# US 12,003,707 B2 · Intra prediction mode encoding/decoding method and apparatus for same

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- Number: US 12,003,707 B2
- Document ID: US12003707B2
- Status: Granted
- Kind: B2
- Application number: 17/965,667
- Filed: 2022-10-13
- Published: 2023-02-09
- Granted: 2024-06-04
- Earliest claimed: 2010-12-21
- Assignees: Electronics and Telecommunications Research Institute
- Applicants: Electronics and Telecommunications Research Institute
- Inventors: Ha Hyun Lee; Hui Yong Kim; Sung Chang Lim; Jong Ho Kim; Jin Ho Lee; Se Yoon Jeong; Suk Hee Cho; Jin Soo Choi; Jin Woong Kim; Chie Teuk Ahn
- Web page: https://patentgrep.com/patent/US12003707B2

## CPC

- H04N 19/107: between spatial and temporal predictive coding, e.g. picture refresh
- H04N 19/105: 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
- H04N 19/109: among a plurality of temporal predictive coding modes
- H04N 19/11: among a plurality of spatial predictive coding modes
- H04N 19/13: Adaptive entropy coding, e.g. adaptive variable length coding [AVLC] or context adaptive binary arithmetic coding [CABAC]
- H04N 19/137: Motion inside a coding unit, e.g. average field, frame or block difference
- H04N 19/157: Assigned coding mode, i.e. the coding mode being predefined or preselected to be further used for selection of another element or parameter
- H04N 19/159: Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction
- H04N 19/176: the region being a block, e.g. a macroblock
- H04N 19/1887: {the unit being a variable length codeword}
- H04N 19/196: being specially adapted for the computation of encoding parameters, e.g. by averaging previously computed encoding parameters (processing of motion vectors H04N19/513)
- H04N 19/50: using predictive coding (H04N19/61 takes precedence)
- H04N 19/52: by predictive encoding
- H04N 19/521: {for estimating the reliability of the determined motion vectors or motion vector field, e.g. for smoothing the motion vector field or for correcting motion vectors}
- H04N 19/593: involving spatial prediction techniques
- H04N 19/61: in combination with predictive coding
- H04N 19/70: characterised by syntax aspects related to video coding, e.g. related to compression standards
- H04N 19/91: Entropy coding, e.g. variable length coding [VLC] or arithmetic coding
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

Disclosed herein is an intra prediction method including: deriving neighbor prediction mode information from a left neighbor prediction mode and an upper neighbor prediction mode; deriving an intra prediction mode for a decoding target unit by using the derived neighbor prediction mode information; and performing intra prediction on the decoding target unit based on the intra prediction mode. According to exemplary embodiments of the present invention, image encoding/decoding efficiency can be improved.

## Claims

### Claim 1

A video decoding method performed by a video decoding apparatus, the video decoding method comprising:
deriving neighbor prediction mode information from a left neighbor prediction mode and an upper neighbor prediction mode;
determining an intra prediction mode of a decoding target unit based on the derived neighbor prediction mode information; and
performing intra prediction for the decoding target unit based on the intra prediction mode of the decoding target unit,
wherein the left neighbor prediction mode is an intra prediction mode of a left neighbor unit adjacent to a left side of the decoding target unit and the upper neighbor prediction mode is an intra prediction mode of an upper neighbor unit adjacent to an upper side of the decoding target unit,
wherein the neighbor prediction mode information includes a mode number of the left neighbor prediction mode and a mode number of the upper neighbor prediction mode,
wherein the determining of the intra prediction mode comprises
determining a plurality of prediction modes for the decoding target unit based on the neighbor prediction mode information;
decoding first information specifying whether the same intra prediction mode as the intra prediction mode of the decoding target unit exists among the plurality of intra prediction modes, from a bitstream;
decoding second information specifying the same intra prediction mode as the intra prediction mode of the decoding target unit among the plurality of intra prediction modes in case the same intra prediction mode as the intra prediction mode of the decoding target unit exists among the plurality of intra prediction modes, from the bitstream; and
determining the intra prediction mode of the decoding target unit from among the plurality of intra prediction modes based on the decoded second information,
wherein, in case the left neighbor prediction mode is the same as the upper neighbor prediction mode, the plurality of intra prediction modes include a predetermined intra prediction mode.

### Claim 2 (depends on 1)

The video decoding method of claim 1, wherein the predetermined intra prediction mode is a DC mode or planar mode.

### Claim 3 (depends on 1)

The video decoding method of claim 1, wherein the number of the plurality of intra prediction modes is a predetermined fixed number.

### Claim 4

A video encoding method performed by a video encoding apparatus, the video encoding method comprising:
determining an intra prediction mode of an encoding target unit;
deriving neighbor prediction mode information from a left neighbor prediction mode and an upper neighbor prediction mode; and
encoding the intra prediction mode of the encoding target unit based on the derived neighbor prediction mode information,
wherein the left neighbor prediction mode is an intra prediction mode of a left neighbor unit adjacent to a left side of the encoding target unit and the upper neighbor prediction mode is an intra prediction mode of an upper neighbor unit adjacent to an upper side of the encoding target unit,
wherein the neighbor prediction mode information includes a mode number of the left neighbor prediction mode and a mode number of the upper neighbor prediction mode,
wherein the encoding of the intra prediction mode comprises
determining a plurality of intra prediction modes for the encoding target unit based on the neighbor prediction mode information;
encoding first information specifying whether the same intra prediction mode as the intra prediction mode of the encoding target unit exists among the plurality of intra prediction modes, into a bitstream; and
encoding second information specifying the same intra prediction mode as the intra prediction mode of the encoding target unit among the plurality of intra prediction modes in case the same intra prediction mode as the intra prediction mode of the encoding target unit exists among the plurality of intra prediction modes, into the bitstream, and
wherein, in case the left neighbor prediction mode is the same as the upper neighbor prediction mode, the plurality of intra prediction modes include a predetermined intra prediction mode.

### Claim 5 (depends on 4)

The video encoding method of claim 4, wherein the predetermined intra prediction mode is a DC mode or planar mode.

### Claim 6 (depends on 4)

The video encoding method of claim 4, wherein the number of the plurality of intra prediction modes is a predetermined fixed number.

### Claim 7

A non-transitory computer-readable recording medium storing a bitstream generated by a video encoding method, the video encoding method comprising:
determining an intra prediction mode of an encoding target unit;
deriving neighbor prediction mode information from a left neighbor prediction mode and an upper neighbor prediction mode; and
encoding the intra prediction mode of the encoding target unit based on the derived neighbor prediction mode information,
wherein the left neighbor prediction mode is an intra prediction mode of a left neighbor unit adjacent to a left side of the encoding target unit and the upper neighbor prediction mode is an intra prediction mode of an upper neighbor unit adjacent to an upper side of the encoding target unit,
wherein the neighbor prediction mode information includes a mode number of the left neighbor prediction mode and a mode number of the upper neighbor prediction mode,
wherein the encoding of the intra prediction mode comprises
determining a plurality of intra prediction modes for the encoding target unit based on the neighbor prediction mode information;
encoding first information specifying whether the same intra prediction mode as the intra prediction mode of the encoding target unit exists among the plurality of intra prediction modes, into a bitstream; and
encoding second information specifying the same intra prediction mode as the intra prediction mode of the encoding target unit among the plurality of intra prediction modes in case the same intra prediction mode as the intra prediction mode of the encoding target unit exists among the plurality of intra prediction modes, into the bitstream, and
wherein, in case the left neighbor prediction mode is the same as the upper neighbor prediction mode, the plurality of intra prediction modes include a predetermined intra prediction mode.