| 引用本文: | 林敏,林庆毫,翁晓雨,陈国捷.应用于H.26X的通用无损帧内编码优化算法[J].哈尔滨工业大学学报,2021,53(8):125.DOI:10.11918/202104004 |
| LIN Min,LIN Qinghao,WENG Xiaoyu,CHEN Guojie.Improved universal lossless intra-frame coding algorithm for H.26X[J].Journal of Harbin Institute of Technology,2021,53(8):125.DOI:10.11918/202104004 |
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| 摘要: |
| 在H.26X系列视频编码标准的无损压缩方案中,通过帧内预测得到的预测残差仍具有较强的空间相关性,直接参与熵编码将导致编码效率下降。与自然图像不同,帧内预测残差的空间相关性体现为含有丰富的边缘特征。为利用帧内预测残差特殊的空间相关性,进一步降低其空域冗余,提高视频帧内编码的效率,提出一种通用的基于残差中值边缘检测的无损帧内编码算法。算法首先对帧内预测残差逐点进行边缘检测,通过分析临近点的数值特征,使用中值边缘检测算法得到当前点的预测值；然后,对比预测值与原始残差值,得到新的预测残差；最后,为确保编码新的预测残差能够提高压缩率,依照当前编码单元的能量是否降低来快速判断是否使用新的残差进行熵编码。实验结果表明:经过该算法处理的编码单元具有更低的空域冗余和残差能量,从而可降低熵编码后的码率。经统计,在H.265与最新的H.266标准中应用提出的优化算法,帧内预测残差的能量平均降低67.9%,平均码率分别降低7.04%和5.98%,同时编解码时间变化细微,具有显著的实用价值。 |
| 关键词: 无损视频压缩 帧内编码 预测残差 高性能视频编码 多功能视频编码 |
| DOI：10.11918/202104004 |
| 分类号:TN919.81 |
| 文献标识码:A |
| 基金项目:国家重点研发计划(2019YFB2204500) |
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| Improved universal lossless intra-frame coding algorithm for H.26X |
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LIN Min,LIN Qinghao,WENG Xiaoyu,CHEN Guojie
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(Key Laboratory of Specialty Fiber Optics and Optical Access Networks (Shanghai University), Shanghai 201900, China)
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| Abstract: |
| In the lossless compression schemes of the H.26X series video coding standards, the residuals obtained by intra-frame prediction still retain strong spatial correlation and directly participating in entropy coding will lead to the decrease in coding efficiency. Unlike natural images, intra-frame prediction residuals contain rich edge features. To utilize the special spatial correlation of residuals, further reducing its spatial redundancy and improving the intra-frame coding efficiency, a universal lossless intra-frame coding algorithm based on residual median edge detection was proposed. The algorithm first performed edge detection on the intra-frame prediction residuals step by step. By analyzing the numerical features of the adjacent residuals, the median edge detection algorithm was applied to obtain new prediction value. Then, new prediction residual was obtained by comparing prediction value and original residual value. Finally, according to whether the energy of the current coding unit was reduced, it could quickly determine whether to use the new residuals for entropy coding, so as to ensure that the coding of the new prediction residuals could improve the compression ratio. Experimental results show that the coding units processed by this algorithm had lower spatial redundancy and residual energy, thereby reducing the bit-rate after entropy coding. Applying the proposed algorithm in H.265 and the latest H.266 standards, the average energy of residuals decreased by 67.9%, and the average bit-rate reduced by 7.04% and 5.98% respectively, while the codec time changed slightly, with significant practical value. |
| Key words: lossless video compression intra-frame coding prediction residuals high efficiency video coding (HEVC) versatile video coding (VVC) |
