Lg Electronics Inc.

Tencent America LLC

Guangdong Oppo Mobile Telecommunications Corp., Ltd.

Vivo Mobile Communication Co., Ltd.

Beijing Xiaomi Mobile Software Co., Ltd.

Xiaomi Inc.

Rosedale Dynamics LLC

Nokia Technologies Oy

Tcl King Electrical Appliances (Huizhou) Co. Ltd.

Ling Li

Jin Seong Heo

Jangwon Choi

Seunghwan Kim

Sunmi Yoo Yoo

Jungah Choi

Shan Liu

Jaehyun Lim

Xiang Li

Xiang Yang Li

Jung Hak Nam

Junghak Nam

Lien-Fei Chen

Xin Zhao

Stephan Wenger

Moonmo Koo

Naeri Park

Hyeongmoon Jang

Byeongdoo Choi

Guichun Li

Seung Hwan Kim

Cheung Auyeung

Liang Zhao

Jongyeul Suh

Bin Zhu

Tung Chin Lee

Soo-Chul Han

An image encoding/decoding method and apparatus are provided. An image decoding method according to the present disclosure may include determining whether a prediction mode of a current block is an intra prediction mode based on information on the prediction mode of the current block, determining whether intra sub-partitions (ISP) is available for the current block, when the prediction mode of the current block is an intra prediction mode, decoding an ISP application indicator indicating whether to apply ISP to the current block, when ISP is available for the current block, and generating a prediction block for the current block by applying ISP to the current block, upon determining that ISP applies to the current block based on the ISP application indicator.

Image encoding/decoding method and apparatus, and method of transmitting bitstream

A method for decoding an image by a decoding device according to the present document comprises the steps of: receiving prediction-related information of a current block; deriving an intra prediction type of the current block on the basis of the prediction-related information; forming an intra prediction mode candidate list of the current block on the basis of intra prediction modes of blocks neighboring the current block; deriving an intra prediction mode of the current block on the basis of the intra prediction mode candidate list; and deriving reference samples of the current block on the basis of the intra prediction type and the intra prediction mode, and deriving a prediction sample on the basis of the reference samples.

Method and device for decoding image by using intra prediction mode candidate list in image coding system

An image decoding method, which is performed by a decoding device according to the present document, is characterized by including: a step for receiving a bitstream including residual information about the current block; a step for deriving a maximum value of the number of context-encoding bins for context syntax elements coded on the basis of context included in the residual information; a step for entropy-decoding the context syntax elements on the basis of the maximum value; a step for deriving conversion coefficients for the current block on the basis of the entropy-decoded context syntax elements; a step for deriving a residual sample for the current block on the basis of the conversion coefficients; and a step for generating a reconstructed picture on the basis of the residual sample for the current block.

Image decoding method and device using residual information in image coding system

An image decoding method performed by a decoding device according to the present disclosure comprises the steps of: receiving a bitstream including prediction information for a current block; deriving a chroma array type for the current block on the basis of a separate color plane flag indicating whether three color components are separately coded and a chroma format index indicating a chroma format sampling structure for the current block, which are included in the prediction information for the current block; deriving prediction samples for the current block on the basis of the derived chroma array type; and deriving reconstructed samples for the current block on the basis of the prediction samples.

Method and device for signaling information on chroma format

A video decoding method according to the present document is characterized by comprising: obtaining Most Probable Mode (MPM) index information and reference line index information from a bitstream; compiling an MPM list including candidate intra prediction modes for the intra prediction of a current block; deriving an intra prediction mode for the current block from among the candidate intra prediction modes included in the MPM list on the basis of the MPM index information; generating prediction samples for the current block on the basis of the intra prediction mode; and generating reconstructed samples for the current block on the basis of the prediction samples, wherein the step for compiling the MPM list involves deriving a DC mode as one of the candidate intra prediction modes, and including the DC mode in the MPM list, the DC mode being derived on the basis of the value of reference line index information indicating a reference line used for the intra prediction of the current block not being zero.

