Inter prediction-based image coding method and device

Patent metadata

Field	Value
Publication number	US-12137213-B2
Application number	US-202318231129-A
Country	US
Kind code	B2
Filing date	Aug 7, 2023
Priority date	Jun 14, 2019
Publication date	Nov 5, 2024
Grant date	Nov 5, 2024

Abstract

An image decoding method according to the present document may comprise: a step for deriving an inter prediction mode from encoded information; a step for constructing reference pictures lists; a step for deriving motion information including reference picture indices for symmetric motion vector differences (SMVD) on the basis of reference pictures included in the reference picture lists; and a step for generating prediction samples on the basis of the motion information. The reference picture indices for SMVD may be derived on the basis of short-term reference pictures included in the reference picture lists.

First claim

What is claimed is:

1. An image decoding method performed by a decoding apparatus, the method comprising:
obtaining image information including prediction related information from a bitstream;
deriving an inter prediction mode for a current block based on the prediction related information;
deriving reference picture lists for the current block;
deriving picture order count (POC) differences between each of reference pictures included in the reference picture lists and current picture;
deriving motion information including reference picture indices for symmetric motion vector differences (SMVD) based on the POC differences; and
generating predicted samples based on the motion information,
wherein the reference picture indices for the SMVD are derived based on short-term reference pictures included in the reference picture lists,
wherein the POC differences include a first POC difference for reference picture list 0 (L0) and a second POC difference for reference picture list 1 (L1),
wherein the first POC difference for the L0 is a POC difference between a first short-term reference picture included in the L0 and the current picture, and the second POC difference for the L1 is a POC difference between a second short-term reference picture included in the L1 and the current picture, and
wherein a reference picture index of the L0 for the SMVD is derived based on the first POC difference, and a reference picture index of the L1 for the SMVD is derived based on the second POC difference.

2. An image encoding method performed by an encoding apparatus, the method comprising:
deriving an inter prediction mode for a current block;
deriving reference picture lists including reference pictures;
deriving picture order count (POC) differences between the reference pictures included in the reference picture lists and the current picture;
deriving motion information including reference picture indices for symmetric motion vector differences (SMVD) based on the POC differences;
generating predicted samples based on the motion information;
generating prediction related information including the inter prediction mode;
deriving residual information based on the predicted samples; and
encoding image information including the prediction related information and the residual information,
wherein the reference picture indices for the SMVD are derived based on short-term reference pictures included in the reference picture lists,
wherein the POC differences include a first POC difference for reference picture list 0 (L0) and a second POC difference for reference picture list 1 (L1),
wherein the first POC difference for the L0 is a POC difference between a first short-term reference picture included in the L0 and the current picture, and the second POC difference for the L1 is a POC difference between a second short-term reference picture included in the L1 and the current picture, and
wherein a reference picture index of the L0 for the SMVD is derived based on the first POC difference, and a reference picture index of the L1 for the SMVD is derived based on the second POC difference.

3. A non-transitory computer readable storage medium storing a bitstream generated by the image encoding method of claim 2 .

4. A transmission method of data for an image, the method comprising:
obtaining a bitstream for the image, wherein the bitstream is generated based on deriving an inter prediction mode for a current block,
deriving reference picture lists including reference pictures,
deriving picture order count (POC) differences between the reference pictures included in the reference picture lists and the current picture,
deriving motion information including reference picture indices for symmetric motion vector differences (SMVD) based on the POC differences,
generating predicted samples based on the motion information,
generating prediction related information including the inter prediction mode,
deriving residual information based on the predicted samples, and
encoding image information including the prediction related information and the residual information; and
transmitting the data comprising the bitstream,
wherein the reference picture indices for the SMVD are derived based on short-term reference pictures included in the reference picture lists,
wherein the POC differences include a first POC difference for reference picture list 0 (L0) and a second POC difference for reference picture list 1 (L1),
wherein the first POC difference for the L0 is a POC difference between a first short-term reference picture included in the L0 and the current picture, and the second POC difference for the L1 is a POC difference between a second short-term reference picture included in the L1 and the current picture, and
wherein a reference picture index of the L0 for the SMVD is derived based on the first POC difference, and a reference picture index of the L1 for the SMVD is derived based on the second POC difference.

Assignees

• Lg Electronics Inc

Inventors

• Park Naeri
• Nam Junghak
• Jang Hyeongmoon

Classifications

• H04N19/176

  the region being a block, e.g. a macroblock · CPC title

• H04N19/159

  Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction · CPC title

• H04N19/137

  Motion inside a coding unit, e.g. average field, frame or block difference · CPC title

• H04N19/105 Primary

  Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for prediction · CPC title

• H04N19/70

  characterised by syntax aspects related to video coding, e.g. related to compression standards · CPC title