title: Detect walls or planar surfaces (with OpenCV)?
body: <p>I'm developing a simple app that analyses video stream from iOS camera, detects walls or planar surfaces and project an image on it. In my case I can't use markers. What OpenCV algorithm should I use? Or maybe there is another library that would do the job?</p>
  
  <p>I find PTAM (<a href="https://www.youtube.com/watch?v=pBI5HwitBX4" rel="noreferrer">https://www.youtube.com/watch?v=pBI5HwitBX4</a>) is doing what I need but I can't find a working code yet and all the resources look dead. I spent a month now on it and start hitting a wall, I would be happy if someone just pointed me to the right direction, please!</p>