Frame-Layer Constant-Quality Rate Control of Regions of Interest for Multiple Encoders With Single Video Source

In this work, we develop a constant-quality rate control algorithm for a surveillance system which consists of one ldquobase encoderrdquo that encodes a down-sampled full-view version of the input video sequence, and one ldquoregion of interest (ROI) encoderrdquo that encodes the region of interest of the input video at the original resolution. Exploiting the inter-relationship between these two independent encoders, the algorithm allocates the bits for the ROI encoder according to the distortion obtained from the corresponding region in the base encoder. Simulation results show that the proposed algorithm can achieve significant reduction in the image quality variation. Compared to the rate control algorithm in JM 8.4, the overall quality is improved and the bit rate is saved.