基于SVAC感兴趣区域的码率控制算法  

Rate Control Algorithm for Region of Interest Based on SVAC

作　　者：欧阳甸[1] 张伟华[1] 董骞[1] 闫雪[1] 

机构地区：[1]公安部第一研究所信息技术事业部,北京100048

出　　处：《数据采集与处理》2014年第1期101-107,共7页Journal of Data Acquisition and Processing

基　　金：国家"十二五"科技支撑计划(2012BAH21B02)资助项目

摘　　要：支持感兴趣区域编码是SVAC标准的重要特性,感兴趣区域编码可以提高图像处理效率并能大大降低码率,但是码率依然会随编码帧的复杂度而波动,导致传输信道利用率较低。SVAC标准目前并没有推荐的码率控制算法。本文提出了一种基于SVAC感兴趣区域的码率控制算法:通过计算图像复杂度信息,对感兴趣区域与背景进行比特数分配,并将比特数优先分配给感兴趣区域;设计虚拟缓存器,通过计算缓存器的占有率实时调整每个编码帧感兴趣区域及背景的量化参数。实验结果表明,该算法将视频编码输出码率稳定在传输信道带宽内,提高了信道的利用率,并且保证了感兴趣区域具有平滑优质的图像质量。Region of interest （ROI） encoding is an important feature of SVAC. The efficiency of image processing can be increased and the bit rate reduces greatly because of ROI, but the bit rate will fluctuate along with complexity of encoding frames. Therefore, availability of communication channel is inefficient. There has been no rate control algorithm recommended by SVAC so far. A rate control algorithm is thus provided for ROI based on SVAC. The bit rate of ROI and back region are allocated by calculating the complexity of image, and the bit rate of ROI will be allocated preferentially. Meanwhile, a virtual buffer is designed. The occu- pancy of virtual buffer is calculated to adjust the quantization parameter （QP） of ROI and back region of every encoding frame in time. Experiment results show that bit rate is stable in com- munication channel whose availability is improved. Besides the image quality of ROI is smooth and excellent.

关 键 词：码率控制 感兴趣区域 SVAC 量化参数 虚拟缓存器 

分 类 号：TN919.81[电子电信—通信与信息系统]