为提高分布式视频编码系统解码WZ(Wyner-Ziv)帧的图像质量,提出了基于广义高斯分布的WZ帧重构算法.该算法充分考虑了边信息与原始WZ帧具有较强相关性的特点,将广义高斯分布作为相关模型;在边信息已知情况下,对给定量化区间、计算WZ帧的条件期望并将其作为WZ重构值;将广义高斯分布的形状参数设为0.5,推导出基于广义高斯分布重构WZ帧的闭式表示.实验结果表明,文中提出的基于广义高斯分布的WZ帧重构算法比最小均方误差(MMSE)重构算法的峰值信噪比提高约0.6dB,并能有效改善重构WZ帧的图像质量.
In order to improve the image quality of the decoded WZ( Wyner-Ziv) frame in the distributed video coding( DVC) system,a WZ frame reconstruction algorithm is proposed based on the generalized Gaussian distribution( GGD). In this algorithm,the strong correlation between the side information and the original WZ frame is taken into account,and the GGD is used as the correlation model. Then,with the known side information and a given quantization interval,the conditional expectation of the WZ frame is calculated as the reconstructed WZ value. Finally,the closed-form expressions of the reconstructed WZ frames based on the GGD are derived by using a shape parameter of 0. 5. Experimental results indicate that,as compared with the MMSE( Minimum Mean Square Error) reconstruction algorithm,the proposed algorithm achieves an average PSNR( Peak Signal to Noise Ratio)increment of about 0. 6 dB and effectively improves the image quality of the decoded WZ frame.