EP-4742657-A1 - ENCODING METHOD, DECODING METHOD, ENCODING DEVICE, AND DECODING DEVICE

Abstract

An encoding method executed by an encoding device includes: in encoding a motion vector, determining, 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 (S3901); and transmitting information indicating the determined prediction mode to a decoding device (S3902). The plurality of predetermined prediction modes include at least: a first mode that uses, as the prediction value, an average value of a plurality of reference motion vectors to be referenced in encoding the motion vector, the average value being converted to an integer by truncating a fractional part of the average value; and a second mode that uses, as the prediction value, an average value of the plurality of reference motion vectors, the average value being converted to an integer by rounding the fractional part of the average value.

Inventors

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

Assignees

• Panasonic Intellectual Property Corporation of America

Dates

Publication Date

20260513

Application Date

20240704

Claims (10)

1. An encoding method executed by an encoding device, the encoding method comprising: in encoding a motion vector, determining, 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; and transmitting information indicating the prediction mode determined to a decoding device, wherein the plurality of predetermined prediction modes include at least: a first mode that uses, as the prediction value, an average value of a plurality of reference motion vectors to be referenced in encoding the motion vector, the average value being converted to an integer by truncating a fractional part of the average value; and a second mode that uses, as the prediction value, an average value of the plurality of reference motion vectors, the average value being converted to an integer by rounding the fractional part of the average value.
2. The encoding method according to claim 1, wherein the average value of the plurality of reference motion vectors is a weighted average value of the plurality of reference motion vectors.
3. The encoding method according to claim 1 or 2, wherein the motion vector is a motion vector of a vertex included in a three-dimensional mesh.
4. The encoding method according to claim 1 or 2, wherein the motion vector is a motion vector of an object in a two-dimensional image.
5. A decoding method executed by a decoding device, the decoding method comprising: in decoding a motion vector, receiving, from an encoding device, information indicating a prediction mode to be used for determining a prediction vector which is a prediction value of the motion vector; and determining, as a prediction mode to be used for decoding the motion vector, a prediction mode indicated in the information received, from among a plurality of predetermined prediction modes, wherein the plurality of predetermined prediction modes include at least: a first mode that uses, as the prediction value, an average value of a plurality of reference motion vectors to be referenced in decoding the motion vector, the average value being converted to an integer by truncating a fractional part of the average value; and a second mode that uses, as the prediction value, an average value of the plurality of reference motion vectors, the average value being converted to an integer by rounding the fractional part of the average value.
6. The decoding method according to claim 5, wherein the average value of the plurality of reference motion vectors is a weighted average value of the plurality of reference motion vectors.
7. The decoding method according to claim 5 or 6, wherein the motion vector is a motion vector of a vertex included in a three-dimensional mesh.
8. The decoding method according to claim 5 or 6, wherein the motion vector is a motion vector of an object in a two-dimensional image.
9. An encoding device comprising: memory; and a circuit having access to the memory, wherein in operation, the circuit: in encoding a motion vector, determines, 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; and transmits information indicating the prediction mode determined to a decoding device, the plurality of predetermined prediction modes include at least: a first mode that uses, as the prediction value, an average value of a plurality of reference motion vectors to be referenced in encoding the motion vector, the average value being converted to an integer by truncating a fractional part of the average value; and a second mode that uses, as the prediction value, an average value of the plurality of reference motion vectors, the average value being converted to an integer by rounding the fractional part of the average value.
10. A decoding device comprising: memory; and a circuit having access to the memory, wherein in operation, the circuit: in decoding a motion vector, receives, from an encoding device, information indicating a prediction mode to be used for determining a prediction vector which is a prediction value of the motion vector; and determines, as a prediction mode to be used for decoding the motion vector, a prediction mode indicated in the received information, from among a plurality of predetermined prediction modes, the plurality of predetermined prediction modes include at least: a first mode that uses, as the prediction value, an average value of a plurality of reference motion vectors to be referenced in decoding the motion vector, the average value being converted to an integer by truncating a fractional part of the average value; and a second mode that uses, as the prediction value, an average value of the plurality of reference motion vectors, the average value being converted to an integer by rounding the fractional part of the average value.

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 motion vectors. An object of the present disclosure is to improve the encoding or decoding process related to motion vectors. [Solution to Problem] An encoding method according to one aspect of the present invention is executed by an encoding device, and includes: in encoding a motion vector, determining, 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; and transmitting information indicating the prediction mode determined to a decoding device. The plurality of predetermined prediction modes include at least: a first mode that uses, as the prediction value, an average value of a plurality of reference motion vectors to be referenced in encoding the motion vector, the average value being converted to an integer by truncating a fractional part of the average value; and a second mode that uses, as the prediction value, an average value of the plurality of reference motion vectors, the average value being converted to an integer by rounding the fractional part of the average value. 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 encoding processing related to motion vectors 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