CN-122003700-A - Method, device and medium for point cloud encoding and decoding

Abstract

A method for point cloud encoding and decoding, in which method a set of triangular meshes of a current frame of a point cloud sequence is determined for a transition between the current frame of the point cloud sequence and a bit stream of the point cloud sequence. Parameters for at least one projection plane of a triangular mesh are determined prior to voxelization of the triangular mesh of the set of triangular meshes. Based on this parameter, conversion is performed.

Inventors

• WANG WENYI
• XU YINGZHAN
• B. Vishwanat
• ZHANG KAI
• ZHANG LI

Assignees

• 抖音视界有限公司
• 字节跳动有限公司

Dates

Publication Date

20260508

Application Date

20241008

Priority Date

20231008

Claims (20)

1. 1. A method for point cloud encoding and decoding, comprising: determining a set of triangular meshes of a current frame of a point cloud sequence for conversion between the current frame and a bit stream of the point cloud sequence; determining parameters for at least one projection plane of a triangular mesh of the set of triangular meshes prior to voxelization of the triangular mesh, and The conversion is performed based on the parameters.
2. 2. The method of claim 1, wherein the parameter comprises a two-dimensional halo parameter, and determining the parameter comprises: the two-dimensional parameters are determined based on the three-dimensional halo region parameters of the triangular mesh.
3. 3. The method of claim 1 or claim 2, wherein the two-dimensional parameter is determined as follows: , Wherein the method comprises the steps of The parameters of the two dimensions are represented by, Representing the three-dimensional halo field parameters, and Representing the area of the voxel ized triangle corresponding to the triangle mesh.
4. 4. A method according to claim 2 or 3, wherein the determination of the two-dimensional parameter is performed in fixed or floating point.
5. 5. The method of any of claims 1 to 4, wherein the parameter is indicated in the bitstream.
6. 6. A method according to any one of claims 1 to 5, wherein the parameters are estimated at the decoder side and/or the encoder side.
7. 7. The method of any of claims 1-6, wherein the parameter is determined by at least one first grid covered by triangles generated by projections of the triangular mesh in the at least one projection plane.
8. 8. The method of claim 7, wherein the at least one first grid is determined to be covered by the triangle if a point in the at least one first grid is within the triangle.
9. 9. The method of any of claims 1-8, wherein three sides of a voxelized triangle corresponding to the triangle mesh are associated with the same parameter.
10. 10. The method of any of claims 1-8, wherein three sides of a voxelized triangle corresponding to the triangle mesh are associated with different parameters.
11. 11. The method of any one of claims 1 to 10, further comprising: A voxelized triangle corresponding to the triangle mesh is projected into the at least one projection plane.
12. 12. The method of claim 11, wherein the voxelized triangles are projected based on orthogonal projection.
13. 13. The method of any one of claims 1 to 11, further comprising: Determining whether at least one second grid in a two-dimensional bounding box of a voxelized triangle corresponding to the triangular mesh in the at least one projection plane is within a triangle generated by projection of the triangular mesh in the at least one projection plane.
14. 14. The method of claim 13, wherein the at least one second grid is determined to be within the triangle if a point in the at least one second grid is within the triangle.
15. 15. The method of claim 14, wherein the point is determined to be within the triangle if at least one of the following conditions is met: , Or (b) , Wherein P represents the point, A, B and C represent three vertices of the triangular mesh arranged counterclockwise, and Representing the parameter.
16. 16. The method of claim 14, wherein the point is determined to be within the triangle if at least one of the following conditions is met: , Or (b) , Wherein P represents the point, A, B and C represent three vertices of the triangular mesh arranged clockwise, and Representing the parameter.
17. 17. The method of claim 14, wherein the point is determined to be within the triangle if at least one of the following conditions is met: , Or (b) , Wherein P represents the point, A, B and C represent three vertices of the triangular mesh arranged counterclockwise, and Representing the parameter.
18. 18. The method of claim 14, wherein the point is determined to be within the triangle if at least one of the following conditions is met: , Or (b) , Wherein P represents the point, A, B and C represent three vertices of the triangular mesh arranged clockwise, and Representing the parameter.
19. 19. The method of claim 13, wherein the at least one second grid is processed in at least one of raster order, morton order, or Hilber order.
20. 20. The method of any of claims 1-19, wherein if a ray is emitted by a grid within a triangle generated by projection of the triangular mesh in the at least one projection plane, the ray intersects the triangular mesh.

