Silhouette 4d: An Inter-Frame Lossless Geometry Coder Of Dynamic Voxelized Point Clouds

This paper presents a lossless inter geometry coder of voxelized point clouds. We build upon our previous work, extending the contexts used in the arithmetic coding to include voxels from a reference point cloud, hence the name, 4D contexts. We show that considering both 3D and 4D contexts leads to a substantial gain compared to considering each one on its own, and we also propose a fast decision method to avoid encoding each slice with both contexts. The proposed codec has the same complexity as our previous intra codec, but it shows an equal or superior performance for all point clouds tested. Results show that the proposed method outperforms all intra and inter state-of-the-art coders on the public available datasets tested.