Optimal sensing redundancy for multiple perspectives of targets in wireless visual sensor networks

Wireless sensor networks can provide visual information from the monitored field when sensor nodes are equipped with low-power cameras. In general, visual monitoring applications supported by sensing technology will have to address many challenging issues when visual information has to be transmitted over resource-constrained sensors. When addressing energy efficiency, sensing redundancy can be exploited to enlarge the network lifetime, whenever inactive sensors are used to replace faulty nodes. The monitoring of multiple targets may be optimized reducing the number of active visual sensors, but the required perspectives of the targets must be considered. In this paper we propose an algorithm to compute the minimum number of visual sensors that should be activated to cover all desired targets, especially addressing the particular problem when single nodes can view multiple targets at the same time. As different concurrent perspectives of the targets may be required, the proposed algorithm can bring significant results to wireless visual sensor network applications.