SSIM-based CTU-level joint optimal bit allocation and rate distortion optimization

作     者：Li, Yang Mou, Xuanqin 

作者机构：Institute of Image Processing and Pattern Recognition Xi'an Jiaotong University Xi'an710049 China 

出 版 物：《arXiv》 (arXiv)

年 卷 期：2020年

核心收录：

主　　题：Signal distortion 

摘      要：Structural similarity (SSIM)-based distortion DSSIM is more consistent with human perception than the traditional mean squared error DMSE. To achieve better video quality, many studies on optimal bit allocation (OBA) and rate-distortion optimization (RDO) used DSSIM as the distortion metric. However, many of them failed to optimize OBA and RDO jointly based on SSIM, thus causing a non-optimal R-DSSIM performance. This problem is due to the lack of an accurate R-DSSIM model that can be used uniformly in both OBA and RDO. To solve this problem, we propose a DSSIM-DMSE model first. Based on this model, the complex R-DSSIM cost in RDO can be calculated as simpler RDMSE cost with a new SSIM-related Lagrange multiplier. This not only reduces the computation burden of SSIM-based RDO, but also enables the R-DSSIM model to be uniformly used in OBA and RDO. Moreover, with the new SSIM-related Lagrange multiplier in hand, the joint relationship of R-DSSIM-λSSIM (the negative derivative of R-DSSIM) can be built, based on which the R-DSSIM model parameters can be calculated accurately. With accurate and unified R-DSSIM 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. An improved version of this manuscript has been accepted by IEEE Transactions on Broadcasting DOI 10.1109/TBC.2021.3068871. The project page is located at http://***/web/xqmou/sosr. Copyright © 2020, The Authors. All rights reserved.