Lg Electronics Inc.

Guangdong Oppo Mobile Telecommunications Corp., Ltd.

Beijing Xiaomi Mobile Software Co., Ltd.

Vivo Mobile Communication Co., Ltd.

Xiaomi Inc.

Rosedale Dynamics LLC

Taissa Research LLC

Junghak Nam

Hyeongmoon Jang

Naeri Park

Jaehyun Lim

Seunghwan Kim

Jin Seong Heo

Moonmo Koo

Sunmi Yoo Yoo

Jungdong Seo

Jaeho Lee

Jangwon Choi

Jungah Choi

Sehoon Yea

Eunyong Son

Ling Li

Chulkeun Kim

Yongjoon Jeon

Hendry Hendry

Seungwook Park

Mehdi Salehifar

Taesup Kim

Seethal Paluri

Jie Zhao

Bumshik Lee

Kyuwoon Kim

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

In the present invention, a method for processing an image on the basis of an intra prediction mode and an apparatus therefor are disclosed. Particularly, the method for processing an image on the basis of an intra prediction mode may comprise the steps of: partitioning a block to be processed, on the basis of an intra prediction mode of the block to be processed; and performing intra prediction for the split block to be processed, wherein the direction in which the block to be processed is split is perpendicular to the prediction direction of the intra prediction mode of the block to be processed.

Method for processing image on basis of intra prediction mode and apparatus therefor

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

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

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

An image decoding method according to the present document comprises a step for performing inverse first-order transform and inverse non-separable transform on a residual sample. The inverse non-separable transform is performed on the basis of a transform index indicating a predetermined transform kernel matrix, the inverse first-order transform is performed on the basis of a multiple transform selection (MTS) index indicating MTS for a horizontal transform kernel and a vertical transform kernel, and a syntax element bin string for the transform index is derived on the basis of first context information when a tree type for a split structure of a target block is not a single tree type and is derived on the basis of second context information when the tree type is the single tree type.

Transform-based image coding method and device therefor

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 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 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 video transform method includes: receiving a quantized transform coefficient for a target block and a transform index for a non-separated secondary transform; inverse-quantizing the quantized transform coefficient; deriving an input transform coefficient size indicating the length of the inverse-quantized transform coefficient to which the non-separated secondary transform has been applied, an output transform coefficient size indicating the length of a modified transform coefficient to which the non-separated secondary transform has been applied, and a transform set mapped to the intra mode of the target block, when the transform index does not indicate that the non-separated secondary transform is not performed; and deriving the modified transform coefficient on the basis of a matrix operation on a transform kernel matrix in the transform set indicated by the transform index, and a transform coefficient list corresponding to the input transform coefficient size.

Video coding method on basis of secondary transform, and device therefor

An image decoding method includes: acquiring a multiple transform selection (MTS) index and residual information from a bitstream; deriving transform coefficients for the current block on the basis of the residual information; and generating residual samples of the current block on the basis of the MTS index and the transform coefficients, wherein the MTS index indicates a transform kernel set to be applied to the current block among transform kernel set candidates, at least one bin among bins of a bin string of the MTS index is derived on the basis of context coding, the context coding is performed on the basis of values of increase and decrease in a context index pertaining to the MTS index, and a single value of increase and decrease in the context index can be used for the context coding of the first bin among the bins of the bin string.

Coding of information about transform kernel set

An image decoding method comprises the steps of: determining whether or not an application condition of decoder-side motion vector refinement (DMVR) for applying motion vector refinement for a current block is satisfied; deriving a minimum sum of absolute differences (SAD) on the basis of L0 and L1 motion vectors of the current block if the application condition of the DMVR is satisfied; deriving refined L0 and L1 motion vectors of the current block based on the minimum SAD; deriving prediction samples of the current block based on the refined L0 and L1 motion vectors; and generating reconstructed samples of the current block based on the prediction samples. With respect to whether or not the application condition of the DMVR is satisfied, the application condition of the DMVR is determined to be satisfied if a prediction mode, in which inter-prediction and intra-prediction are combined, is not applied to the current block.

DMVR-based inter-prediction method and device

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.

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Seoul, South Korea

Junghak Nam