Abstract: A video decoding apparatus includes: a splitter configured to split an image into at least one block; a predictor configured to predict a current sample by using at least one of a value obtained by applying a first weight to a first sample predicted earlier than the current sample in a current block and being adjacent to the current sample in a horizontal direction and a value obtained by applying a first weight to a second sample predicted earlier than the current sample in the current block and being adjacent to the current sample in a vertical direction; and a decoder configured to decode the image by using a residual value of the current sample obtained from a bitstream and a prediction value of the current sample.

Abstract: The present disclosure relates to signaling of sample adaptive offset (SAO) parameters determined to minimize an error between an original image and a reconstructed image in video encoding and decoding operations. An SAO decoding method includes obtaining context-encoded leftward SAO merge information and context-encoded upward SAO merge information from a bitstream of a largest coding unit (MCU); obtaining SAO on/off information context-encoded with respect to each color component, from the bitstream; if the SAO on/off information indicates to perform SAO operation, obtaining absolute offset value information for each SAO category bypass-encoded with respect to each color component, from the bitstream; and obtaining one of band position information and edge class information bypass-encoded with respect to each color component, from the bitstream.

Abstract: The present disclosure relates to signaling of sample adaptive offset (SAO) parameters determined to minimize an error between an original image and a reconstructed image in video encoding and decoding operations. An SAO decoding method includes obtaining context-encoded leftward SAO merge information and context-encoded upward SAO merge information from a bitstream of a largest coding unit (MCU); obtaining SAO on/off information context-encoded with respect to each color component, from the bitstream; if the SAO on/off information indicates to perform SAO operation, obtaining absolute offset value information for each SAO category bypass-encoded with respect to each color component, from the bitstream; and obtaining one of band position information and edge class information bypass-encoded with respect to each color component, from the bitstream.

Abstract: Provided is a video decoding method including: acquiring offset type information of a current block; determining a neighboring sample of a current reconstruction sample of the current block according to an edge direction when the offset type information of the current block indicates an edge type; determining an offset category of the current reconstruction sample based on a sample value gradient between a sample value of the current reconstruction sample and a sample value of the neighboring sample and a difference in the sample value gradient; and applying, from among offsets acquired from a bitstream, an offset according to the determined offset category to the current reconstruction sample.

Abstract: A method of encoding a video is provided, the method includes: determining a filtering boundary on which deblocking filtering is to be performed based on at least one data unit from among a plurality of coding units that are hierarchically configured according to depths indicating a number of times at least one maximum coding unit is spatially spilt, and a plurality of prediction units and a plurality of transformation units respectively for prediction and transformation of the plurality of coding units, determining filtering strength at the filtering boundary based on a prediction mode of a coding unit to which pixels adjacent to the filtering belong from among the plurality of coding units, and transformation coefficient values of the pixels adjacent to the filtering boundary, and performing deblocking filtering on the filtering boundary based on the determined filtering strength.

Abstract: The present disclosure relates to signaling of sample adaptive offset (SAO) parameters determined to minimize an error between an original image and a reconstructed image in video encoding and decoding operations. An SAO decoding method includes obtaining context-encoded leftward SAO merge information and context-encoded upward SAO merge information from a bitstream of a largest coding unit (MCU); obtaining SAO on/off information context-encoded with respect to each color component, from the bitstream; if the SAO on/off information indicates to perform SAO operation, obtaining absolute offset value information for each SAO category bypass-encoded with respect to each color component, from the bitstream; and obtaining one of band position information and edge class information bypass-encoded with respect to each color component, from the bitstream.

Abstract: A video encoding method including determining a phase shift between pixels of an enhancement layer image and a reference layer image, according to a scaling factor between the enhancement layer image and the reference layer image and a color format of the enhancement layer; selecting at least one filter coefficient set corresponding to the phase shift, from filter coefficient data including filter coefficient sets; generating an up-sampled reference layer image by extending a resolution of the reference layer image according to the scaling factor by performing interpolation filtering on the reference layer image by using the filter coefficient set; obtaining a prediction error between the up-sampled reference layer image and the enhancement layer image; generating an enhancement layer bitstream including the prediction error and a scalable codec; and generating a base layer bitstream by encoding the base layer images.

Abstract: Provided is a video decoding method including: obtaining motion prediction mode information regarding a current block in a current picture; when a bi-directional motion prediction mode is indicated, obtaining a first motion vector and a second motion vector indicating a first reference block and a second reference block of the current block in a first reference picture and second reference picture, respectively; generating a pixel value of a first pixel of the first reference block indicated by the first motion vector and a pixel value of a second pixel of the second reference block indicated by the second motion vector by applying an interpolation filter to a first neighboring region of the first pixel and a second neighboring region of the second pixel; generating gradient values of the first pixel and the second pixel by applying a filter to the first neighboring region and the second neighboring region; and generating a prediction pixel value of the current block by using the pixel values and the gradient

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: 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.

