Foreground Detection and Rate Allocation in Multi-Camera Surveillance System

Abstract

In the new generation of video surveillance system, adopting NVR (Network Video Recorder) and IP Camera will become the future trend. When the multiple video streams are transmitted together through the fixed bandwidth channel, an efficient rate allocation mechanism is necessary. In this thesis, we develop an Edge-based Foreground Block Detection (EFBD) method to find out changing (foreground) blocks and then determine the importance of cameras based on EFBD. Accordingly, we propose an Adaptive Q-R-D Rate Allocation (AQRDRA) method to allocate higher bitrate to active cameras for better visual quality. Finally, we develop a multi-camera surveillance system using H.264 codec to implement and verify our proposed methods.

The experiments are conducted under the total available bandwidth 1.1Mbps with eight cameras. The experimental results demonstrate that the proposed scheme outperforms uniformly-distributed rate allocation. Without scarifying inactive camera too much, the proposed scheme can enhance the video quality of active camera by 8.7dB at most. Moreover, our proposed method is beneficial for the H.264 rate control scheme to achieve the target rate.