分布式视频编码中虚拟信道模型的动态估计  

Dynamic estimation of virtual channel model for distributed video coding

作　　者：卿粼波[1] 何小海[1] 张志亮[1] 

机构地区：[1]四川大学电子信息学院图像信息研究所,四川成都610065

出　　处：《光学精密工程》2009年第4期923-929,共7页Optics and Precision Engineering

基　　金：四川省科技攻关项目(No.05GG021-026-03)

摘　　要：针对分布式视频编码系统中虚拟信道的时域动态特性，提出了新的解码端帧级虚拟信道模型的动态估计算法。利用边信息内插阶段所获得的双向运动矢量，对当前帧前后的关键帧进行运动补偿，通过前后关键帧的运动补偿误差来估计当前帧的虚拟信道模型。针对虚拟信道的空域动态特性，还提出了子块级虚拟信道模型的动态估计算法。通过对视频帧进行分块，然后对每个分块都进行参数估计．即可动态地完成各子块对应的虚拟信道模型的估计。实验证明，对于不同运动特性的序列，所提出的虚拟信道模型可使系统的率失真性能提高0．5～1dB，有效地降低了视频编码系统的传输码率。Two kinds of algorithms are proposed to dynamically estimate the precise of the Virtual Channel ModeI（VCM） to improve the performance of Distribution Video Coding（DVC） system. According to the temporal dynamic property of the VCM, a new frame level VCM estimation algorithm at the decoders is proposed. For each coding frame, the bidirectional vectors acquired in side information interpolation are used to get motion compensated versions of the key frames, then, the residuals of the key frames and their compensated motion versions are used to estimate the VCM of current coding frame. According to the spatial dynamic property of the VCM, a novel block level VCM estimation algorithm is proposed also. The video frames are divided into blocks, then the VCM estimation algorithm proposed is adopted to get its own VCM for each block. Experimental results show that for different video sequences, the proposed algorithms improve rate distortion performance by 0.5- 1 dB for the DVC system,and reduce transmission code rates for video encoding systems.

关 键 词：分布式视频编码 WYNER-ZIV 虚拟信道模型 矩估计 

分 类 号：TN919.81[电子电信—通信与信息系统]