title: Which is the better way of calculating frame motion in a video?
body: <p>In order to find successive frame motion differences, I used absolute difference of the frames and then summing up all the pixels to quantify the amount motion. I have done that in OpenCV.</p>
  
  <p>But I recently came to know about Horn and Schunk's Optical flow algorithm and the Macro-Block based motion compensation. OpenCV Library already has in built functions that can compute them. But I do not know how to quantify them. Are they better than the first approach ?</p>
  
  <p>Please help!</p>