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- Committer: Package Import Robot
- Author(s): Jay Berkenbilt
- Date: 2014-06-21 16:35:51 UTC
- mfrom: (1.2.23)
- Revision ID: package-import@ubuntu.com-20140621163551-l7mq3sjc5pkf94eu
Tags: 7.38.6-1
* New upstream version.
* Remove no-longer-needed dependency on gcc 4.7 for armhf. (Closes:
#748006)
* Upstream version includes new German transltion. (Closes: #743613)
* Remove no-longer-needed dependency on gcc 4.7 for armhf. (Closes:
#748006)
* Upstream version includes new German transltion. (Closes: #743613)
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doc/reference/html/libvips-morphology.html
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<html>
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<title>morphology</title>
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<title>VIPS Reference Manual: morphology</title>
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<a href="#libvips-morphology.description" class="shortcut">Description</a>
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<a href="#libvips-morphology.description" class="shortcut">Description</a></span><span id="nav_hierarchy"> <span class="dim">|</span>
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<a href="#libvips-morphology.object-hierarchy" class="shortcut">Object Hierarchy</a></span>
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<div class="refentry">
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<a name="libvips-morphology"></a><div class="titlepage"></div>
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<div class="refnamediv"><table width="100%"><tr>
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<p>morphology — morphological operators, rank filters and related image
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analysis</p>
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</td>
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<td valign="top" align="right"></td>
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<td class="gallery_image" valign="top" align="right"></td>
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</tr></table></div>
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<div class="refsect1">
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<a name="libvips-morphology.stability-level"></a><h2>Stability Level</h2>
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Stable, unless otherwise indicated
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</div>
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<div class="refsynopsisdiv">
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<a name="libvips-morphology.synopsis"></a><h2>Synopsis</h2>
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<pre class="synopsis">
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#include <vips/vips.h>
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enum <a class="link" href="libvips-morphology.html#VipsOperationMorphology" title="enum VipsOperationMorphology">VipsOperationMorphology</a>;
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<span class="returnvalue">int</span> <a class="link" href="libvips-morphology.html#vips-morph" title="vips_morph ()">vips_morph</a> (<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *in</code></em>,
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<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> **out</code></em>,
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<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *mask</code></em>,
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<em class="parameter"><code><a class="link" href="libvips-morphology.html#VipsOperationMorphology" title="enum VipsOperationMorphology"><span class="type">VipsOperationMorphology</span></a> morph</code></em>,
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<em class="parameter"><code>...</code></em>);
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<span class="returnvalue">int</span> <a class="link" href="libvips-morphology.html#vips-rank" title="vips_rank ()">vips_rank</a> (<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *in</code></em>,
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<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> **out</code></em>,
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<em class="parameter"><code><span class="type">int</span> width</code></em>,
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<em class="parameter"><code><span class="type">int</span> height</code></em>,
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<em class="parameter"><code><span class="type">int</span> index</code></em>,
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<em class="parameter"><code>...</code></em>);
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<span class="returnvalue">int</span> <a class="link" href="libvips-morphology.html#vips-countlines" title="vips_countlines ()">vips_countlines</a> (<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *in</code></em>,
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<em class="parameter"><code><span class="type">double</span> *nolines</code></em>,
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<em class="parameter"><code><a class="link" href="libvips-conversion.html#VipsDirection" title="enum VipsDirection"><span class="type">VipsDirection</span></a> direction</code></em>,
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<em class="parameter"><code>...</code></em>);
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<span class="returnvalue">int</span> <a class="link" href="libvips-morphology.html#vips-median" title="vips_median ()">vips_median</a> (<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *in</code></em>,
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<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> **out</code></em>,
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<em class="parameter"><code><span class="type">int</span> size</code></em>,
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<em class="parameter"><code>...</code></em>);
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<span class="returnvalue">int</span> <a class="link" href="libvips-morphology.html#im-label-regions" title="im_label_regions ()">im_label_regions</a> (<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *test</code></em>,
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<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *mask</code></em>,
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<em class="parameter"><code><span class="type">int</span> *segments</code></em>);
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<div class="refsect1">
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<a name="libvips-morphology.functions"></a><h2>Functions</h2>
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<div class="informaltable"><table width="100%" border="0">
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<colgroup>
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<col width="150px" class="functions_return">
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<col class="functions_name">
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</colgroup>
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<tbody>
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<tr>
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<td class="function_type">
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<span class="returnvalue">int</span>
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</td>
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<td class="function_name">
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<a class="link" href="libvips-morphology.html#vips-morph" title="vips_morph ()">vips_morph</a> <span class="c_punctuation">()</span>
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</td>
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</tr>
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<tr>
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<td class="function_type">
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<span class="returnvalue">int</span>
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</td>
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<td class="function_name">
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<a class="link" href="libvips-morphology.html#vips-rank" title="vips_rank ()">vips_rank</a> <span class="c_punctuation">()</span>
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</td>
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</tr>
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<tr>
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<td class="function_type">
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<span class="returnvalue">int</span>
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</td>
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<td class="function_name">
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<a class="link" href="libvips-morphology.html#vips-countlines" title="vips_countlines ()">vips_countlines</a> <span class="c_punctuation">()</span>
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</td>
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</tr>
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<tr>
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<td class="function_type">
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<span class="returnvalue">int</span>
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</td>
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<td class="function_name">
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<a class="link" href="libvips-morphology.html#vips-median" title="vips_median ()">vips_median</a> <span class="c_punctuation">()</span>
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</td>
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</tr>
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<tr>
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<td class="function_type">
