title: What does this MATLAB function do?
body: <pre><code>function sk=skeleton_finding(x)
  
  % calculate distance transform
  dt=bwdist(~x,'cityblock');
  
  % find the local maximum
  n=[0 1;-1 0;0 -1;1 0];
  sk=dt&gt;0;
  for i=1:4
  sk=sk&amp;(dt&gt;=circshift(dt,n(i,:)));
  end
  </code></pre>
  
  <p>Can someone illustrate with an intuitive image that applies this transform?</p>