Abstract: Provided are a method and apparatus, which, during video encoding and decoding processes, obtain chroma intra prediction mode information about a current chroma block, when the chroma intra prediction mode information indicates a direct mode (DM), determine a luma block including a luma sample corresponding to a chroma sample at a lower-right location with respect to a center of the current chroma block, determine a chroma intra prediction mode of the current chroma block based on an intra prediction mode of the determined luma block, and perform intra prediction on the current chroma block, based on the determined chroma intra prediction mode.

Abstract: A video decoding method includes determining, based on an area of a current block, whether a multi-prediction combination mode for predicting the current block by combining prediction results obtained according to a plurality of prediction modes is applied to the current block, when the multi-prediction combination mode is applied to the current block, determining the plurality of prediction modes to be applied to the current block, generating a plurality of prediction blocks of the current block, according to the plurality of prediction modes, and determining a combined prediction block of the current block, by combining the plurality of prediction blocks according to respective weights.

Abstract: Provided is an image processing apparatus including a memory storing instructions, and a processor configured to operate based on the instructions to reconstruct a current block from encoded data of the current block, obtain a quantization error map including sample values calculated based on a quantization parameter included in the encoded data, obtain a first modified block by applying the current block and the quantization error map to a neural network, obtain a first differential block between the current block and the first modified block, obtain a second differential block by changing sample values of the first differential block based on a parameter dependent on a feature of the current block, and obtain a second modified block by combining the current block and the second differential block.

Abstract: An image processing method and an image processing apparatus are provided to obtain input data for deblocking filtering based on deblocking filtering target pixels of at least one line perpendicular to a boundary line of blocks and encoding information about the deblocking filtering target pixels of at least one line, obtain a feature map of the input data by inputting the input data to a first neural network, obtain a deblocking filter coefficient by inputting the feature map to a second neural network, obtain a deblocking filter compensation value by inputting the feature map to a third neural network, obtain a deblocking filter strength by inputting the input data to a fourth neural network, obtain deblocking filtered pixels by performing deblocking filtering on the deblocking filtering target pixels of the at least one line using the deblocking filter coefficient, the deblocking filter compensation value, and the deblocking filter strength.

Abstract: A video decoding method includes determining, based on an area of a current block, whether a multi-prediction combination mode for predicting the current block by combining prediction results obtained according to a plurality of prediction modes is applied to the current block, when the multi-prediction combination mode is applied to the current block, determining the plurality of prediction modes to be applied to the current block, generating a plurality of prediction blocks of the current block, according to the plurality of prediction modes, and determining a combined prediction block of the current block, by combining the plurality of prediction blocks according to respective weights.

Abstract: A video decoding method includes determining, based on an area of a current block, whether a multi-prediction combination mode for predicting the current block by combining prediction results obtained according to a plurality of prediction modes is applied to the current block, when the multi-prediction combination mode is applied to the current block, determining the plurality of prediction modes to be applied to the current block, generating a plurality of prediction blocks of the current block, according to the plurality of prediction modes, and determining a combined prediction block of the current block, by combining the plurality of prediction blocks according to respective weights.

Abstract: A video decoding method includes determining, based on an area of a current block, whether a multi-prediction combination mode for predicting the current block by combining prediction results obtained according to a plurality of prediction modes is applied to the current block, when the multi-prediction combination mode is applied to the current block, determining the plurality of prediction modes to be applied to the current block, generating a plurality of prediction blocks of the current block, according to the plurality of prediction modes, and determining a combined prediction block of the current block, by combining the plurality of prediction blocks according to respective weights.

Abstract: Provided is a video decoding method including obtaining identification information of a first tile and identification information of a last tile from a bitstream, wherein the first and last tiles are included in a first slice, determining an index difference between the first tile and the last tile, based on a result of comparing the identification information of the first tile with the identification information of the last tile, determining the number of tiles included in the first slice, by using the index difference between the first tile and the last tile, and decoding a plurality of tiles included in the first slice according to an encoding order by using the number of tiles included in the first slice, the identification information of the first tile, and the identification information of the last tile.

Abstract: Provided is an image decoding method including determining a current chroma block having a rectangular shape corresponding to a current luma block included in one of a plurality of luma blocks, determining a piece of motion information for the current chroma block and a chroma block adjacent to the current chroma block by using motion information of the current chroma block and the adjacent chroma block, and performing inter prediction on the current chroma block and the adjacent chroma block by using the piece of motion information for the current chroma block and the adjacent chroma block to generate prediction blocks of the current chroma block and the adjacent chroma block.

Abstract: A video decoding method includes obtaining information indicating a first difference between a maximum size of a coding unit having a 1:4 ratio and a size of a largest coding unit, determining the maximum size of the coding unit of having the 1:4 ratio by using the size of the largest coding unit and the first difference, determining a minimum size of the coding unit having the 1:4 ratio based on a minimum size of a coding unit, determining whether a coding having the 1:4 ratio may be generated by splitting a first coding unit based on the maximum size and the minimum size of the coding unit having the 1:4 ratio, and determining a second coding unit including the coding unit having the 1:4 ratio, from the first coding unit, and decoding the second coding unit.

