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<td class="title">Dilations And Erosions</td>
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<h1>mmero
<br>
<span class="subtitle">Erode an image by a structuring element.
</span>
</h1>
<div class="synopsis">
<H2>Synopsis</H2>
<div class="H2">
<div class="prototype">y =
<span class="fun">mmero</span>(
<span class="par">f</span>,
<span class="par">b</span> = None
)
</div>
<p>Implemented in
<b>Python.</b>
</p>
<div class="input">
<H3>Input</H3>
<div class="H3">
<table class="deflist">
<tbody valign="baseline">
<tr>
<td class="term"><span class="par">f</span></td>
<td class="def"><span class="type"><a href="../mmtypes/mmImage.html">Image</a></span> Gray-scale (uint8 or uint16) or binary image.
</td>
</tr>
<tr>
<td class="term"><span class="par">b</span></td>
<td class="def"><span class="type"><a href="../mmtypes/mmSe.html">Structuring Element</a></span><p>Default:
<code>None</code> (3x3 elementary cross)
</p></td>
</tr>
</tbody>
</table>
</div>
</div>
<div class="output">
<H3>Output</H3>
<div class="H3">
<table class="deflist">
<tbody valign="baseline">
<tr>
<td class="term"><span class="par">y</span></td>
<td class="def"><span class="type"><a href="../mmtypes/mmImage.html">Image</a></span></td>
</tr>
</tbody>
</table>
</div>
</div>
</div>
</div>
<div class="descr">
<H2>Description</H2>
<div class="H2">
<p>
<span class="fun">mmero</span> performs the erosion of the image
<code>f</code> by the structuring element
<code>b</code>. Erosion is a neighbourhood operator that compairs locally
<code>b</code> with
<code>f</code>, according to an inclusion rule. Since erosion is a fundamental operator to the construction of all other morphological operators, it is also called an elementary operator of Mathematical Morphology. When
<code>f</code> is a gray-scale image ,
<code>b</code> may be a flat or non-flat structuring element.
</p>
</div>
</div>
<div class="examples">
<H2>Examples</H2>
<div class="H2">
<p>
<div class="bridge">Numerical examples</div>
<div class="example">
<div class="listing">
<pre class="user">>>> f=mmbinary([
[1, 1, 1, 0, 0, 1, 1],
[1, 0, 1, 1, 1, 0, 0],
[0, 0, 0, 0, 1, 0, 0]])</pre>
<pre class="computer"></pre>
<pre class="user">>>> b=mmbinary([1, 1, 0])</pre>
<pre class="computer"></pre>
<pre class="user">>>> mmero(f,b)</pre>
<pre class="computer">array([[1, 1, 1, 0, 0, 0, 1],
[1, 0, 0, 1, 1, 0, 0],
[0, 0, 0, 0, 0, 0, 0]],'1')</pre>
<pre class="user">>>> f=uint8([
[ 0, 1, 2, 50, 4, 5],
[ 2, 3, 4, 0, 0, 0],
[12, 255, 14, 15, 16, 17]])</pre>
<pre class="computer"></pre>
<pre class="user">>>> mmero(f,b)</pre>
<pre class="computer">array([[ 0, 0, 1, 2, 4, 4],
[ 2, 2, 3, 0, 0, 0],
[12, 12, 14, 14, 15, 16]],'b')</pre>
</div>
</div>
<div class="example">
<div class="listing">
<pre class="user">>>> f=mmbinary(mmreadgray('blob.tif'))</pre>
<pre class="computer"></pre>
<pre class="user">>>> bimg=mmbinary(mmreadgray('blob1.tif'))</pre>
<pre class="computer"></pre>
<pre class="user">>>> b=mmimg2se(bimg)</pre>
<pre class="computer"></pre>
<pre class="user">>>> g=mmero(f,b)</pre>
<pre class="computer"></pre>
<pre class="user">>>> mmshow(f)</pre>
<pre class="computer"></pre>
<pre class="user">>>> mmshow(g)</pre>
<pre class="computer"></pre>
<pre class="user">>>> mmshow(g,mmgradm(f))</pre>
<pre class="computer"></pre>
</div>
<table class="images">
<tbody align="center">
<tr class="image" valign="bottom">
<td><img width="239" src="../images/img_mmero_001.jpg"></td>
<td><img width="239" src="../images/img_mmero_002.jpg"></td>
<td class="spare"></td>
</tr>
<tr class="title" valign="baseline">
<td><a href="../images/img_mmero_001.jpg">f</a></td>
<td><a href="../images/img_mmero_002.jpg">g</a></td>
<td class="spare"></td>
</tr>
</tbody>
</table>
<table class="images">
<tbody align="center">
<tr class="image" valign="bottom">
<td><img width="239" src="../images/img_mmero_003.jpg"></td>
<td class="spare"></td>
</tr>
<tr class="title" valign="baseline">
<td><a href="../images/img_mmero_003.jpg">g,mmgradm(f)</a></td>
