US 12,354,315 B2
Method for encoding and decoding a point cloud
Wei Zhang, Shaanxi (CN); and Mary-Luc Georges Henry Champel, Beijing (CN)
Assigned to Beijing Xiaomi Mobile Software Co., Ltd., Beijing (CN); and Xidian University, Xi'An (CN)
Appl. No. 18/001,962
Filed by Beijing Xiaomi Mobile Software Co., Ltd., Beijing (CN); and Xidian University, Shaanxi (CN)
PCT Filed Jun. 24, 2020, PCT No. PCT/CN2020/098272
§ 371(c)(1), (2) Date Dec. 15, 2022,
PCT Pub. No. WO2021/258374, PCT Pub. Date Dec. 30, 2021.
Prior Publication US 2023/0267651 A1, Aug. 24, 2023
Int. Cl. G06T 9/40 (2006.01); G06T 9/00 (2006.01); H04N 19/61 (2014.01)
CPC G06T 9/40 (2013.01) [G06T 9/001 (2013.01); H04N 19/61 (2014.11)] 22 Claims
OG exemplary drawing
 
1. A method for encoding attributes of points of a point cloud to generate a bitstream of compressed point cloud data, wherein the point cloud's geometry is represented by a voxel-based structure with a plurality of nodes having parent-child relationships by recursively splitting a volumetric space containing the point cloud into sub-volumes each associated with a node of the voxel-based structure, the method comprising:
determining a true transform coefficient by applying Region-Adaptive Hierarchal Transform (RAHT), to attributes of a present node;
determining a difference between attributes of a present parent node and each parent node of a first set of parent nodes sharing a face or an edge with the present node, wherein the present parent node is the parent node of the present node;
selecting a second set of parent nodes from the first set of parent nodes according to the difference, wherein the second set of parent nodes includes the present parent node;
determining a predicted value for the attributes of the present node according to attributes of the second set of parent nodes;
determining a predicted transform coefficient by applying the RAHT to the predicted value of the attributes of the present node;
determining a residual from the true transform coefficient and the predicted transform coefficient; and
encoding the residual to produce encoded data of attributes of the point cloud for the bitstream.