011is a TrueType font file, <kbd>ps:helvetica</kbd> is PostScript font, and
3012<kbd>x:fixed</kbd> is X11 font.</p>
3013
3014<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>
3015
3016
3017<div style="margin: auto;">
3018 <h4><a name="foreground" id="foreground"></a>-foreground <em class="arg">color</em></h4>
3019</div>
3020
3021<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>
3022
3023<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p>
3024
3025<p>The default foreground color is black.</p>
3026
3027<div style="margin: auto;">
3028 <h4><a name="format" id="format"></a>-format <em class="arg">type</em></h4>
3029</div>
3030
3031<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>
3032
3033<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>
3034
3035<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>
3036
3037<div style="margin: auto;">
3038 <h4><a name="format_identify_" id="format_identify_"></a>-format <em class="arg">string</em></h4>
3039</div>
3040
3041<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>
3042
3043<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>
3044
3045<div style="margin: auto;">
3046 <h4><a name="frame" id="frame"></a>-frame <em class="arg">geometry</em></h4>
3047</div>
3048
3049<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>
3050
3051<p>The color of the border is specified with the <a href="#mattecolor">-mattecolor</a> command line option. </p>
3052
3053<p>See <a href="../www/command-line-processing.html#geometry">Image Geometry</a> for complete details about the <em class="arg">geometry</em> argument. The <em class="arg">size</em> portion of the <em 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>
3054
3055
3056<div style="margin: auto;">
3057 <h4><a name="frame_import_" id="frame_import_"></a>-frame</h4>
3058</div>
3059
3060<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>
3061
3062<div style="margin: auto;">
3063 <h4><a name="function" id="function"></a>-function <em class="arg">function</em> <em class="arg">parameters</em></h4>
3064</div>
3065
3066<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>
3067
3068<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>
3069
3070<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>
3071
3072<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>
3073
3074<pre class="text">
3075 Polynomial
3076 Sinusoid
3077 Arcsin
3078 Arctan
3079</pre>
3080
3081<p>To print a complete list of <a href="#function">-function</a> operators, use <a href="#list">-list function</a>. Descriptions follow.</p>
3082
3083<dl class="doc">
3084<dt><kbd>Polynomial</kbd></dt>
3085<dd>
3086<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>
3087
3088<div style="text-align: center">
3089 -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>
3090</div>
3091
3092<p>will invoke a polynomial function given by</p>
3093
3094<div style="text-align: center">
3095 <em>a</em><sub><em>n</em></sub> <b><em>u</em></b><sup><em>n</em></sup> +
3096 <em>a</em><sub><em>n</em>-1</sub> <b><em>u</em></b><sup><em>n</em>-1</sup> +
3097 &middot;&middot;&middot; <em>a</em><sub>1</sub> <b><em>u</em></b> + <em>a</em><sub>0</sub>,
3098</div>
3099
3100<p>where <b><em>u</em></b> is pixel's original normalized channel value.</p>
3101
3102<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>
3103
3104<table class="doc">
3105 <col width="35%" />
3106 <col width="35%" />
3107 <col width="30%" />
3108 <tr>
3109 <td>-evaluate Set <em class="arg">value</em> </td>
3110 <td>-function Polynomial <em class="arg">value</em></td>
3111 <td>(Constant functions; set <em class="arg">value</em>&times;100% gray when channels are RGB.)</td>
3112 </tr>
3113 <tr>
3114 <td>-evaluate Add <em class="arg">value</em> </td>
3115 <td>-function Polynomial 1,<em class="arg">value</em></td>
3116 </tr>
3117 <tr>
3118 <td>-evaluate Subtract <em class="arg">value</em> </td>
3119 <td>-function Polynomial 1,&minus;<em class="arg">value</em></td>
3120 </tr>
3121 <tr>
3122 <td>-evaluate Multiply <em class="arg">value</em> </td>
3123 <td>-function Polynomial <em class="arg">value</em>,0</td>
3124 </tr>
3125 <tr>
3126 <td>+level black% x white%</td>
3127 <td>-function Polynomial A,B</td>
3128 <td>(Reduce contrast. Here, A=(white-black)/100 and B=black/100.)</td>
3129 </tr>
3130</table>
3131
3132<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>
3133</dd>
3134
3135<dt><kbd>Sinusoid</kbd></dt>
3136<dd>
3137<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>
3138
3139<div style="text-align: center">
3140 -function <kbd>Sinusoid</kbd> <em class="arg">freq</em>,[<em class="arg">phase</em>,[<em class="arg">amp</em>,[<em class="arg">bias</em>]]]
3141</div>
3142
3143<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>
3144
3145<div style="text-align: center">
3146<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>
3147</div>
3148
3149<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>
3150
3151<p class="crtsnip">
3152 -function Sinusoid 3,-90,.2,.7
3153</p>
3154
3155<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>
3156
3157<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>
3158
3159<table class="doc">
3160 <tr>
3161 <td>-evaluate Sin <em class="arg">freq</em> </td>
3162 <td>-function Sinusoid <em class="arg">freq</em>,0 </td>
3163 </tr>
3164 <tr>
3165 <td>-evaluate Cos <em class="arg">freq</em> </td>
3166 <td>-function Sinusoid <em class="arg">freq</em>,90 </td>
3167 </tr>
3168</table>
3169</dd>
3170
3171<dt><kbd>ArcSin</kbd></dt>
3172<dd>
3173<p>The <kbd>ArcSin</kbd> function generates the inverse curve of a Sinusoid,
3174and can be used to generate cylindrical distortion and displacement maps.
3175The curve can be adjusted relative to both the input values and output range
3176of values.
3177
3178<div style="text-align: center">
3179 -function <kbd>ArcSin</kbd> <em class="arg">width</em>,[<em class="arg">center</em>,[<em class="arg">range</em>,[<em class="arg">bias</em>]]]
3180</div>
3181
3182<p>with all values given in terms of noramlize color values (0.0 for black,
31831.0 for white). Defaulting to values covering the full range from 0.0 to 1.0
3184for bout input (<em class="arg">width</em>), and output (<em
3185class="arg">width</em>) values. '<code>1.0,0.5,1.0,0.5</code>' </p>
3186
3187<div style="text-align: center">
3188<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>
3189</div>
3190
3191</dd>
3192
3193<dt><kbd>ArcTan</kbd></dt>
3194<dd>
3195<p>The <kbd>ArcTan</kbd> function generates a curve that smooth crosses from
3196limit values at infinities, though a center using the given slope value.
3197All these values can be adjusted via the arguments.
3198
3199<div style="text-align: center">
3200 -function <kbd>ArcTan</kbd> <em class="arg">slope</em>,[<em class="arg">center</em>,[<em class="arg">range</em>,[<em class="arg">bias</em>]]]
3201</div>
3202
3203<p>Defaulting to '<code>1.0,0.5,1.0,0.5</code>'.
3204</p>
3205
3206<div style="text-align: center">
3207<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>
3208</div>
3209
3210</dd>
3211
3212</dl>
3213
3214
3215<div style="margin: auto;">
3216 <h4><a name="fuzz" id="fuzz"></a>-fuzz <em class="arg">distance</em>{<em class="arg">%</em>}</h4>
3217</div>
3218
3219<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>
3220
3221<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>
3222
3223<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>
3224
3225
3226<div style="margin: auto;">
3227 <h4><a name="fx" id="fx"></a>-fx <em class="arg">expression</em></h4>
3228</div>
3229
3230<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>
3231
3232<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>
3233
3234<p>See <a href="../www/fx.html">FX, The Special Effects Image Operator</a> for a detailed discussion of this option.</p>
3235
3236
3237<div style="margin: auto;">
3238 <h4><a name="gamma" id="gamma"></a>-gamma <em class="arg">value</em></h4>
3239</div>
3240
3241<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>
3242
3243<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>
3244
3245<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>
3246
3247<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>
3248
3249<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>
3250
3251<p>Note that gamma adjustments are also available via the <a href="#level">-level</a> operator.</p>
3252
3253<div style="margin: auto;">
3254 <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>
3255</div>
3256
3257<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>
3258
3259<p>Convolve the image with a Gaussian or normal distribution. The formula is:</p>
3260
3261<div class="eqn"><img alt="gaussian distribution" width="243px" height="42px" src="../images/gaussian-blur.png"/>
3262</div>
3263
3264<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>
3265
3266<p>This differs from the faster <a href="#blur">-blur</a> operator in that a
3267full 2-dimentional convolution is used to generate the weighted average of the
3268neighbouring pixels. </p>
3269
3270<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how
3271pixels which are outside the image proper are blurred into the final result.
3272</p>
3273
3274
3275<div style="margin: auto;">
3276 <h4><a name="geometry" id="geometry"></a>-geometry <em class="arg">geometry</em></h4>
3277</div>
3278
3279<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>
3280
3281<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>
3282
3283<div style="margin: auto;">
3284 <h4><a name="gravity" id="gravity"></a>-gravity <em class="arg">type</em></h4>
3285</div>
3286
3287<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>
3288
3289<p>Choices include: <kbd>NorthWest</kbd>, <kbd>North</kbd>, <kbd>NorthEast</kbd>,
3290<kbd>West</kbd>, <kbd>Center</kbd>, <kbd>East</kbd>, <kbd>SouthWest</kbd>,
3291<kbd>South</kbd>, <kbd>SouthEast</kbd>. Use <a href="#list">-list gravity</a> to get a complete
3292list of <a href="#gravity">-gravity</a> settings available in your ImageMagick
3293installation.</p>
3294
3295<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>
3296
3297<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>
3298
3299<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>
3300
3301<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>
3302<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>
3303
3304<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>
3305
3306
3307<div style="margin: auto;">
3308 <h4><a name="green-primary" id="green-primary"></a>-green-primary <em class="arg">x,y</em></h4>
3309</div>
3310
3311<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>
3312
3313
3314<div style="margin: auto;">
3315 <h4><a name="hald-clut" id="hald-clut"></a>-hald-clut</h4>
3316</div>
3317
3318<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>
3319
3320<p>A Hald color lookup table is a 3-dimensional color cube mapped to 2
3321dimensions. Create it with the <kbd>HALD:</kbd> prefix (e.g. HALD:8). You
3322can apply any color transformation to the Hald image and then use this option
3323to apply the transform to the image. </p>
3324
3325<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert image.png hald.png -hald-clut transform.png</span></p>
3326<p>This option provides a convenient method for you to use Gimp or Photoshop
3327to make color corrections to the Hald CLUT image and subsequently apply them
3328to multiple images using an ImageMagick script. </p>
3329
3330<p>Note that the representation is only of the normal RGB color space and that
3331the whole color value triplet is used for the interpolated lookup of the
3332represented Hald color cube image. Because of this the operation is not <a
3333href="#channel" >-channel</a> setting effected, nor can it adjust or modify an
3334images transparency or alpha/matte channel.</p>
3335
3336<p>See also <a href="#clut" >-clut</a> which provides color value replacement
3337of the individual color channels, usally involving a simplier gray-scale
3338image. E.g: gray-scale to color replacement, or modification by a histogram
3339mapping. </p>
3340
3341
3342<div style="margin: auto;">
3343 <h4><a name="help" id="help"></a>-help</h4>
3344</div>
3345
3346<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>
3347
3348<div style="margin: auto;">
3349 <h4><a name="highlight-color" id="highlight-color"></a>-highlight-color <em class="arg">color</em></h4>
3350</div>
3351
3352<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>
3353
3354<div style="margin: auto;">
3355 <h4><a name="iconGeometry" id="iconGeometry"></a>-iconGeometry <em class="arg">geometry</em></h4>
3356</div>
3357
3358<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>
3359
3360<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>
3361
3362<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>
3363
3364<div style="margin: auto;">
3365 <h4><a name="iconic" id="iconic"></a>-iconic</h4>
3366</div>
3367
3368<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>
3369
3370<div style="margin: auto;">
3371 <h4><a name="identify" id="identify"></a>-identify</h4>
3372</div>
3373
3374<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>
3375
3376<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>
3377
3378<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>
3379
3380<p>If <a href="#verbose">-verbose</a> preceds this option, copious
3381amounts of image properties are displayed including image statistics, profiles,
3382image histogram, and others.</p>
3383
3384<div style="margin: auto;">
3385 <h4><a name="ift" id="ift"></a>-ift</h4>
3386</div>
3387
3388<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>
3389
3390<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>
3391
3392<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>
3393
3394<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert fft_image.miff -ift fft_image_ift.png</span></p>
3395<p>or</p>
3396
3397<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>
3398
3399<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.
