How to track detected object

Question

I've read a lot about object/tracking detection. There are a lot algorithms in moving objects tracking such as frame differencing, background subtraction etc. Also there are a lot object detection algorithms: Viola Jones, Haar-like features etc. And I use Viola Jones algorithm, Haar-like features and cascade of classifiers to detect objects. So if I use classifiers for face detection for example, my question is how to track all faces on each frames.

Answer 1

Simplest method is to just run the detector for every frame and see the detection overlaps to decide if its same face in next frame. or a sime euclidean distance might be good. This is good if face is always. If the face can be non frontal then you need to do some kind of histgram based tracking which is computationally inexpensive.