2009 UnsupervisedActivityPerceptioni

• (Wang et al., 2009) ⇒ Xiaogang Wang, Xiaoxu Ma, and W. E. L. Grimson. (2009). “Unsupervised Activity Perception in Crowded and Complicated Scenes Using Hierarchical Bayesian Models.” In: IEEE Transactions on Pattern Analysis and Machine Intelligence Journal, 31(3). doi:10.1109/TPAMI.2008.87

Subject Headings: Hierarchical Bayesian Model.

Cited By

• http://scholar.google.com/scholar?q=%222009%22+Unsupervised+Activity+Perception+in+Crowded+and+Complicated+Scenes+Using+Hierarchical+Bayesian+Models
• http://dl.acm.org/citation.cfm?id=1512152.1512378&preflayout=flat#citedby

Quotes

Abstract

We propose a novel unsupervised learning framework to model activities and interactions in crowded and complicated scenes. Hierarchical Bayesian models are used to connect three elements in visual surveillance: low-level visual features, simple "atomic" activities, and interactions. Atomic activities are modeled as distributions over low-level visual features, and multi-agent interactions are modeled as interactions over atomic activities. These models are learnt in an unsupervised way. Given a long video sequence, moving pixels are clustered into different atomic activities and short video clips are clustered into different interactions. In this paper, we propose three hierarchical Bayesian models, Latent Dirichlet Allocation (LDA) mixture model, Hierarchical Dirichlet Process (HDP) mixture model, and Dual Hierarchical Dirichlet Processes (Dual-HDP) model. They advance existing language models, such as LDA [1] and HDP [2]. Our data sets are challenging video sequences from crowded traffic scenes and train station scenes with many kinds of activities co-occurring. Without tracking and human labeling effort, our framework completes many challenging visual surveillance tasks of board interest such as: (1) discovering typical atomic activities and interactions; (2) segmenting long video sequences into different interactions; (3) segmenting motions into different activities; (4) detecting abnormality; and (5) supporting high-level queries on activities and interactions.

References

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	Author	volume	Date Value	title	type	journal	titleUrl	doi	note	year
2009 UnsupervisedActivityPerceptioni	Xiaogang Wang Xiaoxu Ma W. E. L. Grimson			Unsupervised Activity Perception in Crowded and Complicated Scenes Using Hierarchical Bayesian Models				10.1109/TPAMI.2008.87		2009