3400
3401<p>The <a href="http://www.fftw.org/" target="_blank">FFTW</a> delegate library is required to use <a href="#ift">-ift</a>.
3402
3403<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.
3404
3405<div style="margin: auto;">
3406 <h4><a name="immutable" id="immutable"></a>-immutable</h4>
3407</div>
3408
3409<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>
3410
3411<div style="margin: auto;">
3412 <h4><a name="implode" id="implode"></a>-implode <em class="arg">factor</em></h4>
3413</div>
3414
3415<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>
3416
3417<div style="margin: auto;">
3418 <h4><a name="insert" id="insert"></a>-insert <em class="arg">index</em></h4>
3419</div>
3420
3421<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>
3422
3423<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>
3424
3425<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>
3426
3427<div style="margin: auto;">
3428 <h4><a name="intent" id="intent"></a>-intent <em class="arg">type</em></h4>
3429</div>
3430
3431<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>
3432
3433<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>
3434
3435<p>The default intent is undefined.</p>
3436
3437<p>To print a complete list of rendering intents, use <a href="#list">-list intent</a>.</p>
3438
3439<div style="margin: auto;">
3440 <h4><a name="interlace" id="interlace"></a>-interlace <em class="arg">type</em></h4>
3441</div>
3442
3443<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>
3444
3445<p>Choose from:</p>
3446
3447<pre class="text">
3448 none
3449 line
3450 plane
3451 partition
3452 JPEG
3453 GIF
3454 PNG
3455</pre>
3456
3457<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>
3458
3459<p><kbd>None</kbd> means do not interlace (RGBRGBRGBRGBRGBRGB...),</p>
3460
3461<p><kbd>Line</kbd> uses scanline interlacing (RRR...GGG...BBB...RRR...GGG...BBB...), and.</p>
3462
3463<p><kbd>Plane</kbd> uses plane interlacing (RRRRRR...GGGGGG...BBBBBB...).</p>
3464
3465<p><kbd>Partition</kbd> is like plane except the different planes are saved to individual files (e.g. image.R,
3466image.G, and image.B).</p>
3467
3468<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>
3469image.</p>
3470
3471<p>To print a complete list of interlacing schemes, use <a href="#list">-list interlace</a>.</p>
3472
3473<div style="margin: auto;">
3474 <h4><a name="interpolate" id="interpolate"></a>-interpolate <em class="arg">type</em></h4>
3475</div>
3476
3477<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>
3478
3479<p>When looking up the color of a pixel using a non-interger floating point
3480value, you typically fall in between the pixel colors defined by the source
3481image. This setting determines how the color is determined from the colors of
3482the pixels surrounding that point. That is how to determine the color of a
3483point that falls between two, or even four different colored pixels. </p>
3484
3485<pre class="text">
3486 integer: The color of the top-left pixel (floor function)
3487 nearest-neighbor: The nearest pixel to the lookup point (rounded function)
3488 average: The average color of the surrounding four pixels
3489 bilinear A double linear interpolation of pixels (the default)
3490 mesh Divide area into two flat triangular interpolations
3491 bicubic Fitted bicubic-spines of surrounding 16 pixels
3492 spline Direct spline curves (colors are blurred)
3493 filter Use resize <a href="#filter">-filter</a> settings
3494</pre>
3495
3496<p>This most important for distortion operators such as <a href="#distort"
3497>-distort</a>, <a href="#implode" >-implode</a>, <a href="#transform"
3498>-transform</a> and <a href="#fx" >-fx</a>. </p>
3499
3500<p>To print a complete list of interpolation methods, use <a href="#list">-list interpolate</a>.</p>
3501
3502<p>See also <a href="#virtual-pixel" >-virtual-pixel</a>, for control of the
3503lookup for positions outside the boundaries of the image. </p>
3504
3505
3506<div style="margin: auto;">
cristyf3bb4782009-09-08 13:10:04 +00003507 <h4><a name="interline-spacing" id="interline-spacing"></a>-interline-spacing <em class="arg">value</em></h4>
3508</div>
3509
3510<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>
3511
3512<div style="margin: auto;">
cristy3ed852e2009-09-05 21:47:34 +00003513 <h4><a name="interword-spacing" id="interword-spacing"></a>-interword-spacing <em class="arg">value</em></h4>
3514</div>
3515
3516<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>
3517
3518<div style="margin: auto;">
3519 <h4><a name="kerning" id="kerning"></a>-kerning <em class="arg">value</em></h4>
3520</div>
3521
3522<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>
3523
3524<div style="margin: auto;">
3525 <h4><a name="label" id="label"></a>-label <em class="arg">name</em></h4>
3526</div>
3527
3528<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>
3529
3530<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>
3531
3532<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>
3533
3534<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>
3535
3536<p>For example,</p>
3537
3538<p class="crtsnip">
3539 -label "%m:%f %wx%h" bird.miff
3540</p>
3541
3542<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>
3543
3544<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>
3545
3546<p>The label font can be specified with <a href="#font">-font</a>, and the
3547other font attribute settings.</p>
3548
3549<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>
3550
3551
3552<div style="margin: auto;">
3553 <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>
3554</div>
3555
3556<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>
3557
3558<p>Adaptively threshold each pixel based on the value of pixels in a
3559surrounding window. If the current pixel is lighter than this average plus
3560the optional <kbd>offset</kbd>, then it is made white, otherwise it is made
3561black. Small variations in pixel values such as found in scanned documents
3562can be ignored if offset is positive. A negative offset will make it more
3563sensitive to those small variations. </p>
3564
3565<p>This is commonly used to threshold images with an uneven background. It is
3566based on the assumption that average color of the small window is the
3567the local background color, from which to separate the forground color. </p>
3568
3569
3570<div style="margin: auto;">
3571 <h4><a name="layers" id="layers"></a>-layers <em class="arg">method</em></h4>
3572</div>
3573
3574<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>
3575
3576<p>Perform various image operation methods to a ordered sequence of images
3577which may represent either a set of overlaid 'image layers', a GIF disposal
3578animation, or a fully-'coalesced' animation sequence. </p>
3579
3580<table class="doc">
3581 <tbody>
3582 <tr valign="top">
3583 <th align="left" style="width: 8%">Method</th>
3584 <th align="left">Description</th>
3585 </tr>
3586
3587 <tr valign="top">
3588 <td valign="top">compare-any</td>
3589 <td valign="top">Crop the second and later frames to the smallest rectangle
3590 that contains all the differences between the two images. No GIF <a
3591 href="#dispose" >-dispose</a> methods are taken into account. </td>
3592 </tr>
3593
3594 <tr><td></td><td>This exactly the same as the <a href="#deconstruct"
3595 >-deconstruct</a> operator, and does not preserve animations normal
3596 working, especially when animation used layer disposal methods such as
3597 '<kbd>Previous</kbd>' or '<kbd>Background</kbd>'. </td>
3598 </tr>
3599
3600 <tr valign="top">
3601 <td valign="top">compare-clear</td>
3602 <td valign="top">As '<kbd>compare-any</kbd>' but crop to the bounds of any
3603 opaque pixels which become transparent in the second frame. That is the
3604 smallest image needed to mask or erase pixels for the next frame. </td>
3605 </tr>
3606
3607 <tr valign="top">
3608 <td valign="top">compare-overlay</td>
3609 <td valign="top">As '<kbd>compare-any</kbd>' but crop to pixels that add
3610 extra color to the next image, as a result of overlaying color pixels.
3611 That is the smallest single overlaid image to add or change colors. </td>
3612 </tr>
3613
3614 <tr><td></td><td>This can be used with the <a href="#compose" >-compose</a> alpha
3615 composition method '<kbd>change-mask</kbd>', to reduce the image to
3616 just the pixels that need to be overlaid. </td>
3617 </tr>
3618
3619 <tr valign="top">
3620 <td valign="top">coalesce</td>
3621 <td valign="top">Equivalent to a call to the <a href="#coalesce"
3622 >-coalesce</a> operator. Apply the layer disposal methods set in the
3623 current image sequence to form a fully defined animation sequence, as
3624 it should be displayed. Effectively converting a GIF animation into a
3625 'film strip'-like animation. </td>
3626 </tr>
3627
3628 <tr valign="top">
3629 <td valign="top">composite</td>
3630 <td valign="top">Alpha Composition of two image lists, separated by a
3631 "<kbd>null:</kbd>" image, with the destination image list first, and
3632 the source images last. An image from each list are composited
3633 together until one list is finished. The separator image and source
3634 image lists are removed. </td>
3635 </tr>
3636
3637
3638 <tr><td></td><td>The <a href="#geometry" >-geometry</a> offset is adjusted according to
3639 <a href="#gravity" >-gravity</a> in accordance of the virtual canvas
3640 size of the first image in each list. Unlike a normal <a
3641 href="#composite" >-composite</a> operation, the canvas offset is also
3642 added to the final composite positioning of each image. </td>
3643 </tr>
3644
3645 <tr><td></td><td>If one of the image lists only contains one image, that image is
3646 applied to all the images in the other image list, regardless of which
3647 list it is. In this case it is the image meta-data of the list which
3648 preserved. </td>
3649 </tr>
3650
3651
3652 <tr valign="top">
3653 <td valign="top">dispose</td>
3654 <td valign="top">This like '<kbd>coalesce</kbd>' but shows the look of
3655 the animation after the layer disposal method has been applied, before
3656 the next sub-frame image is overlaid. That is the 'dispose' image that
3657 results from the application of the GIF <a href="#dispose"
3658 >-dispose</a> method. This allows you to check what
3659 is going wrong with a particular animation you may be developing.
3660 </td>
3661 </tr>
3662
3663 <tr valign="top">
3664 <td valign="top">flatten</td>
3665 <td valign="top">Create a canvas the size of the first images virtual
3666 canvas using the current <a href="#background" >-background</a> color,
3667 and <a href="#compose" >-compose</a> each image in turn onto that
3668 canvas. Images falling outside that canvas is clipped. Final
3669 image will have a zero virtual canvas offset. </td>
3670 </tr>
3671
3672 <tr><td></td><td>This usally used as one of the final 'image layering' operations
3673 overlaying all the prepared image layers into a final image. </td>
3674 </tr>
3675
3676 <tr><td></td><td>For a single image this method can also be used to fillout a virtual
3677 canvas with real pixels, or to underlay a opaque color to remove
3678 transparency from an image.</td>
3679 </tr>
3680
3681
3682 <tr valign="top">
3683 <td valign="top">merge</td>
3684 <td valign="top">As 'flatten' method but merging all the given image
3685 layers into a new layer image just large enough to hold all the image
3686 without clipping or extra space. The new images virtual offset will
3687 prevere the position of the new layer, even if this offset is
3688 negative. the virtual canvas size of the first image is preserved.
3689 </td>
3690 </tr>
3691
3692 <tr><td></td><td>Caution is advised when handling image layers with negative offsets
3693 as few image file formats handle them correctly. </td>
3694 </tr>
3695
3696 <tr valign="top">
3697 <td valign="top">mosaic</td>
3698 <td valign="top">As 'flatten' method but expanding the initial canvas size
3699 of the first image so as to hold all the image layers. However as a
3700 virtual canvas is 'locked' to the origin, by defination, image layers
3701 with a negative offsets will still be clipped by the top and left
3702 edges.</td>
3703 </tr>
3704
3705 <tr><td></td><td>This method is commonly used to layout individual image using various
3706 offset but without knowning the final canvas size. The resulting image
3707 will, like 'flatten' not have any virtual offset, so can be saved to
3708 any image file format. </td>
3709 </tr>
3710
3711
3712 <tr valign="top">
3713 <td valign="top">optimize</td>
3714 <td valign="top">Optimize a coalesced animation, into GIF animation using
3715 a number of general techniques. This currently a short cut to
3716 apply both the '<kbd>optimize-frame</kbd>', and
3717 '<kbd>optimize-transparency</kbd>' methods but may be expanded to
3718 include other optimization methods as they are developed. </td>
3719 </tr>
3720
3721 <tr valign="top">
3722 <td valign="top">optimize-frame</td>
3723 <td valign="top">Optimize a coalesced animation, into GIF animation by
3724 reducing the number of pixels per frame as much as possible by
3725 attempting to pick the best layer disposal method to use, while ensuring
3726 the result will continue to animate properly. </td>
3727 </tr>
3728
3729 <tr><td></td><td> There is no guarantee that the best optimization is found. But
3730 then no reasonably fast GIF optimization algorithm can do this.
