可扩展视频编码是指已编码码流在解码端能够进行部分解码,且重构图像的质量与接收到的信息量成比例变化,同时空域分辨率和时域分辨率可以根据解码端的要求改变。为了提供小波编码视频码流的高度可扩展性,提出了一种基于小波域规则三角形网格运动补偿的可扩展视频编码方法。该方法首先对参考帧使用冗余离散小波变换(RDWT)进行分解,并在RDWT小波域使用网格运动模型进行运动补偿,以提高运动补偿效率;其次在编码阶段则采用基于子带扫描顺序的改进SPIHT技术来保障码流的可扩展特性。实验表明,该方法在获得较高编码效率的同时,还提供了码流的高度可扩展特性。

Video scalability is referred to that the encoded bitstream can be decoded partly and the reconstruction video quality is proportional to the amount of received information,and the spatial and temporal resolutions can be changed according to the decoder property.This paper presents a highly scalable video codec with wavelet domain motion compensation based on regular triangular mesh,which decomposes the reconstructed reference frame by RDWT,carries out motion compensation in wavelet domain by mesh-based motion model,so that the efficiency of motion compensation is improved.In order to keep not only PSNR scalability but also spatial and temporal resolution scalability,an amended SPIHT method with subbands-scan order is proposed.The experimental results prove that the codec can produce encoded stream with good PSNR and highly scalable functions.