http://docs.opencv.org/doc/tutorials/objdetect/cascade_classifier/cascade_classifier.html#cascade-classifier

I had to change the xml files to have the absolute pathnames.

Than it worked. But the problem is, it is too slow. I don't know why yet.


The following is a video tutorial.
This is good as it covers from the scratch including how to use OpenCV in Xcode.

http://www.youtube.com/watch?v=Jl8NMTfvTgU