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 231 <h1>Module feature Methods</h1>
 232 <p class="navigation-index">[<a href="feature.html#GetImageChannelFeatures">GetImageChannelFeatures</a>]</p>
 233
 234 <h2><a href="http://www.imagemagick.org/api/MagickCore/feature_8c.html" id="GetImageChannelFeatures">GetImageChannelFeatures</a></h2>
 235 <div class="doc-section">
 236
 237 <p>GetImageChannelFeatures() returns features for each channel in the image in each of four directions (horizontal, vertical, left and right diagonals) for the specified distance.  The features include the angular second moment, contrast, correlation, sum of squares: variance, inverse difference moment, sum average, sum varience, sum entropy, entropy, difference variance,  difference entropy, information measures of correlation 1, information measures of correlation 2, and maximum correlation coefficient.  You can access the red channel contrast, for example, like this:</p>
 238
 239 <pre class="text">
 240   channel_features=GetImageChannelFeatures(image,1,exception);
 241   contrast=channel_features[RedChannel].contrast[0];
 242 </pre>
 243
 244 <p>Use MagickRelinquishMemory() to free the features buffer.</p>
 245
 246 <p>The format of the GetImageChannelFeatures method is:</p>
 247
 248 <pre class="code">
 249   ChannelFeatures *GetImageChannelFeatures(const Image *image,
 250     const size_t distance,ExceptionInfo *exception)
 251 </pre>
 252
 253 <p>A description of each parameter follows:</p>
 254
 255 <h5>image</h5>
 256 <p>the image.</p>
 257
 258 <h5>distance</h5>
 259 <p>the distance.</p>
 260
 261 <h5>exception</h5>
 262 <p>return any errors or warnings in this structure.</p>
 263
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