Abstract: Provided is a video decoding method including determining a displacement vector per unit time of pixels of a current block in a horizontal direction or a vertical direction, the pixels including a pixel adjacent to an inside of a boundary of the current block, by using values about reference pixels included in a first reference block and a second reference block, without using a stored value about a pixel located outside boundaries of the first reference block and the second reference block; and obtaining a prediction block of the current block by performing block-unit motion compensation and pixel group unit motion compensation on the current block by using a gradient value in the horizontal direction or the vertical direction of a first corresponding reference pixel in the first reference block which corresponds to a current pixel included in a current pixel group in the current block, a gradient value in the horizontal direction or the vertical direction of a second corresponding reference pixel in the sec

Abstract: Provided are an image decoding method and an image decoding apparatus for performing the image decoding method, the image decoding method including: determining whether or not to obtain second transform set information; determining the second transform set information based on the determining of whether or not to obtain the second transform set information; selecting any one second transform set applied to a second transform block from among a plurality of second transform set candidates corresponding to a plurality of prediction modes, by using the determined second transform set information; generating a first transform block by inverse-transforming the second transform block based on a plurality of transform matrices included in the selected second transform set; and generating a residual block corresponding to the first transform block by inverse-transforming the first transform block based on a first transform matrix.

Abstract: An image decoding method and apparatus according to an embodiment may extract, from a bitstream, a quantization coefficient generated through core transformation, secondary transformation, and quantization; generate an inverse-quantization coefficient by performing inverse quantization on the quantization coefficient; generate a secondary inverse-transformation coefficient by performing secondary inverse-transformation on a low frequency component of the inverse-quantization coefficient, the secondary inverse-transformation corresponding to the secondary transformation; and perform core inverse-transformation on the secondary inverse-transformation coefficient, the core inverse-transformation corresponding to the core transformation.

Abstract: Provided are a method and apparatus for encoding or decoding a 360-degree image. According to an image decoding method and apparatus according to an embodiment, an original 360-degree image is reconstructed by acquiring image data from a bitstream, decoding a projection image of a 360-degree image from the image data, converting the projection image into the 360-degree image, acquiring rotation information of the 360-degree image from the bitstream, and rotating the 360-degree image based on the rotation information.

Abstract: Embodiments herein disclose a method for producing 360 degree image content on a rectangular projection in an electronic device. The method includes obtaining a 360 degree image content represented by packing one or more projection segments arranged in a rectangular projection. The method includes detecting whether at least one discontinuous boundary is present in the 360-degree image content. The at least one discontinuous boundary is detected using the packing of one or more projection segments. The method includes applying at least one padding information on the at least one discontinuous boundary. The method includes producing another 360 degree image content on the rectangular projection in the electronic device based on the padding information.

Abstract: Provided is a video decoding method including: determining an inter prediction mode of a current block when the current block is inter-predicted; determining at least one reference sample location to be referred to by the current block, based on the inter prediction mode of the current block; determining filter information to be applied to at least one reconstructed reference sample corresponding to the at least one reference sample location, based on the inter prediction mode of the current block; performing filtering on the at least one reconstructed reference sample, based on the filter information; and decoding the current block by using prediction samples generated via the filtering.

Abstract: Provided is a method of decoding a video according to an embodiment, the method including determining at least one processing block for splitting the video; determining an order of determining at least one largest coding unit in the at least one processing block; determining at least one largest coding unit on the basis of the determined order; and decoding the determined at least one largest coding unit, wherein the order is one of a plurality of orders for determining a largest coding unit.

Abstract: Provided is a method of decoding a video according to an embodiment, the method including determining at least one processing block for splitting the video; determining an order of determining at least one largest coding unit in the at least one processing block; determining at least one largest coding unit on the basis of the determined order; and decoding the determined at least one largest coding unit, wherein the order is one of a plurality of orders for determining a largest coding unit.

Abstract: Provided is a method of decoding a video according to an embodiment, the method including determining at least one processing block for splitting the video; determining an order of determining at least one largest coding unit in the at least one processing block; determining at least one largest coding unit on the basis of the determined order; and decoding the determined at least one largest coding unit, wherein the order is one of a plurality of orders for determining a largest coding unit.

Abstract: Provided is a method of decoding an image, the method including determining at least one reference region to be referenced by a target region in the image to which a low-quality coding mode is applied; extracting a certain type of information from the determined at least one reference region; and changing pixel values of the target region, based on the extracted type of information.

Abstract: A video decoding method includes obtaining split information indicating whether to split a current block, splitting the current block into two or more lower blocks when the split information indicates to split the current block, obtaining encoding order information indicating an encoding order of the lower blocks of the current block, determining a decoding order of the lower blocks according to the encoding order information, and decoding the lower blocks according to the decoding order.