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<span class="returnvalue">int</span>
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</td>
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<td class="function_name">
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<a class="link" href="libvips-morphology.html#im-label-regions" title="im_label_regions ()">im_label_regions</a> <span class="c_punctuation">()</span>
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</td>
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</tr>
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</tbody>
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</table></div>
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</div>
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<div class="refsect1">
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<a name="libvips-morphology.other"></a><h2>Types and Values</h2>
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<div class="informaltable"><table width="100%" border="0">
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<colgroup>
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<col width="150px" class="name">
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<col class="description">
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</colgroup>
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<tbody><tr>
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<td class="datatype_keyword">enum</td>
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<td class="function_name"><a class="link" href="libvips-morphology.html#VipsOperationMorphology" title="enum VipsOperationMorphology">VipsOperationMorphology</a></td>
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</tr></tbody>
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</table></div>
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</div>
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<div class="refsect1">
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<a name="libvips-morphology.object-hierarchy"></a><h2>Object Hierarchy</h2>
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<pre class="screen">
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</pre>
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</div>
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<div class="refsect1">
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<a name="libvips-morphology.includes"></a><h2>Includes</h2>
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<pre class="synopsis">#include <vips/vips.h>
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</pre>
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</div>
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<div class="refsect1">
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<a name="libvips-morphology.description"></a><h2>Description</h2>
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<p>
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The morphological functions search images
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<p>The morphological functions search images
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for particular patterns of pixels, specified with the mask argument,
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either adding or removing pixels when they find a match. They are useful
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for cleaning up images --- for example, you might threshold an image, and
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then use one of the morphological functions to remove all single isolated
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pixels from the result.
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</p>
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<p>
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If you combine the morphological operators with the mask rotators
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<a href="http://http://www.vips.ecs.soton.ac.uk/libvips-mask.html#im-rotate-imask45"><code class="function">im_rotate_imask45()</code></a>, for example) and apply them repeatedly, you
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pixels from the result.</p>
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<p>If you combine the morphological operators with the mask rotators
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<code class="function">im_rotate_imask45()</code>, for example) and apply them repeatedly, you
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can achieve very complicated effects: you can thin, prune, fill, open edges,
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close gaps, and many others. For example, see `Fundamentals of Digital
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Image Processing' by A. Jain, pp 384-388, Prentice-Hall, 1989 for more
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ideas.
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</p>
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<p>
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Beware that VIPS reverses the usual image processing convention, by
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ideas.</p>
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<p>Beware that VIPS reverses the usual image processing convention, by
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assuming white objects (non-zero pixels) on a black background (zero
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pixels).
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</p>
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<p>
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The mask you give to the morphological functions should contain only the
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pixels).</p>
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<p>The mask you give to the morphological functions should contain only the
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values 0 (for background), 128 (for don't care) and 255 (for object). The
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mask must have odd length sides --- the origin of the mask is taken to be
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the centre value. For example, the mask:
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</p>
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<p>
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3 3
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the centre value. For example, the mask:</p>
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<p> 3 3
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128 255 128
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255 0 255
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128 255 128
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</p>
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<p>
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applied to an image with <a href="http://http://www.vips.ecs.soton.ac.uk/libvips-morphology.html#im-erode"><code class="function">im_erode()</code></a>, will find all black pixels
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4-way connected with white pixels. Essentially, <a href="http://http://www.vips.ecs.soton.ac.uk/libvips-morphology.html#im-dilate"><code class="function">im_dilate()</code></a>
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128 255 128</p>
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<p>applied to an image with <code class="function">im_erode()</code>, will find all black pixels
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4-way connected with white pixels. Essentially, <code class="function">im_dilate()</code>
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sets pixels in the output if any part of the mask matches, whereas
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<a href="http://http://www.vips.ecs.soton.ac.uk/libvips-morphology.html#im-erode"><code class="function">im_erode()</code></a> sets pixels only if all of the mask matches.
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</p>
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<p>
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See <code class="function">im_andimage()</code>, <code class="function">im_orimage()</code> and <code class="function">im_eorimage()</code>
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for analogues of the usual set difference and set union operations.
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</p>
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<code class="function">im_erode()</code> sets pixels only if all of the mask matches.</p>
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<p>See <code class="function">im_andimage()</code>, <code class="function">im_orimage()</code> and <code class="function">im_eorimage()</code>
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for analogues of the usual set difference and set union operations.</p>
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</div>
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<div class="refsect1">
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<a name="libvips-morphology.details"></a><h2>Details</h2>
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<div class="refsect2">
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<a name="VipsOperationMorphology"></a><h3>enum VipsOperationMorphology</h3>
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<pre class="programlisting">typedef enum {
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VIPS_OPERATION_MORPHOLOGY_ERODE,
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VIPS_OPERATION_MORPHOLOGY_DILATE,
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VIPS_OPERATION_MORPHOLOGY_LAST
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} VipsOperationMorphology;
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</pre>
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<p>
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More like hit-miss, really.
