Lg Electronics Inc.

Rosedale Dynamics LLC

Guangdong Oppo Mobile Telecommunications Corp., Ltd.

Vivo Mobile Communication Co., Ltd.

Xiaomi Inc.

Tcl King Electrical Appliances (huizhou) Co. Ltd.

Beijing Xiaomi Mobile Software Co., Ltd.

Jangwon Choi

Jin Seong Heo

Sunmi Yoo Yoo

Jungah Choi

Seunghwan Kim

Ling Li

Jaehyun Lim

Junghak Nam

Seung Hwan Kim

Jaeho Lee

Jungdong Seo

Hyeong Moon Jang

Jung Hak Nam

Summi Yoo

An image decoding method according to the present document comprises the steps of: receiving a bitstream including residual information; deriving a quantized transform coefficient for a current block on the basis of the residual information included in the bitstream; deriving a residual sample for the current block on the basis of the quantized transform coefficient; and generating a restoration picture on the basis of the residual sample for the current block, wherein the residual information includes position information for indicating the position of a transform coefficient, which is not the last 0 in a transform block, and the position information can be derived if a transform skip is not applied to the transform block.

Transform coefficient coding method and device

According to one embodiment of the present document, filtering for chroma blocks can be performed on the basis of luma blocks. For example, a cross component adaptive loop filtering process can be performed. Therefore, the accuracy of in-loop filtering can be improved.

Adaptive loop filtering-based image coding apparatus and method

An image decoding method performed by a decoding device according to the present document is characterized by comprising the steps of: acquiring a block-based delta pulse code modulation (BDPCM) available flag about whether a BDPCM is available for a chroma block and a luma block; acquiring, on the basis of the BDPCM available flag, a BDPCM luma flag about whether to apply the BDPCM to the current luma block; and acquiring, on the basis of the BDPCM available flag, a BDPCM chroma flag about whether to apply the BDPCM to the current chroma blocks.

BDPCM-based image decoding method for luma component and chroma component, and device for same

An image decoding method executed by a decoding apparatus according to the present document comprises the steps of: deriving an intra prediction mode of the current chroma block by means of cross-component linear model (CCLM) mode; deriving downsampled luma samples on the basis of the current luma block; deriving downsampled neighboring luma samples on the basis of neighboring luma samples of the current luma block; and deriving the CCLM parameter on the basis of the downsampled neighboring luma samples and neighboring chroma samples of the current neighboring chroma block, wherein the number of down-sampled neighboring luma samples and number of neighboring chroma samples are equal to the previously set thresh-hold value, and the thresh-hold value is derived on the basis of the width and height of the current chroma block.

CCLM prediction-based image decoding method and apparatus in image coding system

A video decoding method performed by a decoding apparatus according to the present document may comprise the steps of: obtaining, from a bitstream, information indicating a level value of a transform coefficient in a current block; selecting one Rice parameter look-up table for the information indicating the level value of the transform coefficient, from among a plurality of Rice parameter look-up tables; deriving a Rice parameter for the information indicating the level value of the transform coefficient on the basis of the selected Rice parameter look-up table; deriving a bin string for the information indicating the level value of the transform coefficient on the basis of the Rice parameter; and deriving the level value of the transform coefficient on the basis of the bin string.

Method and apparatus for coding transform coefficient in video/image coding system

An image decoding method carried out by a decoding device, according to the present document, comprises the steps of: acquiring a sign data hiding enable flag; acquiring a transform skip residual coding (TSRC) enable flag on the basis of the sign data hiding enable flag; acquiring residual information for a current block, on the basis of the TSRC enable flag; deriving a residual sample of the current block, on the basis of the residual information; and generating a reconstructed picture on the basis of the residual sample, wherein the sign data hiding enable flag is a flag indicating whether sign data hiding is enabled, the TSRC enable flag is a flag indicating whether TSRC is enabled, and the TSRC enable flag is acquired on the basis of the sign data hiding enable flag having a value of zero.

Image decoding method for residual coding, and device therefor

An image decoding method performed by a decoding apparatus according to the present disclosure comprises the steps of: obtaining intra prediction information including at least one of MPM flag information, MRL index information, and planner flag information from a bitstream; checking the MPM flag information; checking the MRL index information on the basis of a case where the MPM flag information indicates that the MRL index information is checked; checking the planner flag information on the basis of a case where a value of the MRL index information is 0; deriving an intra prediction mode for a current block on the basis of the check for the planner flag information; deriving prediction samples for the current block on the basis of the intra prediction mode for the current block; and generating a reconstructed picture on the basis of the prediction samples.

