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

1. A method for receiving point cloud data, the method comprising:

receiving a bitstream including point cloud data,

the point cloud data including geometry data and attribute data;

decoding the geometry data; and

decoding the attribute data,

wherein the geometry data include a tree,

wherein LOD(Level of Detail)s are generated based on the geometry data,

wherein points of the geometry data in the LODs are sorted based on a Morton code,

wherein a point having a lowest point index included in a LOD of which a detail level is an even is sampled and a point having a greatest point index included in a LOD of which a detail level is an odd is sampled.

2. The method of claim 1 ,

wherein the decoding the geometry data includes:

generating the tree for the geometry data,

setting a location of a point representing each node of the tree as a nearest node for a center location of a bounding box of each node.

3. The method of claim 1 ,

wherein the decoding the attribute data includes:

changing a location value of points of the point cloud data into a morton code based on the geometry data and the attribute data,

decoding the points from a depth level of the tree including the points.

4. An apparatus for receiving point cloud data, the apparatus comprising:

a receiver configured to receive a bitstream including point cloud data,

the point cloud data including geometry data and attribute data;

a decoder configured to decode the geometry data; and

a decoder configured to decode the attribute data,

wherein the geometry data including a tree,

wherein LOD(Level of Detail)s are generated based on the geometry data,

wherein points of the geometry data in the LODs are sorted based on a Morton code,

wherein a point having a lowest point index included in a LOD of which a detail level is an even is sampled and a point having a greatest point index included in a LOD of which a detail level is an odd is sampled.

5. The apparatus of claim 4 ,

wherein the decoder for the geometry data is configured to perform:

generating the tree for the geometry data,

setting a location of a point representing each node of the tree as a nearest node for a center location of a bounding box of each node.

6. The apparatus of claim 4 ,

wherein the decoder for the attribute data is configured to perform:

changing a location value of points of the point cloud data into a morton code based on the geometry data and the attribute data,

decoding the points from a depth level of the tree including the points.

7. A method for transmitting point cloud data, the method comprising:

encoding geometry data;

encoding attribute data,

wherein the geometry data including a tree,

wherein LOD(Level of Detail)s are generated based on the geometry data,

wherein points of the geometry data in the LODs are sorted based on a Morton code; and

transmitting a bitstream including point cloud data including the geometry data and the attribute data,

wherein a point having a lowest point index included in a LOD of which a detail level is an even is sampled and a point having a greatest index included in a LOD of which a detail level is an odd is sampled.

8. The method of claim 7 ,

wherein the encoding the geometry data includes:

generating the tree for the geometry data,

setting a location of a point representing each node of the tree as a nearest node for a center location of a bounding box of each node.

9. The method of claim 7 ,

wherein the encoding the attribute data includes:

changing a location value of points of the point cloud data into a morton code based on the geometry data and the attribute data,

encoding the points from a depth level of a tree including the points.

10. An apparatus for transmitting point cloud data, the apparatus comprising:

an encoder configured to encode geometry data;

an encoder configured to encode attribute data,

wherein the geometry data including a tree,

wherein LOD(Level of Detail)s are generated based on the geometry data,

wherein points of the geometry data in the LODs are sorted based on a Morton code; and

a transmitter configured to transmit a bitstream including point cloud data including the geometry data and the attribute data,

wherein a point having a lowest point index included in a LOD of which a detail level is an even is sampled and a point having a greatest point index included in a LOD of which a detail level is an odd is sampled.