作　　者： ; ;

机构地区： 华南理工大学电子与信息学院

出　　处： 《电子学报》 2006年第4期628-633,共6页

摘　　要： 编码数字视频序列经过受噪声影响的信道传输后通常会出现的图像信息丢失．本文提出一种新的基于马尔可夫随机场一最大后验估计(MRF-MAP)的自适应误差掩盖方法,作为在解码器端的后处理工具去解决这种问题．以往的MRF-MAP方法通常会因为迭代造成边缘被模糊,因为初始解不准确而造成块效应．为了保护边缘,本文利用了判别分析法引入像素隶属度,针对像素所处的边缘或平滑区域,自适应确定MRF的Huber函数中边缘阈值T.同时又在Huber函数的线性部分引入斜率k,以消除块效应．仿真结果表明,本文提出的方法无论在主观视觉评价,还是在客观的数值标准下,都能比现存的误差掩盖方法恢复出质量更好的图像． When encoded digital video sequences transmit over noisy communication channels, the information of the images will usually lose. A new adaptive error concealment method based on Markov Random Field （MRF） - Maximum a Posteriori （MAP） is proposed as a post-processing tool at the decoder side to solve this problem. In the former MRF-MAP method, usually iterations will cause edge blurting and inaccurate initial solution will cause blocking effects. In order to protect the edges, Discrimination Analysis method is used to introduce the pixel-subjection-degree. So, edge threshold T for the Huber function of MRF is adaptively obtained, according to the edge or smooth area that the pixel belongs to. In the same time, to eliminate the blocking artifacts, a slope k is also introduced to the linear part of the Huber function. Simulation results show that the proposed method can recover the higher quality image on both subjective visual evaluation and objective numerical metrics, comparing to the existing error concealment methods.

关 键 词： 马尔可夫随机场 最大后验估计 误差掩盖 判别分析

领　　域： [电子电信] [电子电信]