">;</span>
<span class="k">end</span>
</pre></div>


<p>which computes a matrix <code/>M</code> whose value are equal to the
number of overlapping extremal regions. Next, we use <code/>M</code>
and <code/>contour</code> to display the region boundaries:</p>

<div class="highlight"><pre><span class="n">figure</span><span class="p">(</span><span class="mi">2</span><span class="p">)</span> <span class="p">;</span>
<span class="n">clf</span> <span class="p">;</span> <span class="n">imagesc</span><span class="p"