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

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

• a partitioner configured to partition slices including point cloud data into uniform squares by segmenting a maximum axis and a middle axis by a length of a minimum axis of the point cloud data and generate adjacent information for each slice of the partitioned slices, wherein the adjacent information includes a number of points in adjacent slices in four directions including a bottom adjacent slice, a left adjacent slice, a top adjacent slice, and a right adjacent slice for each of the slice of the partitioned slices;
• a refiner configured to merge a first slice of the partitioned slices with one of the adjacent slices having a smallest number of points among the four adjacent slices of the first slice when the number of points in the first slice is less than a minimum number of points;
• split a second slice of the partitioned slices in a direction of one of the adjacent slices among the four adjacent slices of the second slice when the number of points in the second slice is greater than a maximum number of points,
• a geometry encoder configured to encode geometry data of the point cloud data including the merged or split slices;
• a reconstructer configured to reconstruct the geometry data of the point cloud data including the merged or split slices;
• an attribute encoder configured to encode attribute data of the point cloud data based on the reconstructed geometry data;
• and
• a transmitter configured to transmit a bitstream including the encoded geometry data and the encoded attribute.

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

• a receiver configured to receive a bitstream including encoded geometric data and encoded attribute data,
• wherein the point cloud data is included in slices in which the point cloud data is partitioned into uniform squares by segmenting a maximum axis and a middle axis by a length of a minimum axis of the point cloud data,
• wherein adjacent information for each slice of the partitioned slices is generated, wherein the adjacent information includes a number of points in adjacent slices in four directions including a bottom adjacent slice, a left adjacent slice, a top adjacent slice, and a right adjacent slice for each of the slice of the partitioned slices,
• wherein the partitioned slices include a first slice merged with one of the adjacent slices having a smallest number of points among the four adjacent slices of the first slice when the number of points is less than a minimum number of points, and a second slice that is split in a direction of one of the adjacent slices among the four adjacent slices of the second slice when the number of points is greater than a maximum number of points,
• wherein geometry data of the point cloud data including the merged or split slices is encoded,
• wherein the geometry data of the point cloud data including the merged or split slices is reconstructed,
• wherein attribute data of the point cloud data based on the reconstructed geometry data is encoded;
• and
• a decoder configured to decode the encoded geometric data and encoded attribute data.

A method for receiving point cloud data by an apparatus, the method comprising:

• receiving a bitstream including encoded geometry data and encoded attribute data,
• wherein the point cloud data is included in slices in which the point cloud data is partitioned into uniform squares by segmenting a maximum axis and a middle axis by a length of a minimum axis of the point cloud data,
• wherein adjacent information for the partitioned slices is generated, wherein the adjacent information includes a number of points in adjacent slices in four directions including a bottom adjacent slice, a left adjacent slice, a top adjacent slice, and a right adjacent slice for each of the slice of the partitioned slices,
• wherein the partitioned slices include a first slice merged with one of the adjacent slices having a smallest number of points among the four adjacent slices of the first slice when the number of points in the first slice is less than a minimum number of points, and a second slice that is split in a direction of one of the adjacent slices among the four adjacent slices of the second slice when the number of points in the second slice is greater than a maximum number of points,
• wherein geometry data of the point cloud data including the merged or split slices is encoded,
• wherein the geometry data of the point cloud data including the merged or split slices is reconstructed,
• wherein attribute data of the point cloud data based on the reconstructed geometry data is encoded;
• and
• decoding the encoded geometric data and encoded attribute data.