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</p>
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<p>
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See also: <a class="link" href="libvips-morphology.html#vips-morph" title="vips_morph ()"><code class="function">vips_morph()</code></a>.
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</p>
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<div class="variablelist"><table border="0" class="variablelist">
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<colgroup>
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<col align="left" valign="top">
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<col>
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</colgroup>
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<tbody>
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<tr>
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<td><p><a name="VIPS-OPERATION-MORPHOLOGY-ERODE:CAPS"></a><span class="term"><code class="literal">VIPS_OPERATION_MORPHOLOGY_ERODE</code></span></p></td>
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<td>true if all set
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</td>
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</tr>
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<tr>
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<td><p><a name="VIPS-OPERATION-MORPHOLOGY-DILATE:CAPS"></a><span class="term"><code class="literal">VIPS_OPERATION_MORPHOLOGY_DILATE</code></span></p></td>
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<td>true if one set
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</td>
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</tr>
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<tr>
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<td><p><a name="VIPS-OPERATION-MORPHOLOGY-LAST:CAPS"></a><span class="term"><code class="literal">VIPS_OPERATION_MORPHOLOGY_LAST</code></span></p></td>
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<td>
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</td>
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</tr>
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</tbody>
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</table></div>
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</div>
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<hr>
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<div class="refsect2">
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<a name="vips-morph"></a><h3>vips_morph ()</h3>
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<pre class="programlisting"><span class="returnvalue">int</span> vips_morph (<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *in</code></em>,
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<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> **out</code></em>,
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<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *mask</code></em>,
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<em class="parameter"><code><a class="link" href="libvips-morphology.html#VipsOperationMorphology" title="enum VipsOperationMorphology"><span class="type">VipsOperationMorphology</span></a> morph</code></em>,
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<em class="parameter"><code>...</code></em>);</pre>
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<p>
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Performs a morphological operation on <em class="parameter"><code>in</code></em> using <em class="parameter"><code>mask</code></em> as a
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structuring element.
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</p>
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<p>
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The image should have 0 (black) for no object and 255
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<a name="libvips-morphology.functions_details"></a><h2>Functions</h2>
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<div class="refsect2">
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<a name="vips-morph"></a><h3>vips_morph ()</h3>
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<pre class="programlisting"><span class="returnvalue">int</span>
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vips_morph (<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *in</code></em>,
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<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> **out</code></em>,
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<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *mask</code></em>,
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<em class="parameter"><code><a class="link" href="libvips-morphology.html#VipsOperationMorphology" title="enum VipsOperationMorphology"><span class="type">VipsOperationMorphology</span></a> morph</code></em>,
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<em class="parameter"><code>...</code></em>);</pre>
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<p>Performs a morphological operation on <em class="parameter"><code>in</code></em>
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using <em class="parameter"><code>mask</code></em>
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as a
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structuring element. </p>
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<p>The image should have 0 (black) for no object and 255
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(non-zero) for an object. Note that this is the reverse of the usual
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convention for these operations, but more convenient when combined with the
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boolean operators. The output image is the same
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size as the input image: edge pxels are made by expanding the input image
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as necessary.
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</p>
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<p>
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Mask coefficients can be either 0 (for object) or 255 (for background)
165
as necessary.</p>
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<p>Mask coefficients can be either 0 (for object) or 255 (for background)
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or 128 (for do not care). The origin of the mask is at location
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(m.xsize / 2, m.ysize / 2), integer division. All algorithms have been
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169
based on the book "Fundamentals of Digital Image Processing" by A. Jain,
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pp 384-388, Prentice-Hall, 1989.
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</p>
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<p>
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For <span class="type">VIPS_OPERATION_MOPHOLOGY_ERODE</span>,
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pp 384-388, Prentice-Hall, 1989. </p>
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<p>For <span class="type">VIPS_OPERATION_MOPHOLOGY_ERODE</span>,
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172
the whole mask must match for the output pixel to be
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set, that is, the result is the logical AND of the selected input pixels.
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</p>
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<p>
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For <span class="type">VIPS_OPERATION_MOPHOLOGY_DILATE</span>,
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set, that is, the result is the logical AND of the selected input pixels.</p>
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<p>For <span class="type">VIPS_OPERATION_MOPHOLOGY_DILATE</span>,
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the output pixel is set if any part of the mask
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matches, that is, the result is the logical OR of the selected input pixels.
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</p>
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<p>
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See the boolean operations <a class="link" href="libvips-arithmetic.html#vips-andimage" title="vips_andimage ()"><code class="function">vips_andimage()</code></a>, <a class="link" href="libvips-arithmetic.html#vips-orimage" title="vips_orimage ()"><code class="function">vips_orimage()</code></a> and
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<a class="link" href="libvips-arithmetic.html#vips-eorimage" title="vips_eorimage ()"><code class="function">vips_eorimage()</code></a>
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for analogues of the usual set difference and set union operations.
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</p>
201
<p>
202
Operations are performed using the processor's vector unit,
203
if possible. Disable this with --vips-novector or IM_NOVECTOR.
