一种基于帧间信息的组合型差错掩盖算法

A Hybrid Error Concealment Based on Interframe Information

针对帧间编码模式的视频图像在易错信道中传输产生图像块丢失的现象,提出一种基于帧间信息的组合型差错掩盖算法以提高解码端的图像质量.根据丢失块周围已正确接收的图像块的运动矢量信息把丢失块分成低活动块和高活动块两类.对于低活动块,用平均运动矢量法来恢复丢失块;对于高活动块,根据前后帧图像具有空间结构相似性,利用凸集投影的原理来恢复丢失的图像块.实验结果表明采用本文算法恢复的图像主观和客观质量都比传统的算法要高.

The Transmission of encoded video signals in error-prone environments usually lead to packet erasures which often results into a number of missing image blocks at the decoder. In this paper, an efficient error concealment algorithm for video transmission is proposed which based on the intcrframc information. The missing blocks arc classified into low activity blocks and high activity blocks by using the motion vector information of the surrounding correctly received blocks. For the missing blocks, which arc low activity blocks, it can bc concealed by the simple average motion vector （AVMV） method. For the missing high activity blocks, several closed convex sets arc defined, then the method of projections onto convex sets （POCS） is used to recover the missing blocks by combining frequency and spatial domain information. Experimental results show that the proposed algorithm achieves improved visual quality of the reconstructed frames with respect to other classical error concealment algorithms, as well as better PSNR results.