Video Surveillance with PTZ Cameras: The Problem of Maximizing Effective Monitoring Time

The effectiveness of the surveillance (monitoring a set of mobile targets with a set of cameras) depends on the resolution of the monitored images and the duration for which the targets are monitored. PTZ cameras are a natural choice to maintain a desired level of resolution for mobile targets. Maintaining resolution by controlling the camera parameters above a desired threshold value, however, implies that the field of regard of a camera cannot be arbitrarily broadened to include multiple targets. Camera for each target needs to be judiciously chosen to ensure monitoring for prolonged time interval. In this paper we propose a metric viz. average effective monitoring time (AEMT), towards capturing the effectiveness of video based surveillance. To achieve enhanced AEMT, we formulate an optimization problem in terms of associating cameras with the targets based on an appropriate weight function and design an efficient distributed algorithm. Simulation results show that our approach contributes significantly towards improving AEMT.