CN-122002035-A - Encoding and decoding method and device

Abstract

An encoding method performed by at least one processor includes receiving a polygonal mesh including a plurality of vertices defining a plurality of faces, determining a mesh face type of the polygonal mesh, dividing the polygonal mesh into a plurality of sub-meshes, generating a sub-mesh header for at least one of the plurality of sub-meshes according to at least the mesh face type of the polygonal mesh, and generating a bitstream including the polygonal mesh and the sub-mesh header.

Inventors

• HUANG CHAO
• LIU SHAN

Assignees

• 腾讯美国有限责任公司

Dates

Publication Date

20260508

Application Date

20251021

Priority Date

20250818

Claims (17)

1. 1. A method of encoding, the method comprising: Receiving a polygonal mesh, the polygonal mesh comprising a plurality of vertices defining a plurality of faces; determining the type of the grid surface of the polygonal grid; dividing the polygonal mesh into a plurality of sub-meshes; Generating a sub-mesh header for at least one sub-mesh of the plurality of sub-meshes according to at least the mesh face type of the polygonal mesh, and Generating a bit stream comprising the polygon mesh and the sub-mesh header.
2. 2. The method of claim 1, wherein when the mesh face type indicates that the polygon mesh includes more than one type of face, the sub-mesh header includes submesh _face_type, and the submesh _face_type indicates a face type of the at least one sub-mesh.
3. 3. The method of claim 1, wherein the mesh face type is one of a first face type indicating that the polygonal mesh includes triangular faces, a second face type indicating that the polygonal mesh includes quadrilateral faces, a third face type indicating that the polygonal mesh includes both triangular faces and quadrilateral faces, and a fourth face type indicating that the polygonal mesh includes polygonal faces.
4. 4. The method of claim 1, wherein the step of determining the position of the substrate comprises, The sub-grid header further includes a parameter indicating whether all connected components in the at least one sub-grid have the same connectivity, or The sub-grid header further includes a prediction policy indicating how to encode vertices in the at least one sub-grid based on one or more vertices in the at least one sub-grid, or The sub-grid header includes an index encoding policy indicating one of a polygon fanning method and a bi-level method.
5. 5. The method of claim 4, wherein the prediction strategy is a parallelogram prediction strategy.
6. 6. The method of claim 4, wherein the sub-grid header further comprises a parameter indicating at least one of a unidirectional prediction mode and a multi-directional prediction mode.
7. 7. The method of claim 6, wherein the step of providing the first layer comprises, Encoding the vertices in the unidirectional prediction mode using at least one side of the sub-grid header according to the prediction strategy, or The vertices are encoded in the multi-directional prediction mode using at least two sides of the sub-grid header according to the prediction strategy.
8. 8. The method of claim 4, wherein the sub-grid header comprises a traversal policy that indicates the polygon fanning method based on determining the index encoding policy.
9. 9. A decoding method, the method comprising: receiving a bit stream comprising a polygonal mesh and a sub-mesh header, the polygonal mesh being divided into a plurality of sub-meshes; Decoding at least one of the plurality of sub-grids according to the sub-grid header, Wherein the sub-mesh header is generated based on a mesh plane type of the polygonal mesh.
10. 10. The decoding method of claim 9, wherein when the mesh plane type indicates that the polygon mesh includes more than one type of plane, the sub-mesh header includes submesh _face_type, and the submesh _face_type indicates a plane type of the at least one sub-mesh.
11. 11. The decoding method of claim 9 wherein the mesh surface type is one of a first surface type indicating that the polygon mesh comprises triangle surfaces, a second surface type indicating that the polygon mesh comprises quadrilateral surfaces, a third surface type indicating that the polygon mesh comprises both triangle surfaces and quadrilateral surfaces, and a fourth surface type indicating that the polygon mesh comprises polygon surfaces.
12. 12. The decoding method of claim 9, wherein, The sub-grid header further includes a parameter indicating whether all connected components in the at least one sub-grid have the same connectivity, or The sub-grid header also includes a prediction policy that indicates how to decode vertices in the at least one sub-grid based on one or more vertices in the at least one sub-grid.
13. 13. The decoding method of claim 12, wherein the prediction strategy is a parallelogram prediction strategy.
14. 14. The decoding method of claim 12, wherein the sub-grid header further comprises a parameter indicating at least one of a unidirectional prediction mode and a multi-directional prediction mode.
15. 15. The decoding method of claim 14, wherein the vertices are decoded using at least one side of the sub-grid header according to the prediction strategy in the unidirectional prediction mode.
16. 16. A method for storing or transmitting a bitstream, characterized in that the video bitstream is generated according to the method of any one of claims 1 to 8 or the bitstream is decoded according to the method of any one of claims 9 to 15.
17. 17. A codec device comprising a memory for storing instructions and a processor in communication with the memory, wherein the processor is configured, when the processor executes the instructions, to cause the device to perform the method according to any one of claims 1 to 8 or the method according to any one of claims 9 to 15.

