title: OpenCV extrinsic camera from feature points
body: <p>How do I retrieve the rotation matrix, the translation vector and maybe some scaling factors of each camera using OpenCV when I have pictures of an object from the view of each of these cameras? For every picture I have the image coordinates of several feature points. Not all feature points are visible in all of the pictures.
  I want to map the computed 3D coordinates of the feature points of the object to a slightly different object to align the shape of the second object to the first object.</p>
  
  <p>I heard it is possible using <code>cv::calibrateCamera(...)</code> but I can't get quite through it...</p>
  
  <p>Does someone have experiences with that kind of problem?</p>