title: How to fill up the entire internal contour using opencv
body: <p>In the following image, I'm trying to blacken out the internal design band with the name "jupiter"</p>
  
  <p><a href="https://i.stack.imgur.com/QZhKR.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/QZhKR.png" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/FZEpz.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/FZEpz.png" alt="enter image description here"></a></p>
  
  <p>MY DESIRED RESULT IS THE FOLLOWING</p>
  
  <p><a href="https://i.stack.imgur.com/2Cw7p.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/2Cw7p.png" alt="enter image description here"></a></p>
  
  <p>I've tried using RETR_EXTERNAL in and then fillPoly but it only blackens out the "white" portion(the band) of the binary image and not completely as i want it to.</p>
  
  <p>How would I need to improvise to get it to blacken it out completely?</p>
  
  <p><a href="https://i.stack.imgur.com/QtL7k.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/QtL7k.png" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/CWjhQ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/CWjhQ.png" alt="enter image description here"></a></p>