title: Which algorithm can I use for quadrilater/cube detection?
body: <p>For a project, I have to detect a cube with a webcam. I think that OpenCV could be a good solution to find out where is it (real-time).
  I'm new in the computer vision domain, and I wonder which algo can I use ? Hough ?
  I've seen this video (quite impressive!): <a href="http://www.youtube.com/watch?v=ytvO2dijZ7A" rel="nofollow">http://www.youtube.com/watch?v=ytvO2dijZ7A</a>
  Do you know how he was able to do it ?</p>
  
  <p>Thank you a lot for your help</p>