# US 12,120,299 B2 · Image or video coding based on color space conversion

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 12,120,299 B2
- Document ID: US12120299B2
- Status: Granted
- Kind: B2
- Application number: 17/795,071
- Filed: 2021-01-25
- Published: 2023-05-04
- Granted: 2024-10-15
- Earliest claimed: 2020-01-25
- Assignees: LG Electronics Inc.
- Applicants: LG Electronics Inc.
- Inventors: Jie Zhao; Seunghwan Kim
- Web page: https://patentgrep.com/patent/US12120299B2

## 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 19/186: the unit being a colour or a chrominance component
- H04N 19/70: characterised by syntax aspects related to video coding, e.g. related to compression standards
- H04N 19/60: using transform coding
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

According to the disclosure of this document, it is possible to derive a residual sample by applying an adaptive color transform (ACT) to a current block on the basis of ACT-related information, and at this time, the residual sample is clipped and derived on the basis of a clipping range, wherein the clipping range is determined on the basis of a bit depth.

## Claims

### Claim 1

An image decoding method performed by a decoding apparatus,
the method comprising:
obtaining image information including residual information and prediction mode information from a bitstream;
deriving a prediction sample for a current block based on the prediction mode information;
deriving a residual sample for the current block based on the residual information; and
generating a reconstructed sample based on the residual sample and the prediction sample,
wherein the image information includes adaptive color transform (ACT)-related information,
wherein whether to apply an ACT to the residual sample of the current block is determined based on the ACT-related information,
wherein based on the ACT-related information representing that the ACT is applied, clipping is performed on the residual sample to apply the ACT,
wherein the clipping is performed by a clipping range determined based on a bit depth (BitDepth),
wherein the clipping range includes a clipping range for a luma component and a clipping range for a chroma component,
wherein the clipping range for the luma component includes a range between −(1<<BitDepth) and (1<<BitDepth)−1, and
wherein the clipping range for the chroma component includes a range between −(1<<(BitDepth+1)) and (1<<(BitDepth+1))−1.

### Claim 2

An image encoding method performed by an encoding apparatus, the method comprising:
deriving a prediction sample for a current block;
generating prediction mode information;
deriving a residual sample for the current block based on the prediction sample;
generating residual information based on the residual sample; and
encoding image information including the residual information and the prediction mode information,
wherein the image information includes adaptive color transform (ACT)-related information,
wherein whether to apply an ACT to the residual sample of the current block is determined based on the ACT-related information,
wherein based on the ACT-related information representing that the ACT is applied, clipping is performed on the residual sample to apply the ACT,
wherein the clipping is performed according to a clipping range determined based on a bit depth (BitDepth),
wherein the clipping range includes a clipping range for a luma component and a clipping range for a chroma component,
wherein the clipping range for the luma component includes a range between −(1<<BitDepth) and (1<<BitDepth)−1, and
wherein the clipping range for the chroma component includes a range between −(1<<(BitDepth+1)) and (1<<(BitDepth+1))−1.

### Claim 3

A non-transitory computer-readable storage medium storing a bitstream generated by an image encoding method, the image encoding method comprising:
deriving a prediction sample for a current block;
generating prediction mode information;
deriving a residual sample for the current block based on the prediction sample;
generating residual information based on the residual sample; and
encoding image information including the residual information and the prediction mode information,
wherein the image information includes adaptive color transform (ACT)-related information,
wherein whether to apply an ACT to the residual sample of the current block is determined based on the ACT-related information,
wherein based on the ACT-related information representing that the ACT is applied, clipping is performed on the residual sample to apply the ACT,
wherein the clipping is performed according to a clipping range determined based on a bit depth (BitDepth),
wherein the clipping range includes a clipping range for a luma component and a clipping range for a chroma component,
wherein the clipping range for the luma component includes a range between −(1<<BitDepth) and (1<<BitDepth)−1, and
wherein the clipping range for the chroma component includes a range between −(1<<(BitDepth+1)) and (1<<(BitDepth+1))−1.