A Heat-Map-Based Algorithm for Recognizing Group Activities in Videos

• Published in: IEEE transactions on circuits and systems for video technology Vol. 23; no. 11; pp. 1980 - 1992
• Main Authors: Lin, Weiyao, Chu, Hang, Wu, Jianxin, Sheng, Bin, Chen, Zhenzhong
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.11.2013; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Activity recognition; Applied sciences; Diffusion processes; Exact sciences and technology; Feature extraction; group activity; heat map; Heating; Information, signal and communications theory; Pattern recognition; Signal processing; surface matching; Surface treatment; Telecommunications and information theory; Trajectory; Videos; Performance evaluation; Thermal diffusion; heat map; Gesture recognition; Activity levels; group activity; Algorithm; Heat source; surface matching; Multiscale method; A posteriori estimation; Diffusion process; Activity recognition; Curve fitting
• ISSN: 1051-8215; 1558-2205
• DOI: 10.1109/TCSVT.2013.2269780

In this paper, a new heat-map-based algorithm is proposed for group activity recognition. The proposed algorithm first models human trajectories as series of heat sources and then applies a thermal diffusion process to create a heat map (HM) for representing the group activities. Based on this HM, a new key-point-based (KPB) method is used for handling the alignments among HMs with different scales and rotations. A surface-fitting (SF) method is also proposed for recognizing group activities. Our proposed HM feature can efficiently embed the temporal motion information of the group activities while the proposed KPB and SF methods can effectively utilize the characteristics of the HM for activity recognition. Section IV demonstrates the effectiveness of our proposed algorithms.