Method and apparatus of encoding/decoding point cloud captured by a spinning sensors head

1 . A method of encoding, comprising:

receiving sparse geometry data captured by a spinning sensors head;

encoding a point cloud into a bitstream of encoded point cloud data, the point cloud based on the sparse geometry data and each point of the point cloud being associated with spherical coordinates and at least one attribute, said spherical coordinates representing an azimuthal angle representing a capture angle of the sensor of the spinning sensors head that captured the point, an elevation angle relative to an elevation of the sensor that captured the point and a radius depending on a distance of the point from a referential, the encoding comprising:

signaling ( 120 ), in the bitstream, a scaling offset information representing scaling offsets;

for each current point of the point cloud:

encoding ( 130 ) the spherical coordinates of the current point and adding encoded spherical coordinates of the current point to the bitstream;

obtaining ( 140 ) decoded spherical coordinates by decoding the encoded spherical coordinates of the current point;

scaling ( 150 ) the decoded spherical coordinates based on the scaling offsets; and

encoding ( 160 ) at least one attribute of the current point based on the scaled decoded spherical coordinates and adding at least one encoded attribute to the bitstream, the attribute being one of color or reflectance of the current point; and

transmitting the bitstream of encoded point cloud data.

2 . The method of claim 1 , wherein the scaling offsets are determined to guaranty that the scaled spherical coordinates meet at least one of the following:

being non-negative; or

belonging to specific ranges.

3 . The method of claim 2 , wherein the scaling offsets are determined as being lower than minimum values calculated from decoded spherical coordinates of all the points of the point cloud.

4 . The method of claim 2 , wherein the scaling offsets are determined based on sensor and capture characteristics of the sensor spinning head.

5 . The method of claim 1 , wherein the scaling offset information comprises the scaling offsets.

6 . The method of claim 1 , wherein the scaling offset information indicates to use a specific method to determine the scaling offsets.

7 . The method of claim 6 , wherein a specific method uses a clipping or a modulo operation.

8 . An apparatus of encoding, comprising:

one or more processors that, in

response to executing non-transitory instructions, cause the apparatus to:

receive sparse geometry data captured by a spinning sensor head;

encode a point cloud into a bitstream of encoded point cloud data, the point cloud based on the sparse geometry data and each point of the point cloud being associated with spherical coordinates and at least one attribute, said spherical coordinates representing an azimuthal angle representing a capture angle of the sensor of the spinning sensors head that captured the point, an elevation angle relative to an elevation of the sensor that captured the point and a radius depending on a distance of the point from a referential, the encode including:

signal, in the bitstream, a scaling offset information representing scaling offsets;

for each current point of the point cloud:

encode the spherical coordinates of the current point and adding encoded spherical coordinates to the bitstream;

obtain decoded spherical coordinates of the current point by decoding the encoded spherical coordinates;

scale the decoded spherical coordinates of the current point based on the scaling offsets; and

encode at least one attribute of the current point based on the scaled decoded spherical coordinates and adding at least one encoded attribute to the bitstream, the attribute being one of color or reflectance of the current point; and

transmit the bitstream of encoded point cloud data.

9 . A non-transitory storage medium carrying instructions of program code for executing the method according to claim 1 .

10 . A method of decoding a point cloud from a bitstream of encoded point cloud data captured by a spinning sensors head, wherein the method comprises:

receiving the bitstream of encoded point cloud data;

accessing ( 210 ) a scaling offset information from the bitstream;

for each current point of the point cloud:

obtaining ( 220 ) decoded spherical coordinates by decoding encoded spherical coordinates of the current point obtained from the bitstream, the spherical coordinates of the current point representing an azimuthal angle representing a capture angle of the sensor of a spinning sensors head that captured the current point, an elevation angle relative to an elevation of the sensor that captured the current point and a radius depending on a distance of the current point from a referential;

scaling ( 230 ) the decoded spherical coordinates based on scaling offsets obtained from the scaling offset information; and

decoding ( 240 ) attributes of the current point based on the scaled decoded spherical coordinates, the attributes including one of color or reflectance of the current point.

11 . A non-transitory storage medium carrying instructions of program code for executing the method according to claim 10 .

12 . The method of claim 10 , wherein the scaling offsets are determined to guaranty that the scaled spherical coordinates are met at least one of the following:

being non-negative; or

belonging to specific ranges.

13 . The method of claim 12 , wherein the scaling offsets are determined as being lower than minimum values calculated from decoded spherical coordinates of all the points of the point cloud.

14 . The method of claim 12 , wherein the scaling offsets are determined based on sensor and capture characteristics of the sensor spinning head.

15 . The method of claim 10 , wherein the scaling offset information comprises the scaling offsets.

16 . The method of claim 10 , wherein the scaling offset information indicates to use a specific method to determine the scaling offsets.

17 . The method of claim 16 , wherein a specific method uses a clipping or a modulo operation.

18 . An apparatus of decoding a point cloud from a bitstream of encoded point cloud data captured by a spinning sensors head, wherein the apparatus comprises one or more processors configured to perform the method according to claim 10 .

19 . The apparatus of claim 8 , wherein the scaling offsets are determined to guaranty that the scaled spherical coordinates are met at least one of the following:

being non-negative; or

belonging to specific ranges.

20 . The apparatus of claim 18 , wherein the scaling offsets are determined to guaranty that the scaled spherical coordinates are met at least one of the following:

being non-negative; or

belonging to specific ranges.