Abstract: Provided is a video decoding method including obtaining identification information of a first tile and identification information of a last tile from a bitstream, wherein the first and last tiles are included in a first slice, determining an index difference between the first tile and the last tile, based on a result of comparing the identification information of the first tile with the identification information of the last tile, determining the number of tiles included in the first slice, by using the index difference between the first tile and the last tile, and decoding a plurality of tiles included in the first slice according to an encoding order by using the number of tiles included in the first slice, the identification information of the first tile, and the identification information of the last tile.

Abstract: Provided is an image decoding method including determining a current chroma block having a rectangular shape corresponding to a current luma block included in one of a plurality of luma blocks, determining a piece of motion information for the current chroma block and a chroma block adjacent to the current chroma block by using motion information of the current chroma block and the adjacent chroma block, and performing inter prediction on the current chroma block and the adjacent chroma block by using the piece of motion information for the current chroma block and the adjacent chroma block to generate prediction blocks of the current chroma block and the adjacent chroma block.

Abstract: A video decoding method includes: obtaining two or more base motion vectors from an adjacent block of a current block; obtaining correction information for correcting the two or more base motion vectors; determining two or more affine motion vectors by correcting the two or more base motion vectors according to the correction information; obtaining a plurality of affine parameters of the current block according to the two or more affine motion vectors; and predicting the current block according to the plurality of affine parameters.

Abstract: Provided are a method and apparatus, which, during video encoding and decoding processes, obtain chroma intra prediction mode information about a current chroma block, when the chroma intra prediction mode information indicates a direct mode (DM), determine a luma block including a luma sample corresponding to a chroma sample at a lower-right location with respect to a center of the current chroma block, determine a chroma intra prediction mode of the current chroma block based on an intra prediction mode of the determined luma block, and perform intra prediction on the current chroma block, based on the determined chroma intra prediction mode.

Abstract: Provided is a video decoding method including: obtaining, from a picture parameter set, a quantization parameter (QP) initial value to be applied to a current picture, and picture header QP difference value information; when the picture header QP difference value information indicates that QP difference value information is present in a picture header of the current picture, obtaining a first QP difference value for the current picture from the picture header; determining a QP for a coding unit included in the current picture, by using the QP initial value and the first QP difference value; obtaining transform coefficients of the coding unit by performing inverse quantization on the coding unit by using the QP; and reconstructing the coding unit by using the transform coefficients.

Abstract: A video decoding method and device for determining whether a prediction mode of a current block is an affine mode; splitting, when the prediction mode of the current block is the affine mode, a luma block of the current block into a plurality of sub luma blocks having a square shape based on a predefined sub block size; determining a mean luma motion vector for four neighboring sub luma blocks among the plurality of sub luma blocks, by using a motion vector of an upper-left sub luma block of the four sub luma blocks and a motion vector of a lower-right sub luma block of the four sub luma blocks; determining the mean luma motion vector to be a motion vector of a current sub chroma block corresponding to the four sub luma blocks; and performing prediction on the current sub chroma block by using the determined motion vector, in a video encoding and decoding process are suggested.

Abstract: Provided are a video decoding method and a video decoding device, which, during video encoding and decoding processes, obtain most probable mode (MPM) information indicating whether to use MPMs of a current block determined based on at least two of a prediction mode of a left neighboring block adjacent to a left side of the current block, a prediction mode of an upper neighboring block adjacent to an upper side of the current block, and a right neighboring block adjacent to a right side of the current block, obtain extended intra mode set information indicating whether to use an extended intra mode set configured based on the MPMs, and determine an intra prediction mode of the current block based on the MPM information and the extended intra mode set information.

Abstract: A video decoding method includes determining, based on an area of a current block, whether a multi-prediction combination mode for predicting the current block by combining prediction results obtained according to a plurality of prediction modes is applied to the current block, when the multi-prediction combination mode is applied to the current block, determining the plurality of prediction modes to be applied to the current block, generating a plurality of prediction blocks of the current block, according to the plurality of prediction modes, and determining a combined prediction block of the current block, by combining the plurality of prediction blocks according to respective weights.

Abstract: Provided are a video encoding or decoding method and apparatus, which, during video encoding and decoding processes, determine whether an intra prediction mode of the current block is a DC mode, when the intra prediction mode of the current block is the DC mode, in a case where lengths of a height and a width of the current block are the same, determine an average of upper reference samples of the current block and left reference samples of the current block, as a DC value, and in a case where the lengths of the height and the width of the current block are different from each other, determine a weighted average value, which is determined by determining an average of the upper reference samples of the current block as an upper DC value, determine an average of the left reference samples of the current block as a left DC value, and combining the upper value and the left DC value with a predetermined weight, as a DC value, and perform intra prediction on the current block, based on the DC value.

Abstract: Provided are a video decoding method and apparatus and a video encoding method and apparatus which determine whether to use a Most Probable Mode (MPM) list, based on encoding information of a current block, obtain, from a bitstream, intra prediction mode index information indicating one of candidate intra prediction modes included in the MPM list, and determine an intra prediction mode of the current block by using the obtained intra prediction mode index information.