论文标题
基于SSIM的CTU级关节最佳位分配和速率失真优化
SSIM-Based CTU-Level Joint Optimal Bit Allocation and Rate Distortion Optimization
论文作者
论文摘要
结构相似性（SSIM）基于失真$ d_ \ text {ssim} $比传统的均值错误$ d_ \ text {mse} $更与人类感知一致。为了获得更好的视频质量，许多有关最佳位分配（OBA）和利率延伸优化（RDO）的研究使用了$ d_ \ text {ssim} $作为失真度量。但是，他们中的许多人未能基于SSIM共同优化OBA和RDO，从而导致非最佳的R- $ D_ \ text {ssim} $ performance。此问题是由于缺乏准确的R- $ D_ \ Text {SSIM} $模型，该模型可以在OBA和RDO中均匀使用。为了解决此问题，我们提出了$ d_ \ text {ssim} $ - $ d_ \ text {mse} $模型。基于此模型，RDO中的复杂r- $ d_ \ text {ssim} $可以计算为简单的r- $ d_ \ text {mse} $，具有新的与SSIM相关的Lagrange乘数。这不仅减轻了基于SSIM的RDO的计算负担，而且还使R- $ d_ \ text {ssim} $模型可以均匀地用于OBA和RDO。此外，随着新的与SSIM相关的Lagrange乘数，R- $ D_ \ text {ssim} $ - $λ__\ text {ssim} $的联合关系（r- $ d_ \ d_ \ d_ \ text {ssim} $的负衍生物可以基于r- $ d_ cams $ carte cartim text = ssim} $ cartim caster in cartimer casim camiim casine cam pacin} $。使用准确统一的R- $ D_ \ Text {SSIM} $模型，基于SSIM的OBA和基于SSIM的RDO在我们的方案（称为SOSR）中统一在一起。与HEVC参考编码器HM16.20相比，SOSR在同一SSIM下，在跨INTRA，分层和非层次级别的低固定B构型中节省了4％，10％和14％的比特率，这比其他最先进的方案都优于其他原始方案。
Structural similarity (SSIM)-based distortion $D_\text{SSIM}$ is more consistent with human perception than the traditional mean squared error $D_\text{MSE}$. To achieve better video quality, many studies on optimal bit allocation (OBA) and rate-distortion optimization (RDO) used $D_\text{SSIM}$ as the distortion metric. However, many of them failed to optimize OBA and RDO jointly based on SSIM, thus causing a non-optimal R-$D_\text{SSIM}$ performance. This problem is due to the lack of an accurate R-$D_\text{SSIM}$ model that can be used uniformly in both OBA and RDO. To solve this problem, we propose a $D_\text{SSIM}$-$D_\text{MSE}$ model first. Based on this model, the complex R-$D_\text{SSIM}$ cost in RDO can be calculated as simpler R-$D_\text{MSE}$ cost with a new SSIM-related Lagrange multiplier. This not only reduces the computation burden of SSIM-based RDO, but also enables the R-$D_\text{SSIM}$ model to be uniformly used in OBA and RDO. Moreover, with the new SSIM-related Lagrange multiplier in hand, the joint relationship of R-$D_\text{SSIM}$-$λ_\text{SSIM}$ (the negative derivative of R-$D_\text{SSIM}$) can be built, based on which the R-$D_\text{SSIM}$ model parameters can be calculated accurately. With accurate and unified R-$D_\text{SSIM}$ model, SSIM-based OBA and SSIM-based RDO are unified together in our scheme, called SOSR. Compared with the HEVC reference encoder HM16.20, SOSR saves 4%, 10%, and 14% bitrate under the same SSIM in all-intra, hierarchical and non-hierarchical low-delay-B configurations, which is superior to other state-of-the-art schemes.
