Adaptive Multi-level Triangle Soup for Geometry-based Point Cloud Coding

Nowadays, point clouds are considered as a promising representation for future immersive 3D applications. However, to recreate a 3D object or scene with high fidelity, a large number of points is required, often with high coordinates precision. Thus, efficient compression schemes are much needed for transmission and storage of point cloud data. Several types of coding techniques (e.g. 2D mapping, graph transforms, etc.) have been proposed in the literature to solve this problem. Octree-based solutions provide compression efficiency and level-of-detail scalability, especially for large static point clouds. The upcoming MPEG Geometry based Point Cloud Coding (G-PCC) solution provides high coding performance and relies on a static pruned octree, combined with a trisoup (for triangle soup) surface reconstruction. In this paper, the geometry coding process of G-PCC is enhanced by introducing mode decisions, thus enabling the trisoup in leaf nodes at multiple levels of the octree, i.e. allowing a more adaptive octree partitioning. Experimental results report average BD-rate gains of 5.3% (up to 7%) for the geometry component (point-to-plane error) on dense point clouds, with no significant impact on the color coding performance.