Collaborative Nodes Strategy for Target Tracking in Two-tier Wireless Multimedia Sensor Networks

Two-tier network structure is usually used to lighten the energy consumption in Wireless Multimedia Sensor Networks (WMSNs) for large scale surveillance application. Previous methods for target tracking in two-tier WMSNs mostly focused on reducing energy cost to prolong lifetime of the networks without considering the effect of visual target tracking. This paper presents a collaborative multi-tier nodes strategy for visual target tracking in WMSNs. In the proposed method, the target detection and tracking are carried out by the cooperation of lower-tier scalar sensor nodes and upper-tier camera nodes. Each activated camera node uses an adaptive Gaussian mixture model to extract moving target and Mean Shift algorithm for target tracking. A novel function measuring the value of utility of tracking as well as energy cost is used to select optimal camera node. Experimental results show that the method can effectively achieve tradeoff between performance and energy consumption in real scenes.