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EP-4742677-A1 - POINT CLOUD DATA TRANSMISSION DEVICE, POINT CLOUD DATA TRANSMISSION METHOD, POINT CLOUD DATA RECEPTION DEVICE, AND POINT CLOUD DATA RECEPTION METHOD

EP4742677A1EP 4742677 A1EP4742677 A1EP 4742677A1EP-4742677-A1

Abstract

A point cloud data decoding method according to embodiments may comprise the steps of: receiving a bitstream including point cloud data; and decoding the point cloud data. A point cloud data encoding method according to embodiments may comprise the steps of: encoding point cloud data; and transmitting a bitstream including the point cloud data.

Inventors

  • OH, Hyunmook

Assignees

  • LG Electronics Inc.

Dates

Publication Date
20260513
Application Date
20240704

Claims (15)

  1. A method of decoding point cloud data, the method comprising: receiving a bitstream containing point cloud data; and decoding the point cloud data.
  2. The method of claim 1, wherein the decoding of the point cloud data comprises: decoding geometry of the point cloud data; and decoding attributes of the point cloud data, wherein at least one of the geometry or the attributes is contained in a fine slice, the fine slice containing a layer group including at least one layer or a subgroup in the layer group.
  3. The method of claim 2, wherein the point cloud data is decoded based on a context for the point cloud data contained in the fine slice.
  4. The method of claim 2, wherein, based on information indicating a context for the fine slice is stored: the context for the fine slice is used in decoding a subsequent fine slice of the fine slice; a first list including index information related to subgroups for the fine slice is generated; and a second list including index information related to subgroups decoded based on a specific context is generated, wherein, based on that the information included in the first list is the same as the information included in the second list, a context stored in a memory is deleted.
  5. The method of claim 2, wherein, based on information indicating a context for the fine slice is stored: the context for the fine slice is used in decoding a subsequent fine slice of the fine slice; information about a number of subgroups for the fine slice is generated; and a count indicating subgroups decoded based on a specific context is generated, wherein, based on that the information about a number of subgroups is equal to the count, a context stored in a memory is deleted.
  6. The method of claim 5, wherein fine slices containing at least one of the geometry or the attributes have a parent-child relationship based on the layer group or the subgroup, wherein the fine slices are decoded based on a breadth-first search.
  7. The method of claim 2, wherein fine slices containing at least one of the geometry or the attributes have a parent-child relationship based on the layer group or the subgroup, wherein the fine slices are decoded based on a breadth-first search, wherein, based on that after decoding a first layer group, a second layer group is decoded, a context for the first layer group is deleted from a memory, wherein the fine slices are decoded based on a depth-first search, wherein, based on switching from a leaf direction to a root direction, contexts for found fine slices are deleted from the memory.
  8. The method of claim 1, wherein the bitstream contains at least one of: information indicating a search order of fine slices containing at least one of a layer group or a subgroup; information indicating whether a context for a current fine slice is referenced for a subsequent fine slice; information indicating a number of subsequent dependent data units using a context for a current data unit; information indicating a number of layer groups in a list of subsequent data units; information indicating a layer group index of the subsequent data units; information indicating a number of subgroups in each of the layer groups in the list of subsequent data units; or information indicating a subgroup index in each of the layer groups of the subsequent data units.
  9. A device for decoding point cloud data, comprising: a receiver configured to receive a bitstream containing point cloud data; and a decoder configured to decode the point cloud data.
  10. A method of encoding point cloud data, the method comprising: encoding point cloud data; and transmitting a bitstream containing the point cloud data.
  11. The method of claim 10, wherein the encoding of the point cloud data comprises: encoding geometry of the point cloud data; and encoding attributes of the point cloud data, wherein at least one of the geometry or the attributes is contained in a fine slice, the fine slice containing a layer group including at least one layer or a subgroup in the layer group.
  12. The method of claim 11, wherein the point cloud data is encoded based on a context for the point cloud data contained in the fine slice.
  13. The method of claim 11, wherein, based on information indicating a context for the fine slice is stored: the context for the fine slice is used in encoding a subsequent fine slice of the fine slice; a first list including index information related to subgroups for the fine slice is generated; and a second list including index information related to subgroups encoded based on a specific context is generated, wherein, based on that the information included in the first list is the same as the information included in the second list, a context stored in a memory is deleted.
  14. The method of claim 11, wherein, based on information indicating a context for the fine slice is stored: the context for the fine slice is used in encoding a subsequent fine slice of the fine slice; information about a number of subgroups for the fine slice is generated; and a count indicating subgroups encoded based on a specific context is generated, wherein, based on that the information about a number of subgroups is equal to the count, a context stored in a memory is deleted.
  15. A device for encoding point cloud data, comprising: an encoder configured to encode point cloud data; and a transmitter configured to transmit a bitstream containing the point cloud data.