Description

Method, device and medium for point cloud encoding and decoding Technical Field Embodiments of the present disclosure relate generally to video codec technology and, more particularly, to two-dimensional (2D) halo region (halo) parameter determination. Background A point cloud is a collection of individual data points in a three-dimensional (3D) plane, where each point has set coordinates on the X, Y and Z axes. Thus, the point cloud may be used to represent the physical content of a three-dimensional space. For a variety of immersive applications, from augmented reality to autopilot, point clouds have proven to be a promising way to represent 3D visual data. The point cloud codec standard has evolved mainly through the development of the well-known MPEG organization. MPEG is an abbreviation for the moving picture expert group (Moving Picture Experts Group), which is one of the main standardization groups handling multimedia. In 2017, the MPEG 3D graphic codec group (3 DG) published a proposal set (CFP) file to begin developing point cloud codec standards. The final criteria will include two types of solutions. Video-based point cloud compression (V-PCC or VPCC) is applicable to a set of points where the distribution of points is relatively uniform. Geometry-based point cloud compression (G-PCC or GPCC) is suitable for more sparse distributions. However, it is generally desirable to further improve the codec efficiency of conventional point cloud codec techniques. Disclosure of Invention Embodiments of the present disclosure provide a solution for point cloud codec. In a first aspect, a method for point cloud codec is presented. The method includes determining a set of triangular meshes of a current frame for a transition between the current frame of the point cloud sequence and a bit stream of the point cloud sequence, determining parameters for the triangular meshes for at least one projection plane prior to voxelizing the triangular meshes in the set of triangular meshes, and performing the transition based on the parameters. In a second aspect, an apparatus for processing a sequence of point clouds is presented. The apparatus for processing a point cloud sequence includes a processor and a non-transitory memory having instructions thereon. The instructions, when executed by a processor, cause the processor to perform a method according to the first aspect of the present disclosure. In a third aspect, a non-transitory computer readable storage medium is presented. The non-transitory computer readable storage medium stores instructions that cause a processor to perform a method according to the first aspect of the present disclosure. In a fourth aspect, a non-transitory computer readable recording medium is presented. The non-transitory computer readable recording medium stores a bit stream of a point cloud sequence generated by a method performed by a point cloud processing apparatus. The method includes determining a set of triangular meshes of a current frame of the point cloud sequence, determining parameters for the triangular meshes for at least one projection plane prior to voxelating the triangular meshes in the set of triangular meshes, and generating a bitstream based on the parameters. In a fifth aspect, a method for storing a bit stream of a point cloud sequence is presented. The method includes determining a set of triangular meshes of a current frame of the point cloud sequence, determining parameters for the triangular meshes for at least one projection plane prior to voxelating the triangular meshes in the set of triangular meshes, generating a bitstream based on the parameters, and storing the bitstream in a non-transitory computer readable recording medium. This summary is intended to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Drawings The above and other objects, features and advantages of the exemplary embodiments of the present disclosure will become more apparent by the following detailed description with reference to the accompanying drawings. In example embodiments of the present disclosure, like reference numerals generally refer to like components. FIG. 1 illustrates a block diagram of an example point cloud codec system, according to some embodiments of the present disclosure; FIG. 2 illustrates a block diagram of an example of GPCC encoder, according to some embodiments of the present disclosure; fig. 3 illustrates a block diagram of an example of GPCC decoder, according to some embodiments of the present disclosure; FIG. 4 shows the Mfoster-Trumbore algorithm in triangle voxelization; FIG. 5 shows the 3D halo region width controlled by parameter ε; FIG. 6 illustrates an example of improved triangle voxelization in triang