Point cloud data transmission apparatus, point cloud data transmission method, point cloud data reception apparatus, and point cloud data reception method

1. A point cloud data transmission method, the method comprising:

acquiring point cloud data;

encoding geometry information including positions of points of the point cloud data;

generating one or more levels of detail (LODs) based on the geometry information and selecting one or more neighbor points of each point to be attribute-encoded based on the one or more LODs, wherein the selected one or more neighbor points of each point are located within a maximum neighbor point distance, wherein the maximum neighbor point distance is obtained by multiplying a base neighbor point distance by a maximum neighbor point range, wherein the maximum neighbor point range is calculated according to a value of a density of the point cloud data, and wherein the density of the point cloud data is obtained by dividing the base neighbor point distance by a diagonal length of a bounding box of the point cloud data;

encoding attribute information of each point based on the selected one or more neighbor points of each point; and

transmitting the encoded geometry information, the encoded attribute information, and signaling information.

2. The method of claim 1 ,

wherein, when the one or more LODs are generated based on an octree, the base neighbor point distance is determined based on a diagonal distance of one node at a specific LOD.

3. A point cloud data transmission apparatus, the apparatus comprising:

an acquisition unit configured to acquire point cloud data;

a geometry encoder configured to encode geometry information including positions of points of the point cloud data;

an attribute encoder configured to generate one or more levels of detail (LODs) based on the geometry information, select one or more neighbor points of each point to be attribute-encoded based on the one or more LODs, and encode attribute information of each point based on the selected one or more neighbor points of each point, wherein the selected one or more neighbor points of each point are located within a maximum neighbor point distance, wherein the maximum neighbor point distance is obtained by multiplying a base neighbor point distance by a maximum neighbor point range, wherein the maximum neighbor point range is calculated according to a value of a density of the point cloud data, and wherein the density of the point cloud data is obtained by dividing the base neighbor point distance by a diagonal length of a bounding box of the point cloud data; and

a transmitter configured to transmit the encoded geometry information, the encoded attribute information, and signaling information.

4. The apparatus of claim 3 ,

wherein, when the one or more LODs are generated based on an octree, the base neighbor point distance is determined based on a diagonal distance of one node at a specific LOD.

5. A point cloud data reception apparatus, the apparatus comprising:

a receiver configured to receive geometry information, attribute information, and signaling information;

a geometry decoder configured to decode the geometry information based on the signaling information;

an attribute decoder configured to generate one or more levels of detail (LODs) based on the geometry information, select one or more neighbor points of each point to be attribute-decoded based on the one or more LODs, and decode the attribute information of each point based on the selected one or more neighbor points of each point and the signaling information, wherein the selected one or more neighbor points of each point are located within a maximum neighbor point distance, wherein the maximum neighbor point distance is obtained by multiplying a base neighbor point distance by a maximum neighbor point range, wherein the maximum neighbor point range is calculated according to a value of a density of point cloud data, and wherein the density of the point cloud data is obtained by dividing the base neighbor point distance by a diagonal length of a bounding box of the point cloud data; and

a renderer configured to render point cloud data restored based on the decoded geometry information and the decoded attribute information.

6. The apparatus of claim 5 ,

wherein, when the one or more LODs are generated based on an octree, the base neighbor point distance is determined based on a diagonal distance of one node at a specific LOD.

7. A point cloud data reception method, the method comprising:

receiving geometry information, attribute information, and signaling information;

decoding the geometry information based on the signaling information;

generating one or more levels of detail (LODs) based on the geometry information and selecting one or more neighbor points of each point to be attribute-decoded based on the one or more LODs, wherein the selected one or more neighbor points of each point are located within a maximum neighbor point distance, wherein the maximum neighbor point distance is obtained by multiplying a base neighbor point distance by a maximum neighbor point range, wherein the maximum neighbor point range is calculated according to a value of a density of the point cloud data, and wherein the density of the point cloud data is obtained by dividing the base neighbor point distance by a diagonal length of a bounding box of the point cloud data;

decoding the attribute information of each point based on the selected one or more neighbor points of each point and the signaling information; and

rendering point cloud data restored based on the decoded geometry information and the decoded attribute information.

8. The method of claim 7 ,

wherein, when the one or more LODs are generated based on an octree, the base neighbor point distance is determined based on a diagonal distance of one node at a specific LOD.