
 representation of an object (in this implementation we use color
 histograms, as in the original work).  The idea is given a histogram q in
 frame t, find histogram p in frame t+1 that is most similar to q. It
 turns out that this can be formulated as a mean shift problem. Here, the
 kernel is fixed to the Epanechnikov kernel.

 This implementation uses mex files to optimize speed, it is significantly
 faster than  real time for a single object on a 2GHz standard laptop (as
 of 2007).

 If I==[