码率可分级小波视频编码算法的研究  

Research on Rate Scalable Wavelet Video Coding Algorithm

作　　者：刘红梅[1] 肖自美[1] 梁 凡[1] 魏晓晖[2] 

机构地区：[1]中山大学电子与通信工程系,广东广州510275 [2]广东电信科学技术研究院,广东广州510631

出　　处：《软件学报》2002年第4期664-668,共5页Journal of Software

基　　金：广东省自然科学基金资助项目(963037;960033)

摘　　要：对于多种视频传输业务,传统的分层可分级性已不能很好地满足要求,编码器需要提供码率可分级性.采用改进的零树小波编码算法生成了高性能的嵌入式码流,实现了一个码率可分级视频编解码器.而在码率可分级编解码算法中,同一码流需要在较大的码率范围内保持编码效率.目前的解决方案在目标码率提高时,重建图像的质量得不到有效的改善.指出了码率可分级编码算法不仅要考虑误差扩散问题,还要考虑帧间依赖关系,并提出了一种新的算法.实验结果表明,该算法使同一码流能在多种码率下提供更好的重建图像的质量,而且所提算法可用于其他采用运动补偿算法降低时间冗余的码率可分级编解码器中.The traditional layered scalabilities can not satisfy the requirements of various multimedia applications commendably. The codecs need to provide rate scalability. In this paper, a high performance embedded bit stream is produced by adopting an improved version of zerotree wavelet coding algorithm and a rate scalable video codec is implemented. However, in the rate scalable coding scheme, a single bit stream needs to keep coding effectiveness in a wider range of bit rates. The performance of the existing solutions can not improve the qualities of the reconstructed frames effectively when the target bit rate is increased. It is pointed out that besides error propagation, the rate scalable algorithm needs to give attention to the frame dependency, then a new algorithm is proposed. The experimental results show that the proposed algorithm can make the single bit stream produce better qualities at various data rates. This algorithm can also be used in other rate scalable coding schemes that adopt motion compensation to reduce the temporal redundancy.

关 键 词：码率可分级 小波变换 视频编码 嵌入式编码 运动补偿 算法 

分 类 号：TN919.81[电子电信—通信与信息系统] TP391.41[电子电信—信息与通信工程]