title: Video change detection
body: <p>I have been looking for algorithms related to video change detection.</p>
  
  <p>Basically it will see if there is any visual difference in the current frame wrt to previous frame or the first frame of the video and show use the difference.</p>
  
  <p>Can you please suggest an algorithm?</p>
  
  <p>My implementation: I did read video frame by frame and converted to gray scale subtracted each frame with first frame and played the video(current frame-first frame)</p>