Device and method of transmitting point cloud data, device and method of processing point cloud data

1. A method of transmitting point cloud data, the method comprising:

encoding the point cloud data including geometry and attribute, the geometry representing positions of points of the point cloud data, the attribute including at least one of colors and reflectance of the points,

wherein encoding the point cloud data includes:

encoding the geometry; and

encoding the attribute based on complete or partial octree of the encoded geometry, wherein the attribute is encoded based on weight of an LOD (Level Of Detail) of one or more LODs, wherein the weight is derived based on a number of the points and a number of points that belong to a level that is represented by the LOD; and

transmitting a bitstream including the encoded point cloud data

wherein the weight is represented as follows:

W

extended

⁢

⁢

LoD

l

=

Total

⁢

⁢

point

⁢

⁢

number

point

⁢

⁢

number

⁢

⁢

in

⁢

⁢

LoD

l

=

Total

⁢

⁢

point

⁢

⁢

number

∑

i

=

0

l

⁢

point

⁢

⁢

number

⁢

⁢

in

⁢

⁢

R

i

,

W extended LoD i represents the weight, the total point number represents the number of the points, the point number in LOD 1 represents a number of points that belong to a level 1 represented by the LOD 1 , the point number in Ri represents a number of points that only belong to a level i of an LODi, and a value of the point number in LOD 1 is equal to a sum of values of the point number in Ri wherein a value of i is in a range of 0 to 1.

2. The method of claim 1 , wherein encoding the attribute further includes:

generating the one or more LODs by reorganizing the points;

lifting transform decoding the attribute based on the one or more LODs; and

quantization processing the decoded attribute based on the weight.

3. The method of claim 2 , wherein the weight is used to decode the encoded attribute based on the partial octree.

4. The method of claim 3 , wherein the bitstream includes signaling information indicating whether the encoded attribute is decoded based on the partial octree.

5. A method of processing point cloud data, the method comprising:

receiving a bitstream including the point cloud data, the bitstream including signaling information; and

decoding the point cloud data based on the signaling information, decoding the point cloud data including:

decoding geometry included in the point cloud data, the geometry representing positions of points of the point cloud data; and

decoding attribute, which includes at least one of colors and reflectance of the points, based on complete or partial octree of the decoded geometry, wherein the attribute is decoded based on weight of an LOD (Level Of Detail) of one or more LODs, wherein the weight is derived based on a total number of the points and a number of all points belonging to the LOD, the all points belonging to the LOD including points from a first LOD to the LOD.

6. The method of claim 5 , wherein the signaling information includes scalability information indicating whether lifting transform decoding attribute based on the partial octree is allowed.

7. The method of claim 6 , wherein the scalability information indicates whether lifting transform decoding attribute based on the partial octree is allowed, the weight is computed for each point in each LOD from 0 th LOD to the last LOD.

8. The method of claim 7 , wherein decoding attribute includes:

generating the one or more LODs by reorganizing the points;

lifting transform decoding the attribute based on the one or more LODs; and

inverse quantization processing the decoded attribute.

9. The method of claim 8 , wherein the weight is determined by executing a program instruction for deriving the weight.

10. A device of processing point cloud data, the device comprising:

a receiver to receive a bitstream including the point cloud data, the bitstream including signaling information; and

a decoder to decode the point cloud data based on the signaling information, the decoder including:

a geometry decoder configured to decode geometry included in the point cloud data, the geometry representing positions of points of the point cloud data; and

an attribute decoder configured to decoded attribute, which includes at least one of colors and reflectance of the points, based on complete or partial octree of the decoded geometry, wherein the attribute is decoded based on weight of an LOD (Level Of Detail) of one or more LODs, wherein the weight is derived based on a total number of the points and a number of all points belonging to the LOD, the all points belonging to the LOD including points from a first LOD to the LOD.

11. The device of claim 10 , wherein the signaling information includes scalability information indicating whether lifting transform decoding attribute based on the partial octree is allowed.

12. The device of claim 11 , wherein the scalability information indicates whether lifting transform decoding attribute based on the partial octree is allowed, the weight is computed for each point in each LOD from 0 th LOD to the last LOD.

13. The device of claim 12 , wherein the attribute decoder is configured to:

generate the one or more LODs by reorganizing the points;

lifting transform decode the attribute based on the one or more LODs; and

inverse quantization process the decoded attribute.

14. The device of claim 13 , the device comprising a memory to store a program instruction for deriving the weight.