Joint Optimization of Transform and Quantization for High Efficiency Video Coding
Joint Optimization of Transform and Quantization for High Efficiency Video Coding
复制标题
高效视频编码的变换和量化联合优化
DOI：
10.1109/access.2019.2917260
复制
发表时间：
2019
期刊：
影响因子：
3.9
通讯作者：
Qin Jing
中科院分区：
文献类型：
--
作者：
Wang Miaohui;Xie Wuyuan;Xiong Jian;Wang Dayong;Qin Jing
在高效视频编码（HEVC）中，变换和量化是分开执行的，以消除视觉信号的感知冗余。然而，由于视频内容的空间频率特性变化，均匀量化器不可避免地会降低固定变换矩阵的压缩效率。本文介绍了一种用于视频编码的变换和量化联合优化方法。首先，我们通过快速 Karhunen-Loéve 变换 (KLT) 根据重建的参考计算内容相关变换。其次，使用基于模板的速率正则化，我们联合优化变换和量化（JOTQ）作为速率约束优化问题，并获得提高编码性能的可行解决方案。最后，我们设计快速算法和提前终止来降低 JOTQ 的计算复杂度。实验结果表明，JOTQ 优于之前的几种方法，在低延迟和随机访问配置下，Bjøntegaard Delta 速率平均分别降低了 4.11% 和 3.38%。
In high efficiency video coding (HEVC), transformation and quantization are separately performed to eliminate the perceptual redundancy of visual signals. However, a uniform quantizer can inevitably degrade the compression efficiency of fixed transform matrices due to varying space-frequency characteristics of video content. This paper introduces a joint optimization of transform and quantization approach for video coding. First, we compute a content dependent transform from the reconstructed reference by a fast Karhunen-Loéve transform (KLT). Second, using a template-based rate regularization, we jointly optimize transform and quantization (JOTQ) as a rate constrained optimization problem and obtain a feasible solution to improve coding performance. Finally, we design fast algorithms and early terminations to reduce the computational complexity of JOTQ. The experimental results show that JOTQ outperforms several previous methods by providing Bjøntegaard Delta rate reductions of 4.11% and 3.38% on average under the low-delay and random-access configuration, respectively.