title: Count the number of fingers
body: <p>This is an image of convex hull of hand plus defect points:</p>
  
  <p><img src="https://i.stack.imgur.com/ydelH.png" alt="Image"></p>
  
  <p>Where:</p>
  
  <ul>
  <li>Blue circles: start points</li>
  <li>Red circles: end points</li>
  <li>Green circles: depth points.</li>
  </ul>
  
  <p>I want to define the finger counter from defect points. Does any one have any idea to get the number of fingers?</p>