Abstract: Provided are a method and apparatus for intra predicting an image, which generate a prediction value via linear interpolation in horizontal and vertical directions of a current prediction unit. The method includes: generating first and second virtual pixels by using at least one adjacent pixel located upper right and lower left to a current prediction unit; obtaining a first prediction value of a current pixel via linear interpolation using an adjacent left pixel located on the same line as the first virtual pixel and the current pixel; obtaining a second prediction value of the current pixel via linear interpolation using an adjacent upper pixel located on the same column as the second virtual pixel and the current pixel; and obtaining a prediction value of the current pixel by using the first and second prediction values.

Abstract: Entropy encoding and entropy decoding of image data are respectively performed whereby context modeling is performed on a context unit of blocks of the image data based on a context model of a previously encoded or decoded block.

Abstract: A video encoding method is provided. The method includes: encoding a current region of a video by performing a transformation on the current region by using transformation units in a variable tree-structure which are determined from among transformation units that are hierarchically split from a base transformation unit with respect to the current region and which are generated based on a maximum split level of a transformation unit. The method further includes outputting encoded data of the current region, information about an encoding mode, and transformation-unit hierarchical-structure information including maximum size information and minimum size information of the transformation unit with respect to the video.

Abstract: A method and apparatus for encoding and decoding a motion vector of a current block. The method of encoding including: generating information about the motion vector based on a motion vector of a current block and a motion vector predictor of the current block by estimating the motion vector and determining a first motion vector predictor candidate from among a plurality of motion vector predictor candidates as the motion vector predictor based on a result of the estimating; and generating a virtual motion vector by using a second motion vector predictor candidate and the information about the motion vector, generating vector differences between the virtual motion vector and the plurality of motion vector predictor candidates, comparing the vector differences with the information about the motion vector, and selectively excluding the second motion vector predictor candidate according to the comparing.

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: Provided are methods and apparatuses for encoding and decoding a motion vector.

Abstract: Methods and apparatuses for encoding and decoding an intra prediction mode of a prediction unit of a chrominance component based on an intra prediction mode of a prediction unit of a luminance component are provided. When an intra prediction mode of a prediction unit of a luminance component is the same as an intra prediction mode in an intra prediction mode candidate group of a prediction unit of a chrominance component, reconstructing the intra prediction mode candidate group of the prediction unit of the chrominance component by excluding or replacing an intra prediction mode of the prediction unit of the chrominance component which is same as an intra prediction mode of the prediction unit of the luminance component from the intra prediction mode candidate group, and encoding the intra prediction mode of the prediction unit of the chrominance component by using the reconstructed intra prediction mode candidate group.

Abstract: Provided are a method and apparatus for intra predicting an image, which generate a prediction value via linear interpolation in horizontal and vertical directions of a current prediction unit. The method includes: generating first and second virtual pixels by using at least one adjacent pixel located upper right and lower left to a current prediction unit; obtaining a first prediction value of a current pixel via linear interpolation using an adjacent left pixel located on the same line as the first virtual pixel and the current pixel; obtaining a second prediction value of the current pixel via linear interpolation using an adjacent upper pixel located on the same column as the second virtual pixel and the current pixel; and obtaining a prediction value of the current pixel by using the first and second prediction values.

Abstract: Provided are a method and apparatus for intra predicting an image, which generate a prediction value via linear interpolation in horizontal and vertical directions of a current prediction unit. The method includes: generating first and second virtual pixels by using at least one adjacent pixel located upper right and lower left to a current prediction unit; obtaining a first prediction value of a current pixel via linear interpolation using an adjacent left pixel located on the same line as the first virtual pixel and the current pixel; obtaining a second prediction value of the current pixel via linear interpolation using an adjacent upper pixel located on the same column as the second virtual pixel and the current pixel; and obtaining a prediction value of the current pixel by using the first and second prediction values.

Abstract: A method and apparatus for encoding video by using deblocking filtering, and a method and apparatus for decoding video by using deblocking filtering are provided. The method of encoding video includes: splitting a picture into a maximum coding unit; determining coding units of coded depths and encoding modes for the coding units of the maximum coding unit by prediction encoding the coding units of the maximum coding unit based on at least one prediction unit and transforming the coding units based on at least one transformation unit, wherein the maximum coding unit is hierarchically split into the coding units as a depth deepens, and the coded depths are depths where the maximum coding unit is encoded in the coding units; and performing deblocking filtering on video data being inversely transformed into a spatial domain in the coding units, in consideration of the encoding modes.

