People tracking and head detection in Opencv example.

Opencv head detection is much more complicated than the whole body detection.. Learning is the same. All the steps are the same. There is some aspects which just complicate the situation with head detection. First one is that the result detecting the head has more false detection than in case of whole body. There is also important the performace issue. You need to detect in detect multiscale approach just smaller sliding window than in case of whole people detection. That dramatically decrease the performance. The result of the detection should be very slow also on small resolution. 

There is also some positive aspects of head detection. You can simly in multi target tracking example just connect the detection with the tracking history.. That is the main advantage..