oa CameraNets: coverage and data management problems in distributed smart camera networks

Distributed Smart Camera systems (DSCs) consist of a (possibly large) number of cameras that collaborate on a monitoring task. DSCs have a wide range of applications such as surveillance, intelligent traffic systems, environmental monitoring, industrial safety and law enforcement. DSCs automatically control what to monitor and how to act on the collected video. For example, cameras monitoring traffic may change their orientation to track moving traffic and alert responders if an accident occurs.

DSCs differ from conventional multi-camera surveillance systems in that they eliminate the need for a human to control them and to interpret the video. Free of this limitation, DSCs can scale to much higher scales, while improving monitoring effectiveness. However, a number of difficult challenges must be solved before DSCs can realize this potential. In this paper, we discuss our results and activities within a QNRF-funded project looking at two general challenges facing DSCs:

1 - Coverage control: how to control cameras with Pan-Tilt-Zoom capability to track a group of targets and/or areas of interest. We frame the problem as an optimization problem to maximize the value of the covered targets. We show that the problem is NP-hard and develop a family of heuristic approaches with near optimal behavior that do not require central coordination.

2 - Data Management: as the cameras collect their video, they need to relay it for real-time monitoring using a bandwidth constrained network, or store it for later analysis. Cameras can coordinate to eliminate redundancies and to infer the importance of the observed video. Moreover, storage architectures are needed to effectively store the video data and to allow efficient indexing and retrieval.

We report our initial solutions and performance evaluation studies in this area, which were obtained by a mixture of simulation and using an experimental multi-camera test bed that we have started to deploy.