Publications [#338913] of Lawrence Carin
Papers Published
- Pruteanu-Malinici, I; Carin, L. "Infinite hidden Markov models and ISA features for unusual-event detection in video." Proceedings - International Conference on Image Processing, ICIP 5 (January, 2007): V137-V140. [doi]
(last updated on 2024/04/18)Abstract:
We address the problem of unusual-event detection in a video sequence. Invariant subspace analysis (ISA) is used to extract features from the video, and the time-evolving properties of these features are modeled via an infinite hidden Markov model (iHMM), which is trained using "normal"/ "typical" video data. The iHMM automatically determines the proper number of HMM states, and it retains a full posterior density function, on all model parameters. Anomalies (unusual events) are detected subsequently if a low likelihood is observed when associated sequential features are submitted to the trained iHMM. A hierarchical Dirichlet process (HDP) framework is employed in the formulation of the iHMM. The evaluation of posterior distributions for the iHMM is achieved in two ways: via MCMC and using a variational Bayes (VB) formulation. ©2007 IEEE.