Abstract: Provided is a video decoding method for signaling of sample adaptive offset (SAO) parameters, the video decoding method including obtaining, from a bitstream, position information of each of a plurality of bandgroups with respect to a current block comprised in a video; obtaining, from the bitstream, offsets with respect to bands comprised in each of the plurality of bandgroups; determining the plurality of bandgroups so as to compensate for a pixel sample value of the current block, based on the position information of each of the plurality of bandgroups; and compensating for a sample value of a reconstructed pixel comprised in the current block, by using the obtained offsets. In this regard, each of the plurality of determined bandgroups comprises at least one band.

Abstract: Provided is a video decoding method including: obtaining, from a bitstream, prediction motion vector information indicating a prediction motion vector of a current block and difference motion vector information indicating a difference motion vector of the current block; determining the prediction motion vector of the current block according to whether or not an adjacent block of the current block is decoded and the prediction motion vector information; determining a motion vector resolution of the current block according to whether or not the adjacent block of the current block is decoded; determining the difference motion vector of the current block according to the difference motion vector information; determining a motion vector of the current block according to the prediction motion vector, the motion vector resolution, and the difference motion vector; and reconstructing the current block according to the motion vector of the current block, wherein the adjacent block of the current block includes a right

Abstract: Provided are a method and apparatus for performing transformation and inverse transformation on a current block by using multi-core transform kernels in video encoding and decoding processes.

Abstract: Provided are a video encoding method and apparatus to which an interpolation filter is applied according to characteristics of an image for motion compensation, and a video decoding method and apparatus corresponding thereto. The video encoding method according to various embodiments includes determining a degree of change between neighboring samples of at least one integer pixel unit adjacent to a reference sample of an integer pixel unit of a current sample and the reference sample; determining an interpolation filter among interpolation filters having different frequency passbands and configured to produce reference samples of a sub-pixel unit to predict the current sample, based on the degree of change; determining a predicted sample value of the current sample by using a reference sample of a sub-pixel unit produced by applying the determined interpolation filter; and encoding a residual value between the predicted sample value and a sample value of the current sample.

Abstract: A video decoding apparatus according to an embodiment may include: a receiver configured to receive a bitstream of an encoded video; a predictor configured to change a distribution of pixel values of neighboring reference pixels that are previously decoded, and generate a prediction block by performing intra prediction on a current block by using the neighboring reference pixels the distribution of the pixel values of which is changed; and a decoder configured to reconstruct the current block based on residual data obtained from the bitstream and the prediction block.

Abstract: The present disclosure provides an image encoding method and apparatus and an image decoding method and apparatus for generating a reconstructed image having a minimized error between an original image and the reconstructed image at a high bit depth and a high bit rate. The image decoding method includes parsing offset values and an offset type from a bitstream; parsing a class based on the offset type from the bitstream; selecting a plurality of pixels from among pixels adjacent to a reconstructed pixel, based on the class, and calculating a reference value based on sample values of the plurality of pixels; determining a category based on a magnitude of a difference value between the reference value and a sample value of the reconstructed pixel; selecting an offset value from among the offset values, the offset value corresponding to the category; and compensating for the sample value of the reconstructed pixel by using the selected offset value.

Abstract: A video encoding method and apparatus, and a video decoding method and apparatus for generating a reconstructed image having a minimized error between an original image and the reconstructed image. The video decoding method accompanied by a sample adaptive offset (SAO) adjustment, the method includes: obtaining 5 slice SAO parameters with respect to a current slice from a slice header of a received bitstream; obtaining luma SAO use information for a luma component of the current slice and chroma SAO use information for chroma components thereof from among the slice SAO parameters; determining whether to perform a SAO operation on the luma component of 10 the current slice based on the obtained luma SAO use information; and equally determining whether to perform the SAO adjustment on a first chroma component and a second chroma component of the current slice based on the obtained chroma SAO use information.

Abstract: Provided is a video decoding method including determining a displacement vector per unit time of pixels of a current block in a horizontal direction or a vertical direction, the pixels including a pixel adjacent to an inside of a boundary of the current block, by using values about reference pixels included in a first reference block and a second reference block, without using a stored value about a pixel located outside boundaries of the first reference block and the second reference block; and obtaining a prediction block of the current block by performing block-unit motion compensation and pixel group unit motion compensation on the current block by using a gradient value in the horizontal direction or the vertical direction of a first corresponding reference pixel in the first reference block which corresponds to a current pixel included in a current pixel group in the current block, a gradient value in the horizontal direction or the vertical direction of a second corresponding reference pixel in the sec

Abstract: A video encoding method and apparatus and video decoding method and apparatus generate a restored image having a minimum error with respect to an original image based on offset merge information indicating whether offset parameters of a current block and at least one neighboring block from among blocks of video are identical.