Abstract: According to one embodiment of the present document, a method by which a decoding device decodes an image is provided. The method comprises the steps of: acquiring, from a bitstream, image information including decoder side intra mode derivation (DIMD)-related information; determining whether a DIMD mode is applied to the current block on the basis of the DIMD-related information; deriving an intra prediction mode for the current block on the basis of the determined result; and generating prediction samples for the current block on the basis of the intra prediction mode.

Abstract: According to the disclosure of the present document, an image decoding method performed by a decoding device comprises the steps of: acquiring, through a bitstream, image information including prediction mode information and residual information; deriving a prediction mode of a current block on the basis of the prediction mode information; deriving prediction samples on the basis of the prediction mode; deriving residual samples on the basis of the residual information; generating reconstruction samples on the basis of the prediction samples and the residual samples; deriving filter coefficients for an adaptive loop filter (ALF) procedure for the reconstruction samples; and generating modified reconstruction samples on the basis of the reconstruction samples and the filter coefficients, wherein the image information includes a first adaptation parameter set (APS) including an ALF data field, and the ALF data field includes ALF parameters used to derive the filter coefficients.

Abstract: According to the disclosure of the present document, scaling list data transmitted from an adaptation parameter set (APS) can be signaled through a hierarchical structure. In addition, by setting a limit on the scaling list data transmitted from the APS, it is possible to reduce the amount of data which has to be signaled for video/image coding, and facilitate implementation.

Abstract: A video decoding method by a video decoding apparatus includes: parsing, from a picture parameter set of a bitstream, a first flag related to whether a weighted prediction is applied to slices referring to the picture parameter set; parsing, from the picture parameter set, a second flag related to whether information about the weighted prediction is present in a picture header of the bitstream or is present in a slice header of the bitstream based on the first flag; parsing a prediction weighted table syntax from the picture header or the slice header based on the first flag and the second flag; generating prediction samples for the current block by performing weighted prediction for the current block in a current picture based on syntax elements in the prediction weighted table syntax; and generating reconstructed samples based on the prediction samples.

Abstract: An image decoding method, according to the present disclosure may comprise: acquiring, from a bitstream, image information including adaptive loop filter (ALF) information including, alternative filter information for a chroma component of a current block, and residual information; generating reconstructed samples for the current block on the basis of the residual information; and generating modified reconstructed samples for the chroma component of the current block on the basis of the alternative filter information.

Abstract: A method by which a video decoding device decodes a video, according to the present document, can comprise the steps of: parsing, from a bitstream, number information related to the number of slices of which the height within a tile of a current picture is explicitly signaled; parsing, from the bitstream, on the basis of the number information, height information related to the height of the slices of which the height is explicitly signaled; deriving the number of slices in the tile on the basis of the number information and the height information; generating prediction samples by predicting the current block of the current picture on the basis of the slices within the tile; generating reconstructed samples on the basis of the prediction samples; and generating a reconstructed picture for the current picture on the basis of the reconstructed samples.

Abstract: According to the disclosure of the present document, reshaper data and/or an ALF parameter can be signaled adaptively from a parameter set, thereby reducing the amount of data to be signaled for video/image coding and improving coding efficiency.

Abstract: Provided are an image encoding/decoding method and device. An image decoding method performed by an image decoding device according to the present disclosure includes the steps of: determining a quantization parameter of the current block on the basis of whether color space conversion is applied to a residual sample of the current block; determining a transform coefficient of the current block on the basis of the quantization parameter; determining the residual sample of the current block by using the transform coefficient; and resetting the value of the residual sample on the basis of whether the color space conversion is applied.

Abstract: An image encoding/decoding method and apparatus for signaling a high level syntax (HLS) and a method of transmitting a bitstream are provided. An image decoding method according to the present disclosure may include obtaining first information indicating whether to constrain luma mapping with chroma scaling (LMCS), obtaining second information indicating whether LMCS for a current video sequence is allowed, and reconstructing a current picture within the current video sequence based on the second information. A value of the second information may be determined based on a value of the first information.

Abstract: A video decoding method performed by a video decoding apparatus, according to the present document, comprises: parsing number information about the number of slices of which heights are explicitly signaled in a tile of a current picture from a bitstream; parsing height information about the heights of slices of which heights are explicitly signaled from the bitstream based on the number information; deriving the number of slices in the tile based on the number information and the height information; and decoding the current picture based on the slices in the tile, wherein the height information includes the same number of syntax elements as a value of the number information, and based on the value of the number information being n, the heights of a 0th slice to an n?1th slice in the tile may be derived based on the syntax elements.

