A low-energy video event data recorder using dual image/video codec

Energy consumption is a crucial issue of mobile surveillance cameras owing to limited battery capacity. The lifetime of the system is significantly extended by the event-driven operation; the system mostly stays in sleep mode and wakes up only when an event is detected. In this paper, we propose a design of a low-energy surveillance camera that records events such as the abnormal movement of objects, or physical damage to the camera itself. Unlike conventional event-driven approaches, the proposed system records video from 10 seconds before the event detection because the most critical information is often before or at the moment of event detection, not after the detection. Two different encoders, a low-power encoder and a high-compression encoder, are employed together to implement the low-energy surveillance camera. Experimental results show that the energy consumption of the whole system is reduced by up to 74.9% (by 66.8% on average) compared with conventional always-on system.