Alternative:  Multi-plane calibration 
Images courtesy Jean-Yves Bouguet, Intel Corp.
Advantage
•Only requires a plane
•Don’t have to know positions/orientations
•Good code available online!
–Intel’s OpenCV library:  http://www.intel.com/research/mrl/research/opencv/ 
–Matlab version by Jean-Yves Bouget:  http://www.vision.caltech.edu/bouguetj/calib_doc/index.html
–Zhengyou Zhang’s web site:  http://research.microsoft.com/~zhang/Calib/