EP-4742160-A1 - ENCODING METHOD, DECODING METHOD, ENCODING DEVICE, AND DECODING DEVICE

Abstract

An encoding method executed by an encoding device that encodes a motion vector of a vertex included in a three-dimensional mesh includes: determining on a per group basis, from among a plurality of predetermined prediction modes, a prediction mode to be used for determining a prediction vector which is a prediction value of the motion vector, the group being a unit for determining the prediction vector (S3701); and transmitting (i) information indicating the determined prediction mode and (ii) the total number of the plurality of predetermined prediction modes to a decoding device (S3702).

Inventors

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

Assignees

• Panasonic Intellectual Property Corporation of America

Dates

Publication Date

20260513

Application Date

20240704

Claims (14)

1. An encoding method executed by an encoding device that encodes a motion vector of a vertex included in a three-dimensional mesh, the encoding method comprising: determining on a per group basis, from among a plurality of predetermined prediction modes, a prediction mode to be used for determining a prediction vector which is a prediction value of the motion vector, the group being a unit for determining the prediction vector; and transmitting (i) information indicating the prediction mode determined and (ii) a total number of the plurality of predetermined prediction modes to a decoding device.
2. The encoding method according to claim 1, wherein the motion vector includes an X component, a Y component, and a Z component, the determining includes determining, as the prediction mode, on the per group basis, a first prediction mode that is a prediction mode for the X component, a second prediction mode that is a prediction mode for the Y component, and a third prediction mode that is a prediction mode for the Z component, and the transmitting includes transmitting, as the information indicating the prediction mode, first information indicating the first prediction mode, second information indicating the second prediction mode, and third information indicating the third prediction mode.
3. The encoding method according to claim 1 or 2, wherein the plurality of predetermined prediction modes include at least a prediction mode that uses, as the prediction value, a median value of motion vectors of a plurality of points adjacent to the vertex.
4. The encoding method according to claim 1 or 2, wherein the plurality of predetermined prediction modes include at least a prediction mode that uses, as the prediction value, a motion vector of a vertex corresponding to the vertex in a reference frame that is referenced during encoding of a frame including the vertex.
5. The encoding method according to claim 1 or 2, wherein the plurality of predetermined prediction modes include at least a prediction mode that uses a fixed value as the prediction value.
6. The encoding method according to claim 1 or 2, further comprising: among the plurality of predetermined prediction modes, setting a prediction value of each of one or more prediction modes to which prediction values are not assigned to 0, wherein in the determining, the prediction mode is determined using the plurality of predetermined prediction modes after the setting.
7. A decoding method executed by a decoding device that decodes a motion vector of a vertex included in a three-dimensional mesh, the decoding method comprising: receiving, from an encoding device, (i) information indicating a prediction mode that is used for determining a prediction vector which is a prediction value of the motion vector, the prediction mode being determined from among a plurality of predetermined prediction modes on a per group basis, the group being a unit for determining the prediction vector, and (ii) a total number of the plurality of predetermined prediction modes; and determining a prediction mode to be used for decoding the motion vector to be the prediction mode indicated in the information received, using the total number of the plurality of predetermined prediction modes.
8. The decoding method according to claim 7, wherein the motion vector includes an X component, a Y component, and a Z component, the receiving includes receiving, as the information indicating the prediction mode, on the per group basis, first information indicating a first prediction mode that is a prediction mode for the X component, second information indicating a second prediction mode that is a prediction mode for the Y component, and third information indicating a third prediction mode that is a prediction mode for the Z component, and determining prediction modes to be used for decoding the X component, the Y component, and the Z component of the motion vector to respectively be the first prediction mode, the second prediction mode, and the third prediction mode indicated in the information received, using the total number of the plurality of predetermined prediction modes.
9. The decoding method according to claim 7 or 8, wherein the plurality of predetermined prediction modes include at least a prediction mode that uses, as the prediction value, a median value of motion vectors of a plurality of points adjacent to the vertex.
10. The decoding method according to claim 7 or 8, wherein the plurality of predetermined prediction modes include at least a prediction mode that uses, as the prediction value, a motion vector of a vertex corresponding to the vertex in a reference frame that is referenced during encoding of a frame including the vertex.
11. The decoding method according to claim 7 or 8, wherein the plurality of predetermined prediction modes include at least a prediction mode that uses a fixed value as the prediction value.
12. The decoding method according to claim 7 or 8, further comprising: among the plurality of predetermined prediction modes, setting a prediction value of each of one or more prediction modes to which prediction values are not assigned to 0, wherein in the determining, the prediction mode to be used for decoding the motion vector is determined using the plurality of predetermined prediction modes after the setting.
13. An encoding device that encodes a motion vector of a vertex included in a three-dimensional mesh, the encoding device comprising: memory; and a circuit having access to the memory, wherein in operation, the circuit: determines on a per group basis, from among a plurality of predetermined prediction modes, a prediction mode to be used for determining a prediction vector which is a prediction value of the motion vector, the group being a unit for determining the prediction vector; and transmits (i) information indicating the prediction mode determined and (ii) a total number of the plurality of predetermined prediction modes to a decoding device.
14. A decoding device that decodes a motion vector of a vertex included in a three-dimensional mesh, the decoding device comprising: memory; and a circuit having access to the memory, wherein in operation, the circuit: receives, from an encoding device, (i) information indicating a prediction mode that is used for determining a prediction vector which is a prediction value of the motion vector, the prediction mode being determined from among a plurality of predetermined prediction modes on a per group basis, the group being a unit for determining the prediction vector, and (ii) a total number of the plurality of predetermined prediction modes; and determines a prediction mode to be used for decoding the motion vector to be the prediction mode indicated in the information received, using the total number of the plurality of predetermined prediction modes.