Abstract: Provided is an image decoding method including: determining at least one prediction block included in a current picture from among pictures forming an image; determining a first motion vector related to a current prediction block from among the at least one prediction block; determining a first reference block included in a first reference picture, based on the first motion vector; determining a second reference block included in a second reference picture, based on a location of the first reference block; and decoding the current picture by performing inter prediction on the current prediction block by using at least one of the first reference block and the second reference block, wherein the second reference picture includes a prediction value of the first reference picture. Also, provided are an image decoding apparatus performing the image decoding method, and an image encoding method and apparatus corresponding to the image decoding method and apparatus.

Abstract: A video decoding apparatus includes: a splitter configured to split an image into at least one block; a predictor configured to predict a current sample by using at least one of a value obtained by applying a first weight to a first sample predicted earlier than the current sample in a current block and being adjacent to the current sample in a horizontal direction and a value obtained by applying a first weight to a second sample predicted earlier than the current sample in the current block and being adjacent to the current sample in a vertical direction; and a decoder configured to decode the image by using a residual value of the current sample obtained from a bitstream and a prediction value of the current sample.

Abstract: A method of encoding a video is provided, the method includes: determining a filtering boundary on which deblocking filtering is to be performed based on at least one data unit from among a plurality of coding units that are hierarchically configured according to depths indicating a number of times at least one maximum coding unit is spatially spilt, and a plurality of prediction units and a plurality of transformation units respectively for prediction and transformation of the plurality of coding units, determining filtering strength at the filtering boundary based on a prediction mode of a coding unit to which pixels adjacent to the filtering belong from among the plurality of coding units, and transformation coefficient values of the pixels adjacent to the filtering boundary, and performing deblocking filtering on the filtering boundary based on the determined filtering strength.

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 image encoding and decoding methods and apparatuses using weighted bi-prediction. The image decoding method and apparatus according to one embodiment obtain one or more prefixes including a first counter value indicating the number of additional syntax elements subsequent to main syntax elements from a received bitstream, obtain the additional syntax elements including weight information and information about whether to perform weighted bi-prediction on prediction units separated for predicting a current block, based on the one or more prefixes, and generate a prediction block including a prediction value, based on the main syntax elements and the additional syntax elements.

Abstract: Provided are a method and apparatus of encoding a video by compensating for a pixel value and a method and apparatus of decoding a video by compensating for a pixel value. The method of encoding the video includes: encoding image data; decoding the encoded image data and generating a restored image by performing loop filtering on the decoded image data; determining a compensation value corresponding to errors between a predetermined group restored pixels in the restored image and corresponding original pixels, and a pixel group including a restored pixel to be compensated for by using the compensation value; and encoding the compensation value and transmitting the encoded compensation value and a bitstream of the encoded image data.

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: Disclosed are a video encoding method and apparatus and a video decoding method and apparatus. The method of encoding video includes: producing a first predicted coding unit of a current coding unit, which is to be encoded; determining whether the current coding unit comprises a portion located outside a boundary of a current picture; and producing a second predicted coding unit is produced by changing a value of pixels of the first predicted coding unit by using the pixels of the first predicted coding unit and neighboring pixels of the pixels when the current coding unit does not include a portion located outside a boundary of the current picture. Accordingly, a residual block that is the difference between the current encoding unit and the second predicted encoding unit, can be encoded, thereby improving video prediction efficiency.

Abstract: Disclosed are a video encoding method and apparatus and a video decoding method and apparatus. The method of encoding video includes: producing a first predicted coding unit of a current coding unit, which is to be encoded; determining whether the current coding unit comprises a portion located outside a boundary of a current picture; and producing a second predicted coding unit is produced by changing a value of pixels of the first predicted coding unit by using the pixels of the first predicted coding unit and neighboring pixels of the pixels when the current coding unit does not include a portion located outside a boundary of the current picture. Accordingly, a residual block that is the difference between the current encoding unit and the second predicted encoding unit, can be encoded, thereby improving video prediction efficiency.

Abstract: Disclosed are a video encoding method and apparatus and a video decoding method and apparatus. The method of encoding video includes: producing a first predicted coding unit of a current coding unit, which is to be encoded; determining whether the current coding unit comprises a portion located outside a boundary of a current picture; and producing a second predicted coding unit is produced by changing a value of pixels of the first predicted coding unit by using the pixels of the first predicted coding unit and neighboring pixels of the pixels when the current coding unit does not include a portion located outside a boundary of the current picture. Accordingly, a residual block that is the difference between the current encoding unit and the second predicted encoding unit, can be encoded, thereby improving video prediction efficiency.