3731 However this does seem to do better than most other GIF frame
3732 optimizers seen. </td>
3733 </tr>
3734
3735 <tr valign="top">
3736 <td valign="top">optimize-plus</td>
3737 <td valign="top">As '<kbd>optimize-frame</kbd>' but attempt to improve the
3738 overall optimization by adding extra frames to the animation, without
3739 changing the final look or timing of the animation. The frames are
3740 added to attempt to separate the clearing of pixels from the
3741 overlaying of new additional pixels from one animation frame to the
3742 next. If this does not improve the optimization (for the next frame
3743 only), it will fall back to the results of the previous normal
3744 '<kbd>optimize-frame</kbd>' technique. </td>
3745 </tr>
3746
3747 <tr><td></td><td>There is the possibility that the change in the disposal style will
3748 result in a worsening in the optimization of later frames, though this
3749 is unlikely. In other words there no guarantee that it is better than
3750 the normal '<kbd>optimize-frame</kbd>' technique. For some animations
3751 however you can get a vast improvment in the final animation size. </td>
3752 </tr>
3753
3754 <tr valign="top">
3755 <td valign="top">optimize-transparency</td>
3756 <td valign="top">Given a GIF animation, replace any pixel in the sub-frame
3757 overlay images with transparency, if it does not change the resulting
3758 animation by more than the current <a href="#fuzz" >-fuzz</a> factor.
3759 </td>
3760 </tr>
3761
3762 <tr><td></td><td>This should allow a existing frame optimized GIF animation to compress
3763 into a smaller file size due to larger areas of one (transparent)
3764 color rather than a pattern of multiple colors repeating the current
3765 disposed image of the last frame. </td>
3766 </tr>
3767
3768 <tr valign="top">
3769 <td valign="top">remove-dups</td>
3770 <td valign="top">Remove (and merge time delays) of duplicate consecutive
3771 images, so as to simplify layer overlays of coalesced animations.
3772 </td>
3773 </tr>
3774
3775 <tr><td></td><td>Usually this a result of using a constant time delay across the
3776 whole animation, or after a larger animation was split into smaller
3777 sub-animations. The duplicate frames could also have been used as
3778 part of some frame optimization methods. </td>
3779 </tr>
3780
3781 <tr valign="top">
3782 <td valign="top">remove-zero</td>
3783 <td valign="top">Remove any image with a zero time delay, unless ALL the
3784 images have a zero time delay (and is not a proper timed animation, a
3785 warning is then issued). </td>
3786 </tr>
3787
3788 <tr><td></td><td>In a GIF animation, such images are usually frames which provide
3789 partial intermediary updates between the frames that are actually
3790 displayed to users. These frames are usally added for improved frame
3791 optimization in GIF animations. </td>
3792 </tr>
3793
3794 <tr valign="top">
3795 <td valign="top">trim-bounds</td>
3796 <td valign="top">Find the bounds of all the images in the current
3797 image sequence, then adjust the offsets so all images are contained on
3798 a minimal positive canvas. None of the image data is modified, only
3799 there virtual canvas size and offset. The all the image is given
3800 the same canvas size, and and will have a positive offset, but will
3801 remain in the same position relative to each other. As a result of the
3802 minimal canvas size at least one image will touch every edge of that
3803 canvas. The image data however may be transparent.
3804 </td>
3805 </tr>
3806
3807 </tbody>
3808</table>
3809
3810<p>To print a complete list of layer types, use <a href="#list">-list layers</a>.</p>
3811
3812<p>The operators <a href="#coalesce" >-coalesce</a>, <a href="#deconstruct"
3813>-deconstruct</a>, <a href="#flatten" >-flatten</a>, and <a href="#mosaic"
3814>-mosaic</a> are only aliases for the above methods. Also see <a
3815href="#page" >-page</a>, <a href="#repage" >-repage</a> operators, the <a
3816href="#compose" >-compose</a> setting, and the GIF <a href="#dispose"
3817>-dispose</a> and <a href="#delay" >-delay</a> settings. </p>
3818
3819
3820<div style="margin: auto;">
3821 <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>
3822</div>
3823
3824<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>
3825
3826<p>Given one, two or three values delimited with commas: black-point,
3827white-point, gamma (for example: 10,250,1.0 or 2%,98%,0.5). The black and
3828white points range from 0 to <em class="QR">QuantumRange</em>, or from 0 to 100%; if the white
3829point is omitted it is set to (<em class="QR">QuantumRange</em> - black_point), so as to center
3830contrast changes. If a <kbd>%</kbd> sign is present anywhere in the string,
3831both black and white points are percentages of the full color range. Gamma
3832will do a <a href="#gamma">-gamma</a> adjustment of the values. If it is
3833omitted, the default of 1.0 (no gamma correction) is assumed.</p>
3834
3835<p>In normal usage (<kbd>-level</kbd>) the image values are stretched so that
3836the given '<kbd>black_point</kbd>' value in the original image is set to
3837zero (or black), while the given '<kbd>white_point</kbd>' value is set to
3838<em class="QR">QuantumRange</em> (or white). This provides you with direct contrast adjustments
3839to the image. The '<kbd>gamma</kbd>' of the resulting image will then be
3840adjusted. </p>
3841
3842<p>From ImageMagick v6.4.1-9 using the plus form of the operator (<kbd>+level</kbd>) or
3843adding the special '!' flag anywhere in the argument list, will cause the
3844operator to do the reverse of the level adjustment. That is a zero, or
3845<em class="QR">QuantumRange</em> value (black, and white, resp.) in the original image, is
3846adjusted to the given level values, allowing you to de-contrast, or compress
3847the channel values within the image. The '<kbd>gamma</kbd>' is adjusted before the level adjustment to de-contrast the image is made. </p>
3848
3849<p>Only the channels defined by the current <a href="#channel">-channel</a>
3850setting are adjusted (defaults to RGB color channels only), allowing you to
3851limit the effect of this operator. </p>
3852
3853<p>Please note that the transparency channel is treated as 'matte'
3854values (0 is opaque) and not as 'alpha' values (0 is transparent).</p>
3855
3856
3857<div style="margin: auto;">
3858 <h4><a name="level-colors" id="level-colors"></a>-level-colors {<em
3859 class="arg">black_color</em>}{,}{<em class="arg">white_color</em>}</h4>
3860</div>
3861
3862<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>
3863
3864<p>This function is exactly like <a href="#level">-level</a>, except that the
3865value value for each color channel is determined by the
3866'<kbd>black_color</kbd>' and '<kbd>white_color</kbd>' colors given (as
3867described under the <a href="#fill">-fill</a> option). </p>
3868
3869<p>This effectivally means the colors provided to <kbd>-level-colors</kbd>
3870is mapped to become 'black' and 'white' respectivally, with all the other
3871colors linearly adjusted (or clipped) to match that change. Each channel is
3872adjusted separatally using the channel values of the colors specified. </p>
3873
3874<p>On the other hand the plus form of the operator (<kbd>+level-colors</kbd>)
3875will map the image color 'black' and 'white' to the given colors
3876respectivally, resulting in a gradient (de-contrasting) tint of the image to
3877those colors. This can also be used to convert a plain gray-scale image into a
3878one using the gradient of colors specified. </p>
3879
3880<p>By supplying a single color with a comma separator either before or after
3881that color, will just replace the respective 'black' or 'white' point
3882respectivally. But if no comma separator is provided, the given color is
3883used for both the black and white color points, making the operator either
3884threshold the images around that color (- form) or set all colors to that
3885color (+ form). </p>
3886
3887
3888<div style="margin: auto;">
3889 <h4><a name="limit" id="limit"></a>-limit <em class="arg">type value</em></h4>
3890</div>
3891
3892<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>
3893
3894<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>
3895
cristy6b636652009-12-05 17:16:11 +00003896<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 +00003897
3898<p class="crtsnip">
cristyd934d102009-10-10 12:55:13 +00003899 -limit memory 32MiB -limit map 64MiB
cristy3ed852e2009-09-05 21:47:34 +00003900</p>
3901
3902<p>Use <a href="#list">-list resource</a> to list the current limits. For example, our system shows these limits:</p>
3903
cristy6b636652009-12-05 17:16:11 +00003904<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
3905------------------------------------------------------------------------------
3906 768 12.404GB 8.6642GiB 23.104GiB 18.446744EB 8 unlimited</pre>
cristy3ed852e2009-09-05 21:47:34 +00003907</span></p>
3908<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>
3909
3910<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>
3911
3912<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>
3913
3914<p class="crtsnip">
3915-limit area 10mb
3916</p>
3917
3918<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>
3919
3920<p class="crtsnip">
3921-limit area 10mb -limit disk 500mb
3922</p>
3923
3924<p>Here ImageMagick stops processing if an image requires more than 500MB of disk storage.</p>
3925
3926<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>
3927
3928<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.
3929</p>
3930
3931<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.
