Estimating Tracking Sources and Sinks

When tracking in a particular environment, objects tend to appear and disappear at certain locations. These locations may correspond to doors, garages, tunnel entrances, or even the edge of a camera view. A tracking system with knowledge of these locations is capable of improved initialization of tracking sequences, reconstitution of broken tracking sequences, and determination of tracking sequence termination. Further, knowledge of these locations is useful for activity-level descriptions of tracking sequences and for understanding relationships between non-overlapping camera views. This paper introduces a method for simultaneously solving these coupled problems: inferring the parameters of a source and sink model for a scene; and fixing broken tracking sequences and other tracking failures. A model selection criterion is also explained which allows determination of the number of sources and sinks in an environment. Results in multiple environments illustrate the effectiveness of this method.