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</p>
205
<div class="variablelist"><table border="0" class="variablelist">
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matches, that is, the result is the logical OR of the selected input pixels.</p>
177
<p>See the boolean operations <a class="link" href="libvips-arithmetic.html#vips-andimage" title="vips_andimage ()"><code class="function">vips_andimage()</code></a>, <a class="link" href="libvips-arithmetic.html#vips-orimage" title="vips_orimage ()"><code class="function">vips_orimage()</code></a> and
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<a class="link" href="libvips-arithmetic.html#vips-eorimage" title="vips_eorimage ()"><code class="function">vips_eorimage()</code></a>
179
for analogues of the usual set difference and set union operations.</p>
180
<p>Operations are performed using the processor's vector unit,
181
if possible. Disable this with --vips-novector or IM_NOVECTOR.</p>
182
<div class="refsect3">
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<a name="id-1.3.11.9.2.11"></a><h4>Parameters</h4>
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<div class="informaltable"><table width="100%" border="0">
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<colgroup>
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<col align="left" valign="top">
208
<col>
186
<col width="150px" class="parameters_name">
187
<col class="parameters_description">
188
<col width="200px" class="parameters_annotations">
209
189
</colgroup>
210
190
<tbody>
211
191
<tr>
212
<td><p><span class="term"><em class="parameter"><code>in</code></em> :</span></p></td>
213
<td>input image</td>
214
</tr>
215
<tr>
216
<td><p><span class="term"><em class="parameter"><code>out</code></em> :</span></p></td>
217
<td>output image</td>
218
</tr>
219
<tr>
220
<td><p><span class="term"><em class="parameter"><code>mask</code></em> :</span></p></td>
221
<td>morphology with this mask</td>
222
</tr>
223
<tr>
224
<td><p><span class="term"><em class="parameter"><code>morph</code></em> :</span></p></td>
225
<td>operation to perform</td>
226
</tr>
227
<tr>
228
<td><p><span class="term"><em class="parameter"><code>...</code></em> :</span></p></td>
229
<td>
230
<code class="literal">NULL</code>-terminated list of optional named arguments</td>
231
</tr>
232
<tr>
233
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
234
<td>0 on success, -1 on error</td>
192
<td class="parameter_name"><p>in</p></td>
193
<td class="parameter_description"><p>input image</p></td>
194
<td class="parameter_annotations"> </td>
195
</tr>
196
<tr>
197
<td class="parameter_name"><p>out</p></td>
198
<td class="parameter_description"><p>output image</p></td>
199
<td class="parameter_annotations"> </td>
200
</tr>
201
<tr>
202
<td class="parameter_name"><p>mask</p></td>
203
<td class="parameter_description"><p>morphology with this mask</p></td>
204
<td class="parameter_annotations"> </td>
205
</tr>
206
<tr>
207
<td class="parameter_name"><p>morph</p></td>
208
<td class="parameter_description"><p>operation to perform</p></td>
209
<td class="parameter_annotations"> </td>
210
</tr>
211
<tr>
212
<td class="parameter_name"><p>...</p></td>
213
<td class="parameter_description"><p><a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>-terminated list of optional named arguments</p></td>
214
<td class="parameter_annotations"> </td>
235
215
</tr>
236
216
</tbody>
237
217
</table></div>
238
218
</div>
219
<div class="refsect3">
220
<a name="id-1.3.11.9.2.12"></a><h4>Returns</h4>
221
<p> 0 on success, -1 on error</p>
222
<p></p>
223
</div>
224
</div>
239
225
<hr>
240
226
<div class="refsect2">
241
<a name="vips-rank"></a><h3>vips_rank ()</h3>
242
<pre class="programlisting"><span class="returnvalue">int</span> vips_rank (<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *in</code></em>,
243
<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> **out</code></em>,
244
<em class="parameter"><code><span class="type">int</span> width</code></em>,
245
<em class="parameter"><code><span class="type">int</span> height</code></em>,
246
<em class="parameter"><code><span class="type">int</span> index</code></em>,
247
<em class="parameter"><code>...</code></em>);</pre>
248
<p>
249
<a class="link" href="libvips-morphology.html#vips-rank" title="vips_rank ()"><code class="function">vips_rank()</code></a> does rank filtering on an image. A window of size <em class="parameter"><code>width</code></em> by
250
<em class="parameter"><code>height</code></em> is passed over the image. At each position, the pixels inside the
251
window are sorted into ascending order and the pixel at position <em class="parameter"><code>index</code></em> is
252
output. <em class="parameter"><code>index</code></em> numbers from 0.
253
</p>
254
<p>
255
It works for any non-complex image type, with any number of bands.
227
<a name="vips-rank"></a><h3>vips_rank ()</h3>
228
<pre class="programlisting"><span class="returnvalue">int</span>
229
vips_rank (<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *in</code></em>,
230
<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> **out</code></em>,
231
<em class="parameter"><code><span class="type">int</span> width</code></em>,
232
<em class="parameter"><code><span class="type">int</span> height</code></em>,
233
<em class="parameter"><code><span class="type">int</span> index</code></em>,
234
<em class="parameter"><code>...</code></em>);</pre>
235
<p>vips_rank() does rank filtering on an image. A window of size <em class="parameter"><code>width</code></em>
236
by
237
<em class="parameter"><code>height</code></em>
238
is passed over the image. At each position, the pixels inside the
239
window are sorted into ascending order and the pixel at position <em class="parameter"><code>index</code></em>
240
is
241
output. <em class="parameter"><code>index</code></em>
242
numbers from 0.</p>
243
<p>It works for any non-complex image type, with any number of bands.
