title: Opencv get average color of detected object
body: <p>I have a mask of an object I've detected. Now I want to calculate the average color of the object. Is there a way to just check the unmasked pixels? </p>
  
  <p>And what would be the best way to get the average color? </p>
  
  <p>Should I use a Cluster or  get the average g,b and r values ?</p>
  
  <p>(I'm using python 3.5 and opencv 3.1 with extras.)
  Thanks in advance </p>