3932</p>
3933
3934<div style="margin: auto;">
3935 <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>
3936</div>
3937
3938<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>
3939
cristyd934d102009-10-10 12:55:13 +00003940<p>This is very similar to <a href="#contrast-stretch" >-contrast-stretch</a>,
3941and uses a 'histogram bin' to determine the range of color values that needs to
3942be stretched. However it then stretchs those colors using the <a
3943href="#level" >-level</a> operator.</p>
3944
3945<p>As such while the initial determination may have 'binning' round off
3946effects, the image colors are stretched mathematically, rather than using the
3947histogram bins. This makes the operator more accurate. </p>
3948
3949<p>note however that a <a href="#linear-stretch" >-linear-stretch</a> of
3950'<kbd>0</kbd>' does nothing, while a value of '<kbd>1</kbd>' does a near
3951perfect stretch of the color range. </p>
3952
3953<p>See also <a href="#auto-level" >-auto-level</a> for a 'perfect'
3954normalization of mathematical images. </p>
3955
3956<p>This operator is under review for re-development. </p>
3957
3958
cristy3ed852e2009-09-05 21:47:34 +00003959<div style="margin: auto;">
3960 <h4><a name="linewidth" id="linewidth"></a>-linewidth</h4>
3961</div>
3962
3963<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>
3964
3965<div style="margin: auto;">
3966 <h4><a name="liquid-rescale" id="liquid-rescale"></a>-liquid-rescale <em class="arg">geometry</em></h4>
3967</div>
3968
3969<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>
3970
3971<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>
3972
3973<div style="margin: auto;">
3974 <h4><a name="list" id="list"></a>-list <em class="arg">type</em></h4>
3975</div>
3976
3977<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>
3978
3979<pre class="text">
3980 coder
3981 color
3982 configure
3983 delegate
3984 font
3985 format
3986 list
3987 log
3988 magic
3989 module
3990 resource
3991 threshold
3992</pre>
3993
3994<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>
3995
3996<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>identify -list list</span></p>
3997<div style="margin: auto;">
3998 <h4><a name="log" id="log"></a>-log <em class="arg">string</em></h4>
3999</div>
4000
4001<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>
4002
4003<p>This option specifies the format for the log printed when the <a href="#debug">-debug</a> option is active.</p>
4004
4005<p>You can display the following components by embedding special format characters:</p>
4006
4007<pre class="text">
4008 %d domain
4009 %e event
4010 %f function
4011 %l line
4012 %m module
4013 %p process ID
4014 %r real CPU time
4015 %t wall clock time
4016 %u user CPU time
4017 %% percent sign
4018 \n newline
4019 \r carriage return
4020</pre>
4021
4022<p>For example:</p>
4023
4024<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>
4025<p>The default behavior is to print all of the components.</p>
4026
4027<div style="margin: auto;">
4028 <h4><a name="loop" id="loop"></a>-loop <em class="arg">iterations</em></h4>
4029</div>
4030
4031<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>
4032
4033<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>
4034
4035<div style="margin: auto;">
4036 <h4><a name="lowlight-color" id="lowlight-color"></a>-lowlight-color <em class="arg">color</em></h4>
4037</div>
4038
4039<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>
4040
4041<div style="margin: auto;">
4042 <h4><a name="magnify" id="magnify"></a>-magnify <em class="arg">factor</em></h4>
4043</div>
4044
4045<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>
4046
4047
4048<div style="margin: auto;">
4049 <h4><a name="map" id="map"></a>-map <em class="arg">type</em></h4>
4050</div>
4051
4052<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>
4053
4054<p>Choose from these <em class="arg">Standard Colormap</em> types:</p>
4055
4056<pre class="text">
4057 best
4058 default
4059 gray
4060 red
4061 green
4062 blue
4063</pre>
4064
4065<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>
4066
4067
4068<div style="margin: auto;">
4069 <h4><a name="map_stream_" id="map_stream_"></a>-map <em class="arg">components</em></h4>
4070</div>
4071
4072<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>
4073
4074<p>Here are the valid components of a map:</p>
4075
4076<pre class="text">
4077 r red pixel component
4078 g green pixel component
4079 b blue pixel component
4080 a alpha pixel component (0 is transparent)
4081 o opacity pixel component (0 is opaque)
4082 i grayscale intensity pixel component
4083 c cyan pixel component
4084 m magenta pixel component
4085 y yellow pixel component
4086 k black pixel component
4087 p pad component (always 0)
4088</pre>
4089
4090<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>
4091
4092<div style="margin: auto;">
4093 <h4><a name="mask" id="mask"></a>-mask
4094<em class="arg">filename</em></h4>
4095</div>
4096
4097<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>
4098
4099<p>Use <a href="#mask">+mask</a> to remove the image mask.</p>
4100
4101<div style="margin: auto;">
4102 <h4><a name="mattecolor" id="mattecolor"></a>-mattecolor <em class="arg">color</em></h4>
4103</div>
4104
4105<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>
4106
4107<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p>
4108
4109<p>The default matte color is <kbd>#BDBDBD</kbd>, <span style="background-color: #bdbdbd;">this shade of gray</span>.</p>
4110
4111<div style="margin: auto;">
cristyd2baf7d2010-03-06 04:26:44 +00004112 <h4><a name="maximum" id="maximum"></a>-maximum</h4>
4113</div>
4114
4115<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>return the maximum intensity of an image sequence.</td><td style='text-align:right;'></td></tr></table>
4116
4117<div style="margin: auto;">
cristy3ed852e2009-09-05 21:47:34 +00004118 <h4><a name="median" id="median"></a>-median <em class="arg">radius</em></h4>
4119</div>
4120
4121<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>
4122
4123<div style="margin: auto;">
4124 <h4><a name="metric" id="metric"></a>-metric <em class="arg">type</em></h4>
4125</div>
4126
4127<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>
4128
4129<p>Choose from:</p>
4130
4131<pre class="text">
4132 AE absolute number of differnet pixels
4133 MAE mean absolute error (normalized), average channel error distance
4134 MEPP mean error per pixel (normalized mean error, normalized peak error)
4135 MSE mean error squared, average of the channel error squared
4136 PAE peak absolute (normalize peak absolute)
4137 PSNR peak signal to noise ratio
4138 RMSE root mean squared (normalized root mean squared)
4139</pre>
4140
4141<p>The '<kbd>AE</kbd>' or absolute count of pixels that are different, can be
4142controled using a <a href="#fuzz" >-fuzz</a> factor to ignore pixels which
4143only changed by a small amount. The '<kbd>PAE</kbd>' can be used to find the
4144size of the <a href="#fuzz" >-fuzz</a> factor needed to make all pixels
4145'similar'. </p>
4146
4147<p>The '<kbd>MEPP</kbd>' metric returns three different metrics
4148('<kbd>MAE</kbd>', '<kbd>MAE</kbd>' normalized, and '<kbd>PAE</kbd>'
4149normalized) from the single comparision run. </p>
4150
4151<p>To print a complete list of metrics, use the <a href="#list">-list metrics</a> option.</p>
4152
cristyd2baf7d2010-03-06 04:26:44 +00004153<div style="margin: auto;">
4154 <h4><a name="minimum" id="minimum"></a>-minimum</h4>
4155</div>
4156
4157<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>return the minimum intensity of an image sequence.</td><td style='text-align:right;'></td></tr></table>
4158
cristy3ed852e2009-09-05 21:47:34 +00004159
4160<div style="margin: auto;">
4161 <h4><a name="mode" id="mode"></a>-mode <em class="arg">value</em></h4>
4162</div>
4163
4164<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>
4165
4166<p>Choose the <em class="arg">value</em> from these styles: <kbd>Frame, Unframe, or Concatenate</kbd></p>
4167
4168<p>Use the <a href="#list" >-list</a> option with a '<kbd>Mode</kbd>'
4169argument for a list of <a href="#mode" >-mode</a> arguments available
4170in your ImageMagick installation.</p>
4171
4172
4173<div style="margin: auto;">
4174 <h4><a name="modulate" id="modulate"></a>-modulate <em class="arg">brightness</em>[,<em class="arg">saturation</em>,<em class="arg">hue</em>]</h4>
4175</div>
4176
4177<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>
4178
4179<p>The arguments are given as a percentages of variation. A value of 100 means no change, and any
4180missing values are taken to mean 100.</p>
4181
4182<p>The <em class="arg">brightness</em> is a multiplier of the overall brightness of the image, so 0
4183means pure black, 50 is half as bright, 200 is twice as bright. To invert its
4184meaning <a href="#negate">-negate</a> the image before and after. </p>
4185
4186<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>
4187
4188<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
4189shades to purple, and so on. A value of either 0 or 200 results in a complete
4190180 degree rotation of the image. Using a value of 300 is a 360 degree
4191rotation resulting in no change to the original image. </p>
4192
4193<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>
4194
4195<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>
4196
4197<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>
4198<div style="margin: auto;">
4199 <h4><a name="monitor" id="monitor"></a>-monitor</h4>
4200</div>
4201
4202<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>
4203
4204
4205<div style="margin: auto;">
4206 <h4><a name="monochrome" id="monochrome"></a>-monochrome</h4>
4207</div>
4208
4209<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>
4210
4211
4212<div style="margin: auto;">
4213 <h4><a name="morph" id="morph"></a>-morph <em class="arg">frames</em></h4>
4214</div>
4215
4216<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>
4217
4218<p>Both the image pixels and size are linearly interpolated to give the
4219appearance of a meta-morphosis from one image to the next, over all the images
4220in the current image list. The added images are the equivalent of a <a
4221href="#blend">-blend</a> composition. The <em class="arg">frames</em>
4222argument determine how many images to interpolate between each image. </p>
4223
4224
4225<div style="margin: auto;">
cristy488844c2010-01-22 14:02:05 +00004226 <h4><a name="morphology" id="morphology"></a>-morphology</h4>
4227 <h4><a name="morphology" id="morphology"></a>-morphology <em class="arg">method</em> <em class="arg">kernel</em></h4>
4228</div>
4229
4230<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>apply a morphology method to the image</td><td style='text-align:right;'></td></tr></table>
4231
4232<div style="margin: auto;">
cristy3ed852e2009-09-05 21:47:34 +00004233 <h4><a name="mosaic" id="mosaic"></a>-mosaic</h4>
4234</div>
4235
4236<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>
4237
4238
4239<div style="margin: auto;">
4240 <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>
4241</div>
4242
4243<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>
4244
4245<p>Blur with the given radius, standard deviation (sigma), and angle. The
4246angle given is the angle toward which the image is blurred. That is the
4247direction people would consider the object is coming from. </p>
4248
4249<p>Note that the blur is not uniform distribution, giving the motion a
4250definate sense of direction of movement. </p>
4251
4252<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how
4253pixels which are outside the image proper are blurred into the final result.
4254</p>
4255
4256<div style="margin: auto;">
4257 <h4><a name="name" id="name"></a>-name</h4>
4258</div>
4259
4260<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>
4261<div style="margin: auto;">
4262 <h4><a name="negate" id="negate"></a>-negate</h4>
4263</div>
4264
cristyb29bc032010-02-01 20:29:43 +00004265<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>replace each pixel with its complementary color.</td><td style='text-align:right;'></td></tr></table>
cristy3ed852e2009-09-05 21:47:34 +00004266
4267<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>
4268
4269<div style="margin: auto;">
4270 <h4><a name="noise" id="noise"></a>-noise <em class="arg">radius</em><br/>
4271 +noise <em class="arg">type</em></h4>
4272</div>
4273
4274<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>
4275
4276<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>
4277
4278<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>
4279
4280<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>
4281
4282<pre class="text">
4283Gaussian
4284Impulse
4285Laplacian
4286Multiplicative
4287Poisson
4288Random
4289Uniform
4290</pre>
4291
4292<p>To print a complete list of noises, use the <a href="#list">-list noise</a> option.</p>
4293
cristy83543962009-10-16 19:04:28 +00004294<p>Also see the <a href="#evaluate">-evaluate</a> noise functions that allos
4295the use of a controlling value to specify teh amount of noise that should be
4296added to an image. </p>
4297
cristy3ed852e2009-09-05 21:47:34 +00004298
4299<div style="margin: auto;">
4300 <h4><a name="normalize" id="normalize"></a>-normalize</h4>
4301</div>
4302
4303<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>
4304
cristyd934d102009-10-10 12:55:13 +00004305<p>The intensity values are stretched to cover the entire range of possible
4306values. While doing so, black-out at most <em>2%</em> of the pixels and
4307white-out at most <em>1%</em> of the pixels.</p>
cristy3ed852e2009-09-05 21:47:34 +00004308
cristyd934d102009-10-10 12:55:13 +00004309<p>Note that as of ImageMagick 6.4.7-0, <a href="#normalize" >-normalize</a>
4310is equivalent to <a href="#contrast-stretch" >-contrast-stretch 2%x1%</a>.
4311(Before this version, it was equivalent to <a href="#contrast-stretch"
4312>-contrast-stretch 2%x99%</a>).</p>
cristy3ed852e2009-09-05 21:47:34 +00004313
cristyd934d102009-10-10 12:55:13 +00004314<p>All the channels are normalized in concert by the came amount so as to
4315preserve color integrity, when the default <a href="#channel" >+channel</a>
4316setting is in use. Specifing any other <a href="#channel" >-channel</a>
4317setting will normalize the RGB channels independently.</p>
4318
4319<p>See <a href="#contrast-stretch" >-contrast-stretch</A> for more details.
