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

Abstract: According to embodiments of the present document, information for carrying out in-loop filtering across virtual boundaries can be efficiently signaled. For example, in-loop filtering can be carried out on the basis of signaling of information which is related to whether in-loop filtering across virtual boundaries is enabled or not.

Abstract: Embodiments of the disclosure provide methods and devices for decoding video signals using inter prediction. According to an embodiment of the disclosure, a method for processing a video signal comprises constructing a reference picture list of a current picture in the video signal and performing a prediction for a current picture by using the reference picture list, wherein constructing the reference picture list comprising, if a first entry of the reference picture list corresponds to a short-term reference picture (STRP), obtaining a picture order count (POC) difference between a picture related to the first entry and another picture, and if a second entry of the reference picture list corresponds to a long-term reference picture (LTRP), obtaining a POC modulo value of a picture related to the second entry. A reference picture list for identifying a picture may be generated in a simplified and effective manner. Thus, the compression performance may be increased, and the computation time may be decreased.

Abstract: Embodiments of the disclosure provide methods and devices for decoding video signals using inter prediction. According to an embodiment of the disclosure, a method for processing a video signal comprises constructing a reference picture list of a current picture in the video signal and performing a prediction for a current picture by using the reference picture list, wherein constructing the reference picture list comprising, if a first entry of the reference picture list corresponds to a short-term reference picture (STRP), obtaining a picture order count (POC) difference between a picture related to the first entry and another picture, and if a second entry of the reference picture list corresponds to a long-term reference picture (LTRP), obtaining a POC modulo value of a picture related to the second entry. A reference picture list for identifying a picture may be generated in a simplified and effective manner. Thus, the compression performance may be increased, and the computation time may be decreased.

Abstract: According to embodiments described herein, sub-pictures and/or virtual boundaries can be used for coding an image. For example, sub-pictures in the current picture can be used for predicting, reconstructing, and/or filtering the current picture. Virtual boundaries can be used for filtering reconstructed samples of the current picture. Through image coding based on the subpictures and/or virtual boundaries according to embodiments described herein, the subjective/objective quality of an image can be improved, and the consumption of hardware resources necessary for the coding can be reduced.

Abstract: A video decoding method performed by a video decoding apparatus according to the present document may comprise the steps of: parsing a prediction weighted table syntax from a bitstream; parsing number information about weighted reference pictures in a reference picture list from the prediction weighted table syntax; deriving a weighting factor-related flag about the reference picture list on the basis of the number information; performing weighted prediction on a current block on the basis of the weighting factor-related flag so as to derive prediction samples of the current block; generating residual samples on the basis of residual information obtained from the bitstream; and reconstructing a current picture on the basis of the prediction samples and the residual samples, wherein the prediction weighted table syntax is parsed from a picture header of the bitstream.

Abstract: An image encoding/decoding method and apparatus are provided. An image decoding method performed by an image decoding apparatus comprises 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 comprise a first flag specifying whether wraparound motion compensation is enabled for a current picture including the current block.

Abstract: A video decoding method performed by a video decoding apparatus, according to the present document, comprises the steps of: parsing a flag for weighted prediction from a bitstream; parsing a prediction weighted table syntax from the bitstream on the basis of the flag; generating prediction samples by performing weighted prediction on a current block within a current picture on the basis of the prediction weighted table syntax; and generating reconstructed samples for the current block on the basis of the prediction samples, wherein the prediction weighted table syntax may be parsed from a picture header or slice header of the bitstream on the basis of a value of the flag.

Abstract: A method for decoding an image by a decoding device, according to the present disclosure, can signal picture partitioning related information on the basis of a flag indicating whether sub-picture information exists and a flag indicating whether subpictures each include a single slice.

Abstract: An image encoding/decoding method and apparatus are provided. An image decoding method performed by an image decoding apparatus may comprise parsing weight information specifying a weight for a reference sample from a bitstream according to a weight parameter syntax structure, and decoding a current block by performing inter prediction based on the weight information. The parsing according to the weight parameter syntax structure may comprise obtaining weight number information specifying the number of weight information obtained from the bitstream according to the weight parameter syntax structure and obtaining weight information from the weight parameter syntax structure based on the weight number information.

