	US 12,439,084 B2
	Method and apparatus of encoding/decoding point cloud captured by a spinning sensors head
Sebastien Lasserre, Beijing (CN); and Jonathan Taquet, Beijing (CN)
Assigned to BEIJING XIAOMI MOBILE SOFTWARE CO., LTD., Beijing (CN)
Appl. No. 18/575,807
Filed by BEIJING XIAOMI MOBILE SOFTWARE CO., LTD., Beijing (CN)
PCT Filed Apr. 20, 2022, PCT No. PCT/CN2022/088037 § 371(c)(1), (2) Date Dec. 29, 2023, PCT Pub. No. WO2023/273537, PCT Pub. Date Jan. 5, 2023.
Claims priority of application No. 21305921 (EP), filed on Jul. 2, 2021.
Prior Publication US 2024/0163480 A1, May 16, 2024
Int. Cl. H04N 19/597 (2014.01); H04N 19/91 (2014.01)

CPC H04N 19/597 (2014.11) [H04N 19/91 (2014.11)]

13 Claims

7. A method of decoding a point cloud captured by a set of sensors from a bitstream of encoded point cloud data, comprising:

decoding, by a decoder from the bitstream, an information representative of a number (Ndup_n) of duplicated points associated with an already decoded current point (P_n) of the point cloud;

reconstructing, by the decoder, a number of duplicated points, which equals to the decoded number (Ndup_n) of duplicated points, each duplicated point having a same azimuthal angle equaling to an azimuthal angle of the already decoded current point (P_n), and a sensor index equaling to a sensor index of the already decoded current point (P_n), wherein the azimuthal angle represents a capture angle of a sensor that captured the already decoded current point (P_n), and the sensor index is associated with the sensor;

decoding, by the decoder, an order index difference (Δo_next) from the bitstream for a next point (P_next), the next point (P_next) having an order index (o(P_next)) different of an order index (o(P_n)) of the already decoded current point (P_n), an order index being associated with a point of the point cloud according to a rank of the point in a list of ordered points obtained by ordering points of the point cloud according to a lexicographic order based first on azimuthal angles and then on sensor indices associated with the points of the point cloud, or inversely;

obtaining, by the decoder, an order index (o(P_next)) for the next point (P_next) from the decoded order index difference (Δo_next) and the order index (o(P_n)) of the already decoded current point (P_n);

obtaining, by the decoder, a sensor index (λ_next) associated with a sensor that captured the next point (P_next) and an azimuthal angle (ϕ_next) representing a capture angle of the sensor from the order index (o(P_next)) of the next point (P_next); and

updating, by the decoder, the already decoded current (P_n) to a new already decoded current point by taking the next point (P_next) as being the new already decoded current point.