256
244
The input is expanded by copying edge pixels before performing the
257
245
operation so that the output image has the same size as the input.
258
Edge pixels in the output image are therefore only approximate.
259
</p>
260
<p>
261
For a median filter with mask size m (3 for 3x3, 5 for 5x5, etc.) use
262
</p>
263
<p>
264
vips_rank( in, out, m, m, m * m / 2 );
265
</p>
266
<p>
267
The special cases n == 0 and n == m * m - 1 are useful dilate and
268
expand operators.
269
</p>
270
<p>
271
See also: <a class="link" href="libvips-convolution.html#vips-conv" title="vips_conv ()"><code class="function">vips_conv()</code></a>, <a class="link" href="libvips-morphology.html#vips-median" title="vips_median ()"><code class="function">vips_median()</code></a>, <code class="function">vips_spcor()</code>.
272
</p>
273
<div class="variablelist"><table border="0" class="variablelist">
246
Edge pixels in the output image are therefore only approximate.</p>
247
<p>For a median filter with mask size m (3 for 3x3, 5 for 5x5, etc.) use</p>
248
<p> vips_rank( in, out, m, m, m * m / 2 );</p>
249
<p>The special cases n == 0 and n == m * m - 1 are useful dilate and
250
expand operators.</p>
251
<p>See also: <a class="link" href="libvips-convolution.html#vips-conv" title="vips_conv ()"><code class="function">vips_conv()</code></a>, <a class="link" href="libvips-morphology.html#vips-median" title="vips_median ()"><code class="function">vips_median()</code></a>, <code class="function">vips_spcor()</code>.</p>
252
<div class="refsect3">
253
<a name="id-1.3.11.9.3.10"></a><h4>Parameters</h4>
254
<div class="informaltable"><table width="100%" border="0">
274
255
<colgroup>
275
<col align="left" valign="top">
276
<col>
256
<col width="150px" class="parameters_name">
257
<col class="parameters_description">
258
<col width="200px" class="parameters_annotations">
277
259
</colgroup>
278
260
<tbody>
279
261
<tr>
280
<td><p><span class="term"><em class="parameter"><code>in</code></em> :</span></p></td>
281
<td>input image</td>
282
</tr>
283
<tr>
284
<td><p><span class="term"><em class="parameter"><code>out</code></em> :</span></p></td>
285
<td>output image</td>
286
</tr>
287
<tr>
288
<td><p><span class="term"><em class="parameter"><code>width</code></em> :</span></p></td>
289
<td>width of region</td>
290
</tr>
291
<tr>
292
<td><p><span class="term"><em class="parameter"><code>height</code></em> :</span></p></td>
293
<td>height of region</td>
294
</tr>
295
<tr>
296
<td><p><span class="term"><em class="parameter"><code>index</code></em> :</span></p></td>
297
<td>select pixel</td>
298
</tr>
299
<tr>
300
<td><p><span class="term"><em class="parameter"><code>...</code></em> :</span></p></td>
301
<td>
302
<code class="literal">NULL</code>-terminated list of optional named arguments</td>
303
</tr>
304
<tr>
305
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
306
<td>0 on success, -1 on error</td>
262
<td class="parameter_name"><p>in</p></td>
263
<td class="parameter_description"><p>input image</p></td>
264
<td class="parameter_annotations"> </td>
265
</tr>
266
<tr>
267
<td class="parameter_name"><p>out</p></td>
268
<td class="parameter_description"><p>output image</p></td>
269
<td class="parameter_annotations"> </td>
270
</tr>
271
<tr>
272
<td class="parameter_name"><p>width</p></td>
273
<td class="parameter_description"><p>width of region</p></td>
274
<td class="parameter_annotations"> </td>
275
</tr>
276
<tr>
277
<td class="parameter_name"><p>height</p></td>
278
<td class="parameter_description"><p>height of region</p></td>
279
<td class="parameter_annotations"> </td>
280
</tr>
281
<tr>
282
<td class="parameter_name"><p>index</p></td>
283
<td class="parameter_description"><p>select pixel</p></td>
284
<td class="parameter_annotations"> </td>
285
</tr>
286
<tr>
287
<td class="parameter_name"><p>...</p></td>
288
<td class="parameter_description"><p><a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>-terminated list of optional named arguments</p></td>
289
<td class="parameter_annotations"> </td>
307
290
</tr>
308
291
</tbody>
309
292
</table></div>
310
293
</div>
294
<div class="refsect3">
295
<a name="id-1.3.11.9.3.11"></a><h4>Returns</h4>
296
<p> 0 on success, -1 on error</p>
297
<p></p>
298
</div>
299
</div>
311
300
<hr>
312
301
<div class="refsect2">
313
<a name="vips-countlines"></a><h3>vips_countlines ()</h3>
314
<pre class="programlisting"><span class="returnvalue">int</span> vips_countlines (<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *in</code></em>,
315
<em class="parameter"><code><span class="type">double</span> *nolines</code></em>,
316
<em class="parameter"><code><a class="link" href="libvips-conversion.html#VipsDirection" title="enum VipsDirection"><span class="type">VipsDirection</span></a> direction</code></em>,
317
<em class="parameter"><code>...</code></em>);</pre>
318
<p>
319
Function which calculates the number of transitions
302
<a name="vips-countlines"></a><h3>vips_countlines ()</h3>
303
<pre class="programlisting"><span class="returnvalue">int</span>
304
vips_countlines (<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *in</code></em>,
305
<em class="parameter"><code><span class="type">double</span> *nolines</code></em>,
306
<em class="parameter"><code><a class="link" href="libvips-conversion.html#VipsDirection" title="enum VipsDirection"><span class="type">VipsDirection</span></a> direction</code></em>,
307
<em class="parameter"><code>...</code></em>);</pre>
308
<p>Function which calculates the number of transitions
320
309
between black and white for the horizontal or the vertical
321
310
direction of an image. black<128 , white>=128
322
311
The function calculates the number of transitions for all
323
312
Xsize or Ysize and returns the mean of the result
324
Input should be one band, 8-bit.
