title: Cropping Concave polygon from Image using Opencv python
body: <p>How can I crop a concave polygon from an image. My Input image look like 
  <img src="https://i.stack.imgur.com/qrJTd.png" alt="this">.</p>
  
  <p>and the coordinates of <strong>closed</strong> polygon are 
  [10,150],[150,100],[300,150],[350,100],[310,20],[35,10]. I want region bounded by concave polygon to be cropped using opencv. I searched for other similar questions but I did not able to find correct answer. That's why I am asking it ? Can you help me.</p>
  
  <p>Any help would be highly appreciated.!!!</p>