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

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

encoding the point cloud data; and

transmitting a bitstream containing the point cloud data,

wherein the encoding the point cloud data includes:

geometry encoding geometry information of the point cloud data based on a tree including the point cloud data, and

wherein the geometry information is quantized based on a quantization parameter, and an offset is further applied to the point cloud data to scale a position of the geometry information.

2. The method of claim 1 , further comprising:

partitioning a space of the point cloud data based on a partition unit,

wherein the encoding comprises:

encoding attribute information about the point cloud data,

wherein the encoding of the geometry information comprises:

generating an octree for the point cloud data.

3. The method of claim 2 , wherein, when the partitioning unit is a block, the generating of the octree comprises:

constructing the octree on a basis of the block; or

constructing the octree on a basis of a slice including the block.

4. The method of claim 2 , wherein the generating of the octree comprises:

when the partition unit is a block, constructing the octree on a basis of a slice including the block; and

when the slice includes a first block and a second block overlapping each other, generating ID information about points in an overlapping area.

5. The method of claim 2 , wherein, the generating of the octree comprises:

when the partition unit is a block, constructing the octree on a basis of a slice including the block; and

when the slice includes a first block and a second block overlapping each other, adjusting a position of the second block to an area of a virtual block based on an offset value, the virtual block not overlapping the first block.

6. A device for transmitting point cloud data, the device comprising:

an encoder configured to encode the point cloud data; and

a transmitter configured to transmit a bitstream containing the point cloud data,

wherein the encoder further includes:

a geometry encoder configured to geometry encode geometry information of the point cloud data based on a tree including the point cloud data, and

wherein the geometry information is quantized based on a quantization parameter, and an offset is further applied to the point cloud data to scale a position of the geometry information.

7. The device of claim 6 , further comprising:

a spatial partitioner configured to partition a space of the point cloud data based on a partition unit,

wherein the encoder comprises:

an attribute encoder configured to encode attribute information about the point cloud data,

wherein the geometry encoder comprises:

an octree generator configured to generate an octree for the point cloud data.

8. The device of claim 7 , wherein, when the partitioning unit is a block, the octree generator is configured to:

construct the octree on a basis of the block; or

construct the octree on a basis of a slice including the block.

9. The device of claim 7 , wherein the octree generator is configured to:

when the partition unit is a block, construct the octree on a basis of a slice including the block; and

when the slice includes a first block and a second block overlapping each other, generate ID information about points in an overlapping area.

10. The device of claim 7 , wherein the octree generator is configured to:

when the partition unit is a block, construct the octree on a basis of a slice including the block; and

when the slice includes a first block and a second block overlapping each other, adjust a position of the second block to an area of a virtual block based on an offset value, the virtual block not overlapping the first block.

11. A method of receiving point cloud data, the method comprising:

receiving a bitstream containing the point cloud data; and

decoding the point cloud data,

wherein the decoding the point cloud includes:

geometry decoding geometry information of the point cloud data based on a tree including the point cloud data, and

wherein an offset is applied to the point cloud data to scale a position of the geometry information, and the geometry information is de-quantized based on a quantization parameter.

12. The method of claim 11 , wherein the decoding comprises:

decoding attribute information of the point cloud data,

wherein the decoding of the geometry information comprises:

reconstructing an octree for the point cloud data.

13. The method of claim 12 , wherein the reconstructing of the octree comprises:

checking whether the point cloud data is data partitioned based on a tile or a slice.

14. The method of claim 12 , wherein, when the point cloud data is partitioned based on a block, the reconstructing of the octree comprises:

checking whether a type of overlap applied to the point cloud data is an independent octree or an octree excluding position adjustment and additional information.

15. The method of claim 12 , wherein, when the point cloud data is partitioned based on a block, the reconstructing of the octree comprises:

checking whether a type of overlap applied to the point cloud data is an octree excluding position adjustment and including additional block information or an octree including the position adjustment;

reconstructing a virtual position of the block for the point cloud data based on signaling information for each block contained in the bitstream.

16. A device for receiving point cloud data, the device comprising:

a receiver configured to receive a bitstream containing the point cloud data; and

a decoder configured to decode the point cloud data,

wherein the decoder includes:

a geometry decoder configured to geometry decode geometry information of the point cloud data based on a tree including the point cloud information, and

wherein an offset is applied to the point cloud data to scale a position of the geometry information, and the geometry data is de-quantized based on a quantization parameter.

17. The device of claim 16 , wherein the decoder comprises:

an attribute decoder configured to decode attribute information of the point cloud data,

wherein the geometry decoder comprises:

an octree reconstructor configured to reconstruct an octree for the point cloud data.

18. The device of claim 17 , wherein the octree reconstructor checks whether the point cloud data is data partitioned based on a tile or a slice.

19. The device of claim 17 , wherein, when the point cloud data is partitioned based on a block, the octree reconstructor is configured to check whether a type of overlap applied to the point cloud data is an independent octree or an octree excluding position adjustment and additional information.

20. The device of claim 17 , wherein, when the point cloud data is partitioned based on a block, the octree reconstructor is configured to:

check whether a type of overlap applied to the point cloud data is an octree excluding position adjustment and including additional block information or an octree including the position adjustment;

reconstruct a virtual position of the block for the point cloud data based on signaling information for each block contained in the bitstream.