title: To get the center mask from an image of masks using Python3 and opencv
body: <p>Suppose I have these sets of images:</p>
  <p><a href="https://i.stack.imgur.com/E6AF1.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/E6AF1.png" alt="enter image description here" /></a></p>
  <p>I want to take the center coordinate mask, i.e., the circular one which has the cell:</p>
  <p><a href="https://i.stack.imgur.com/kA5L8.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/kA5L8.png" alt="enter image description here" /></a></p>
  <p>To finally isolate the cell</p>
  <p><a href="https://i.stack.imgur.com/fa3yy.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/fa3yy.png" alt="enter image description here" /></a></p>
  <p>How to achieve these using Python3 and opencv?</p>