Abstract: A video decoding method performed by a video decoding device according to the present document may comprise the steps of: acquiring image information from a bitstream, wherein the image information includes a picture header associated with a current picture, and the current picture includes multiple slices; on the basis of the picture header, acquiring at least one of a first flag indicating whether information required for an inter-prediction operation exists in the picture header and a second flag indicating whether information required for an intra-prediction operation exists in the picture header; on the basis of at least one of the first flag and the second flag, generating prediction samples by performing at least one of intra-prediction and inter-prediction with respect to a current block in the current picture; generating residual samples on the basis of residual information acquired from the image information; and generating reconstruction samples on the basis of the prediction samples and the residu

Abstract: A video decoding method can comprise the steps of: acquiring image information from a bitstream, the image information including a picture header related to a current picture, and the current picture including a plurality of slices; parsing, from the picture header, a first flag indicating whether information necessary for an inter prediction operation is in the picture header and/or a second flag indicating whether information necessary for an intra prediction operation is in the picture header; parsing, from the picture header, the information necessary for the inter prediction operation and/or the information necessary for the intra prediction operation based on the first flag and/or the second flag; and generating prediction samples based on the information necessary for the inter prediction operation and/or the information necessary for the intra prediction operation.

Abstract: According to the disclosure of the present document, a quantization parameter for a quantized escape value in a palette mode can be derived on the basis of minimum quantization parameter information about a conversion skip mode to perform a scaling process on the quantized escape value. Therethrough, the data amount that is required to be signaled for palette mode coding can be reduced, and the efficiency of escape coding in the palette mode can be enhanced.

Abstract: A video decoding method performed by a video decoding device according to the present document comprises the steps of: acquiring image information from a bitstream, the image information including a picture header associated with the current picture including a plurality of slices; parsing, from the picture header, a first flag indicating whether information necessary for an inter-prediction operation for a decoding process is present in the picture header; parsing, from the picture header, a second flag indicating whether information necessary for an intra-prediction operation for the decoding process is present in the picture header; and generating prediction samples by performing at least one of intra-prediction or inter-prediction for the slices in the current picture on the basis of the first flag or the second flag.

Abstract: An image encoding/decoding method and apparatus are provided. An image decoding method performed by an image decoding apparatus comprises decoding a first flag specifying whether in-loop filtering is able to be performed across a boundary of a subpicture from a bitstream and performing the in-loop filtering on a boundary of a current block, based on the first flag. Based on the boundary of the current block being a boundary of a current subpicture including the current block, the in-loop filtering on the boundary of the current block is not performed, based on the first flag for the current subpicture specifying that the in-loop filtering is not able to be performed across the boundary of the current subpicture or the first flag for an adjacent subpicture adjacent to the boundary of the current block specifying that the in-loop filtering is not able to be performed across the boundary of the adjacent subpicture.

Abstract: According to the disclosure of the present document, information regarding ALF filter coefficients may be encoded/decoded by fixed order-based exponential golomb coding. In addition, information regarding a fixed filter in ALF may be binarized by fixed-length coding. Accordingly, signaling efficiency can be increased, and coding complexity can be decreased.

Abstract: An image encoding/decoding method and apparatus are provided. An image decoding method includes obtaining inter prediction information of a current block and wraparound information from a bitstream, and generating a prediction block of the current block based on the inter prediction information and the wraparound information. The wraparound information may include a first flag specifying whether wraparound motion compensation is enabled for a current video sequence including the current block. The first flag may have a first value specifying that the wraparound motion compensation is disabled, based on that one or more subpicture, which is coded independently and has a width different from a width of a current picture, is present in the current video sequence.

Abstract: According to the disclosure of the present document, ALF parameters and/or LMCS parameters may be hierarchically signaled, thereby enabling a reduction in data volume to be signaled for video/image coding and an increase in coding efficiency.

Abstract: A video decoding method performed by a video decoding apparatus, according to the present document, comprises the steps of: obtaining image information from a bitstream, wherein the image information includes a picture header associated with a current picture, and the current picture includes a plurality of slices; parsing at least one of a first flag and a second flag from the picture header; generating prediction samples by performing at least one of intra prediction and inter prediction on a current block in the current picture on the basis of at least one of the first flag and the second flag; generating reconstructed samples on the basis of the prediction samples; and generating a reconstructed picture on the basis of the reconstructed samples.

Abstract: An image decoding method performed by a decoding device, according to the present document, comprises the steps of: deriving a chroma quantization parameter table on the basis of quantization parameter data; deriving a quantization parameter for combined chroma coding on the basis of the chroma quantization parameter table; deriving prediction samples of a current chroma block on the basis of prediction information; deriving transform coefficients of the current chroma block on the basis of residual information; deriving residual samples by dequantizing the transform coefficients on the basis of the quantization parameter; and generating a reconstructed picture on the basis of the prediction samples and the residual samples.