Lg Electronics Inc.

Guangdong Oppo Mobile Telecommunications Corp., Ltd.

Beijing Xiaomi Mobile Software Co., Ltd.

Vivo Mobile Communication Co., Ltd.

Rosedale Dynamics LLC

Tcl King Electrical Appliances (huizhou) Co. Ltd.

Taissa Research LLC

Hyeongmoon Jang

Junghak Nam

Naeri Park

Jaehyun Lim

Seunghwan Kim

Moonmo Koo

Jaeho Lee

Seungwook Park

Jin Seong Heo

Yongjoon Jeon

Eunyong Son

Jungdong Seo

Sunmi Yoo Yoo

Hendry Hendry

Ling Li

Jie Zhao

Sehoon Yea

Bumshik Lee

Seethal Paluri

Mehdi Salehifar

An image decoding method according to the present document may comprise the steps of: receiving image information including residual information and an LFNST index from a bitstream; deriving a transform coefficient on the basis of the residual information; deriving a flag variable related to whether LFNST is applied to a current block on the basis of the LFNST index; and performing the LFNST on the basis of the flag variable and the transform coefficient, wherein the flag variable is derived for each color component of the current block.

Image coding method and device therefor

A video decoding method performed by a decoding apparatus includes the steps of: deriving control points (CP) for a current block; acquiring movement vectors for the CPs; deriving a sample unit movement vector in the current block on the basis of the acquired movement vectors; and deriving a prediction sample for the current block on the basis of the sample unit movement vector. According to the present invention, it is possible to effectively perform, through sample unit motion vectors, inter-prediction not only in a case where an image in the current block is plane-shifted but also in a case where there are various image distortions.

Inter prediction method and apparatus in video coding system

A method by which a decoding device decodes an image, according to the present document, comprises the steps of: receiving prediction mode information about a current block; receiving intra sub-partitions (ISP)-related information about the current block on the basis of the size and the maximum conversion block size of the current block; deriving an intra prediction mode of the current block on the basis of the prediction mode information; and generating a prediction sample of the current block on the basis of the intra prediction mode and the ISP-related information.

Intra prediction method and device based on intra sub-partitions in image coding system

According to the disclosure of the present document, when the inter-prediction type of the current block indicates biprediction, weight index information for a candidate in a merge candidate list or sub-block merge candidate list can be derived, and coding efficiency can be raised.

Image decoding method for deriving weight index information for biprediction, and device for same

According to embodiments of the present document, information for performing in-loop filtering across boundaries can be efficiently signaled. For example, the boundaries may include boundaries of tiles, slices, and/or sub-pictures.

In-loop filtering-based image coding device and method

Provided is an image decoding method performed by a decoding apparatus including deriving a temporary reference motion vector for a current block included in a current picture, deriving a reference motion vector for the current block by applying clipping to the temporary reference motion vector, deriving a motion vector for the current block based on the reference motion vector, deriving a predicted block for the current block based on the motion vector for the current block, and generating a reconstructed picture for the current picture based on the predicted block for the current block, wherein a number of bits of a binary code representing the reference motion vector is less than a number of bits of a binary code representing the temporary reference motion vector.

Method and apparatus for deriving motion vector

The present invention discloses an image coding/decoding method and an apparatus for the method. More specifically, a method for filtering an image by a decoding apparatus comprises deriving boundaries of a block divided into quad-tree plus binary-tree structure; determining an edge among boundaries of the block to which de-blocking filtering is applied; determining a type of de-blocking filtering to be applied to the edge; and performing de-blocking filtering to a picture sample restored according to the de-blocking filtering type, wherein the edge or the type of de-blocking filtering is determined by considering width or height of the block.

Image coding/decoding method and apparatus therefor

According to embodiments of the present document, a prediction procedure may be performed for image/video coding, and the prediction procedure may include symmetric motion vector differences (SMVDs) and merge mode motion vector differences (MMVDs) according to an inter prediction. The inter prediction may be performed on the basis of reference pictures of a current picture, and types (e.g., a long term reference picture, a short term reference picture, etc.) of the reference pictures may be considered for the inter prediction. Therefore, performance and coding efficiency in the prediction procedure can be improved.

Method and device for image coding using motion vector differences

A decoding method performed by a decoding device according to the present document comprises the steps of determining a prediction mode of a current block on the basis of information about a prediction mode obtained from a bitstream; constructing a merge candidate list on the basis of the prediction mode; deriving motion information of the current block on the basis of the merge candidate list; and generating prediction samples of the current block on the basis of the motion information, wherein the bitstream includes information about a combined inter-picture merge and intra-picture prediction (CIIP) available flag indicating whether the CIIP is available, and the determination step may include a step of acquiring a regular merge flag from the bitstream on the basis of the CIIP available flag.

Method and device for removing redundant syntax from merge data syntax

A method for decoding an image, according to the present document, comprises: receiving a bitstream including BDPCM information; deriving residual samples for a current block on the basis of the BDPCM information; deriving prediction samples for the current block on the basis of the BDPCM information; generating a reconstructed picture on the basis of the residual samples and the prediction samples; and performing deblocking filtering on the reconstructed picture, wherein when BDPCM is applied to the current block, the deblocking filtering is not performed.

Method for coding image on basis of deblocking filtering, and apparatus therefor

According to the disclosure of the present document, filter length can be determined on the basis of the distance between block boundaries in a deblocking filtering process, the deblocking filtering can be performed on the basis of the filter length, and thereby, the picture quality of the image/video can be enhanced, and the effects of improved subjective picture quality relative to complexity and simplification of H/W design can be obtained.

Image or video coding using deblocking filtering

According to the disclosure of the present document, slices included in a current picture are decoded, a picture output flag for the current picture is derived after decoding of all the slices in the current picture is completed, and an output for the current picture may be determined on the basis of the picture output flag. The current picture may be displayed as 'not needed for output' on the basis of the value of the picture output flag being 0, and the current picture may be displayed as “needed for output” on the basis of the value of the picture output flag being 1.

Image or video coding on basis of information related to picture output

An image decoding method according to the present document is characterized in that: decoder-side motion vector refinement (DMVR) is applied to derive refined L0 and L1 motion vectors on the basis of L0 and L1 motion vectors of the current block; prediction samples of the current block are derived on the basis of L0 prediction samples derived on the basis of the refined L0 motion vector and L1 prediction samples derived on the basis of the refined L1 motion vector; and recovery samples of the current block are generated on the basis of the prediction samples, wherein the L0 prediction samples are derived on the basis of an L0 reference picture and the refined L0 motion vector, the L1 prediction samples are derived on the basis of an L1 reference picture and the refined L1 motion vector, and in the step for deriving the prediction samples, whether to apply a bi-directional optical flow (BDOF) process is determined on the basis of whether a first POC difference between the current picture and the L0 reference picture and a second POC difference between the current picture and the L1 reference picture are the same.

Inter-prediction method and device based on DMVR and BDOF

According to the disclosure of the present document, in a subblock-based temporal motion vector prediction (sbTMVP), a position of a subblock for deriving a motion vector per subblock unit can be efficiently calculated, and thus video/image coding efficiency can be increased and hardware implementation can be simplified.

Inter-prediction-based image or video coding using sbTMVP

According to the disclosure of the present document, weight index information for sub-block merge candidates of a current block can be derived and coding efficiency can be increased.

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Seoul, South Korea

Hyeongmoon Jang