高效率视频编码中基于块整合的错误隐藏算法

针对新一代视频编码标准高效率视频编码(HEVC)编码单元(CU)尺寸较大所导致的丢包后错误隐藏恢复效果不佳的问题,提出了对CU下的分割块进行块融合的错误隐藏方法。首先,分析了残差能量与块分割的相关性;然后,通过参考帧残差能量与所设阈值进行比较判决,对当前丢失CU分割块进行融合,得到丢失CU的块分割方式;其次,对矢量外推法进行权值优化,保证了算法在HEVC错误隐藏的适用性;最后,对融合块采用优化后的矢量外推法进行错误隐藏。实验结果表明,与经典错误隐藏方法如拷贝法、运动补偿法等相比,基于块融合的错误隐藏在保证解码视频结构相似性(SSIM)的同时提高了不同运动性的解码视频峰值信噪比(PSNR),验证了算法的可行性。

Error concealment for high efficiency video coding based on block-merging

The Coding Unit (CU) size in High Efficiency Video Coding (HEVC) is more times than that in previous coding standards, so the error concealment in HEVC has a poor result in video decoding when packet loss occurs. An error concealment method based on block-merging of segmentation block under CU was proposed. Firstly, the correlation between residual energy and block segmentation was analyzed. Secondly, the reference frame residual energy was compared with a set threshold, and the lost CU segmentation block was merged based on the comparison information. Then, the vector extrapolation method was optimized by weights to ensure the applicability of the proposed algorithm in HEVC error concealment. Finally, the optimized vector extrapolation method was used for error concealment of merged block. The experimental results show that,compared with the classic error concealment methods such as the methods of copy, motion compensation, the proposed method guarantees the Structural Similarity Index Measurement (SSIM) of decoded video and improves the Peak Signal-To-Noise Ratio (PSNR) of decoded video in different motility, and the feasibility of the proposed algorithm is verified.