Point cloud data transmission device and method, and point cloud data reception device and method
A point cloud data transmission method according to the embodiments may comprise the steps of encoding point cloud data, and transmitting the point cloud data. A point cloud data reception method according to the embodiments may comprise the steps of receiving a bitstream comprising point cloud data, and decoding the point cloud data.
1 . A device comprising:
a memory; and
at least one processor connected to the memory, the at least one processor configured to:
encode a geometry layer group including a subgroup including geometry data for one or more levels of a tree including points; and
encode an attribute layer group including a subgroup including attribute data for the one or more levels of the tree including the points,
wherein the geometry layer group is encoded based on context information related to the subgroup in the geometry layer group,
wherein the geometry layer group is identified based on an layer group identifier and the subgroup of the geometry layer group is identified based on a subgroup identifier.
2 . A method comprising:
decoding a geometry layer group including a subgroup including geometry data for one or more levels of a tree including points; and
decoding an attribute layer group including a subgroup including attribute data for the one or more levels of the tree including the points,
wherein the geometry layer group is decoded based on context information related to the subgroup in the geometry layer group,
wherein the geometry layer group is identified based on an layer group identifier and the subgroup of the geometry layer group is identified based on a subgroup identifier.
3 . The method of claim 2 , further comprising:
receiving a bitstream including the geometry layer group and the attribute layer group and selecting a tile of the bitstream; and
selecting a slice of the tile, or
the method further comprising:
receiving a bitstream including the geometry layer group and the attribute layer group and selecting a tile of the bitstream;
selecting a slice of the tile; and
selecting a layer group and a subgroup related to the slice, or
the method further comprising:
receiving the bitstream and selecting a tile of the bitstream;
selecting a layer group and a subgroup of the tile, or
the method further comprising:
receiving the bitstream and decoding a layer group and a subgroup of the bitstream.
4 . The method of claim 3 , further comprising
wherein the slice comprises the layer group of the points and a subgroup of the layer group,
wherein the layer group contains the points based on a resolution of the points and a region of interest (ROI).
5 . The method of claim 4 , further comprising:
loading a context table of a slice related to the layer group; and
decoding a node of the layer group by referencing the context table,
wherein the points are decoded based on information related to a node included in a subgroup bounding box including the node, while nodes outside the subgroup bounding box are not used,
wherein the referenced context table is generated from a slice consecutive to the slice of the layer group,
wherein nodes belonging to the subgroup are used as neighbors of the points,
wherein occupancy information about the neighbors is included in an atlas.
6 . A method of transmitting data for point cloud data comprising:
obtaining a bitstream generated by encoding a geometry layer group including a subgroup including geometry data for one or more levels of a tree including points; and encoding an attribute layer group including a subgroup including attribute data for the one or more levels of the tree including the points, wherein the geometry layer group is encoded based on context information related to the subgroup in the geometry layer group, wherein the geometry layer group is identified based on an layer group identifier and the subgroup of the geometry layer group is identified based on a subgroup identifier; and
transmitting data for the point cloud data including the bitstream.
7 . A method comprising:
encoding a geometry layer group including a subgroup including geometry data for one or more levels of a tree including points; and
encoding an attribute layer group including a subgroup including attribute data for the one or more levels of the tree including the points,
wherein the geometry layer group is encoded based on context information related to the subgroup in the geometry layer group, and
wherein the geometry layer group is identified based on a layer group identifier and the subgroup of the geometry layer group is identified based on a subgroup identifier.
8 . The method of claim 7 ,
wherein the attribute layer group is encoded based on a LoD (level of detail).
9 . The method of claim 7 ,
wherein the geometry layer group includes one or more subgroups,
wherein the bitstream contains information about a layer group including the one or more levels, and information about the subgroup.
10 . The method of claim 7 ,
wherein the encoding the geometry layer group comprises:
directly encoding a point of a sub-node of a node in the tree based on a relationship between the node and the sub-node; and
separately transmitting a bitstream containing the directly encoded point.
11 . The method of claim 7 , further comprising:
slicing the points based on a layer group,
selecting a slice of a bitstream including the geometry layer group and the attribute layer group,
wherein the slice comprises the layer group and a subgroup of the layer group,
wherein the layer group contains the points based on a resolution of the points and a region of interest (ROI).
12 . The method of claim 11 , further comprising:
loading a context table of a slice related to the layer group; and
encoding a node of the layer group by referencing the context table,
wherein the points are encoded based on information related to a node included in a subgroup bounding box including the node, while nodes outside the subgroup bounding box are not used,
wherein the referenced context table is generated from a slice consecutive to the slice of the layer group,
wherein nodes belonging to the subgroup are used as neighbors of the points,
wherein occupancy information about the neighbors is stored in an atlas.