Low-energy video event data recorder using dual image/video codec

Abstract

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 abnormal movement of objects, or physical damage to the camera itself. The system is optimized to minimize energy consumption of whole system by designing the event detector properly. 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 only 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. The performance of the event detector is very important, because it decides the frequency of system wake-up which significantly affects the energy consumption of the system. The design parameters of the event detector is carefully chosen such that the energy consumption of the proposed system is minimized while the probability of not recording an important event is kept below a given level. Experimental results show that the energy consumption of the whole system is reduced by up to 75.1% (by 61.0% on average) compared with conventional always-on system.

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