title: OpenCV parallel lines cull
body: <p>I have an algorithm that simply goes through a number of corners and finds those which are parallel. My problem is, as shown below, that I sometimes get false positive results. </p>
  
  <p>To eliminate this I was going to check if both points fell onto a single hough line but this would be quite computationally intensive and I was wondering if anyone had any simpler ideas.</p>
  
  <p>Thanks.</p>
  
  <p><img src="https://i.stack.imgur.com/TgPXk.png" alt="False Positive Parallel Line"></p>