Method and apparatus for encoding 3D mesh models, and method and apparatus for decoding encoded 3D mesh models

摘要

3D mesh models are widely used in various applications for representing 3D objects. These models are made of vertices and corresponding triangles, which can be compressed based on prediction and residuals. The present invention improves the accuracy of parallelogram prediction, particularly near sharp features. The proposed 3D mesh model encoding comprises analyzing the spatial or dihedral angles between triangles, clustering triangles with similar or equal dihedral angles, and defining a representative dihedral angle for each cluster. Triangles of each cluster are then encoded relative to individual prediction triangles having the representative dihedral angle according to the cluster. Additionally, the prediction triangle may be mirrored. An indication of the encoding mode is inserted into each vertex of the encoded bitstream. A decoder extracts the encoding mode indication, reconstructs the individual prediction triangles based on the respective representative dihedral angles and performs triangle prediction and reconstruction.