325
</p>
326
<p>
327
See also: <a class="link" href="libvips-morphology.html#vips-morph" title="vips_morph ()"><code class="function">vips_morph()</code></a>, <code class="function">vips_zerox()</code>, <a class="link" href="libvips-convolution.html#vips-conv" title="vips_conv ()"><code class="function">vips_conv()</code></a>.
328
</p>
329
<div class="variablelist"><table border="0" class="variablelist">
330
<colgroup>
331
<col align="left" valign="top">
332
<col>
333
</colgroup>
334
<tbody>
335
<tr>
336
<td><p><span class="term"><em class="parameter"><code>in</code></em> :</span></p></td>
337
<td>input image</td>
338
</tr>
339
<tr>
340
<td><p><span class="term"><em class="parameter"><code>nolines</code></em> :</span></p></td>
341
<td>output average number of lines</td>
342
</tr>
343
<tr>
344
<td><p><span class="term"><em class="parameter"><code>direction</code></em> :</span></p></td>
345
<td>count lines horizontally or vertically</td>
346
</tr>
347
<tr>
348
<td><p><span class="term"><em class="parameter"><code>...</code></em> :</span></p></td>
349
<td>
350
<code class="literal">NULL</code>-terminated list of optional named arguments</td>
351
</tr>
352
<tr>
353
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
354
<td>0 on success, -1 on error.</td>
355
</tr>
356
</tbody>
357
</table></div>
358
</div>
359
<hr>
360
<div class="refsect2">
361
<a name="vips-median"></a><h3>vips_median ()</h3>
362
<pre class="programlisting"><span class="returnvalue">int</span> vips_median (<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *in</code></em>,
363
<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> **out</code></em>,
364
<em class="parameter"><code><span class="type">int</span> size</code></em>,
365
<em class="parameter"><code>...</code></em>);</pre>
366
<p>
367
A convenience function equivalent to:
368
</p>
369
<p>
370
vips_rank( in, out, size, size, (size * size) / 2 );
371
</p>
372
<p>
373
See also: <a class="link" href="libvips-morphology.html#vips-rank" title="vips_rank ()"><code class="function">vips_rank()</code></a>.
374
</p>
375
<div class="variablelist"><table border="0" class="variablelist">
376
<colgroup>
377
<col align="left" valign="top">
378
<col>
379
</colgroup>
380
<tbody>
381
<tr>
382
<td><p><span class="term"><em class="parameter"><code>in</code></em> :</span></p></td>
383
<td>input image</td>
384
</tr>
385
<tr>
386
<td><p><span class="term"><em class="parameter"><code>out</code></em> :</span></p></td>
387
<td>output image</td>
388
</tr>
389
<tr>
390
<td><p><span class="term"><em class="parameter"><code>size</code></em> :</span></p></td>
391
<td>size of region</td>
392
</tr>
393
<tr>
394
<td><p><span class="term"><em class="parameter"><code>...</code></em> :</span></p></td>
395
<td>
396
<code class="literal">NULL</code>-terminated list of optional named arguments</td>
397
</tr>
398
<tr>
399
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
400
<td>0 on success, -1 on error</td>
401
</tr>
402
</tbody>
403
</table></div>
404
</div>
405
<hr>
406
<div class="refsect2">
407
<a name="im-label-regions"></a><h3>im_label_regions ()</h3>
408
<pre class="programlisting"><span class="returnvalue">int</span> im_label_regions (<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *test</code></em>,
409
<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *mask</code></em>,
410
<em class="parameter"><code><span class="type">int</span> *segments</code></em>);</pre>
411
<p>
412
<a class="link" href="libvips-morphology.html#im-label-regions" title="im_label_regions ()"><code class="function">im_label_regions()</code></a> repeatedly scans <em class="parameter"><code>test</code></em> for regions of 4-connected pixels
313
Input should be one band, 8-bit.</p>
314
<p>See also: <a class="link" href="libvips-morphology.html#vips-morph" title="vips_morph ()"><code class="function">vips_morph()</code></a>, <code class="function">vips_zerox()</code>, <a class="link" href="libvips-convolution.html#vips-conv" title="vips_conv ()"><code class="function">vips_conv()</code></a>.</p>
315
<div class="refsect3">
316
<a name="id-1.3.11.9.4.6"></a><h4>Parameters</h4>
317
<div class="informaltable"><table width="100%" border="0">
318
<colgroup>
319
<col width="150px" class="parameters_name">
320
<col class="parameters_description">
321
<col width="200px" class="parameters_annotations">
322
</colgroup>
323
<tbody>
324
<tr>
325