4320Also see <a href="#auto-level" >-auto-level</a> for a 'perfect' normalization
cristy83543962009-10-16 19:04:28 +00004321that is better suited to mathematically generated images. </p>
cristyd934d102009-10-10 12:55:13 +00004322
4323<p>This operator is under review for re-development. </p>
cristy3ed852e2009-09-05 21:47:34 +00004324
4325
4326<div style="margin: auto;">
4327 <h4><a name="ordered-dither" id="ordered-dither"></a>-ordered-dither <em class="arg">threshold_map</em>{,<em class="arg">level</em>...}</h4>
4328</div>
4329
cristyd934d102009-10-10 12:55:13 +00004330<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
4331class="arg">threshold map</em> specified, and a uniform color map with the
4332given 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 +00004333
4334<p>You can choose from these standard threshold maps:</p>
4335
4336<pre class="text">
cristyd934d102009-10-10 12:55:13 +00004337 threshold
cristy3ed852e2009-09-05 21:47:34 +00004338 checks
4339 o2x2
4340 o3x3
4341 o4x4
4342 o8x8
4343 h4x4a
4344 h6x6a
4345 h8x8a
4346 h4x4o
4347 h6x6o
4348 h8x8o
4349 h16x16o
4350</pre>
4351
cristyd934d102009-10-10 12:55:13 +00004352<p>The '<kbd>o</kbd>' maps are ordered diffused pixel threshold maps, while the
4353'<kbd>h</kbd>' maps are halftone threshold maps which are either 'a' angled, or
4354'o' orthogonal. The '<kbd>checks</kbd>' produce a 3 level checkerbord dither
4355pattern. Or you can define your own <em class="arg" >threshold map</em> in a
4356personal or system "<kbd>thresholds.xml</kbd>" XML file. </p>
cristy3ed852e2009-09-05 21:47:34 +00004357
cristyd934d102009-10-10 12:55:13 +00004358<p>To print a complete list of threshold, use the <a href="#list" >-list
4359threshold</a> option.</p>
cristy3ed852e2009-09-05 21:47:34 +00004360
cristyd934d102009-10-10 12:55:13 +00004361<p>It is recommended that the <a href="#map" >+map</a> operator be used after
4362applying <a href="#ordered-dither" >-ordered-dither</a> to reduce the number of
cristy3ed852e2009-09-05 21:47:34 +00004363colors an animated image sequence, to less that 256 colors. This ensures that
4364a common or global color table is used when saving the result to a color
4365limited file format such as GIF. </p>
4366
cristyd934d102009-10-10 12:55:13 +00004367<p>Note that at this time the exact same threshold dithering map is used for
4368all color channels, no attempt is made to offset or rotate the map for
4369different channels is made, to create an offset printing effect. (possible
4370future expansion) </p>
cristy3ed852e2009-09-05 21:47:34 +00004371
4372
4373<div style="margin: auto;">
4374 <h4><a name="opaque" id="opaque"></a>-opaque <em class="arg">color</em></h4>
4375</div>
4376
4377<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>
4378
cristyc54f5d42009-11-27 21:36:31 +00004379<p>The <em class="arg">color</em> argument is defined using the format
cristyd934d102009-10-10 12:55:13 +00004380described under the <a href="#fill" >-fill</a> option. The <a href="#fuzz"
4381>-fuzz</a> setting can be used to match and replace colors similar to the one
4382given.</p>
cristy3ed852e2009-09-05 21:47:34 +00004383
cristyd934d102009-10-10 12:55:13 +00004384<p>The <a href="#transparent" >-transparent</a> operator is exactly the same
4385as <a href="#opaque" >-opaque</a> but makes the matching color transparent,
cristy3ed852e2009-09-05 21:47:34 +00004386rather than the same as the current <a href="#fill">-fill</a> color. </p>
4387
cristyc54f5d42009-11-27 21:36:31 +00004388<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 +00004389
4390
cristy3ed852e2009-09-05 21:47:34 +00004391
4392<div style="margin: auto;">
4393 <h4><a name="orient" id="orient"></a>-orient <em class="arg">image orientation</em></h4>
4394</div>
4395
4396<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>
4397
4398<p>Choose from these orientations:</p>
4399
4400<pre class="text">
4401 bottom-left
4402 bottom-right
4403 left-bottom
4404 left-top
4405 right-bottom
4406 right-top
4407 top-left
4408 top-right
4409 undefined
4410</pre>
4411
cristyd934d102009-10-10 12:55:13 +00004412<p>To print a complete list of orientations, use the <a href="#list" >-list
4413orientation</a> option.</p>
cristy3ed852e2009-09-05 21:47:34 +00004414
4415
4416<div style="margin: auto;">
4417 <h4><a name="page" id="page"></a>-page <em class="arg">geometry</em><br/>
4418 -page <em class="arg">media</em>[<em class="arg">offset</em>][{<em class="arg">^!&lt;&gt;</em>}]<br/>
4419 +page
4420 </h4>
4421</div>
4422
4423<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>
4424
4425<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>
4426
4427<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>
4428
4429<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>
4430<table id="geometryTable" cellpadding="2" cellspacing="0" border="1" width="50%" style="margin-left: auto; margin-right: auto;">
4431<thead>
4432 <tr valign="top">
4433 <th align="center"><em class="arg">media</em></th>
4434 <th align="center"><em class="arg">width</em></th>
4435 <th align="center"><em class="arg">height</em></th>
4436 </tr>
4437</thead>
4438<tbody>
4439<tr><td align="left"> 11x17 </td> <td align="right"> 792</td> <td align="right"> 1224</td> </tr>
4440<tr><td align="left"> Ledger </td> <td align="right"> 1224</td> <td align="right"> 792</td> </tr>
4441<tr><td align="left"> Legal </td> <td align="right"> 612</td> <td align="right"> 1008</td> </tr>
4442<tr><td align="left"> Letter </td> <td align="right"> 612</td> <td align="right"> 792</td> </tr>
4443<tr><td align="left"> LetterSmall</td> <td align="right"> 612</td> <td align="right"> 792</td> </tr>
4444<tr><td align="left"> ArchE </td> <td align="right"> 2592</td> <td align="right"> 3456</td> </tr>
4445<tr><td align="left"> ArchD </td> <td align="right"> 1728</td> <td align="right"> 2592</td> </tr>
4446<tr><td align="left"> ArchC </td> <td align="right"> 1296</td> <td align="right"> 1728</td> </tr>
4447<tr><td align="left"> ArchB </td> <td align="right"> 864</td> <td align="right"> 1296</td> </tr>
4448<tr><td align="left"> ArchA </td> <td align="right"> 648</td> <td align="right"> 864</td> </tr>
4449<tr><td align="left"> A0 </td> <td align="right"> 2380</td> <td align="right"> 3368</td> </tr>
4450<tr><td align="left"> A1 </td> <td align="right"> 1684</td> <td align="right"> 2380</td> </tr>
4451<tr><td align="left"> A2 </td> <td align="right"> 1190</td> <td align="right"> 1684</td> </tr>
4452<tr><td align="left"> A3 </td> <td align="right"> 842</td> <td align="right"> 1190</td> </tr>
4453<tr><td align="left"> A4 </td> <td align="right"> 595</td> <td align="right"> 842</td> </tr>
4454<tr><td align="left"> A4Small </td> <td align="right"> 595</td> <td align="right"> 842</td> </tr>
4455<tr><td align="left"> A5 </td> <td align="right"> 421</td> <td align="right"> 595</td> </tr>
4456<tr><td align="left"> A6 </td> <td align="right"> 297</td> <td align="right"> 421</td> </tr>
4457<tr><td align="left"> A7 </td> <td align="right"> 210</td> <td align="right"> 297</td> </tr>
4458<tr><td align="left"> A8 </td> <td align="right"> 148</td> <td align="right"> 210</td> </tr>
4459<tr><td align="left"> A9 </td> <td align="right"> 105</td> <td align="right"> 148</td> </tr>
4460<tr><td align="left"> A10 </td> <td align="right"> 74</td> <td align="right"> 105</td> </tr>
4461<tr><td align="left"> B0 </td> <td align="right"> 2836</td> <td align="right"> 4008</td> </tr>
4462<tr><td align="left"> B1 </td> <td align="right"> 2004</td> <td align="right"> 2836</td> </tr>
4463<tr><td align="left"> B2 </td> <td align="right"> 1418</td> <td align="right"> 2004</td> </tr>
4464<tr><td align="left"> B3 </td> <td align="right"> 1002</td> <td align="right"> 1418</td> </tr>
4465<tr><td align="left"> B4 </td> <td align="right"> 709</td> <td align="right"> 1002</td> </tr>
4466<tr><td align="left"> B5 </td> <td align="right"> 501</td> <td align="right"> 709</td> </tr>
4467<tr><td align="left"> C0 </td> <td align="right"> 2600</td> <td align="right"> 3677</td> </tr>
4468<tr><td align="left"> C1 </td> <td align="right"> 1837</td> <td align="right"> 2600</td> </tr>
4469<tr><td align="left"> C2 </td> <td align="right"> 1298</td> <td align="right"> 1837</td> </tr>
4470<tr><td align="left"> C3 </td> <td align="right"> 918</td> <td align="right"> 1298</td> </tr>
4471<tr><td align="left"> C4 </td> <td align="right"> 649</td> <td align="right"> 918</td> </tr>
4472<tr><td align="left"> C5 </td> <td align="right"> 459</td> <td align="right"> 649</td> </tr>
4473<tr><td align="left"> C6 </td> <td align="right"> 323</td> <td align="right"> 459</td> </tr>
4474<tr><td align="left"> Flsa </td> <td align="right"> 612</td> <td align="right"> 936</td> </tr>
4475<tr><td align="left"> Flse </td> <td align="right"> 612</td> <td align="right"> 936</td> </tr>
4476<tr><td align="left"> HalfLetter </td> <td align="right"> 396</td> <td align="right"> 612</td> </tr>
4477</tbody>
4478</table>
4479
4480
4481
4482
4483<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>
4484
4485<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>
4486
4487<p>The default page dimensions for a TEXT image is 612x792.</p>
4488
4489<p>This option is used in concert with <a href="#density">-density</a>.</p>
4490
4491<p>Use <a href="#page">+page</a> to remove the page settings for an image.</p>
4492
4493<div style="margin: auto;">
4494 <h4><a name="paint" id="paint"></a>-paint <em class="arg">radius</em></h4>
4495</div>
4496
4497<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>
4498
4499<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>
4500
4501<div style="margin: auto;">
4502 <h4><a name="path" id="path"></a>-path <em class="arg">path</em></h4></div>
4503
4504<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>
4505
4506<div style="margin: auto;">
4507 <h4><a name="pause_animate_" id="pause_animate_"></a>-pause <em class="arg">seconds</em></h4>
4508</div>
4509
4510<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>
4511
4512<p>Pause for the specified number of seconds before repeating the animation.</p>
4513
4514<div style="margin: auto;">
4515 <h4><a name="pause_import_" id="pause_import_"></a>-pause <em class="arg">seconds</em></h4>
4516</div>
4517
4518<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>
4519
4520<p>Pause for the specified number of seconds before taking the next snapshot.</p>
4521
4522<div style="margin: auto;">
4523 <h4><a name="ping" id="ping"></a>-ping</h4>
4524</div>
4525
4526<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>
4527
4528<div style="margin: auto;">
4529 <h4><a name="pointsize" id="pointsize"></a>-pointsize <em class="arg">value</em></h4>
4530</div>
4531
4532<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>
4533
4534<div style="margin: auto;">
4535 <h4><a name="polaroid" id="polaroid"></a>-polaroid <em class="arg">angle</em></h4>
4536</div>
4537
4538<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>
4539
4540<p>Use <kbd>+polaroid</kbd> to rotate the image at a random angle between -15 and +15 degrees.</p>
4541
4542<div style="margin: auto;">
4543 <h4><a name="posterize" id="posterize"></a>-posterize <em class="arg">levels</em></h4>
4544</div>
4545
4546<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>
4547
4548<div style="margin: auto;">
cristyd43a46b2010-01-21 02:13:41 +00004549 <h4><a name="precision" id="precision"></a>-precision <em class="arg">value</em></h4>
4550</div>
4551
4552<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>
4553
4554<div style="margin: auto;">
cristy3ed852e2009-09-05 21:47:34 +00004555 <h4><a name="preview" id="preview"></a>-preview <em class="arg">type</em></h4>
4556</div>
4557
4558<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>
4559
4560<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>
4561
4562<pre class="text">
4563 Rotate
4564 Shear
4565 Roll
4566 Hue
4567 Saturation
4568 Brightness
4569 Gamma
4570 Spiff
4571 Dull
4572 Grayscale
4573 Quantize
4574 Despeckle
4575 ReduceNoise
4576 Add Noise
4577 Sharpen
4578 Blur
4579 Threshold
4580 EdgeDetect
4581 Spread
4582 Shade
4583 Raise
4584 Segment
4585 Solarize
4586 Swirl
4587 Implode
4588 Wave
4589 OilPaint
4590 CharcoalDrawing
4591 JPEG
4592</pre>
4593
4594<p>To print a complete list of previews, use the <a href="#list">-list preview</a> option.</p>
4595
4596<p>The default preview is <kbd>JPEG</kbd>.</p>
4597
4598<div style="margin: auto;">
4599 <h4><a name="print" id="print"></a>-print <em class="arg">string</em></h4>
4600</div>
4601
4602<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>
4603
4604<div style="margin: auto;">
4605 <h4><a name="process" id="process"></a>-process <em class="arg">command</em></h4>
4606</div>
4607
4608<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>
4609
4610<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>
4611
4612<div style="margin: auto;">
4613 <h4><a name="profile" id="profile"></a>-profile <em class="arg">filename</em><br/>
4614 +profile <em class="arg">profile_name</em></h4>
4615</div>
4616
4617<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>
4618
4619<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>
4620
4621<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>
4622
4623<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>
4624
4625<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>
4626
4627<p>For example, to extract the Exif data (which is stored in JPEG files in the <em class="arg">APP1</em> profile), use.</p>
4628
4629<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert cockatoo.jpg profile.exif</span></p>
4630<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>
4631
4632<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>
4633<p>Furthermore, since ICC profiles are not necessarily symmetric, extra conversion steps can yield unwanted results.
