摘要： 对H.264视频码流的帧内编码帧(I帧)进行空域错误掩盖时，单纯使用加权像素平均插值算法或方向插值算法不能得到满意的效果。因此，使用一种基于方向熵的自适应选择算法，根据丢失宏块周围的边缘信息自适应地选择加权像素平均插值算法或者该文提出的一种方向插值算法进行空域掩盖。该文提出方向插值算法，使用“双圈法”精确估计丢失宏块内的边缘方向，计算周围8个宏块中此方向上的边缘强度，根据边缘强度将丢失宏块划分成不同的区域分别进行方向插值。实验结果表明，该算法不仅提高了方向插值的精确性，也避免了虚假边缘的产生，有效地提高了错误图像的掩盖效果。

关键词: 错误掩盖, 方向熵, 双圈法, 方向插值, 加权像素平均

Abstract: It can not give satisfying results when applying error concealment to intra frames of H.264 by simply using weighted pixel value averaging(WPVA) or directional interpolation. A directional entropy based adaptive spatial interpolation algorithm is presented. The algorithm adaptively switches between WPVA and an improved directional interpolation algorithm is also presented here according to edge information around lost area in a frame. The directional interpolation algorithm presented here use a ‘two loop method’ to give more precise estimate of edges in the lost area compared to other directional interpolation algorithm. Experimental results show that the algorithm can achieve good directional interpolation concealment results, and can avoid fake edges.

Key words: error concealment, directional entropy, two loop method, directional interpolation, weighted pixel value averaging

中图分类号: 

• TP312