TY - JOUR T1 - Interpretation of state sequences in HMM for activity representation JF - Proc. IEEE Conf. Acoustic Speech and Signal Processing Y1 - 2005 A1 - Cuntoor, N.P. A1 - Yegnanarayana,B. A1 - Chellapa, Rama AB - We propose a method for activity representation based on seman-tic events, using the HMM framework. For every time instant, the probability of event occurrence is computed by exploring a subset of state sequences. The idea is that while activity trajectories may have large variations at the data or the state levels, they may ex- hibit similarities at the event level. Our experiments show the ap- plication of these events to activity recognition in an office envi- ronment and to anomalous trajectory detection using surveillance video data. VL - 2 ER -