Intra prediction method on basis of MPM list and apparatus therefor

According to a disclosure of the present document, information associated with a deblocking filter for performing deblocking filtering may include chroma component filter parameter information associated with deblocking parameter offsets that are applied to a chroma component. The chroma component filter parameter information may be selectively signaled on the basis of a chroma tool offset presence flag. Therefore, an effect of increasing overall coding efficiency may be derived by signaling chroma component filter parameter information only in the case of not a monochrome color format.

Image coding method based on chroma deblocking parameter information for monochrome color format in video or image coding system

An image decoding method carried out by a decoding device, according to the present document, comprises the steps of: acquiring prediction-related information for a current block; acquiring a dependent quantization enable flag related to whether dependent quantization is available; acquiring, on the basis of the dependent quantization enable flag, a transform skip residual coding (TSRC) enable flag related to whether TSRC is available; acquiring residual information of residual coding syntax for the current block, which has been derived on the basis of the TSRC enable flag; deriving motion information of the current block on the basis of the prediction-related information; deriving a prediction sample of the current block on the basis of the motion information; deriving a residual sample of the current block on the basis of the residual information; and generating a reconstructed picture on the basis of the prediction sample and the residual sample.

Image decoding method associated with transform skip residual coding, and device therefor

According to one embodiment of the present document, an in-loop filtering procedure in an image/video coding procedure may comprise a cross-component adaptive loop filtering procedure. CCALF, according to the present embodiment, can increase the accuracy of in-loop filtering.

Apparatus and method for coding image

A method for decoding a video performed by a decoding device according to the present document is characterized by comprising: a step for acquiring video information including prediction mode information and residual information through a bitstream; a step for deriving a prediction mode of a current block on the basis of the prediction mode information; a step for deriving a prediction sample on the basis of the prediction mode; a step for deriving a current residual coefficient on the basis of residual syntax elements for the current residual coefficient in the current block; a step for deriving a residual sample on the basis of the current residual coefficient; and a step for deriving a reconstructed sample of the current block on the basis of the prediction sample and the residual sample.

Method for decoding video for residual coding and device therefor

A video decoding method according to this document includes constructing a most probable mode (MPM) list by deriving MPM candidates for a current block based on a neighboring block adjacent to the current block, deriving an intra prediction mode for the current block based on the MPM list, generating predicted samples by performing prediction for the current block based on the intra prediction mode, and generating a reconstructed picture for the current block based on the predicted samples.

Intra prediction-based image coding method and apparatus using MPM list

An image decoding method performed by a decoding apparatus according to the present document comprises the steps of: obtaining a Block-based Delta Pulse Code Modulation (BDPCM) available flag indicating whether or not BDPCM is available for a chroma block and a luma block; obtaining BDPCM-related information for a current luma block and current chroma blocks on the basis of the BDPCM available flag; and generating reconstructed samples for the current luma block and the current chroma blocks on the basis of the BDPCM-related information.

Image decoding method using BDPCM and apparatus thereof

According to embodiments of the present document, an intra-prediction mode candidate list of a current block can be constructed by means of a process of constructing a common intra-prediction mode list with respect to intra-prediction types. Therefore, the dependency of the intra-prediction types in the process of constructing the intra-prediction mode list is reduced, and thus the coding efficiency of an intra-prediction can be enhanced.

Image decoding method and device and image encoding method and device in image coding system

An image decoding method includes obtaining image information including residual information and prediction-related information through a bitstream, deriving transform coefficients based on the residual information, generating residual samples for a current block based on the transform coefficients, deriving an intra prediction mode for the current block based on the prediction-related information, generating prediction samples for the current block based on the intra prediction mode, generating reconstructed samples for the current block based on the prediction samples and the residual samples, wherein the image information includes flag information related to whether an intra prediction mode type for the current block is a matrix-based intra prediction (MIP), wherein the intra prediction mode type for the current block is determined as the MIP based on the flag information, and wherein the prediction samples for the current block are generated based on MIP samples.

Growing community of inventors

Seoul, South Korea

Jangwon Choi