Dependence-Based Coarse-to-Fine Approach for Reducing Distortion Accumulation in G-PCC Attribute Compression
Tian Guo, Hui Yuan, Raouf Hamzaoui, Xiaohui Wang, Lu Shan Wang
Abstract
Geometry-based point cloud compression (G-PCC) is a state-of-the-art point cloud compression standard. While G-PCC achieves excellent performance, its reliance on the predicting transform leads to a significant dependence problem, which can easily result in distortion accumulation. This not only increases bitrate consumption but also degrades reconstruction quality. To address these challenges, we propose a dependence-based coarse-to-fine approach for distortion accumulation in G-PCC attribute compression. Our method consists of three modules: level-based adaptive quantization, point-based adaptive quantization, and Wiener filter-based refinement level quality enhancement. The level-based adaptive quantization module addresses the interlevel-of-detail (LOD) dependence problem, while the point-based adaptive quantization module tackles the interpoint dependence problem. On the other hand, the Wiener filter-based refinement level quality enhancement module enhances the reconstruction quality of each point based on the dependence order among LODs. Extensive experimental results demonstrate the effectiveness of the proposed method. Notably, when the proposed method was implemented in the latest G-PCC test model (TMC13v23.0), a Bj<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\phi$</tex-math></inline-formula>ntegaard delta rate of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$-$</tex-math></inline-formula>4.9%, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$-$</tex-math></inline-formula>12.7%, and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$-$</tex-math></inline-formula>14.0% was achieved for the Luma, Chroma Cb, and Chroma Cr components, respectively.