title: How to get the external contour of a floorplan in python?
body: <p>What is the best way to get a floorplan external contour?</p>
  
  <p><a href="https://i.stack.imgur.com/1tl6D.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/1tl6D.jpg" alt="enter image description here"></a></p>
  
  <p>Snakes algorithm doesn't work well because some floorplans are too convex.</p>