【作者】 黄文楷； 孙季丰；

【Author】 Huang Wen-kai,Sun Ji-feng (College of Electronics & Information,South China University of Technology,Guangzhou,China,510641)

【机构】 华南理工大学电子与信息学院；

【摘要】 利用传统空间内插方法对视频中的丢失块进行错误隐藏时,容易在人眼敏感的边缘区域产生模糊。本文提出了一种复杂度低的空域内插错误隐藏算法用于重建在无线信道传输中的Intra帧。首先,利用改进的灵活宏块扫描顺序(FlexibleMB Order FMO)的方法,将扫描顺序打乱组成新的片组(Slice)进行传输,确保即使某个Slice丢失,丢失宏块周围至少有两个正确接收的Slice可进行错误隐藏:其次,利用相邻宏块边界的梯度预测并恢复丢失宏块(MB)的边缘信息。最后,将丢失宏块划分成更小的块,每个块中的象素值根据最有代表性边界点相位多方向加权内插得到。试验表明本算法能够恢复丢失宏块中的高低频分量信息,在具有明显边缘的区域,比传统的空域内插方法有更好的视觉效果,其PSNR也比传统方法提高大约1.5～2.5dB。更多还原

【Abstract】 A low complexity spatial-domain error concealment method is proposed to reconstruct I-frame of video when transmitted through unreliable channels in wireless network.The proposed concealment algorithm works with the following steps. First,the improved Flexible Macroblock Order(FMO) method is used to reorder MBs to a new Slice for transmitting.Ensure that even if one Slice missing,around this missing MB at least two correct received MBs are available.Then,the missing edges in a lost MB are detected and recoveried by using neighborhood MBs’ gradient data.Finally,the lost MB is divided into several smaller segments,each pixel in a segment is directionally interpolated from representative boundary pixels adjacent to the segment. Experimental results show that the proposed algorithm can recover high as well as low frequency information in lost MBs and provide better visual quality and achieved with 1.5-2.5dB increase in PSNR in comparison with the conventional spatial domain interpolation.更多还原