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EP-4738261-A1 - DECODING METHOD, ENCODING METHOD, DECODING DEVICE, AND ENCODING DEVICE

EP4738261A1EP 4738261 A1EP4738261 A1EP 4738261A1EP-4738261-A1

Abstract

A decoding method includes: deriving sorted edge vertices of a node according to a TriSoup scheme (S301); deriving a face vertex provided on a surface of the node except for edges of the node (S302); selecting two adjacent edge vertices that are adjacent to each other in sort order and closest to the face vertex among the sorted edge vertices (S303); and generating a TriSoup triangle by using the face vertex and one of the two adjacent edge vertices (S304).

Inventors

  • ITO, ATSUSHI
  • SUGIO, TOSHIYASU
  • NISHI, TAKAHIRO
  • IGUCHI, NORITAKA

Assignees

  • Panasonic Intellectual Property Corporation of America

Dates

Publication Date
20260506
Application Date
20240521

Claims (9)

  1. A decoding method comprising: deriving sorted edge vertices of a node according to a TriSoup scheme; deriving a face vertex provided on a surface of the node except for edges of the node; selecting two adjacent edge vertices that are adjacent to each other in sort order and closest to the face vertex among the sorted edge vertices; and generating a TriSoup triangle by using the face vertex and one of the two adjacent edge vertices.
  2. The decoding method according to claim 1, wherein an order of the face vertex in the sort order is set between orders of the two adjacent edge vertices.
  3. The decoding method according to claim 1, wherein in the deriving of the sorted edge vertices, edge vertices of the node and face vertices of the node are projected on a plane having a predetermined normal direction, and the edge vertices are sorted based on values of arctangents related to vectors connecting each of the edge vertices projected on the plane and a centroid vertex.
  4. The decoding method according to claim 1, wherein in the deriving of the sorted edge vertices, edge vertices of the node and centroid vertices of the node are projected on a plane having a predetermined normal direction, and the decoding method further comprises, when a first centroid vertex projected on an edge of the node on the plane is included among the centroid vertices projected on the plane: sorting first vertices including the edge vertices and the first centroid vertex; selecting two adjacent edge vertices that are adjacent to each other in sort order among the first vertices sorted, the two adjacent edge vertices being closest to a second face vertex among the centroid vertices, the second face vertex being projected on a part of the node other than the edges on the plane; and generating a TriSoup triangle by using the second face vertex and one of the two adjacent edge vertices.
  5. The decoding method according to claim 1, wherein in the selecting of the two adjacent edge vertices: midpoints of pairs of edge vertices that are adjacent to each other in the sort order, among the sorted edge vertices, are calculated; and a pair of edge vertices corresponding to a midpoint that is closest to the face vertex, among the midpoints calculated, is selected as the two adjacent edge vertices.
  6. An encoding method comprising: deriving sorted edge vertices of a node according to a TriSoup scheme; deriving a face vertex provided on a surface of the node except for edges of the node; selecting two adjacent edge vertices that are adjacent to each other in sort order and closest to the face vertex among the sorted edge vertices; and generating a TriSoup triangle by using the face vertex and one of the two adjacent edge vertices.
  7. The encoding method according to claim 6, an order of the face vertex in the sort order is set between orders of the two adjacent edge vertices, and orders of the sorted edge vertices and the face vertex that have been set are to be used in encoding attribute information of a three-dimensional point.
  8. A decoding device comprising: a processor; and memory, wherein using the memory, the processor: derives sorted edge vertices of a node according to a TriSoup scheme; derives a face vertex provided on a surface of the node except for edges of the node; selects two adjacent edge vertices that are adjacent to each other in sort order and closest to the face vertex among the sorted edge vertices; and generates a TriSoup triangle by using the face vertex and one of the two adjacent edge vertices.
  9. An encoding device comprising: a processor; and memory, wherein using the memory, the processor: derives sorted edge vertices of a node according to a TriSoup scheme; derives a face vertex provided on a surface of the node except for edges of the node; selects two adjacent edge vertices that are adjacent to each other in sort order and closest to the face vertex among the sorted edge vertices; and generates a TriSoup triangle by using the face vertex and one of the two adjacent edge vertices.