<td class="parameter_name"><p>in</p></td>
326
<td class="parameter_description"><p>input image</p></td>
327
<td class="parameter_annotations"> </td>
328
</tr>
329
<tr>
330
<td class="parameter_name"><p>nolines</p></td>
331
<td class="parameter_description"><p>output average number of lines</p></td>
332
<td class="parameter_annotations"> </td>
333
</tr>
334
<tr>
335
<td class="parameter_name"><p>direction</p></td>
336
<td class="parameter_description"><p>count lines horizontally or vertically</p></td>
337
<td class="parameter_annotations"> </td>
338
</tr>
339
<tr>
340
<td class="parameter_name"><p>...</p></td>
341
<td class="parameter_description"><p><a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>-terminated list of optional named arguments</p></td>
342
<td class="parameter_annotations"> </td>
343
</tr>
344
</tbody>
345
</table></div>
346
</div>
347
<div class="refsect3">
348
<a name="id-1.3.11.9.4.7"></a><h4>Returns</h4>
349
<p> 0 on success, -1 on error.</p>
350
<p></p>
351
</div>
352
</div>
353
<hr>
354
<div class="refsect2">
355
<a name="vips-median"></a><h3>vips_median ()</h3>
356
<pre class="programlisting"><span class="returnvalue">int</span>
357
vips_median (<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *in</code></em>,
358
<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> **out</code></em>,
359
<em class="parameter"><code><span class="type">int</span> size</code></em>,
360
<em class="parameter"><code>...</code></em>);</pre>
361
<p>A convenience function equivalent to:</p>
362
<p> vips_rank( in, out, size, size, (size * size) / 2 );</p>
363
<p>See also: <a class="link" href="libvips-morphology.html#vips-rank" title="vips_rank ()"><code class="function">vips_rank()</code></a>.</p>
364
<div class="refsect3">
365
<a name="id-1.3.11.9.5.7"></a><h4>Parameters</h4>
366
<div class="informaltable"><table width="100%" border="0">
367
<colgroup>
368
<col width="150px" class="parameters_name">
369
<col class="parameters_description">
370
<col width="200px" class="parameters_annotations">
371
</colgroup>
372
<tbody>
373
<tr>
374
<td class="parameter_name"><p>in</p></td>
375
<td class="parameter_description"><p>input image</p></td>
376
<td class="parameter_annotations"> </td>
377
</tr>
378
<tr>
379
<td class="parameter_name"><p>out</p></td>
380
<td class="parameter_description"><p>output image</p></td>
381
<td class="parameter_annotations"> </td>
382
</tr>
383
<tr>
384
<td class="parameter_name"><p>size</p></td>
385
<td class="parameter_description"><p>size of region</p></td>
386
<td class="parameter_annotations"> </td>
387
</tr>
388
<tr>
389
<td class="parameter_name"><p>...</p></td>
390
<td class="parameter_description"><p><a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>-terminated list of optional named arguments</p></td>
391
<td class="parameter_annotations"> </td>
392
</tr>
393
</tbody>
394
</table></div>
395
</div>
396
<div class="refsect3">
397
<a name="id-1.3.11.9.5.8"></a><h4>Returns</h4>
398
<p> 0 on success, -1 on error</p>
399
<p></p>
400
</div>
401
</div>
402
<hr>
403
<div class="refsect2">
404
<a name="im-label-regions"></a><h3>im_label_regions ()</h3>
405
<pre class="programlisting"><span class="returnvalue">int</span>
406
im_label_regions (<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *test</code></em>,
407
<em class="parameter"><code><a class="link" href="VipsImage.html" title="VipsImage"><span class="type">VipsImage</span></a> *mask</code></em>,
408
<em class="parameter"><code><span class="type">int</span> *segments</code></em>);</pre>
409
<p>im_label_regions() repeatedly scans <em class="parameter"><code>test</code></em>
410
for regions of 4-connected pixels
413
411
with the same pixel value. Every time a region is discovered, those
414
pixels are marked in <em class="parameter"><code>mask</code></em> with a unique serial number. Once all pixels
415
have been labelled, the operation returns, setting <em class="parameter"><code>segments</code></em> to the number
416
of discrete regions which were detected.
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</p>
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<p>
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<em class="parameter"><code>mask</code></em> is always a 1-band <code class="literal">IM_BANDFMT_UINT</code> image of the same dimensions as
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<em class="parameter"><code>test</code></em>.
