Abstract: A video decoding method comprises: deriving L0 and L1 motion vectors of a current block; deriving decoder-side motion vector refinement (DMVR) flag information indicating whether to apply a DMVR to the current block; when the DMVR flag information indicates that the DMVR is to be applied to the current block, deriving refined L0 and L1 motion vectors based on the L0 and L1 motion vectors by applying the DMVR to the current block; 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 predicted samples, wherein deriving DMVR flag information comprises deriving the DMVR flag information by applying the DMVR to the current block when the height of the current block is 8 or more, and when the values of L0 and L1 luma weighted prediction flag information are both 0.

Abstract: An image decoding method according to the present document may comprise: a step for deriving an inter prediction mode from encoded information; a step for constructing reference pictures lists; a step for deriving motion information including reference picture indices for symmetric motion vector differences (SMVD) on the basis of reference pictures included in the reference picture lists; and a step for generating prediction samples on the basis of the motion information. The reference picture indices for SMVD may be derived on the basis of short-term reference pictures included in the reference picture lists.

Abstract: According to a disclosure of the present document, when the type of inter-prediction of a current block is indicated as biprediction, weight index information for a candidate within a merge candidate list or a sub-block merge candidate list may be derived, and coding efficiency may be increased.

Abstract: A method for image decoding, according to the present document, may comprise the steps of: deriving an intra prediction mode of a chroma block as a cross-component linear model (CCLM) mode; updating the intra prediction mode of the chroma block on the basis of an intra prediction mode of a luma block corresponding to the chroma block; and determining an LFNST set including LFNST matrices on the basis of the updated intra prediction mode, wherein the updated intra prediction mode is derived as an intra prediction mode corresponding to a specific position in the luma block, and the specific position is set on the basis of a color format of the chroma block.

Abstract: An image decoding method according to the present document comprises the steps of: on the basis of an intra prediction mode of a chroma block being a cross-component linear model (CCLM) mode and an intra prediction mode of a luma block corresponding to the chroma block being a palette mode, updating the intra prediction mode of the chroma block to an intra DC mode; on the basis of the updated intra prediction mode, determining an LFNST set including LFNST matrices; and performing LFNST on the chroma block on the basis of an LFNST matrix derived from the LFNST set, wherein the intra DC mode is an intra prediction mode corresponding to a specific location within the luma block.

Abstract: Disclosed are a method for decoding a video signal and an apparatus therefor. Specifically, a method for decoding an image may include: partitioning a current coding tree block into a plurality of coding blocks so that coding blocks partitioned from the current coding tree block are included in a current picture when the current coding tree block is out of a boundary of the current picture; parsing a first syntax element indicating whether a current coding block is partitioned into a plurality of subblocks when the current coding block satisfies a predetermined condition; and determining a split mode of the current coding block based on the syntax element.

Abstract: According to embodiments of the present document, a prediction procedure can be performed for image video coding, and the prediction procedure can comprise merge mode motion vector differences (MMVD) and symmetric motion vector differences (SMVD) according inter prediction. The inter prediction can be performed on the basis of reference pictures of a current picture, and types of the reference pictures (e.g. a long-term reference picture, a short-term reference picture, etc.) can be considered for the inter prediction. Accordingly, performance and coding efficiency in the prediction procedure can be increased.

Abstract: 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.

Abstract: A method by which a decoding device decodes an image, according to the present document, comprises the steps of: generating a restoration picture on the basis of prediction samples of a coding block; deriving a boundary strength (BS) for a boundary of the coding block in the restoration picture; performing deblocking filtering on the boundary of the coding block on the basis of the boundary strength; and deriving a modified restoration picture for the restoration picture on the basis of the deblocking filtering, wherein the boundary strength is derived on the basis of a prediction mode of a first block and a second block that are adjacent to the boundary of the coding block, and the prediction mode of the first block or the second block is derived on the basis of whether the prediction mode of the first block or the second block is a current picture referencing (CPR) mode to be coded in reference to a current picture.

Abstract: An image decoding method performed by a decoding apparatus includes the operations of: deriving a correspondence block corresponding to the current block of the current picture, the correspondence block being located in a co-located picture; deriving a movement vector of the correspondence block; scaling the movement vector of the correspondence block based on a first temporal distance and second temporal distance, the first temporal distance being the difference between the POC values of the co-located picture and POC values of the reference picture of the correspondence block, and the second temporal distance being the difference between the POC values of the co-located picture and POC values of the current picture containing the current block; deriving the movement vector updated based on the scaled movement vector and location of the current block; and deriving a movement vector of the current block based on the updated movement vector.

Abstract: A method by which a decoding device performs image decoding, according to the present document, comprises the steps of: deriving a reference block on the basis of a motion shift; determining whether a subblock temporal motion vector predictor (sbTMVP) candidate is available, on the basis of whether the reference block is a current picture referencing (CPR) block; deriving motion information about a current block on the basis of the sbTMVP candidate when the sbTMVP candidate is available; generating prediction samples on the basis of the motion information; and generating a restored picture on the basis of the prediction samples, wherein the sbTMVP candidate is determined to be unavailable with respect to the reference block which is the CPR block.

