Abstract: Provided is a method of decoding an image, the method including: determining at least one coding unit for splitting an image, based on block shape information of a current coding unit; determining at least one transformation unit, based on a shape of the current coding unit included in the at least one coding unit; and decoding the image by performing inverse transformation based on the at least one transformation unit, wherein the block shape information indicates whether the current coding unit is a square shape or a non-square shape. Also, provided is an encoding method corresponding to the decoding method. In addition, provided is an encoding apparatus or decoding apparatus capable of performing the encoding or decoding method.

Abstract: Provided are a method and device for generating a prediction block of a chroma component from a luma component reconstructed through modeling using a correlation between the luma component and the chroma component during video encoding and decoding processes. A video decoding method proposed in the disclosure includes: deriving weight information and deviation information about a chroma sample of a reconstructed adjacent chroma block neighboring a current chroma block and a reconstructed luma sample of an adjacent luma block corresponding to the adjacent chroma block in order to reconstruct chroma samples of the current chroma block; reconstructing luma samples of a current luma block corresponding to the current chroma block according to a prediction mode of the current luma block; and reconstructing the chroma samples of the current chroma block by using the reconstructed luma samples of the current luma block, the weight information, and the deviation information.

Abstract: Provided is a method of decoding an image, the method including: determining at least one coding unit for splitting an image, based on block shape information of a current coding unit; determining at least one transformation unit, based on a shape of the current coding unit included in the at least one coding unit; and decoding the image by performing inverse transformation based on the at least one transformation unit, wherein the block shape information indicates whether the current coding unit is a square shape or a non-square shape. Also, provided is an encoding method corresponding to the decoding method. In addition, provided is an encoding apparatus or decoding apparatus capable of performing the encoding or decoding method.

Abstract: Provided is a video decoding method including obtaining a bitstream including residual data about a residual block of a current block, determining a plurality of prediction directions with respect to the current block, determining a plurality of reference samples included in a neighboring region of the current block in a current image, by using the plurality of prediction directions that are determined, generating a prediction block of the current block by using the plurality of reference samples, obtaining a residual block of the current block based on the residual data about the residual block of the current block, and reconstructing the current block by using the prediction block of the current block and the residual block of the current block.

Abstract: Provided is a method of decoding an image, the method including: determining at least one prediction unit included in a current frame that is one of at least one frame forming the image; determining a reference region to be referred to by a current prediction unit that is one of the at least one prediction unit; changing a sample value included in at least one of the current prediction unit and the reference region, based on an analyzing result of a sample value of the reference region; determining a sample value included in the current prediction unit, based on a result of changing the sample value; and decoding the image based on the determined sample value of the current prediction unit.

Abstract: Provided is an image decoding method of decoding an image, the image decoding method including: obtaining at least one of block shape information and split shape information about a first coding unit included in the image, from a bitstream; determining at least one second coding unit included in the first coding unit based on at least one of the block shape information and the split shape information; and decoding the image based on the at least one second coding unit, wherein the block shape information indicates a shape of the first coding unit and the split shape information indicates whether the first coding unit is split into the at least one second coding unit. Also, provided is an image encoding method corresponding to the image decoding method. Also, provided is an image encoding apparatus and image decoding apparatus for respectively performing the image encoding method and image decoding method.

Abstract: Provided are a method and apparatus for performing intra prediction, in a video encoding and decoding procedure, by configuring an additional mode set based on most probable mode (MPM) modes of a current block, and determining an intra prediction mode of the current block, based on the MPM modes and the additional mode set. To solve the technical problems, a video decoding method provided in the present disclosure includes configuring an additional mode set based on MPM modes of a current block; determining an intra prediction mode of the current block, based on the MPM modes and the additional mode set; and performing intra prediction on the current block, based on the intra prediction mode.

Abstract: Provided are a video decoding method including determining at least one first block for partitioning a current frame which is one of at least one frame included in a video, determining a first prediction mode indicating an intra-prediction method to be performed on a current first block which is one of the at least one first block based on first intra-prediction mode information obtained from a bitstream when intra-prediction is performed on the current first block, determining a plurality of second blocks included in the current first block, determining second prediction modes indicating intra-prediction methods to be performed on the plurality of second blocks based on at least one of the first prediction mode and second intra-prediction mode information obtained from the bitstream with respect to each of the plurality of second blocks, and decoding the video by performing intra-prediction based on the first prediction mode and the second prediction mode; and a video decoding apparatus capable of performing

Abstract: Provided is an image decoding method including: generating an intra prediction value of a current sample based on a position of the current sample in a current block and an intra prediction mode of the current block; determining, based on the position of the current sample in the current block, a sample value of at least one filtering reference sample to be filtered and a first weight with respect to the filtering reference sample and a second weight with respect to the intra prediction value of the current sample; generating a filtered prediction sample value of the current sample based on the determined sample value of the filtering reference sample to be filtered, the intra prediction value of the current sample, the first weight with respect to the filtering reference sample, and the second weight with respect to the intra prediction value of the current sample; and generating a prediction block of the current block, the prediction block including the filtered prediction sample value of the current sample

Abstract: Provided is a video decoding method including obtaining, from a bitstream, information about a prediction mode of a current block; when the prediction mode of the current block is an intra mode, obtaining information about an intra prediction mode of the current block; obtaining a predicted sample value of the current block by using at least one sample that is from among samples included in an adjacent reference region of a plurality of lines and is located, from the current block, in an intra prediction direction indicated by an intra prediction mode. The adjacent reference region of the plurality of lines may include a plurality of lines that are in a vertical direction and located at a left side of the current block, or a plurality of lines that are in a horizontal direction and located at an upper side of the current block.