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</p>
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<p>
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This operation is useful for, for example, blob counting. You can use the
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pixels are marked in <em class="parameter"><code>mask</code></em>
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with a unique serial number. Once all pixels
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have been labelled, the operation returns, setting <em class="parameter"><code>segments</code></em>
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to the number
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of discrete regions which were detected.</p>
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<p><em class="parameter"><code>mask</code></em>
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is always a 1-band <code class="literal">IM_BANDFMT_UINT</code> image of the same dimensions as
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<em class="parameter"><code>test</code></em>
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.</p>
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<p>This operation is useful for, for example, blob counting. You can use the
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morphological operators to detect and isolate a series of objects, then use
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<a class="link" href="libvips-morphology.html#im-label-regions" title="im_label_regions ()"><code class="function">im_label_regions()</code></a> to number them all.
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</p>
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<p>
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Use <code class="function">im_histindexed()</code> to (for example) find blob coordinates.
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</p>
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<p>
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See also: <code class="function">im_histindexed()</code>
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</p>
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<div class="variablelist"><table border="0" class="variablelist">
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<colgroup>
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<col align="left" valign="top">
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<col>
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</colgroup>
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<tbody>
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<tr>
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<td><p><span class="term"><em class="parameter"><code>test</code></em> :</span></p></td>
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<td>image to test</td>
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</tr>
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<tr>
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<td><p><span class="term"><em class="parameter"><code>mask</code></em> :</span></p></td>
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<td>write labelled regions here</td>
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</tr>
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<tr>
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<td><p><span class="term"><em class="parameter"><code>segments</code></em> :</span></p></td>
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<td>return number of regions here</td>
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</tr>
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<tr>
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<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
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<td>0 on success, -1 on error.</td>
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</tr>
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</tbody>
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</table></div>
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<a class="link" href="libvips-morphology.html#im-label-regions" title="im_label_regions ()"><code class="function">im_label_regions()</code></a> to number them all.</p>
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<p>Use <code class="function">im_histindexed()</code> to (for example) find blob coordinates.</p>
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<p>See also: <code class="function">im_histindexed()</code></p>
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<div class="refsect3">
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<a name="id-1.3.11.9.6.9"></a><h4>Parameters</h4>
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<div class="informaltable"><table width="100%" border="0">
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<colgroup>
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<col width="150px" class="parameters_name">
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<col class="parameters_description">
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<col width="200px" class="parameters_annotations">
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</colgroup>
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<tbody>
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<tr>
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<td class="parameter_name"><p>test</p></td>
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<td class="parameter_description"><p>image to test</p></td>
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<td class="parameter_annotations"> </td>
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</tr>
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<tr>
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<td class="parameter_name"><p>mask</p></td>
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<td class="parameter_description"><p>write labelled regions here</p></td>
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<td class="parameter_annotations"> </td>
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</tr>
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<tr>
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<td class="parameter_name"><p>segments</p></td>
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<td class="parameter_description"><p>return number of regions here</p></td>
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<td class="parameter_annotations"> </td>
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</tr>
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</tbody>
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</table></div>
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</div>
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<div class="refsect3">
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<a name="id-1.3.11.9.6.10"></a><h4>Returns</h4>
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<p> 0 on success, -1 on error.</p>
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<p></p>
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</div>
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</div>
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</div>
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<div class="refsect1">
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<a name="libvips-morphology.other_details"></a><h2>Types and Values</h2>
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<div class="refsect2">
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<a name="VipsOperationMorphology"></a><h3>enum VipsOperationMorphology</h3>
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<p>More like hit-miss, really. </p>
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<p>See also: <a class="link" href="libvips-morphology.html#vips-morph" title="vips_morph ()"><code class="function">vips_morph()</code></a>.</p>
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<div class="refsect3">
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<a name="id-1.3.11.10.2.5"></a><h4>Members</h4>
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<div class="informaltable"><table width="100%" border="0">
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<colgroup>
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<col width="300px" class="enum_members_name">
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<col class="enum_members_description">
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<col width="200px" class="enum_members_annotations">
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</colgroup>
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<tbody>
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<tr>
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<td class="enum_member_name"><p><a name="VIPS-OPERATION-MORPHOLOGY-ERODE:CAPS"></a>VIPS_OPERATION_MORPHOLOGY_ERODE</p></td>
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<td class="enum_member_description">
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<p>true if all set</p>
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</td>
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<td class="enum_member_annotations"> </td>
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</tr>
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<tr>
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<td class="enum_member_name"><p><a name="VIPS-OPERATION-MORPHOLOGY-DILATE:CAPS"></a>VIPS_OPERATION_MORPHOLOGY_DILATE</p></td>
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<td class="enum_member_description">
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<p>true if one set</p>
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</td>
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<td class="enum_member_annotations"> </td>
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</tr>
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<tr>
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<td class="enum_member_name"><p><a name="VIPS-OPERATION-MORPHOLOGY-LAST:CAPS"></a>VIPS_OPERATION_MORPHOLOGY_LAST</p></td>
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<td class="enum_member_description"> </td>
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<td class="enum_member_annotations"> </td>
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</tr>
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</tbody>
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</table></div>
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</div>
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</div>
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</div>
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<div class="refsect1">
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</div>
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<div class="footer">
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