Abstract: An image encoding method may include acquiring image information including inter prediction mode information and residual information through a bitstream, generating residual samples based on the residual information, generating prediction samples of a current block by applying a prediction mode determined based on the inter prediction mode information, and generating reconstructed samples based on the prediction samples and the residual samples. Based on a CIIP mode being not enabled, a partitioning prediction mode in which prediction is performed by dividing the current block into two partitions being not enabled, a value of the first flag for a subblock merge mode being equal to 0 and a value of the third flag for a MMVD being equal to 0, the inter prediction mode information includes merge index information indicating one of merge candidates included in a merge candidate list generated for the regular merge mode.

Abstract: An image decoding method performed by the decoding apparatus according to this document comprising deriving a temporary reference motion vector for a current block based on a reference candidate block of the current block, deriving a reference motion vector by compressing the temporary reference motion vector based on a shifting operation, deriving a motion vector for the current block based on the reference motion vector, deriving prediction samples for the current block based on the motion vector for the current block, and generating reconstructed samples for the current block based on the prediction samples for the current block, wherein a total number of bits of the binary code representing the reference motion vector is less than a total number of bits of the binary code representing the temporary reference motion vector.

Abstract: A decoding method performed by a decoding device, according to the present document, may comprise the steps of: acquiring a sequence parameter set from a bitstream; acquiring a combined inter-picture merge and intra-picture prediction (CIIP) enable flag from the sequence parameter set; determining, on the basis of the CIIP enable flag and the size of a current block, whether a regular merge flag is included in the bitstream; parsing the regular merge flag in the bitstream on the basis that a condition based on the CIIP enable flag and a condition based on the size of the current block are satisfied; generating prediction samples of the current block on the basis of the regular merge flag; and generating a restoration picture on the basis of the prediction samples.

Abstract: Disclosed herein are a method for decoding a video signal and a device therefor. Specifically, a method for decoding an image based on an inter prediction mode may include: if a merge mode is applied to a current block, generating a merge candidate list by using a spatial neighboring block and a temporal neighboring block of the current block; obtaining a merge index indicating a candidate to be used for an inter prediction of the current block in the merge candidate list; deriving a motion vector of each of subblocks included in the current block based on a motion vector of the candidate used for the inter prediction of the current block; and generating a prediction sample of the current block by using the motion vector of each of subblocks.

Abstract: A video signal processing method comprises obtaining a merge subblock index for a current block for which a parameter for subblock-based inter prediction is derived from a surrounding block; obtaining control point motion vectors for control points of the current block, based on the merge subblock index, the merge subblock index being related to one candidate in a subblock-based merge candidate list; applying one or more offsets to the control point motion vectors, based on a merge with motion vector direction index for refining the control point motion vectors; determining a motion vector for each subblock based on the respective positions of the subblocks in the current block and the control point motion vectors to which the one or more offsets have been applied; and generating prediction samples for the current block based on a reference picture related to the subblock merge index and the motion vectors for each subblock.

Abstract: An image decoding method performed by a decoding device according to the present document comprises the steps of: deriving a temporary reference motion vector regarding a current block on the basis of a temporal periphery block included in a reference picture of a current picture including the current block; deriving a binary code indicating a reference motion vector by applying a shifting operation to a binary code indicating the temporary reference motion vector; storing information regarding the binary code indicating the reference motion vector; deriving a motion vector regarding the current block on the basis of the reference motion vector; deriving a predicted block regarding the current block on the basis of the motion vector regarding the current block; and generating a restored picture regarding the current picture on the basis of the predicted block regarding the current block.

Abstract: A method for image decoding, according to the present document, may comprise the steps of: deriving an intra prediction mode of a chroma block as a cross-component linear model (CCLM) mode; updating the intra prediction mode of the chroma block on the basis of an intra prediction mode of a luma block corresponding to the chroma block; and determining an LFNST set including LFNST matrices on the basis of the updated intra prediction mode, wherein the updated intra prediction mode is derived as an intra prediction mode corresponding to a specific position in the luma block, and the specific position is set on the basis of a color format of the chroma block.

Abstract: According to embodiments according to the present document, merge mode motion vector differences (MMVD) and symmetric motion vector differences (SMVD) may be performed on the basis of reference picture types and, in particular, short-term reference pictures may be used. Accordingly, prediction performance and coding efficiency in an inter prediction mode may be increased.

Abstract: An image decoding method according to the present document comprises the steps of: on the basis of an intra prediction mode of a chroma block being a cross-component linear model (CCLM) mode and an intra prediction mode of a luma block corresponding to the chroma block being a palette mode, updating the intra prediction mode of the chroma block to an intra DC mode; on the basis of the updated intra prediction mode, determining an LFNST set including LFNST matrices; and performing LFNST on the chroma block on the basis of an LFNST matrix derived from the LFNST set, wherein the intra DC mode is an intra prediction mode corresponding to a specific location within the luma block.