Improved Region-of-Interest based Rate Control for Error Resilient HEVC Framework

In this paper, we propose the improvement of Region-of-Interest (ROI) rate control on our previously proposed error resilient framework for High Efficiency Video Coding (HEVC). Reference picture selection (RPS) method and ROI-based intra refresh method are jointly considered in our previous work [6]. In addition, we also proposed ROI-based CTU depth level decision algorithm for reducing the complexity of the algorithm. To enable coding unit (CU) level intra refresh, we also integrate ROI information into the existing rate control. The ROI information is used not only for intra refresh frame but also for every frame in this paper. Experimental results show that the improved rate control contributes to the better quality than the work in [6] and HEVC with reference picture selection (RPS). For 10% packet error rate, the average PSNR improvement for 720p sequences and WVGA sequences are about 0.5 dB and 0.2 dB respectively. The maximum PSNR improvement is 0.88 dB and the minimum value is 0.13 dB. In addition, we also evaluate the impact of ROI-based CTU depth level decision module over complexity reduction by comparing proposed algorithm with and without CTU depth level decision module. Results show that ROI-based CTU depth level decision module can reduce the computational cost from 1.2% to 11.37%.