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Computer Modeling and Recognition of Human-Human Interactions


Human Activity Recognition

J. K. Aggarwal

Department of Electrical and Computer Engineering

The University of Texas at Austin


Monday, April 11

3105 EB


Computer vision research has (slowly) progressed, over the past 25 years, from recognizing the motion of rigid, planar objects to 3-dimensional, articulate non-rigid objects. Today, one of the major objectives is the tracking, recognition and understanding the activities of humans and vehicles moving in everyday surroundings. The effort to develop computer systems able to detect humans and to recognize their activities is part of a larger effort to develop personal assistants. The understanding of human activity is a diverse and complex subject that includes tracking and modeling human activity, and representing video events at the semantic level. Its scope ranges from understanding the actions of an isolated person to understanding the actions and interactions of a crowd.In general, human interactions are diverse and difficult to interpret. Occlusion, shadows lighting conditions make tracking and recognition difficult. Professor Aggarwal will present his research on modeling and recognition of human actions and interactions. The work includes the study of interactions at the gross level as well as at the detailed level. The two levels present different problems in terms of observation and analysis. The issues relating to segmentation and tracking of individual body parts will be explored.At the gross level we model persons as blobs, and at the detailed level we conceptualize human actions in terms of an operational triplet 'agent-motion-target' similar to 'verb argument structure' in linguistics. We use dictionary-based definitions of human interactions as domain knowledge and construct the classification rules for the human interactions. The applications of research to surveillance and computer animation will be discussed, as well as the issue of what the computer 'sees' vs. what a human 'sees'.


J.K. Aggarwal has served on the faculty of The University of Texas in the Department of Electrical and Computer Engineering since 1964. He is currently one of the Cullen Professors of Electrical and Computer Engineering. Professor Aggarwal earned his B.Sc. from University of Bombay, India in 1957, B. Eng. from University of Liverpool, Liverpool, England, 1960, M.S. and Ph.D. from University of Illinois, Urbana, Illinois, in 1961 and 1964 respectively. A fellow of IEEE and IAPR, Professor Aggarwal received the Best Paper Award of the Pattern Recognition Society in 1975, the Senior Research Award of the American Society of Engineering Education in 1992 and the IEEE Computer Society Technical Achievement Award in 1996. He is the recipient of the 2004 K. S. Fu Prize of the IAPR and the 2005 Leon K. Kirchmayer Graduate Teaching Award of the IEEE. He is the author or editor of 7 books and 52 book chapters, author of over 200 journal papers, as well as numerous proceeding papers and technical reports.