US 11,900,641 B2
Methods and devices for binary entropy coding of point clouds
Sébastien Lasserre, Thorigné-Fouillard (FR)
Assigned to Malikie Innovations Limited, Dublin (IE)
Appl. No. 17/280,753
Filed by BlackBerry Limited, Waterloo (CA)
PCT Filed Oct. 2, 2019, PCT No. PCT/EP2019/076711
§ 371(c)(1), (2) Date Mar. 26, 2021,
PCT Pub. No. WO2020/070192, PCT Pub. Date Apr. 9, 2020.
Claims priority of application No. 18290113 (EP), filed on Oct. 2, 2018.
Prior Publication US 2021/0350583 A1, Nov. 11, 2021
Int. Cl. G06T 9/40 (2006.01); G06F 17/18 (2006.01); H03M 7/30 (2006.01); H04N 19/105 (2014.01); G06T 9/00 (2006.01); G06T 17/10 (2006.01); H04N 19/13 (2014.01); H04N 19/169 (2014.01); H04N 19/46 (2014.01); H04N 19/96 (2014.01)
CPC G06T 9/40 (2013.01) [G06F 17/18 (2013.01); G06T 9/001 (2013.01); G06T 17/10 (2013.01); H03M 7/6005 (2013.01); H03M 7/6011 (2013.01); H04N 19/105 (2014.11); H04N 19/13 (2014.11); H04N 19/1883 (2014.11); H04N 19/46 (2014.11); H04N 19/96 (2014.11)] 24 Claims
OG exemplary drawing
 
1. A method of encoding a point cloud to generate a bitstream of compressed point cloud data, the point cloud being defined in a tree structure having a plurality of nodes having parent-child relationships and that geometrically represent a volumetric space recursively split into sub-volumes containing points of the point cloud, wherein occupancy of sub-volumes of a volume is indicated using a bit sequence in which each bit indicates occupancy of a respective sub-volume in a scan order within the volume, which has a plurality of neighbouring volumes, the method comprising:
determining, for a current node associated with a current volume split into first sub-volumes, a first bit sequence indicating occupancy statuses of the first sub-volumes, wherein each first sub-volume corresponds to a child node of the current node; and
for at least one bit in the first bit sequence of the current volume:
determining, based on occupancy data for second sub-volumes of at least one neighbouring volume of the current volume, a sub-volume neighbour configuration that depends on an occupancy pattern of a group of the second sub-volumes that neighbour a first sub-volume of the current volume that corresponds to the at least one bit in the first bit sequence;
selecting a probability for use in entropy encoding of the at least one bit in the first bit sequence, wherein the probability is selected based at least in part on the sub-volume neighbour configuration; and
entropy encoding the at least one bit in the first bit sequence based on the probability using a binary entropy encoder to produce encoded binarized data for the bitstream.