# US 12,192,468 B2 · Image decoding method using image information comprising TSRC available flag and apparatus therefor

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- Number: US 12,192,468 B2
- Document ID: US12192468B2
- Status: Granted
- Kind: B2
- Application number: 17/797,922
- Filed: 2021-02-05
- Published: 2023-03-23
- Granted: 2025-01-07
- Earliest claimed: 2020-02-05
- Assignees: LG Electronics Inc.
- Applicants: LG Electronics Inc.
- Inventors: Jungah Choi; Sunmi Yoo; Jin Heo; Jangwon Choi; Seunghwan Kim
- Web page: https://patentgrep.com/patent/US12192468B2

## CPC

- H04N 19/12: Selection from among a plurality of transforms or standards, e.g. selection between discrete cosine transform [DCT] and sub-band transform or selection between H.263 and H.264
- H04N 19/132: Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking
- 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 19/18: the unit being a set of transform coefficients
- H04N 19/46: Embedding additional information in the video signal during the compression process (H04N19/517, H04N19/68, H04N19/70 take precedence)
- H04N 19/70: characterised by syntax aspects related to video coding, e.g. related to compression standards
- H04N 19/11: among a plurality of spatial predictive coding modes
- H04N 19/124: Quantisation
- H04N 19/593: involving spatial prediction techniques
- H04N 19/61: in combination with predictive coding
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

An image decoding method performed by a decoding apparatus, according to the present document, comprises the steps of: acquiring a dependent quantization available flag; and acquiring a transform skip residual coding (TSRC) available flag on the basis of the dependent quantization available flag.

## Claims

### Claim 1

An image decoding method performed by a decoding apparatus, the method comprising:
obtaining a transform skip flag for whether transform skip is applied to a current block;
obtaining a dependent quantization enabled flag;
obtaining a Transform Skip Residual Coding (TSRC) disabled flag based on the dependent quantization enabled flag;
obtaining residual information of a residual coding syntax for the current block derived based on the TSRC disabled flag;
obtaining intra prediction mode information for the current block;
deriving an intra prediction mode of the current block based on the intra prediction mode information;
deriving a prediction sample of the current block based on the intra prediction mode;
deriving a residual sample of the current block based on the residual information; and
generating a reconstructed picture based on the prediction sample and the residual sample,
wherein the TSRC disabled flag having a value of 1 represents that TSRC is not enabled,
wherein the transform skip flag having a value of 1 represents that the transform skip is applied,
wherein, based on the dependent quantization enabled flag, the TSRC disabled flag and transform skip flag, whether a residual coding syntax for a non-transform skip block and dependent quantization are used is determined,
wherein, based on the transform skip flag having the value of 1, the dependent quantization is not used, and
wherein, based on the residual coding syntax for a non-transform skip block being used in case of the TSRC disabled flag having the value of 1, the dependent quantization is not used.

### Claim 2

An image encoding method performed by an encoding apparatus, the method comprising:
deriving an intra prediction mode of a current block;
deriving a prediction sample of the current block based on the intra prediction mode;
encoding intra prediction mode information for the current block;
encoding a transform skip flag for whether transform skip is applied to the current block;
encoding a dependent quantization enabled flag;
encoding a Transform Skip Residual Coding (TSRC) disabled flag based on the dependent quantization enabled flag;
determining a residual coding syntax for the current block based on the TSRC disabled flag;
encoding residual information of the determined residual coding syntax for the current block; and
generating a bitstream including the residual information,
wherein the TSRC disabled flag having a value of 1 represents that TSRC is not enabled,
wherein the transform skip flag having a value of 1 represents that the transform skip is applied,
wherein, based on the dependent quantization enabled flag, the TSRC disabled flag and transform skip flag, whether a residual coding syntax for a non-transform skip block and dependent quantization are used is determined,
wherein, based on the transform skip flag having the value of 1, the dependent quantization is not used, and
wherein, based on the residual coding syntax for a non-transform skip block being used in case of the TSRC disabled flag having the value of 1, the dependent quantization is not used.

### Claim 3

A non-transitory computer-readable storage medium storing a bitstream generated by a method, the method comprising:
deriving an intra prediction mode of a current block;
deriving a prediction sample of the current block based on the intra prediction mode;
encoding intra prediction mode information for the current block;
encoding a transform skip flag for whether transform skip is applied to the current block;
encoding a dependent quantization enabled flag;
encoding a Transform Skip Residual Coding (TSRC) disabled flag based on the dependent quantization enabled flag;
determining a residual coding syntax for the current block based on the TSRC disabled flag;
encoding residual information of the determined residual coding syntax for the current block; and
generating the bitstream including the residual information,
wherein the TSRC disabled flag having a value of 1 represents that TSRC is not enabled,
wherein the transform skip flag having a value of 1 represents that the transform skip is applied,
wherein, based on the dependent quantization enabled flag, the TSRC disabled flag and transform skip flag, whether a residual coding syntax for a non-transform skip block and dependent quantization are used is determined,
wherein, based on the transform skip flag having the value of 1, the dependent quantization is not used, and
wherein, based on the residual coding syntax for a non-transform skip block being used in case of the TSRC disabled flag having the value of 1, the dependent quantization is not used.