4634CMYK profiles are often very asymmetric since they involve 3&minus;&gt;4 and 4&minus;&gt;3 channel mapping.
4635</p>
4636
4637<div style="margin: auto;">
4638 <h4><a name="quality" id="quality"></a>-quality <em class="arg">value</em></h4>
4639</div>
4640
4641<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>
4642
4643<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>
4644
4645<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>
4646
4647<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>
4648
4649<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>
4650
4651<p>If filter-type is 4 or less, the specified filter-type is used for all scanlines:</p>
4652
4653<pre class="text">
4654 0: none
4655 1: sub
4656 2: up
4657 3: average
4658 4: Paeth
4659</pre>
4660
4661<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>
4662
4663<p>If filter-type is 6, adaptive filtering with <em class="arg">minimum-sum-of-absolute-values</em> is used.</p>
4664
4665<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>
4666
4667<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>
4668
4669<p>For further information, see the <a href="http://www.w3.org/pub/WWW/TR">PNG</a> specification.</p>
4670
4671<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>
4672
4673<div style="margin: auto;">
4674 <h4><a name="quantize" id="quantize"></a>-quantize <em class="arg">colorspace</em></h4>
4675</div>
4676
4677<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>
4678
4679<p>To print a complete list of colorspaces, use the <a href="#list">-list colorspace</a> option.</p>
4680
4681
4682<div style="margin: auto;">
4683 <h4><a name="quiet" id="quiet"></a>-quiet</h4>
4684</div>
4685
4686<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>
4687
4688<div style="margin: auto;">
4689 <h4><a name="radial-blur" id="radial-blur"></a>-radial-blur <em class="arg">angle</em></h4>
4690</div>
4691
4692<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>
4693
4694<p>Note that this is actually a rotational blur rather than a radial and as
4695such actually mis-named. </p>
4696
4697<p>The <a href="#virtual-pixel">-virtual-pixel</a> setting will determine how
4698pixels which are outside the image proper are blurred into the final result.
4699</p>
4700
4701
4702<div style="margin: auto;">
4703 <h4><a name="raise" id="raise"></a>-raise <em class="arg">thickness</em></h4>
4704</div>
4705
4706<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>
4707
4708<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>.
4709</p>
4710
4711<p>Unlike the similar <a href="#frame">-frame</a> option, <a href="#raise">-raise</a> does not alter the dimensions of the image.</p>
4712
4713<div style="margin: auto;">
4714 <h4><a name="random-threshold" id="random-threshold"></a>-random-threshold <em class="arg">low</em>x<em class="arg">high</em></h4>
4715</div>
4716
4717<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>
4718
4719<div style="margin: auto;">
4720 <h4><a name="recolor" id="recolor"></a>-recolor <em class="arg">matrix</em></h4>
4721</div>
4722
4723<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>
4724
cristy2744bd92009-11-08 22:57:52 +00004725<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
4726Flash except that the offset is scaled to 1.0 (divide Flash offset by 255).</p>
cristy3ed852e2009-09-05 21:47:34 +00004727
4728<div style="margin: auto;">
4729 <h4><a name="red-primary" id="red-primary"></a>-red-primary <em class="arg">x,y</em></h4>
4730</div>
4731
4732<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>
4733
4734<div style="margin: auto;">
4735 <h4><a name="regard-warnings" id="regard-warnings"></a>-regard-warnings</h4>
4736</div>
4737
4738<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>
4739
4740<div style="margin: auto;">
4741 <h4><a name="remap" id="remap"></a>-remap <em class="arg">filename</em></h4>
4742</div>
4743
4744<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>
4745
4746<p>If the <a href="#dither">-dither</a> setting is enabled (the default) then
4747the given colors are dithered over the image as necessary, otherwise the closest
4748color (in RGB colorspace) is selected to replace that pixel in the image. </p>
4749
4750<p>As a side effect of applying a <a href="#remap">-remap</a> of colors across all
4751images in the current image sequence, all the images will have the same color
4752table. That means that when saved to a file format such as GIF, it will use
4753that color table as a single common or global color table, for all the images,
4754without requiring extra local color tables. </p>
4755
4756<p>Use <a href="#remap">+remap</a> to reduce all images in the current image
4757sequence to use a common color map over all the images. This equivalent to
4758appending all the images together (without extra background colors) and color
4759reducing those images using <a href="#colors">-colors</a> with a 256 color
4760limit, then <a href="#remap">-remap</a> those colors over the original list of
4761images. This ensures all the images follow a single color map. </p>
4762
4763<p>If the number of colors over all the images is less than 256, then <a
4764href="#remap">+remap</a> should not perform any color reduction or dithering, as
4765no color changes are needed. In that case, its only effect is to force the use
4766of a global color table. This recommended after using either <a
4767href="#colors">-colors</a> or <a href="#ordered-dither">-ordered-dither</a> to
4768reduce the number of colors in an animated image sequence. </p>
4769
4770<div style="margin: auto;">
4771 <h4><a name="region" id="region"></a>-region <em class="arg">geometry</em></h4>
4772</div>
4773
4774<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>
4775
4776<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>
4777
4778<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>
4779
4780<div style="margin: auto;">
4781 <h4><a name="remote" id="remote"></a>-remote</h4>
4782</div>
4783
4784<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>
4785
4786<p>The only command recognized is the name of an image file to load.</p>
4787
4788<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>
4789
4790<div style="margin: auto;">
4791 <h4><a name="render" id="render"></a>-render</h4>
4792</div>
4793
4794<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>
4795
4796<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>
4797
4798<div style="margin: auto;">
4799<h4><a name="repage" id="repage"></a>-repage <em class="arg">geometry</em></h4>
4800</div>
4801
4802<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>
4803
4804<p>This option is like <a href="#page">-page</a> but acts as an image operator
4805rather than a setting. You can separately set the canvas size or the offset
4806of the image on that canvas by only providing those components. </p>
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.</p>
4809
4810<p>If a <kbd>!</kbd> flag is given the offset given is added to the existing
4811offset to move the image relative to its previous position. This useful for
4812animation sequences. </p>
4813
4814<p>A given a canvas size of zero such as '<kbd>0x0</kbd>' forces it to
4815recalculate the canvas size so the image (at its current offset) will appear
4816completely on that canvas (unless it has a negative offset).</p>
4817
4818<p>Use <a href="#repage">+repage</a> to completely remove/reset the virtual
4819canvas meta-data from the images. </p>
4820
4821<p>The <a href="#set">-set</a> '<kbd>page</kbd>' option can be used to
4822directly assign virtual canvas meta-data. </p>
4823
4824
4825<div style="margin: auto;">
4826 <h4><a name="resample" id="resample"></a>-resample <em class="arg">horizontal</em>x<em class="arg">vertical</em></h4>
4827</div>
4828
4829<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>
4830
4831<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>
4832
4833<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>
4834
4835<div style="margin: auto;">
4836 <h4><a name="resize" id="resize"></a>-resize <em class="arg">geometry</em></h4>
4837</div>
4838
4839<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>
4840
4841<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>
4842
4843<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>
4844
cristy13538962010-02-26 17:53:04 +00004845<p>Many image processing algorithms assume your image is in a linear-light coding. If your image is gamma-corrected, you can remove the nonlinear gamma correction, apply the transform, then restore it like this:</p>
4846
4847<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert portrait.jpg -gamma .45455 -resize 25% -gamma 2.2 -quality 92 passport.jpg</span></p>
cristy3ed852e2009-09-05 21:47:34 +00004848<div style="margin: auto;">
4849 <h4><a name="respect-parentheses" id="respect-parentheses"></a>-respect-parentheses</h4>
4850</div>
4851
4852<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>
4853
4854<div style="margin: auto;">
4855 <h4><a name="reverse" id="reverse"></a>-reverse</h4>
4856</div>
4857
4858<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>
4859
4860
4861<div style="margin: auto;">
4862 <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>
4863</div>
4864
4865<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>
4866
4867<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>
4868
4869
4870<div style="margin: auto;">
4871 <h4><a name="rotate" id="rotate"></a>-rotate <em class="arg">degrees</em>{<em class="arg">&lt;</em>}{<em class="arg">&gt;</em>}</h4>
4872</div>
4873
4874<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>
4875
4876<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>
4877
4878<p>Empty triangles in the corners, left over from rotating the image, are
4879filled with the <kbd>background</kbd> color. </p>
4880
4881<p>See also the <a href="#distort">-distort</a> operator and specifically the
4882'<kbd>ScaleRotateTranslate</kbd>' distort method. </p>
4883
4884
4885<div style="margin: auto;">
4886 <h4><a name="sample" id="sample"></a>-sample <em class="arg">geometry</em></h4>
4887</div>
4888
4889<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>
4890
4891<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>
4892
4893<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>
4894
4895
4896<div style="margin: auto;">
4897 <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>
4898</div>
4899
4900<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>
4901
4902<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>
4903
4904<div style="margin: auto;">
4905 <h4><a name="scale" id="scale"></a>-scale <em class="arg">geometry</em></h4>
4906</div>
4907
4908<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>
4909
4910<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>
4911
4912<div style="margin: auto;">
4913 <h4><a name="scene" id="scene"></a>-scene <em class="arg">value</em></h4>
4914</div>
4915
4916<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>
4917
4918<p>This option sets the scene number of an image or the first image in an image sequence.</p>
4919
4920<div style="margin: auto;">
4921 <h4><a name="screen" id="screen"></a>-screen</h4>
4922</div>
4923
4924<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>
4925
4926<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>
4927
4928<div style="margin: auto;">
4929 <h4><a name="seed" id="seed"></a>-seed</h4>
4930</div>
4931
4932<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>
4933
4934<div style="margin: auto;">
4935 <h4><a name="segment" id="segment"></a>-segment <em class="arg">cluster-threshold</em>x<em class="arg">smoothing-threshold</em></h4>
4936</div>
4937
4938<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>
4939
4940<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>
4941
4942<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>
4943
4944<p>If the <a href="#verbose">-verbose</a> setting is defined, a detailed report
4945of the color clusters is returned.</p>
4946
4947
4948<div style="margin: auto;">
4949 <h4><a name="selective-blur" id="selective-blur"></a>-selective-blur <em class="arg">geometry</em></h4>
4950</div>
4951
4952<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>
4953
4954<div style="margin: auto;">
4955 <h4><a name="separate" id="separate"></a>-separate</h4>
4956</div>
4957
4958<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>
4959
4960<div style="margin: auto;">
4961 <h4><a name="sepia-tone" id="sepia-tone"></a>-sepia-tone <em class="arg">threshold</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 a sepia-toned photo.</td><td style='text-align:right;'></td></tr></table>
4965
4966<p>Specify <em class="arg">threshold</em> as the percent threshold of the intensity (0 - 99.9%).</p>
4967
4968<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>
4969
4970<div style="margin: auto;">
4971 <h4><a name="set" id="set"></a>-set <em class="arg">attribute value</em></h4>
4972</div>
4973