Abstract: Provided is an image encoding or decoding method and apparatus for post-processing an intra- or inter-predicted block based on pixel gradients. In the image decoding method and apparatus according to an embodiment, prediction mode information of a current block to be decoded and filtering information indicating whether to filter a predicted block are obtained from a bitstream, a first predicted block of the current block is generated based on the prediction mode information, a second predicted block is generated by changing a pixel value of a current pixel in the first predicted block based on gradient values between the current pixel and adjacent pixels of the current pixel, when the filtering information indicates to filter the first predicted block, a residual corresponding to a difference value between the current block and the second predicted block is reconstructed by extracting the residual from the bitstream, and the current block is decoded by adding the residual to the second predicted block.

Abstract: Provided is a method of decoding an image, the method including: determining at least one coding unit for splitting an image, based on block shape information of a current coding unit; determining at least one transformation unit, based on a shape of the current coding unit included in the at least one coding unit; and decoding the image by performing inverse transformation based on the at least one transformation unit, wherein the block shape information indicates whether the current coding unit is a square shape or a non-square shape. Also, provided is an encoding method corresponding to the decoding method. In addition, provided is an encoding apparatus or decoding apparatus capable of performing the encoding or decoding method.

Abstract: Provided are a method and device for encoding or decoding a luma block and a chroma block.

Abstract: Provided are a method and apparatus for encoding or decoding a coding unit on an outline of a picture. An image decoding method and apparatus according to an embodiment determine whether a current coding unit extends across an outline of a picture, by comparing a location of the current coding unit in the picture to at least one of a width and a height of the picture, split the current coding unit in at least one direction into a plurality of coding units based on a shape of the current coding unit upon determining that the current coding unit extends across the outline of the picture, obtain block shape information and split type information of the current coding unit from a bitstream and split the current coding unit into a plurality of coding units based on the block shape information and the split type information upon determining that the current coding unit does not extend across the outline of the picture, and decode a coding unit that is no longer split among the plurality of coding units.

Abstract: Provided are a method and device for encoding or decoding an image by using a block map. In the method and device for decoding an image according to an embodiment set forth herein, a bitstream of an encoded image is received, one or more blocks in a picture are determined using split information obtained from the bitstream, a block map indicating whether or not a previous block among the one or more blocks has been decoded is determined, a neighboring region which is available to be referred to for a current block to be decoded in a certain scan order among the one or more blocks is determined, and the current block is decoded based on the neighboring region which is available to be referred to.

Abstract: Provided are a video encoding method and a video encoding apparatus capable of performing the video encoding method. The video encoding method according to an embodiment includes generating a first predicted block by performing intra prediction on a current block by using neighboring pixels of the current block which have been previously encoded and reconstructed; determining a reference block corresponding to the current block and included in a reconstructed pixel region encoded and reconstructed prior to the current block; generating a residual block, based on the reference block; generating a second predicted block by adding residual values of pixels included in the residual block and intra prediction values of pixels included in the first predicted block; determining the first predicted block or the second predicted block to be a predicted block of the current block; and generating a bitstream including residual data of the current block generated from the determined predicted block.

Abstract: Provided are a video decoding method including determining at least one first block for partitioning a current frame which is one of at least one frame included in a video, determining a first prediction mode indicating an intra-prediction method to be performed on a current first block which is one of the at least one first block based on first intra-prediction mode information obtained from a bitstream when intra-prediction is performed on the current first block, determining a plurality of second blocks included in the current first block, determining second prediction modes indicating intra-prediction methods to be performed on the plurality of second blocks based on at least one of the first prediction mode and second intra-prediction mode information obtained from the bitstream with respect to each of the plurality of second blocks, and decoding the video by performing intra-prediction based on the first prediction mode and the second prediction mode; and a video decoding apparatus capable of performing

Abstract: Provided is a video decoding method including obtaining, from a bitstream, information about a prediction mode of a current block; when the prediction mode of the current block is an intra mode, obtaining information about an intra prediction mode of the current block; obtaining a predicted sample value of the current block by using at least one sample that is from among samples included in an adjacent reference region of a plurality of lines and is located, from the current block, in an intra prediction direction indicated by an intra prediction mode. The adjacent reference region of the plurality of lines may include a plurality of lines that are in a vertical direction and located at a left side of the current block, or a plurality of lines that are in a horizontal direction and located at an upper side of the current block.

Abstract: Provided is an image encoding or decoding method and apparatus for post-processing an intra- or inter-predicted block based on pixel gradients. In the image decoding method and apparatus according to an embodiment, prediction mode information of a current block to be decoded and filtering information indicating whether to filter a predicted block are obtained from a bitstream, a first predicted block of the current block is generated based on the prediction mode information, a second predicted block is generated by changing a pixel value of a current pixel in the first predicted block based on gradient values between the current pixel and adjacent pixels of the current pixel, when the filtering information indicates to filter the first predicted block, a residual corresponding to a difference value between the current block and the second predicted block is reconstructed by extracting the residual from the bitstream, and the current block is decoded by adding the residual to the second predicted block.