发表机构
SZ DJI Technologies Co., Ltd.（深圳大疆创新科技有限公司）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
针对AVS3中现有自适应环路滤波适应性不足的问题，提出基于灵活区域划分及系数合并的FRALF方案，在较低复杂度增加下提升编码效率。
AI 中文摘要
视频编码中的自适应环路滤波（ALF）旨在通过使用基于维纳的滤波器最小化原始样本与重建样本之间的均方误差，因其在提高编码效率方面的显著能力而受到越来越多的关注。在第二代和第三代音频视频编码标准（即AVS2和AVS3）中，ALF被采纳为环路滤波器之一。在当前设计中，每帧最多被划分为16个区域，随后推导出相应的滤波器系数并用于重建每个区域。本文提出了一种基于灵活区域的ALF（FRALF）方案，以提高AVS3中现有ALF的适应性，该方案引入了多种区域划分模板，如$2\ imes4$、$4\ imes4$、$4\ imes8$和$8\ imes8$。我们随后提出了滤波器系数合并算法，通过估计不同划分区域的失真水平来进一步提高编码效率。所提出的FRALF能够综合全面地考虑局部纹理特征以及非局部相似性。实验结果表明，FRALF在相对较低的复杂度增加下优于AVS3中现有的基于区域的ALF。
英文摘要
Adaptive loop filter (ALF) for video coding, which is designed to minimize the mean square error between original and reconstructed samples by using Wiener-based filter, has attracted increasing attention for its significant capability in improving coding efficiency. In the second and third Audio Video Coding Standard, i.e., AVS2 and AVS3, ALF is adopted as one of the in-loop filters. In current design, each frame is divided into 16 regions at most and corresponding filter coefficients are then derived and utilized to reconstruct each region. In this paper, a flexible-region based ALF (FRALF) scheme is proposed to improve the adaptability of existing ALF in AVS3, which introduces multiple region partition templates, such as $2\times4$, $4\times4$, $4\times8$ and $8\times8$. We subsequently propose the filter coefficients merging algorithm to further improve coding efficiency by estimating the distortion level of different partition regions. The proposed FRALF can fully consider the local texture characteristics as well as non-local similarities synthetically. The experimental results show that FRALF outperforms the existing region-based ALF in AVS3 with relatively low complexity increasing.
CommentsThis paper was submitted to PCS2019
