CN分布的估计.DOC

中图分类号：TN919.81 文献标识码:A 分布式视频编码中相关噪声分布的非参数估计 胡晓飞 ，朱秀昌 南京邮电大学 图像处理与图像通信江苏省重点实验室 江苏南京 210003 摘 要：目的：针对分布式视频编码系统中相关噪声（Correlation Noise, CN）分布难以准确模拟的问题，根据CN分布的特点，建立了基于最优窗宽的核密度估计-均匀分布模型(Kernel Density Estimation-Uniform Distribution Model, KDEUDM)，比较了变换域Wyner-Ziv（Transform Domain Wyner-Ziv, TDWZ）系统中CN的参数估计法和非参数估计法所建立的噪声模型对系统性能的影响实验结果表明，非参数估计方法能较准确地模拟CN的分布，用非参数估计法建立的噪声模型能使WZ帧编码在高码率下最高能节约10%的码率on-parametric estimation for correlation noise distribution in distributed video coding Hu Xiaofei , Zhu Xiuchang Image Processing and Image Communication Key Laboratory, Nanjing University of Posts and Communications; Nanjing 210003，China Abstract: Objective：Since it is difficult to estimate the correlation noise distribution, a non-parametric estimation method for correlation noise is proposed. Method: According to the feature of correlation noise, kernel density estimation-uniform distribution model based on optimal bandwidth is proposed. The impact of noise model using parameter estimation method and non-parametric estimation method on the system performance in transform domain Wyner-Ziv system is compared. Result：The experiments results show that non-parametric estimation method can simulate correlation noise distribution and the established noise model using non-parametric estimation method can save rate about 10% at most at high bit rate for WZ frame. Conclusion：Non-parametric estimation method is an effective noise estimation method for TDWZ system. Key words: Distributed Video Coding; Transform Domain Wyner-Ziv; Correlation Noise Distribution; Kernel Density Estimation; Noise Model 0 引言 虽然以MPEG-X和H.26X为代表的传统视频编码器Discrete Cosine Transform, DCT）结合帧间预测技术的混合编码器，在编码端需要完成变换、量化、熵编码、以及运动估计和运动补偿等大量的运算，而解码器仅仅利用来自编码器的信息重建视频信号，这使得编码复杂度远远高于解码复杂度近年来兴起的无线视频监控、无线传感器网络、移动可视电话等面向上行链路、低功耗、低带宽的应用需求，其无线视频编码设备简单且，而解码设备一般无能量限制且有较强的处理能力。传统的复杂的编码器显然不适用于这种场合，复杂度不对称的结构需要逆转来适应新的应用需求Distributed Video Coding, DVC）就是一种适合此类应用场合，最大限度地减小编码复杂度，在解码端挖掘视频信号的时间冗余度的全新的视频编码方案。由于DVC在编码效率上与传统的视频编码框架还有一定的距离目前，