Fan Jiang, Ying Wu, Senior Member, IEEE, and

Aggelos K. Katsaggelos, Fellow, IEEEIEEE TRANSACTIONS ON IMAGE

PROCESSING, VOL. 18, NO. 4, APRIL 2009

IntroductionHidden Markov Model (HMM)

Cross Likelihood Ratio (CLR)X = training trajectoryY = likelihood trajectoryλx, λy = HMM of X or Y

Bayesian Information Criterion (BIC)

Dissimilarity

TRAJECTORY CLUSTERINGDynamic hierarchical clustering (DHC)

Fifteen categories of any three trajectory groups according to different nearest neighbors

Merging can be rejected (exclusion) if

Substituting BIC

Where :

Assume :

Sufficient condition to be satisfied

2-depth greedy search algorithm

NORMAL CLUSTER IDENTIFICATION ANDABNORMALITY DETECTION

If

then trajectory i is unusual

Examples of normal (a)–(d) and unusual (e)–(h) trajectories.

Thank You