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149
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151
152<div class="main">
153
cristy83543962009-10-16 19:04:28 +0000[diff] [blame]154<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]155
156<h2><a href="http://www.imagemagick.org/api/MagickCore/histogram
cristy83543962009-10-16 19:04:28 +0000[diff] [blame]157_8c.html" target="source" name="GetImageHistogram">GetImageHistogram</a></h2>
158<div class="doc-section">
159
160<p>GetImageHistogram() returns the unique colors in an image.</p></ol>
161
162<p>The format of the GetImageHistogram method is:</p>
163
164<pre class="code">
165 unsigned long GetImageHistogram(const Image *image,
166 unsigned long *number_colors,ExceptionInfo *exception)
167</pre>
168
169<p>A description of each parameter follows.</p></ol>
170
171<h5>image</h5>
172<ol><p>the image.</p></ol>
173
174<h5>file</h5>
175<ol><p>Write a histogram of the color distribution to this file handle.</p></ol>
176
177<h5>exception</h5>
178<ol><p>return any errors or warnings in this structure.</p></ol>
179
180 </div>
181<h2><a href="http://www.imagemagick.org/api/MagickCore/histogram
182_8c.html" target="source" name="IsHistogramImage">IsHistogramImage</a></h2>
183<div class="doc-section">
184
185<p>IsHistogramImage() returns MagickTrue if the image has 1024 unique colors or less.</p></ol>
186
187<p>The format of the IsHistogramImage method is:</p>
188
189<pre class="code">
190 MagickBooleanType IsHistogramImage(const Image *image,
191 ExceptionInfo *exception)
192</pre>
193
194<p>A description of each parameter follows.</p></ol>
195
196<h5>image</h5>
197<ol><p>the image.</p></ol>
198
199<h5>exception</h5>
200<ol><p>return any errors or warnings in this structure.</p></ol>
201
202 </div>
203<h2><a href="http://www.imagemagick.org/api/MagickCore/histogram
204_8c.html" target="source" name="IsPaletteImage">IsPaletteImage</a></h2>
205<div class="doc-section">
206
207<p>IsPaletteImage() returns MagickTrue if the image is PseudoClass and has 256 unique colors or less.</p></ol>
208
209<p>The format of the IsPaletteImage method is:</p>
210
211<pre class="code">
212 MagickBooleanType IsPaletteImage(const Image *image,
213 ExceptionInfo *exception)
214</pre>
215
216<p>A description of each parameter follows.</p></ol>
217
218<h5>image</h5>
219<ol><p>the image.</p></ol>
220
221<h5>exception</h5>
222<ol><p>return any errors or warnings in this structure.</p></ol>
223
224 </div>
225<h2><a href="http://www.imagemagick.org/api/MagickCore/histogram
cristy3ed852e2009-09-05 21:47:34 +0000[diff] [blame]226_8c.html" target="source" name="MinMaxStretchImage">MinMaxStretchImage</a></h2>
227<div class="doc-section">
228
229<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>
230
231<p>If the adjustment values are both zero this function is equivelent to a perfect normalization (or autolevel) of the image.</p></ol>
232
233<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>
234
235<p>The 'SyncChannels' is turned on in the 'DefaultChannels' setting by default.</p></ol>
236
237<p>The format of the MinMaxStretchImage method is:</p>
238
239<pre class="code">
240 MagickBooleanType MinMaxStretchImage(Image *image,
241 const ChannelType channel, const double black_adjust,
242 const double white_adjust)
243</pre>
244
245<p>A description of each parameter follows:</p></ol>
246
247<h5>image</h5>
248<ol><p>The image to auto-level</p></ol>
249
250<h5>channel</h5>
251<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>
252
253<h5>black_adjust, white_adjust</h5>
254<ol><p>Move the Black/White Point inward from the minimum and maximum points by this color value.</p></ol>
255
256 </div>
cristy83543962009-10-16 19:04:28 +0000[diff] [blame]257<h2><a href="http://www.imagemagick.org/api/MagickCore/histogram
258_8c.html" target="source" name="GetNumberColors">GetNumberColors</a></h2>
259<div class="doc-section">
260
261<p>GetNumberColors() returns the number of unique colors in an image.</p></ol>
262
263<p>The format of the GetNumberColors method is:</p>
264
265<pre class="code">
266 unsigned long GetNumberColors(const Image *image,FILE *file,
267 ExceptionInfo *exception)
268</pre>
269
270<p>A description of each parameter follows.</p></ol>
271
272<h5>image</h5>
273<ol><p>the image.</p></ol>
274
275<h5>file</h5>
276<ol><p>Write a histogram of the color distribution to this file handle.</p></ol>
277
278<h5>exception</h5>
279<ol><p>return any errors or warnings in this structure.</p></ol>
280
281 </div>
282<h2><a href="http://www.imagemagick.org/api/MagickCore/histogram
283_8c.html" target="source" name="UniqueImageColors">UniqueImageColors</a></h2>
284<div class="doc-section">
285
286<p>UniqueImageColors() returns the unique colors of an image.</p></ol>
287
288<p>The format of the UniqueImageColors method is:</p>
289
290<pre class="code">
291 Image *UniqueImageColors(const Image *image,ExceptionInfo *exception)
292</pre>
293
294<p>A description of each parameter follows.</p></ol>
295
296<h5>image</h5>
297<ol><p>the image.</p></ol>
298
299<h5>exception</h5>
300<ol><p>return any errors or warnings in this structure.</p></ol>
301
302 </div>
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