Abstract: An image encoding/decoding method and apparatus are provided. An image decoding method performed by an image decoding apparatus comprises 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 comprise a first flag specifying whether wraparound motion compensation is enabled for a current picture including the current block.

Abstract: According to the disclosure of the present document, scaling list data transferred from an adaptation parameter set (APS) can be signaled through a hierarchical structure, and restrictions are placed on the scaling list data transferred from the APS, whereby the amount of data to be signaled for video/image coding can be reduced, and easiness in implementation can be provided.

Abstract: An image encoding/decoding method and apparatus is provided. The image decoding method performed by the image decoding apparatus may comprise determining inter-layer direct reference and determining the number of sublayers of a current layer based on the inter-layer direct reference.

Abstract: According to the disclosure of the present document, scaling list data delivered in an adaptation parameter set (APS) may be signaled through a hierarchical structure, and the amount of data that needs to be signaled for video/image coding may be reduced and implementation may be facilitated by placing limits on the scaling list data delivered in the APS.

Abstract: An image encoding/decoding method and apparatus are provided. The image decoding method performed by the image decoding apparatus according to the present disclosure may include: obtaining, from a bitstream, maximum temporal identifier information indicating a maximum temporal identifier of a reference layer which is referred to for inter-layer prediction of a current layer; and performing, based on the maximum temporal identifier information, a sub-bitstream extraction process from the bitstream, wherein, in the sub-bitstream extraction process, among parameter sets of the reference layer, a parameter set not referred to for the inter-layer prediction of the current layer may be removed from the bitstream.

Abstract: A picture decoding method performed by a decoding apparatus according to the present disclosure includes obtaining motion prediction information from bitstream, generating an affine MVP candidate list including affine MVP candidates for a current block, deriving CPMVPs for respective CPs of the current block based on one of the affine MVP candidates included in the affine MVP candidate list, deriving the CPMVDs for the CPs of the current block based on information on CPMVDs for each of the CPs included in the obtained motion prediction information, deriving CPMVs for the CPs of the current block based on the CPMVPs and the CPMVDs, deriving prediction samples for the current block based on the CPMVs, and generating reconstructed samples for the current block based on the derived prediction samples.

Abstract: An image encoding/decoding method and apparatus for signaling a VPS and a recording medium storing a bitstream are provided. An image decoding method may comprise obtaining first information indicating whether each output layer set (OLS) specified by a video parameter set (VPS) includes only one layer, obtaining second information indicating the number of decoded picture buffer (DPB) parameter syntax structures in the VPS, based on the first information, obtaining the DPB parameter syntax structures in the VPS based on the second information, and managing a DPB based on the DPB parameter syntax structures.

Abstract: An image encoding/decoding method and apparatus are provided. The image decoding method performed by the image decoding apparatus, according to the present disclosure, may comprise the steps of: determining whether a color space transformation is applied to residual samples of a current block; determining quantization parameter of the current block on the basis of whether the color space transformation is applied; and determining a transformation coefficient of the current block on the basis of the quantization parameter. The step of determining the quantization parameter may be performed by limiting the range of an effective value of the quantization parameter such that a value of the quantization parameter has a value less than or equal to a predetermined upper value and greater than or equal to a predetermined lower value.

Abstract: According to the present disclosure, ALF parameters and/or LMCS parameters can be hierarchically signaled, which enables a reduction in the amount of data to be signaled for video/image coding and an increase in the coding efficiency.

Abstract: Embodiments of the disclosure provide methods and devices for decoding video signals using inter prediction. According to an embodiment of the disclosure, a method for processing a video signal comprises constructing a reference picture list of a current picture in the video signal and performing a prediction for a current picture by using the reference picture list, wherein constructing the reference picture list comprising, if a first entry of the reference picture list corresponds to a short-term reference picture (STRP), obtaining a picture order count (POC) difference between a picture related to the first entry and another picture, and if a second entry of the reference picture list corresponds to a long-term reference picture (LTRP), obtaining a POC modulo value of a picture related to the second entry. A reference picture list for identifying a picture may be generated in a simplified and effective manner. Thus, the compression performance may be increased, and the computation time may be decreased.