Description

[Technical Field] The present disclosure relates to a decoding method, an encoding method, a decoding device, and an encoding device. [Background Art] Devices or services utilizing three-dimensional data are expected to find their widespread use in a wide range of fields, such as computer vision that enables autonomous operations of cars or robots, map information, monitoring, infrastructure inspection, and video distribution. Three-dimensional data is obtained through various means including a distance sensor such as a rangefinder, as well as a stereo camera and a combination of a plurality of monocular cameras. Methods of representing three-dimensional data include a method known as a point cloud scheme that represents the shape of a three-dimensional structure by a point cloud in a three-dimensional space. In the point cloud scheme, the positions and colors of a point cloud are stored. While point cloud is expected to be a mainstream method of representing three-dimensional data, a massive amount of data of a point cloud necessitates compression of the amount of three-dimensional data by encoding for accumulation and transmission, as in the case of a two-dimensional moving picture (examples include Moving Picture Experts Group-4 Advanced Video Coding (MPEG-4 AVC) and High Efficiency Video Coding (HEVC) standardized by MPEG). Meanwhile, point cloud compression is partially supported by, for example, an open-source library (Point Cloud Library) for point cloud-related processing. Furthermore, a technique for searching for and displaying a facility located in the surroundings of the vehicle by using three-dimensional map data is known (see, for example, Patent Literature (PTL) 1). [Citation List] [Patent Literature] [PTL 1] International Publication WO 2014/020663 [Summary of Invention] [Technical Problem] In such encoding and decoding of three-dimensional data, there is a demand for improving the accuracy of three-dimensional data that is restored. The present disclosure has an object to provide a decoding method, an encoding method, a decoding device, or an encoding device capable of improving the accuracy of three-dimensional data that is restored. [Solution to Problem] A decoding method according to an aspect of the present disclosure includes: deriving sorted edge vertices of a node according to a TriSoup scheme; deriving a face vertex provided on a surface of the node except for edges of the node; selecting two adjacent edge vertices that are adjacent to each other in sort order and closest to the face vertex among the sorted edge vertices; and generating a TriSoup triangle by using the face vertex and one of the two adjacent edge vertices. An encoding method according to an aspect of the present disclosure includes: deriving sorted edge vertices of a node according to a TriSoup scheme; deriving a face vertex provided on a surface of the node except for edges of the node; selecting two adjacent edge vertices that are adjacent to each other in sort order and closest to the face vertex among the sorted edge vertices; and generating a TriSoup triangle by using the face vertex and one of the two adjacent edge vertices. [Advantageous Effects of Invention] The present disclosure can provide a decoding method, an encoding method, a decoding device, or an encoding device capable of improving the accuracy of three-dimensional data that is restored. [Brief Description of Drawings] [FIG. 1] FIG. 1 is a diagram illustrating an example of an original point cloud according to an embodiment.[FIG. 2] FIG. 2 is a diagram illustrating an example of a trimmed octree according to the embodiment.[FIG. 3] FIG. 3 is a diagram illustrating an example in which a leaf-node according to the embodiment is two-dimensionally displayed.[FIG. 4] FIG. 4 is a diagram for describing a method for generating a centroid vertex according to the embodiment.[FIG. 5] FIG. 5 is a diagram for describing the method for generating a centroid vertex according to the embodiment.[FIG. 6] FIG. 6 is a diagram illustrating an example of vertex information according to the embodiment.[FIG. 7] FIG. 7 is a diagram illustrating an example of a TriSoup surface according to the embodiment.[FIG. 8] FIG. 8 is a diagram for describing point cloud reconstruction processing according to the embodiment.[FIG. 9] FIG. 9 is a diagram illustrating an example of a point cloud according to the embodiment.[FIG. 10] FIG. 10 is a diagram illustrating an example of centroid vertex generation according to the embodiment.[FIG. 11] FIG. 11 is a diagram illustrating an example of triangle (TriSoup surface) generation according to the embodiment.[FIG. 12] FIG. 12 is a diagram illustrating an example of face vertex generation according to the embodiment.[FIG. 13] FIG. 13 is a diagram illustrating an example of surfaces about which the connectivity evaluation and reconstruction of the centroid vertex are performed according to the embodiment.[FIG. 14] FIG. 14 is a flowchart of enc