Description

Encoding and decoding method and device Technical Field The present disclosure relates to video codec technology. More particularly, the present disclosure relates to a codec method and apparatus. Background Polygonal meshes are typically composed of several connected components (connected component, CC), which may have different characteristics, so it is beneficial to divide them into different CC groups (called slices in this disclosure) based on the characteristics of the CC so that they can be compressed adaptively and efficiently. It may also be beneficial to group CCs into different sub-grids based on their characteristics so that they can be compressed adaptively and efficiently. Since these connected components may have different characteristics, it is not efficient to encode them as a whole. Disclosure of Invention According to an aspect of the present disclosure, there is provided an encoding method including receiving a polygonal mesh including a plurality of vertices defining a plurality of faces, determining a mesh face type of the polygonal mesh, dividing the polygonal mesh into a plurality of sub-meshes, generating a sub-mesh header for at least one of the plurality of sub-meshes according to at least the mesh face type of the polygonal mesh, and generating a bitstream including the polygonal mesh and the sub-mesh header. According to an aspect of the present disclosure, there is provided a decoding method including receiving a bitstream including a polygonal mesh and a sub-mesh header, the polygonal mesh being divided into a plurality of sub-meshes, and decoding at least one sub-mesh of the plurality of sub-meshes according to the sub-mesh header, wherein the sub-mesh header is generated based on a mesh plane type of the polygonal mesh. According to an aspect of the present disclosure, there is provided a method for storing or transmitting a bitstream generated according to the above method for encoding or decoded according to the above method for decoding. According to an aspect of the present disclosure, there is provided a codec device comprising a memory for storing instructions and a processor in communication with the memory, wherein the processor is configured to cause the device to perform the above method for encoding or the above method for decoding when the processor executes the instructions. In the present application, embodiments of the present disclosure divide connected components into sub-grids or slices according to characteristics of the connected components, and apply a high-level syntax for polygonal grid compression, which is advantageous for adaptively and efficiently compressing, thereby improving coding efficiency. Drawings Further features, properties and various advantages of the disclosed subject matter will become more apparent from the following detailed description and drawings in which: fig. 1 is a schematic illustration of a block diagram of a communication system according to an embodiment of the present disclosure. Fig. 2 is a schematic illustration of a block diagram of a streaming system according to an embodiment of the present disclosure. Fig. 3 is a schematic illustration of an example trellis encoder, according to an embodiment of the disclosure. Fig. 4 is a flowchart of an example process of encoding a polygonal mesh according to an embodiment of the present disclosure. Fig. 5 illustrates an example process for geometric encoding according to an embodiment of this disclosure. Fig. 6 illustrates an example process for how each slice is encoded according to an embodiment of the present disclosure. Fig. 7-9 show lossless results of adding a geometric slice layer (no adaptive coding mode) relative to TM 5.0a using a default configuration, according to an embodiment of the present disclosure. Fig. 10-12 illustrate lossless results of adding a geometric slice layer plus adaptive coding mode versus TM 5.0 per grid configuration, according to an embodiment of the present disclosure. Fig. 13-15 show additional lossless results of adding a geometric slice layer (no adaptive coding mode) relative to TM 5.0a using a default configuration, according to an embodiment of the present disclosure. Fig. 16-18 illustrate additional lossless results for adding a geometric slice layer plus adaptive coding mode versus TM 5.0 per grid configuration, according to embodiments of the present disclosure. Fig. 19 and 20 show the results of a double degree-26 c6346a relative to P01T0 according to an embodiment of the disclosure. Fig. 21 and 22 show the results of parallelogram prediction-a 8fc726b versus the bi-degree-26 c6346a according to an embodiment of the disclosure. Fig. 23 and 24 show the results of reflection prediction-6 f012e07 relative to parallelogram prediction-a 8fc726b according to embodiments of the present disclosure. Fig. 25 shows the results of special UV treatment-9 a10dee4 versus reflection prediction-6 f012e07 according to embodiments of the present disclos