Description

[Technical Field] The present disclosure relates to, for example, an encoding method. [Background Art] PTL 1 proposes a method and a device for encoding and decoding three-dimensional mesh data. [Citation List] [Patent Literature] [PTL 1] Japanese Unexamined Patent Application Publication No. 2006-187015 [Summary of Invention] [Technical Problem] There is a demand for further improvement in an encoding or decoding process related to three-dimensional data. An object of the present disclosure is to improve the encoding or decoding process related to three-dimensional data. [Solution to Problem] An encoding method according to one aspect of the present invention is executed by an encoding device that encodes a motion vector of a vertex included in a three-dimensional mesh, and includes: determining on a per group basis, from among a plurality of predetermined prediction modes, a prediction mode to be used for determining a prediction vector which is a prediction value of the motion vector, the group being a unit for determining the prediction vector; and transmitting (i) information indicating the prediction mode determined and (ii) a total number of the plurality of predetermined prediction modes to a decoding device. Note that these general or specific aspects may be implemented using a system, a device, an integrated circuit, a computer program, or a computer-readable recording medium such as a CD-ROM, or any combination of systems, devices, integrated circuits, computer programs, and recording media. [Advantageous Effects of Invention] The present disclosure can contribute toward improving processing of encoding three-dimensional data and the like. [Brief Description of Drawings] [FIG. 1] FIG. 1 is a conceptual diagram illustrating a three-dimensional mesh according to an embodiment.[FIG. 2] FIG. 2 is a conceptual diagram illustrating basic elements of the three-dimensional mesh according to the embodiment.[FIG. 3] FIG. 3 is a conceptual diagram illustrating mapping according to the embodiment.[FIG. 4] FIG. 4 is a block diagram illustrating a configuration example of an encoding/decoding system according to the embodiment.[FIG. 5] FIG. 5 is a block diagram illustrating a configuration example of an encoding device according to the embodiment.[FIG. 6] FIG. 6 is a block diagram illustrating another configuration example of the encoding device according to the embodiment.[FIG. 7] FIG. 7 is a block diagram illustrating a configuration example of a decoding device according to the embodiment.[FIG. 8] FIG. 8 is a block diagram illustrating another configuration example of the decoding device according to the embodiment.[FIG. 9] FIG. 9 is a conceptual diagram illustrating a configuration example of a bitstream according to the embodiment.[FIG. 10] FIG. 10 is a conceptual diagram illustrating another configuration example of the bitstream according to the embodiment.[FIG. 11] FIG. 11 is a conceptual diagram illustrating yet another configuration example of the bitstream according to the embodiment.[FIG. 12] FIG. 12 is a block diagram illustrating a specific example of the encoding/decoding system according to the embodiment.[FIG. 13] FIG. 13 is a conceptual diagram illustrating a configuration example of point cloud data according to the embodiment.[FIG. 14] FIG. 14 is a conceptual diagram illustrating a data file example of the point cloud data according to the embodiment.[FIG. 15] FIG. 15 is a conceptual diagram illustrating a configuration example of mesh data according to the embodiment.[FIG. 16] FIG. 16 is a conceptual diagram illustrating a data file example of the mesh data according to the embodiment.[FIG. 17] FIG. 17 is a conceptual diagram illustrating a type of three-dimensional data according to the embodiment.[FIG. 18] FIG. 18 is a block diagram illustrating a configuration example of a three-dimensional data encoder according to the embodiment.[FIG. 19] FIG. 19 is a block diagram illustrating a configuration example of a three-dimensional data decoder according to the embodiment.[FIG. 20] FIG. 20 is a block diagram illustrating another configuration example of the three-dimensional data encoder according to the embodiment.[FIG. 21] FIG. 21 is a block diagram illustrating another configuration example of the three-dimensional data decoder according to the embodiment.[FIG. 22] FIG. 22 is a conceptual diagram illustrating a specific example of encoding processing according to the embodiment.[FIG. 23] FIG. 23 is a conceptual diagram illustrating a specific example of decoding processing according to the embodiment.[FIG. 24] FIG. 24 is a block diagram illustrating an implementation example of the encoding device according to the embodiment.[FIG. 25] FIG. 25 is a block diagram illustrating an implementation example of the decoding device according to the embodiment.[FIG. 26] FIG. 26 is a block diagram illustrating a configuration example of the encoding/decoding system according to the embodiment.[FIG. 27