<td class="spare"></td>
</tr>
</tbody>
</table>
</div>
<div class="bridge">Gray-scale image:</div>
<div class="example">
<div class="listing">
<pre class="user">>>> f=mmreadgray('pcb_gray.tif')</pre>
<pre class="computer"></pre>
<pre class="user">>>> b=mmsedisk(3)</pre>
<pre class="computer"></pre>
<pre class="user">>>> mmshow(f)</pre>
<pre class="computer"></pre>
<pre class="user">>>> mmshow(mmero(f,b))</pre>
<pre class="computer"></pre>
</div>
<table class="images">
<tbody align="center">
<tr class="image" valign="bottom">
<td><img width="256" src="../images/img_mmero_004.jpg"></td>
<td><img width="256" src="../images/img_mmero_005.jpg"></td>
<td class="spare"></td>
</tr>
<tr class="title" valign="baseline">
<td><a href="../images/img_mmero_004.jpg">f</a></td>
<td><a href="../images/img_mmero_005.jpg">mmero(f,b)</a></td>
<td class="spare"></td>
</tr>
</tbody>
</table>
</div>
</p>
</div>
</div>
<div class="equation">
<H2>Equation</H2>
<div class="H2">
<p>
<div class="bridge">Flat structuring element:</div>
<div class="eqfig">
<img src="../images/eq_mmero001.png">
</div>
<div class="bridge">Non-flat structuring element:</div>
<div class="eqfig">
<img src="../images/eq_mmero002.png">
</div>Where
<div class="eqfig">
<img src="../images/eq_mmero003.png">
</div>
</p>
</div>
</div>
<div class="sourcecode">
<H2>Source Code</H2>
<div class="H2">
<pre class="listing">
def mmero(f, b=None):
if b is None: b = mmsecross()
y = mmneg(mmdil(mmneg(f),mmsereflect(b)))
return y
</pre>
</div>
</div>
<div class="seealso">
<H2>See also</H2>
<div class="H2">
<table class="deflist">
<tbody valign="baseline">
<tr>
<td class="term"><a href="../morph/mmfreedom.html">mmfreedom</a></td>
<td class="def">Control automatic data type conversion.</td>
</tr>
<tr>
<td class="term"><a href="../morph/mmdil.html">mmdil</a></td>
<td class="def">Dilate an image by a structuring element.</td>
</tr>
<tr>
<td class="term"><a href="../morph/mmimg2se.html">mmimg2se</a></td>
<td class="def">Create a structuring element from a pair of images.</td>
</tr>
<tr>
<td class="term"><a href="../morph/mmsebox.html">mmsebox</a></td>
<td class="def">Create a box structuring element.</td>
</tr>
<tr>
<td class="term"><a href="../morph/mmsecross.html">mmsecross</a></td>
<td class="def">Diamond structuring element and elementary 3x3 cross.</td>
</tr>
<tr>
<td class="term"><a href="../morph/mmcero.html">mmcero</a></td>
<td class="def">Erode an image conditionally.</td>
</tr>
<tr>
<td class="term"><a href="../morph/mmdist.html">mmdist</a></td>
<td class="def">Distance transform.</td>
</tr>
<tr>
<td class="term"><a href="../morph/mmsesum.html">mmsesum</a></td>
<td class="def">N-1 iterative Minkowski additions</td>
</tr>
</tbody>
</table>
</div>
</div>
<div class="seealso">
<H2>See also</H2>
<div class="H2">
<table class="deflist">
<tbody valign="baseline">
<tr>
<td class="term"><a href="../morph/mmfreedom.html">mmfreedom</a></td>
<td class="def">Control automatic data type conversion.</td>
</tr>
<tr>
<td class="term"><a href="../morph/mmdil.html">mmdil</a></td>
<td class="def">Dilate an image by a structuring element.</td>
</tr>
<tr>
<td class="term"><a href="../morph/mmsecross.html">mmsecross</a></td>
<td class="def">Diamond structuring element and elementary 3x3 cross.</td>
</tr>
<tr>
<td class="term"><a href="../morph/mmcero.html">mmcero</a></td>
<td class="def">Erode an image conditionally.</td>
</tr>
<tr>
<td class="term"><a href="../morph/mmdist.html">mmdist</a></td>
<td class="def">Distance transform.</td>
</tr>
</tbody>
</table>
</div>
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<td class="copyright">Copyright (c) 2003, Roberto A. Lotufo, UNICAMP-University of Campinas; Rubens C. Machado, CenPRA-Renato Archer Research Center.</td>
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distrib
>
Mandriva
>
2010.0
>
i586
>
media
>
contrib-release
>
by-pkgid
>
4a71d9984febeb5a206904a5a379841a
>
files
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684
