title: How to identify incomplete rectangles in openCV
body: <p>How would I go around identifying and extracting rectangles from an image such as the one shown below. </p>
  
  <p>Note that my rectangles might be incomplete and have some missing edges and some sides might be partial lines.</p>
  
  <p>Thanks !</p>
  
  <p><a href="https://i.stack.imgur.com/cgEPA.png" rel="noreferrer"><img src="https://i.stack.imgur.com/cgEPA.png" alt="image sample"></a></p>