Design of energy-aware video codec-based system

Lifetimes of battery-powered monitoring and surveillance systems are limited by the given battery capacity. This could lead either to a complete loss, or to a significant loss of quality in the recorded image, of events. In this paper, we propose a energy-aware video codec-based system design which exploits event characteristics to minimize the energy consumption through energy-aware architecture exploration. Given event statistics, the proposed energy-aware system design methodology carries out the architecture exploration of a wireless surveillance node (WSN) consisting of image sensor, event detector, video encoder, transceiver and memory. Hierarchical event detection algorithms are utilized for trade-offs between energy consumption and detection accuracy. Even if sophisticated event detection algorithms require high computational complexity, they contribute to reduce the number of false detected events. Based on operational framework of power-rate-distortion relationship analysis, we build an energy-rate-distortion optimization technique which gives an energy-optimal operating point of the video encoder under the given memory constraint. Experimental results show that the proposed method prolongs the lifetime of WSN up to 3.76 times compared to an existing bitrate allocation method which does not consider event statistics and hierarchical event detection.