Description

[Technical Field] Embodiments relate to methods and devices for processing point cloud content. [Background Art] Point cloud content is content represented by a point cloud, which is a set of points belonging to a coordinate system representing a three-dimensional space. The point cloud content may express media configured in three dimensions, and is used to provide various services such as virtual reality (VR), augmented reality (AR), mixed reality (MR), and self-driving services. However, tens of thousands to hundreds of thousands of point data are required to represent point cloud content. Therefore, there is a need for a method for efficiently processing a large amount of point data. [Disclosure] [Technical Problem] Embodiments provide a device and method for efficiently processing point cloud data. Embodiments provide a point cloud data processing method and device for addressing latency and encoding/decoding complexity. The technical scope of the embodiments is not limited to the aforementioned technical objects, and may be extended to other technical objects that may be inferred by those skilled in the art based on the entire contents disclosed herein. [Technical Solution] A method of decoding point cloud data according to embodiments may include receiving a bitstream containing point cloud data, and decoding the point cloud data. A method of encoding point cloud data according to embodiments may include encoding point cloud data, and transmitting a bitstream containing the point cloud data. [Advantageous Effects] Devices and methods according to embodiments may process point cloud data with high efficiency. The devices and methods according to the embodiments may provide a high-quality point cloud service. The devices and methods according to the embodiments may provide point cloud content for providing general-purpose services such as a VR service and a self-driving service. [Description of Drawings] The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the disclosure and together with the description serve to explain the principle of the disclosure. For a better understanding of various embodiments described below, reference should be made to the description of the following embodiments in connection with the accompanying drawings. The same reference numbers will be used throughout the drawings to refer to the same or like parts. FIG. 1 shows an exemplary point cloud content providing system according to embodiments;FIG. 2 is a block diagram illustrating a point cloud content providing operation according to embodiments;FIG. 3 illustrates an exemplary point cloud encoder according to embodiments;FIG. 4 shows an example of an octree and occupancy code according to embodiments;FIG. 5 illustrates an example of point configuration in each LOD according to embodiments;FIG. 6 illustrates an example of point configuration in each LOD according to embodiments;FIG. 7 illustrates a point cloud decoder according to embodiments;FIG. 8 illustrates a transmission device according to embodiments;FIG. 9 illustrates a reception device according to embodiments;FIG. 10 illustrates an exemplary structure operable in connection with point cloud data transmission/reception methods/devices according to embodiments;FIG. 11 illustrates a process of encoding, transmitting, and decoding point cloud data according to embodiments;FIG. 12 illustrates a layer-based point cloud data configuration according to embodiments;FIG. 13 illustrates a structure of geometry and attribute bitstreams according to embodiments;FIG. 14 illustrates bitstream configurations according to embodiments and a bitstream sorting method according to embodiments;FIG. 15 illustrates a bitstream sorting method according to embodiments;FIG. 16 illustrates a bitstream sorting method according to embodiments;FIG. 17 illustrates a method of selecting geometry data and attribute data according to embodiments;FIG. 18 illustrates a method of selecting a bitstream according to embodiments;FIG. 19 illustrates a method of configuring slices containing point cloud data according to embodiments;FIG. 20 illustrates a geometry tree structure based on a single slice and segmented slices according to embodiments;FIG. 21 illustrates a layer group structure of a geometry coding tree and an aligned layer group structure of an attribute coding tree according to embodiments;FIG. 22 illustrates a layer group and sub-group structure according to embodiments;FIG. 23 illustrates an example of context reference between layer groups according to embodiments;FIG. 24 illustrates an example of context reference between groups according to embodiments;FIG. 25 illustrates an example of context buffer management according to embodiments;FIG. 26 illustrates an example of context buffer management according to embodiments;FIG. 27 illustrates an example