MPM list-based intra prediction method and device

An image encoding/decoding method and apparatus are provided. An image decoding method performed by an image decoding apparatus may include determining a chroma array type of a current image, determining an adaptive loop filter (ALF) indicator of a chroma component based on the chroma array type, and performing ALF filtering with respect to a reconstructed image based on a value of the ALF indicator. The value of the ALF indicator may be determined to be a predetermined value without being obtained from a bitstream, based on the chroma array type being a predetermined type, and the value of the ALF indicator may be obtained from the bitstream, based on the chroma array type being not the predetermined type.

Image encoding/decoding method and device for signaling filter information on basis of chroma format, and method for transmitting bitstream

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

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

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

Aspects of the disclosure provide a method and an apparatus including processing circuitry for video decoding. The processing circuitry decodes, from a coded video bitstream, a first syntax element indicating whether a first component in the coded video bitstream is coded based on a second component in the coded video bitstream. The processing circuitry determines whether to decode one or more second syntax elements for a chroma related coding tool based on the first syntax element. The chroma related coding tool is a luma mapping with chroma scaling coding tool or a cross-component adaptive loop filter. The one or more second syntax elements are decoded when the first syntax element indicates that the first component is coded based on the second component. The one or more second syntax elements are not decoded when the first syntax element indicates that the first component is not coded based on the second component.

Signaling presence of chroma component in video bitstream

In a method, coded information of a current block and neighboring blocks of the current block in a current picture is received from a coded video bitstream. A list of merge candidates of the current block is generated based on the neighboring blocks of the current block. The list of merge candidates of the current block is divided into a plurality of subgroups. Each of the plurality of subgroups includes one or more merge candidates. The one or more merge candidates are ordered within each subgroup by a respective template matching (TM) cost associated with each of the one or more merge candidates. The current block is reconstructed based on a merge candidate selected from the list of merge candidates of the current block.

Grouping based adaptive reordering of merge candidate

An image encoding/decoding method and apparatus are provided. An image decoding method performed by an image decoding apparatus may include determining a prediction mode of a current block, generating a prediction block of the current block based on intra block copy (IBC) prediction mode information, based on the prediction mode of the current block being an IBC prediction mode, determining a size of a transform block of the current block based on a color component of the current block, generating a residual block of the current block based on the size of the transform block; and reconstructing the current block based on the prediction block and the residual block of the current block.

Image encoding/decoding method and device using maximum transform size restriction of chroma component encoding block, and method for transmitting bitstream

In a method of decoding, coded information of a coding unit (CU), a template region, and a plurality of reference regions is received. The coded information includes a first syntax element indicating whether the CU is predicted based on a template matching based multiple reference line (MRL) intra prediction mode. In response to the first syntax element indicating that the CU is predicted based on the template matching based multiple reference line (MRL) intra prediction mode, a plurality of cost values is determined between (i) respective prediction samples of the template region based on samples in each of the plurality of reference regions, and (ii) reconstructed samples of the template region corresponding to the respective prediction samples. A reference region from the plurality of reference regions is determined based on the plurality of cost values. Samples of the CU are reconstructed based on the samples in the determined reference region.

Intra mode selection and signaling

One or more intra mode predictors of a current block are determined, where the one or more intra mode predictors are derived based on the neighboring samples of the current block via either a decoder side intra mode derivation (DIMD) or a template-based intra mode derivation (TIMD). Whether a position dependent intra prediction combination (PDPC) is to be applied is determined based on the one or more intra mode predictors. In response to the determining that the PDPC is to be applied, a fusion process is performed on the one or more intra mode predictors to combine the one or more intra mode predictors into a single intra mode predictor. The PDPC is applied based on the single intra mode predictor to generate a modified predictor of the current block. The current block is reconstructed based on the modified predictor generated by the PDPC.

Applying PDPC after fusion of plural intra mode predictors

In the method, coded information of a coding unit (CU) in a picture of a video is received from a coded video bitstream. The CU is partitioned into a first partition and a second partition based on a geometric partition mode (GPM). The first partition and the second partition are rectangular partitions that are adjacent to each other and divided by a straight partition line. A first intra prediction mode for the first partition of the CU and a second intra prediction mode for the second partition of the CU are determined. The first intra prediction mode is different from the second intra prediction mode. The first partition of the CU is reconstructed based on the first intra prediction mode and the second partition of the CU is reconstructed based on the second intra prediction mode.

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Ling Li