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<h1>mmlabel
<br>
<span class="subtitle">Label a binary image.
</span>
</h1>
<div class="synopsis">
<H2>Synopsis</H2>
<div class="H2">
<div class="prototype">y =
<span class="fun">mmlabel</span>(
<span class="par">f</span>,
<span class="par">Bc</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> Binary image.
</td>
</tr>
<tr>
<td class="term"><span class="par">Bc</span></td>
<td class="def"><span class="type"><a href="../mmtypes/mmSe.html">Structuring Element</a></span><p>( connectivity).</p><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><p>If number of labels is less than 65535, the data type is uint16, otherwise it is int32.</p></td>
</tr>
</tbody>
</table>
</div>
</div>
</div>
</div>
<div class="descr">
<H2>Description</H2>
<div class="H2">
<p>
<span class="fun">mmlabel</span> creates the image
<code>y</code> by labeling the connect components of a binary image
<code>f</code>, according to the connectivity defined by the structuring element
<code>Bc</code>. The background pixels (with value 0) are not labeled. The maximum label value in the output image gives the number of its connected components.
</p>
</div>
</div>
<div class="examples">
<H2>Examples</H2>
<div class="H2">
<p>
<div class="bridge">Numerical Example</div>
<div class="example">
<div class="listing">
<pre class="user">>>> f=mmbinary([
[0,1,0,1,1],
[1,0,0,1,0]])</pre>
<pre class="computer"></pre>
<pre class="user">>>> g=mmlabel(f)</pre>
<pre class="computer"></pre>
<pre class="user">>>> print g</pre>
<pre class="computer">[[0 1 0 2 2]
[3 0 0 2 0]]</pre>
</div>
</div>
<div class="bridge">Image Example</div>
<br>The maximum label value gives the number of connected blobs in the image.
<br>
<div class="example">
<div class="listing">
<pre class="user">>>> f = mmreadgray('blob3.tif')</pre>
<pre class="computer"></pre>
<pre class="user">>>> g=mmlabel(f)</pre>
<pre class="computer"></pre>
<pre class="user">>>> nblobs=mmstats(g,'max')</pre>
<pre class="computer"></pre>
<pre class="user">>>> print nblobs</pre>
<pre class="computer">18.0</pre>
<pre class="user">>>> mmshow(f)</pre>
<pre class="computer"></pre>
<pre class="user">>>> mmlblshow(g)</pre>
<pre class="computer"></pre>
</div>
<table class="images">
<tbody align="center">
<tr class="image" valign="bottom">
<td><img width="128" src="../images/img_mmlabel_001.jpg"></td>
<td><img width="128" src="../images/img_mmlabel_002.jpg"></td>
<td class="spare"></td>
</tr>
<tr class="title" valign="baseline">
<td><a href="../images/img_mmlabel_001.jpg">f</a></td>
<td><a href="../images/img_mmlabel_002.jpg">g</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="eqfig">
<img src="../images/eq_mmlabel001.png">
</div>Where
<i>H</i> is the number of image rows, and
<i>y1</i> and
<i>y2</i> are the row and column coordinates respectively.
</p>
</div>
</div>
<div class="sourcecode">
<H2>Source Code</H2>
<div class="H2">
<pre class="listing">
def mmlabel(f, Bc=None):
from Numeric import allclose, ravel, nonzero, array
if Bc is None: Bc = mmsecross()
assert mmisbinary,'Can only label binary image'
zero = mmsubm(f,f) # zero image
faux=f
r = array(zero)
label = 1
y = mmgray( f,'uint16',0) # zero image (output)
while not allclose(faux,0):
x=nonzero(ravel(faux))[0] # get first unlabeled pixel
fmark = array(zero)
fmark.flat[x] = 1 # get the first unlabeled pixel
r = mminfrec( fmark, faux, Bc) # detects all pixels connected to it
faux = mmsubm( faux, r) # remove them from faux
r = mmgray( r,'uint16',label) # label them with the value label
y = mmunion( y, r) # merge them with the labeled image
label = label + 1
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/mmlabelflat.html">mmlabelflat</a></td>
<td class="def">Label the flat zones of gray-scale images.</td>
</tr>
<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/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/mmareaopen.html">mmareaopen</a></td>
<td class="def">Area opening</td>
</tr>
<tr>
<td class="term"><a href="../morph/mmblob.html">mmblob</a></td>
<td class="def">Blob measurements from a labeled image.</td>
</tr>
<tr>
<td class="term"><a href="../morph/mmgrain.html">mmgrain</a></td>
<td class="def">Gray-scale statistics for each labeled region.</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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710
