Jeffrey Mark Siskind, NEC Research Institute, Inc.
This paper presents an implemented system that classifies simple spatial motion events, such as pick-up and put-down, from video input. Unlike previous systems which classify events based on their motion profile, this system uses changes in the state of force-dynamic relations, such as support, contact, and attachment, to distinguish between event types. This paper presents an overview of the entire system along with the details of the algorithm that recovers force-dynamic interpretations using prioritized circumscription and a stability test based on a reduction to linear programming. This paper also presents an example illustrating the end-to-end performance of the system classifying an event from video input.