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162
163<div class="main">
164
cristy83543962009-10-16 19:04:28 +0000[diff] [blame]165<p class="navigation-index">[<a href="#GetImageHistogram">GetImageHistogram</a> &bull; <a href="#IsHistogramImage">IsHistogramImage</a> &bull; <a href="#IsPaletteImage">IsPaletteImage</a> &bull; <a href="#MinMaxStretchImage">MinMaxStretchImage</a> &bull; <a href="#GetNumberColors">GetNumberColors</a> &bull; <a href="#UniqueImageColors">UniqueImageColors</a>]</p>
cristy3ed852e2009-09-05 21:47:34 +0000[diff] [blame]166
167<h2><a href="http://www.imagemagick.org/api/MagickCore/histogram
cristy83543962009-10-16 19:04:28 +0000[diff] [blame]168_8c.html" target="source" name="GetImageHistogram">GetImageHistogram</a></h2>
169<div class="doc-section">
170
171<p>GetImageHistogram() returns the unique colors in an image.</p></ol>
172
173<p>The format of the GetImageHistogram method is:</p>
174
175<pre class="code">
cristybb503372010-05-27 20:51:26 +0000[diff] [blame]176 size_t GetImageHistogram(const Image *image,
177 size_t *number_colors,ExceptionInfo *exception)
cristy83543962009-10-16 19:04:28 +0000[diff] [blame]178</pre>
179
180<p>A description of each parameter follows.</p></ol>
181
182<h5>image</h5>
183<ol><p>the image.</p></ol>
184
185<h5>file</h5>
186<ol><p>Write a histogram of the color distribution to this file handle.</p></ol>
187
188<h5>exception</h5>
189<ol><p>return any errors or warnings in this structure.</p></ol>
190
191 </div>
192<h2><a href="http://www.imagemagick.org/api/MagickCore/histogram
193_8c.html" target="source" name="IsHistogramImage">IsHistogramImage</a></h2>
194<div class="doc-section">
195
196<p>IsHistogramImage() returns MagickTrue if the image has 1024 unique colors or less.</p></ol>
197
198<p>The format of the IsHistogramImage method is:</p>
199
200<pre class="code">
201 MagickBooleanType IsHistogramImage(const Image *image,
202 ExceptionInfo *exception)
203</pre>
204
205<p>A description of each parameter follows.</p></ol>
206
207<h5>image</h5>
208<ol><p>the image.</p></ol>
209
210<h5>exception</h5>
211<ol><p>return any errors or warnings in this structure.</p></ol>
212
213 </div>
214<h2><a href="http://www.imagemagick.org/api/MagickCore/histogram
215_8c.html" target="source" name="IsPaletteImage">IsPaletteImage</a></h2>
216<div class="doc-section">
217
218<p>IsPaletteImage() returns MagickTrue if the image is PseudoClass and has 256 unique colors or less.</p></ol>
219
220<p>The format of the IsPaletteImage method is:</p>
221
222<pre class="code">
223 MagickBooleanType IsPaletteImage(const Image *image,
224 ExceptionInfo *exception)
225</pre>
226
227<p>A description of each parameter follows.</p></ol>
228
229<h5>image</h5>
230<ol><p>the image.</p></ol>
231
232<h5>exception</h5>
233<ol><p>return any errors or warnings in this structure.</p></ol>
234
235 </div>
236<h2><a href="http://www.imagemagick.org/api/MagickCore/histogram
cristy3ed852e2009-09-05 21:47:34 +0000[diff] [blame]237_8c.html" target="source" name="MinMaxStretchImage">MinMaxStretchImage</a></h2>
238<div class="doc-section">
239
240<p>MinMaxStretchImage() uses the exact minimum and maximum values found in each of the channels given, as the BlackPoint and WhitePoint to linearly stretch the colors (and histogram) of the image. The stretch points are also moved further inward by the adjustment values given.</p></ol>
241
242<p>If the adjustment values are both zero this function is equivelent to a perfect normalization (or autolevel) of the image.</p></ol>
243
244<p>Each channel is stretched independantally of each other (producing color distortion) unless the special 'SyncChannels' flag is also provided in the channels setting. If this flag is present the minimum and maximum point will be extracted from all the given channels, and those channels will be stretched by exactly the same amount (preventing color distortion).</p></ol>
245
cristy031b7a82010-04-08 00:33:24 +0000[diff] [blame]246<p>In the special case that only ONE value is found in a channel of the image that value is not stretched, that value is left as is.</p></ol>
247
cristy3ed852e2009-09-05 21:47:34 +0000[diff] [blame]248<p>The 'SyncChannels' is turned on in the 'DefaultChannels' setting by default.</p></ol>
249
250<p>The format of the MinMaxStretchImage method is:</p>
251
252<pre class="code">
253 MagickBooleanType MinMaxStretchImage(Image *image,
254 const ChannelType channel, const double black_adjust,
255 const double white_adjust)
256</pre>
257
258<p>A description of each parameter follows:</p></ol>
259
260<h5>image</h5>
261<ol><p>The image to auto-level</p></ol>
262
263<h5>channel</h5>
264<ol><p>The channels to auto-level. If the special 'SyncChannels' flag is set, all the given channels are stretched by the same amount.</p></ol>
265
266<h5>black_adjust, white_adjust</h5>
267<ol><p>Move the Black/White Point inward from the minimum and maximum points by this color value.</p></ol>
268
269 </div>
cristy83543962009-10-16 19:04:28 +0000[diff] [blame]270<h2><a href="http://www.imagemagick.org/api/MagickCore/histogram
271_8c.html" target="source" name="GetNumberColors">GetNumberColors</a></h2>
272<div class="doc-section">
273
274<p>GetNumberColors() returns the number of unique colors in an image.</p></ol>
275
276<p>The format of the GetNumberColors method is:</p>
277
278<pre class="code">
cristybb503372010-05-27 20:51:26 +0000[diff] [blame]279 size_t GetNumberColors(const Image *image,FILE *file,
cristy83543962009-10-16 19:04:28 +0000[diff] [blame]280 ExceptionInfo *exception)
281</pre>
282
283<p>A description of each parameter follows.</p></ol>
284
285<h5>image</h5>
286<ol><p>the image.</p></ol>
287
288<h5>file</h5>
289<ol><p>Write a histogram of the color distribution to this file handle.</p></ol>
290
291<h5>exception</h5>
292<ol><p>return any errors or warnings in this structure.</p></ol>
293
294 </div>
295<h2><a href="http://www.imagemagick.org/api/MagickCore/histogram
296_8c.html" target="source" name="UniqueImageColors">UniqueImageColors</a></h2>
297<div class="doc-section">
298
299<p>UniqueImageColors() returns the unique colors of an image.</p></ol>
300
301<p>The format of the UniqueImageColors method is:</p>
302
303<pre class="code">
304 Image *UniqueImageColors(const Image *image,ExceptionInfo *exception)
305</pre>
306
307<p>A description of each parameter follows.</p></ol>
308
309<h5>image</h5>
310<ol><p>the image.</p></ol>
311
312<h5>exception</h5>
313<ol><p>return any errors or warnings in this structure.</p></ol>
314
315 </div>
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