像素域基于广义高斯分布的WZ帧重构方案设计

为提高分布式视频编码系统解码WZ帧的图像质量,提出了像素域基于广义高斯分布的WZ帧重构方案. 该方案充分考虑了边信息与原始WZ帧间的相关性,以广义高斯分布作为虚拟相关信道模型,提高率失真性能;用广义高斯分布做相关噪声模型,对给定量化区间,计算边信息已知情况下WZ的条件期望作为WZ重构值;为了不过多地增加重构方案的复杂度,将广义高斯分布的形状参数固定为0.5,推导出重构WZ帧的闭式表示. 实验结果表明,基于广义高斯分布的WZ帧重构方案能有效提高率失真性能和改善重构WZ帧的图像质量.

Design of WZ Frame Reconstruction Technology Based on Generalized Gaussian Distribution in Pixel-Domain

In order to improve the image quality of the decoded WZ ( Wyner-Ziv ) frame in distributed video coding system, WZ frame reconstruction technology based on generalized Gaussian distribution ( GGD) was proposed. The correlation between the side information and the original WZ frame was con-sidered as well. GGD was used for virtual correlation channel model so as to improve the rate distortion ( RD) performance. Meanwhile,the condition expectation of the WZ was computed as the reconstructed WZ value for the given quantization interval and the known side information in which GGD is used as cor-relation noise model. The shape parameter of GGD is fixed to 0. 5 so that it won’ t add extra complexity to the reconstruction technology. The closed-form expression of the optimal reconstructed values was de-rived. Experiments indicate that the proposed WZ frame reconstruction technology can improve the RD performance and image quality of the decoded WZ frame.