Effective visual surveillance with cooperation of multiple active cameras

This paper presents a nearly real-time surveillance system to track multiple moving objects by controlling multiple pan-tilt camera platforms. In order to describe the relationship between the targets and camera in this surveillance system, the input/output hidden Markov model (HMM) is applied here in the well-defined spherical camera coordinate. For the less number of cameras to effectively monitor a wide surveillance space, the overall cameras have to closely cooperate. We propose a hierarchical camera selection and task distribution strategy, and the action decision of each camera platform is according to its assigned role. Furthermore, an optimal camera action selection strategy is presented for one camera which is assigned to track multi-target within its limited field of view. The maximization of mutual information for the action design is evaluated by the Monte Carlo method. The overall performance has been validated in the experiments of real-time surveillance.