4974<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>
4975
4976<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>
4977
4978<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>
4979<p>The <a href="#repage">-repage</a> operator will also set the
4980'<kbd>page</kbd>' attribute of images already in memory, but allows you to
4981separately set the virtual canvas's size and offset components, and also allows
4982relative offset changes, and automatic canvas size re-calculating. The above
4983<a href="#set">-set</a> option is purely a direct, unmodified assignment of the
4984virtual canvas (page) meta-data. </p>
4985
4986<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>
4987
4988<div style="margin: auto;">
4989 <h4><a name="shade" id="shade"></a>-shade <em class="arg">azimuth</em>x<em class="arg">elevation</em></h4>
4990</div>
4991
4992<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>
4993
4994<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>
4995
4996<div style="margin: auto;">
4997 <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>
4998</div>
4999
5000<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>
5001
5002<div style="margin: auto;">
5003 <h4><a name="shared-memory"
5004id="shared-memory"></a>-shared-memory</h4>
5005</div>
5006
5007<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>
5008
5009<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>
5010
5011<div style="margin: auto;">
5012 <h4><a name="sharpen" id="sharpen"></a>-sharpen <em class="arg">radius</em>{x<em class="arg">sigma</em>}</h4>
5013</div>
5014
5015<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>
5016
5017<p>Use a Gaussian operator of the given radius and standard deviation (sigma).</p>
5018
5019<div style="margin: auto;">
5020 <h4><a name="shave" id="shave"></a>-shave <em class="arg">geometry</em></h4>
5021</div>
5022
5023<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>
5024
5025<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>
5026
5027<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>
5028
5029<div style="margin: auto;">
5030 <h4><a name="shear" id="shear"></a>-shear <em class="arg">Xdegrees</em>[x<em class="arg">Ydegrees</em>]</h4>
5031</div>
5032
5033<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>
5034
5035<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>
5036
5037<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>
5038
5039<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>
5040
5041<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>
5042
5043<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>
5044<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>
5045
5046<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert logo: -shear 20x60 logo-sheared.png</span></p>
5047<div style="margin: auto;">
5048 <h4><a name="sigmoidal" id="sigmoidal-contrast"></a>-sigmoidal-contrast <em class="arg">contrast</em>x<em class="arg">mid-point</em></h4>
5049</div>
5050
5051<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>
5052
5053<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>
5054
5055<div style="margin: auto;">
5056 <h4><a name="silent" id="silent"></a>-silent</h4>
5057</div>
5058
5059<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>
5060
5061<div style="margin: auto;">
5062 <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>
5063</div>
5064
5065<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>
5066
5067<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>
5068
5069<p>For Photo CD images, choose from these sizes:</p>
5070
5071<pre class="text">
5072 192x128
5073 384x256
5074 768x512
5075 1536x1024
5076 3072x2048
5077</pre>
5078
cristy3ed852e2009-09-05 21:47:34 +00005079<div style="margin: auto;">
5080 <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>
5081</div>
5082
5083<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>
5084
5085<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>
5086
5087<div style="margin: auto;">
5088 <h4><a name="snaps" id="snaps"></a>-snaps <em class="arg">value</em></h4>
5089</div>
5090
5091<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>
5092
5093<p>Use this option to grab more than one image from the X server screen, to create an animation sequence.</p>
5094
5095<div style="margin: auto;">
5096 <h4><a name="solarize" id="solarize"></a>-solarize <em class="arg">threshold</em></h4>
5097</div>
5098
5099<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>
5100
5101<p>Specify <em class="arg">factor</em> as the percent threshold of the intensity (0 - 99.9%).</p>
5102
5103<p>This option produces a <em class="arg">solarization</em> effect seen when exposing a photographic film to light during the development process.</p>
5104
5105<div style="margin: auto;">
5106 <h4><a name="sparse-color" id="sparse-color"></a>-sparse-color <em
5107 class="arg">method</em> '<em class="arg">x</em>,<em class="arg">y</em> <em class="arg">color</em> ...'</h4>
5108</div>
5109
5110<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>
5111
5112
5113<table class="doc">
5114 <tbody>
5115 <tr valign="top">
5116 <th align="left" style="width: 8%">Method</th>
5117 <th align="left">Description</th>
5118 </tr>
5119
5120 <tr valign="top">
5121 <td valign="top">voronoi</td>
5122 <td valign="top">Simply map each pixel to the to nearest color point
5123 given. The result are polygonal 'cells' of solid color. </td>
5124 </tr>
5125
5126 <tr valign="top">
5127 <td valign="top">shepards</td>
5128 <td valign="top">Colors points basied on the ratio of inverse distance
5129 squared. Generating spots of color in a sea of the average of
5130 colors. </td>
5131 </tr>
5132
5133 <tr valign="top">
5134 <td valign="top">barycentric</td>
5135 <td valign="top">three point triangle of color given 3 points.
5136 Giving only 2 points will form a linear gradient between those points.
5137 Gradient is however not restricted to just the triangle or line. </td>
5138 </tr>
5139
5140 <tr valign="top">
5141 <td valign="top">bilinear</td>
5142 <td valign="top">Like barycentric but for 4 points. Less than 4 points
5143 fall back to barycentric. </td>
5144 </tr>
5145
5146 </tbody>
5147</table>
5148
5149<p>The points are placed according to the images location on the virtual
5150canvas (<a href="#page" >-page</a> or <a href="#repage" >-repage</a>
5151offset), and do not actually have to exist on the given image, but may be
5152some point beyond the edge of the image. All points are floating point values.
5153</p>
5154
5155<p>Only the color channels defined by the <a href="#channel" >-channel</a> are
5156modified, whcih means the matte/alpha transparency channel is not effected by
5157default. If enabled, the image also needs a the matte/alpha channel to be
5158enabled for this operator to effect an images transparency. This is typical
5159transparency handling for images. </p>
5160
5161<p>All the above methods when given a single point of color will replace all
5162the colors in the image with the color given, regardless of the point. This is
5163logical, and provides an alternative technique to recolor a image to some
5164default value. </p>
5165
5166
5167<div style="margin: auto;">
5168 <h4><a name="splice" id="splice"></a>-splice <em class="arg">geometry</em></h4>
5169</div>
5170
5171<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>
5172
5173<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>
5174
5175<div style="margin: auto;">
5176 <h4><a name="spread" id="spread"></a>-spread <em class="arg">amount</em></h4>
5177</div>
5178
5179<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>
5180
5181<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>
5182
5183<div style="margin: auto;">
5184 <h4><a name="stegano" id="stegano"></a>-stegano <em class="arg">offset</em></h4>
5185</div>
5186
5187<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>
5188
5189<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>
5190
5191<div style="margin: auto;">
5192 <h4><a name="stereo" id="stereo"></a>-stereo <em class="arg">+x</em>{<em class="arg">+y</em>}</h4>
5193</div>
5194
5195<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>
5196
5197<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>
5198
5199<div style="margin: auto;">
5200 <h4><a name="storage-type" id="storage-type"></a>-storage-type <em class="arg">type</em></h4>
5201</div>
5202
5203<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>
5204
5205<pre class="text">
5206 char store pixels as unsigned characters
5207 double store pixels as doubles
5208 float store pixels as floats
5209 integer store pixels as integers
5210 long store pixels as longs
5211 quantum store pixels in the native depth of your ImageMagick distribution
5212 short store pixels as unsigned shorts
5213</pre>
5214
5215<p>Float and double types are normalized from 0.0 to 1.0 otherwise the pixels
5216values range from 0 to the maximum value the storage type can support.</p>
5217
5218<div style="margin: auto;">
5219 <h4><a name="stretch" id="stretch"></a>-stretch <em class="arg">fontStretch</em></h4>
5220</div>
5221
5222<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>
5223
5224<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>
5225
5226<pre class="text">
5227 Any
5228 Condensed
5229 Expanded
5230 ExtraCondensed
5231 ExtraExpanded
5232 Normal
5233 SemiCondensed
5234 SemiExpanded
5235 UltraCondensed
5236 UltraExpanded
5237</pre>
5238
5239<p>To print a complete list of stretch types, use <a href="#list">-list stretch</a>.</p>
5240
5241<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>
5242
5243<div style="margin: auto;">
5244 <h4><a name="strip" id="strip"></a>-strip</h4>
5245</div>
5246
5247<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>
5248
5249<div style="margin: auto;">
5250 <h4><a name="stroke" id="stroke"></a>-stroke <em class="arg">color</em></h4>
5251</div>
5252
5253<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>
5254
5255<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p>
5256
5257<p>See <a href="#draw">-draw</a> for further details.</p>
5258
5259<div style="margin: auto;">
5260 <h4><a name="strokewidth" id="strokewidth"></a>-strokewidth <em class="arg">value</em></h4>
5261</div>
5262
5263<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>
5264
5265<p>See <a href="#draw">-draw</a> for further details.</p>
5266
5267<div style="margin: auto;">
5268 <h4><a name="style" id="style"></a>-style <em class="arg">fontStyle</em></h4>
5269</div>
5270
5271<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>
5272
5273<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>
5274
5275<pre class="text">
5276 Any
5277 Italic
5278 Normal
5279 Oblique
5280</pre>
5281
5282<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>
5283
5284<div style="margin: auto;">
5285 <h4><a name="swap" id="swap"></a>-swap <em class="arg">index,index</em></h4>
5286</div>
5287
5288<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>
5289
5290<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>
5291
5292<div style="margin: auto;">
5293 <h4><a name="swirl" id="swirl"></a>-swirl <em class="arg">degrees</em></h4>
5294</div>
5295
5296<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>
5297
5298<p><em class="arg">Degrees</em> defines the tightness of the swirl.</p>
5299
5300<div style="margin: auto;">
5301 <h4><a name="taint" id="taint"></a>-taint</h4>
5302</div>
5303
5304<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>
5305
5306<div style="margin: auto;">
5307 <h4><a name="text-font" id="text-font"></a>-text-font <em class="arg">name</em></h4>
5308</div>
5309
5310<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>
5311
5312<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>
5313
5314<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>
5315
5316<div style="margin: auto;">
5317 <h4><a name="texture" id="texture"></a>-texture <em class="arg">filename</em></h4>
5318</div>
5319
5320<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>
5321
5322<div style="margin: auto;">
5323 <h4><a name="threshold" id="threshold"></a>-threshold <em class="arg">value</em>{<em class="arg">%</em>}</h4>
5324</div>
5325
5326<!-- {<em class="arg">green,blue,opacity</em>}
5327<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>
5328-->
5329
5330<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>
5331
5332<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>
5333
5334<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.
5335</p>
5336
5337<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>
5338
5339<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert in.png -channel red -threshold 50% out.png</span></p>
5340<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>
5341
5342
5343<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>
5344<p>Note that the values of the transparency channel is treated as 'matte'
5345values (0 is opaque) and not as 'alpha' values (0 is transparent).</p>
5346
5347<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>.
