Contextual Homogeneity-Based Patch Decomposition Method for Higher Point Cloud Compression

Point cloud content is widely used to store and represent 3D volumetric objects with a complex and detailed representation from any direction of view. However, the amount of data needed for point cloud content is much larger than that of 2D representations. To overcome this difficulty, MPEG has started to develop a Video-based Point Cloud Compression (V-PCC) that is designed by projecting point cloud content into 2D content and compressing the 2D content using conventional 2D video codecs. Compression efficiency of the V-PCC can be achieved when 3D motion flow and textual conformity on 3D surfaces are preserved through 2D projections that are favorable to the 2D video codec. As mentioned above, point cloud content has a complex geometry, therefore when decomposing a point from 3D coordinates to construct a 2D patch, several situations must be considered in addition to the location of adjacent points. This paper addresses the issues in such complex geometry by proposing a method that preserves 3D homogeneity in 2D patches. Comprehensive experiments are conducted to demonstrate bitrate savings of 0.5%, 0.6%, 7.8%, 7.0% and 5.5% in random access mode and 0.1%, 0.0%, 7.0%, 4.2% and 3.3% in all intra mode for D1, D2, Y, Cb, and Cr, respectively, compared to the reference software.