5348</p>
5349
5350<div style="margin: auto;">
5351 <h4><a name="thumbnail" id="thumbnail"></a>-thumbnail <em class="arg">geometry</em></h4>
5352</div>
5353
5354<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>
5355
5356<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>
5357
5358<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>
5359
5360<div style="margin: auto;">
5361 <h4><a name="tile" id="tile"></a>-tile <em class="arg">filename</em></h4>
5362</div>
5363
5364<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>
5365
5366<div style="margin: auto;">
5367 <h4>-tile <em class="arg">geometry</em></h4>
5368</div>
5369
5370<table style='background-color:#FFFFE0; margin-left:40px; margin-right:40px; width:88%'><tr><td style='width:75%'>Specify the layout of images .</td><td style='text-align:right;'>[<a href="../www/montage.html">montage</a>]</td></tr></table>
5371
5372<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>
5373
5374<div style="margin: auto;">
5375 <h4>-tile</h4>
5376</div>
5377
5378<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>
5379
5380<div style="margin: auto;">
5381 <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>
5382</div>
5383
5384<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>
5385
5386<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>
5387
5388<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>
5389
5390<div style="margin: auto;">
5391 <h4><a name="tint" id="tint"></a>-tint <em class="arg">value</em></h4>
5392</div>
5393
5394<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>
5395
5396<p>Tint the image with the fill color.</p>
5397
5398<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>
5399
5400<div style="margin: auto;">
5401 <h4><a name="title" id="title"></a>-title <em class="arg">string</em></h4>
5402</div>
5403
5404<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>
5405
5406<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>
5407
5408<p>For example,</p>
5409
5410<p class="crtsnip">
5411 -title "%m:%f %wx%h"
5412</p>
5413
5414<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>
5415
5416
5417<div style="margin: auto;">
5418 <h4><a name="transform" id="transform"></a>-transform</h4>
5419</div>
5420
5421<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>
5422
5423<p>This option applies the transformation matrix from a previous <a href="#affine">-affine</a> option.</p>
5424
5425<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>
5426<div style="margin: auto;">
5427 <h4><a name="transparent" id="transparent"></a>-transparent <em class="arg">color</em></h4>
5428</div>
5429
5430<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>
5431
5432<p>The <em class="arg">color</em> argument is defined using the format
5433described under the <a href="#fill">-fill</a> option. The <a href="#fuzz"
5434>-fuzz</a> setting can be used to match and replace colors similar to the one
5435given. </p>
5436
5437<p>The <a href="#opaque">-opaque</a> operator is exactly the same as <a
5438href="#transparent" >-transparent</a> but replaces the matching color same as
5439the current <a href="#fill">-fill</a> color setting. </p>
5440
5441<p>This does not define the 'transparency color' used for color-mapped image
5442formats, such as GIF. For that use <a href="#transparent-color"
5443>-transparent-color</a> </p>
5444
cristyc54f5d42009-11-27 21:36:31 +00005445<p>Use <a href="#opaque">+opaque</a> to invert the pixels matched, that is
cristy3ed852e2009-09-05 21:47:34 +00005446paint any pixel that does not match the target color, with the fill color.</p>
5447
5448
5449<div style="margin: auto;">
5450 <h4><a name="transparent-color" id="transparent-color"></a>-transparent-color <em class="arg">color</em></h4>
5451</div>
5452
5453<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>
5454
5455<p>Sometimes this is used for saving to image formats such as
5456GIF and PNG8 which uses this color to represent boolean transparency. This
5457does not make a color transparent, it only defines what color the transparent
5458color is in the color palette of the saved image. Use <a
5459href="#transparent">-transparent</a> to make an opaque color transparent.</p>
5460
5461<p>This option allows you to have both an opaque visible color, as well as a
5462transparent color of the same color value without conflict. That is, you can
5463use the same color for both the transparent and opaque color areas within an
5464image. This, in turn, frees to you to select a transparent color that is
5465appropriate when an image is displayed by an application that does not handle a
5466transparent color index, while allowing ImageMagick to correctly handle images of this
5467type. </p>
5468
5469<p>The default transparent color is <kbd>#00000000</kbd>, which is fully transparent black.</p>
5470
5471<div style="margin: auto;">
5472 <h4><a name="transpose" id="transpose"></a>-transpose</h4>
5473</div>
5474
5475<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>
5476
5477<p> This option mathematically transposes the pixel array. It is equivalent to the sequence <kbd>-flip -rotate 90</kbd>.
5478</p>
5479
5480<div style="margin: auto;">
5481 <h4><a name="transverse" id="transverse"></a>-transverse</h4>
5482</div>
5483
5484<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>
5485
5486
5487<div style="margin: auto;">
5488 <h4><a name="treedepth" id="treedepth"></a>-treedepth <em class="arg">value</em></h4>
5489</div>
5490
5491<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>
5492
5493<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>
5494
5495<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>
5496
5497<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>
5498
5499<div style="margin: auto;">
5500 <h4><a name="trim" id="trim"></a>-trim</h4>
5501</div>
5502
5503<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>
5504
5505<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>
5506
5507<p>The page or virtual canvas information of the image is preserved allowing
5508you to extract the result of the <a href="#trim">-trim</a> operation from the
5509image. Use a <a href="#repage">+repage</a> to remove the virtual canvas page
5510information if it is unwanted.</p>
5511
5512<p>If the trimmed image 'disappears' an warning is produced, and a special
5513single pixel transparent 'missed' image is returned, in the same way as when a
5514<a href="#crop">-crop</a> operation 'misses' the image proper. </p>
5515
5516
5517<div style="margin: auto;">
5518 <h4><a name="type" id="type"></a>-type <em class="arg">type</em></h4>
5519</div>
5520
5521<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>
5522 <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>
5523
5524<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>
5525
5526<p class='crt'><span class="crtprompt"> $magick&gt; </span><span class='crtin'>convert bird.png -type TrueColor bird.jpg</span></p>
5527<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>
5528
5529<p>Use <a href="#type">-type optimize</a> to ensure the image is written in the smallest possible file size.</p>
5530
5531<div style="margin: auto;">
5532 <h4><a name="undercolor" id="undercolor"></a>-undercolor <em class="arg">color</em></h4>
5533</div>
5534
5535<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>
5536
5537<p>The color is specified using the format described under the <a href="#fill">-fill</a> option.</p>
5538
5539<p>See <a href="#draw">-draw</a> for further details.</p>
5540
5541
5542<div style="margin: auto;">
5543 <h4><a name="update" id="update"></a>-update <em class="arg">seconds</em></h4>
5544</div>
5545
5546<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>
5547
5548<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>
5549
5550
5551<div style="margin: auto;">
5552 <h4><a name="unique-colors" id="unique-colors"></a>-unique-colors</h4>
5553</div>
5554
5555<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>
5556
5557
5558<div style="margin: auto;">
5559 <h4><a name="units" id="units"></a>-units <em class="arg">type</em></h4>
5560</div>
5561
5562<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>
5563
5564<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>
5565
5566
5567<div style="margin: auto;">
5568 <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>
5569</div>
5570
5571<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>
5572
5573<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>
5574
5575<p>The parameters are:</p>
5576
5577<pre class="text">
5578 radius: The radius of the Gaussian, in pixels, not counting the center
5579 pixel (default 0).
5580 sigma: The standard deviation of the Gaussian, in pixels (default 1.0).
5581 amount: The fraction of the difference between the original and the blur
5582 image that is added back into the original (default 1.0).
5583 threshold: The threshold, as a fraction of <em class="QR">QuantumRange</em>, needed to apply the
5584 difference amount (default 0.05).
5585</pre>
5586
5587
5588<div style="margin: auto;">
5589 <h4><a name="verbose" id="verbose"></a>-verbose</h4>
5590</div>
5591
5592<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>
5593
5594
5595<div style="margin: auto;">
5596 <h4><a name="version" id="version"></a>-version</h4>
5597</div>
5598
5599<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>
5600
5601
5602<div style="margin: auto;">
5603 <h4><a name="view" id="view"></a>-view <em class="arg">string</em></h4>
5604</div>
5605
5606<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>
5607
5608
5609<div style="margin: auto;">
5610 <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>
5611</div>
5612
5613<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>
5614
5615
5616<div style="margin: auto;">
5617 <h4><a name="virtual-pixel" id="virtual-pixel"></a>-virtual-pixel <em class="arg">method</em></h4>
5618</div>
5619
5620<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>
5621
5622<p>This option defines what color source should be used if and when a color
5623lookup completely 'misses' the source image. The color(s) that appear to
5624surround the source image. Generally this color is derived from the source
5625image, but could also be set to a specify background color. </p>
5626
5627<p>Choose from these methods:</p>
5628
5629<pre class="text">
5630 background: the area surrounding the image is the background color
5631 black: the area surrounding the image is black
5632 checker-tile: alternate squares with image and background color
5633 dither: non-random 32x32 dithered pattern
5634 edge: extend the edge pixel toward infinity
5635 gray: the area surrounding the image is gray
5636 horizontal-tile: horizontally tile the image, background color above/below
5637 horizontal-tile-edge: horizontally tile the image and replicate the side edge pixels
5638 mirror: mirror tile the image
5639 random: choose a random pixel from the image
5640 tile: tile the image (default)
5641 transparent: the area surrounding the image is transparent blackness
5642 vertical-tile: vertically tile the image, sides are background color
5643 vertical-tile-edge: vertically tile the image and replicate the side edge pixels
5644 white: the area surrounding the image is white
5645</pre>
5646
5647<p>The default value is "edge".</p>
5648
5649<p>This most important for distortion operators such as <a href="#distort"
5650>-distort</a>, <a href="#implode" >-implode</a>, and <a href="#fx" >-fx</a>.
5651However it also effects operations that may access pixels just outside the
5652image proper, such as <a href="#convolve">-convolve</a>, <a
5653href="#blur">-blur</a>, and <a href="#sharpen">-sharpen</a>. </p>
5654
5655<p>To print a complete list of virtual pixel types, use the <a href="#list">-list virtual-pixel</a> option.</p>
5656
5657
5658<div style="margin: auto;">
5659 <h4><a name="visual" id="visual"></a>-visual <em class="arg">type</em></h4>
5660</div>
5661
5662<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>
5663
5664<p>Choose from these visual classes:</p>
5665
5666<pre class="text">
5667 StaticGray
5668 GrayScale
5669 StaticColor
5670 PseudoColor
5671 TrueColor
5672 DirectColor
5673 default
5674 visual id
5675</pre>
5676
5677<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>
5678
5679
5680<div style="margin: auto;">
5681 <h4><a name="watermark" id="watermark"></a>-watermark <em
5682 class="arg">brightness</em>x<em class="arg">saturation</em></h4>
5683</div>
5684
5685<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
5686saturation.</td><td style='text-align:right;'>[<a href="../www/composite.html">composite</a>]</td></tr></table>
5687
5688<p>Take a grayscale image (with alpha mask) and modify the destination image's
5689brightness according to watermark image's grayscale value and the <em
5690class="arg">brightness</em> percentage. The destinations color saturation
5691attribute is just direct modified by the <em class="arg">saturation</em>
5692percentage, which defaults to 100 percent (no color change). </p>
5693
5694
5695<div style="margin: auto;">
5696 <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>
5697</div>
5698
5699<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>
5700
5701<p>Specify <em class="arg">amplitude</em> and <em class="arg">wavelength</em> of the wave.</p>
5702
5703<div style="margin: auto;">
5704 <h4><a name="weight" id="weight"></a>-weight <em class="arg">fontWeight</em></h4>
5705</div>
5706
5707<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>
5708
5709<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>
5710
5711<table class="doc">
5712 <col width="25%" />
5713 <col width="75%" />
5714 <thead>
5715 <tr>
5716 <th><em class="arg">fontWeight</em></th>
5717 <th>Description</th>
5718 </tr>
5719 </thead>
5720 <tbody>
5721 <tr><td>All </td> <td>No effect. </td></tr>
5722 <tr><td>Bold </td> <td>Same as <em class="arg">fontWeight</em> = 700.</td></tr>
5723 <tr><td>Bolder </td> <td>Add 100 to font weight if currently &le; 800.</td></tr>
5724 <tr><td>Lighter </td> <td>Subtract 100 to font weight if currently &le; 100.</td></tr>
5725 <tr><td>Normal </td> <td>Same as <em class="arg">fontWeight</em> = 400.</td></tr>
5726 </tbody>
5727 </table>
5728
5729<p>To print a complete list of weight types, use <a href="#list">-list weight</a>.</p>
5730
5731<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>
5732
5733<div style="margin: auto;">
5734 <h4><a name="white-point" id="white-point"></a>-white-point <em class="arg">x,y</em></h4>
5735</div>
5736
5737<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>
5738
5739<div style="margin: auto;">
cristy5cadd612009-09-21 19:33:41 +00005740 <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 +00005741</div>
5742
cristy5cadd612009-09-21 19:33:41 +00005743<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>
5744
5745<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.
5746</p>
cristy3ed852e2009-09-05 21:47:34 +00005747
5748<div style="margin: auto;">
5749 <h4><a name="window" id="window"></a>-window <em class="arg">id</em></h4>
5750</div>
5751
5752<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>
5753
5754<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>
5755
5756<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>
5757
5758<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>
5759
5760<div style="margin: auto;">
5761 <h4><a name="window-group" id="window-group"></a>-window-group</h4>
5762</div>
5763
5764<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>
5765
5766<div style="margin: auto;">
5767 <h4><a name="write" id="write"></a>-write <em class="arg">filename</em></h4>
5768</div>
5769
5770<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>
5771 <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>
5772
5773<p>Use <a href="#compress">-compress</a> to specify the type of image compression.</p>
5774
cristyf3bb4782009-09-08 13:10:04 +00005775
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5777
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