Abstract: A method and apparatus for encoding and decoding a motion vector of a current block. The method of encoding including: generating information about the motion vector based on a motion vector of a current block and a motion vector predictor of the current block by estimating the motion vector and determining a first motion vector predictor candidate from among a plurality of motion vector predictor candidates as the motion vector predictor based on a result of the estimating; and generating a virtual motion vector by using a second motion vector predictor candidate and the information about the motion vector, generating vector differences between the virtual motion vector and the plurality of motion vector predictor candidates, comparing the vector differences with the information about the motion vector, and selectively excluding the second motion vector predictor candidate according to the comparing.

Abstract: Provided are a method and apparatus for intra predicting an image, which generate a prediction value via linear interpolation in horizontal and vertical directions of a current prediction unit. The method includes: generating first and second virtual pixels by using at least one adjacent pixel located upper right and lower left to a current prediction unit; obtaining a first prediction value of a current pixel via linear interpolation using an adjacent left pixel located on the same line as the first virtual pixel and the current pixel; obtaining a second prediction value of the current pixel via linear interpolation using an adjacent upper pixel located on the same column as the second virtual pixel and the current pixel; and obtaining a prediction value of the current pixel by using the first and second prediction values.

Abstract: A method of decoding a video includes determining an initial value of a quantization parameter (QP) used to perform inverse quantization on coding units included in a slice segment, based on syntax obtained from a bitstream; determining a slice-level initial QP for predicting the QP used to perform inverse quantization on the coding units included in the slice segment, based on the initial value of the QP; and determining a predicted QP of a first quantization group of a parallel-decodable data unit included in the slice segment, based on the slice-level initial QP.

Abstract: Provided are a method and apparatus for intra predicting an image, which generate a prediction value via linear interpolation in horizontal and vertical directions of a current prediction unit. The method includes: generating first and second virtual pixels by using at least one adjacent pixel located upper right and lower left to a current prediction unit; obtaining a first prediction value of a current pixel via linear interpolation using an adjacent left pixel located on the same line as the first virtual pixel and the current pixel; obtaining a second prediction value of the current pixel via linear interpolation using an adjacent upper pixel located on the same column as the second virtual pixel and the current pixel; and obtaining a prediction value of the current pixel by using the first and second prediction values.

Abstract: A method of decoding an image in which wherein, when a prediction mode is an inter prediction mode, not an intra prediction mode, a size of at least one prediction unit in the coding unit is determined independently from a size of at least one transformation unit in the coding unit.

Abstract: Entropy encoding and entropy decoding of image data are respectively performed whereby context modeling is performed on a context unit of blocks of the image data based on a context model of a previously encoded or decoded block.

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: Methods and apparatuses for encoding and decoding an intra prediction mode of a prediction unit of a chrominance component based on an intra prediction mode of a prediction unit of a luminance component are provided. When an intra prediction mode of a prediction unit of a luminance component is the same as an intra prediction mode in an intra prediction mode candidate group of a prediction unit of a chrominance component, reconstructing the intra prediction mode candidate group of the prediction unit of the chrominance component by excluding or replacing an intra prediction mode of the prediction unit of the chrominance component which is same as an intra prediction mode of the prediction unit of the luminance component from the intra prediction mode candidate group, and encoding the intra prediction mode of the prediction unit of the chrominance component by using the reconstructed intra prediction mode candidate group.

Abstract: An encoding method and apparatus and a decoding method and apparatus for determining a motion vector of a current block based on a motion vector of at least one previously-encoded or previously-decoded block are provided. The decoding method includes: decoding information regarding a prediction direction from among a first direction, a second direction, and bi-directions, and information regarding pixel values of the current block; determining the prediction direction in which the current block is to be predicted, based on the decoded information regarding the prediction direction, and determining a motion vector for predicting the current block in the determined prediction direction; and restoring the current block, based on the determined motion vector and the decoded information regarding the pixel values, wherein the first direction is a direction from a current picture to a previous picture, and the second direction is a direction from the current picture to a subsequent picture.

Abstract: A method of decoding video, the method including receiving and parsing a bitstream which includes encoded video; extracting encoded image data relating to a current picture, which image data is assigned to at least one maximum coding unit, information relating to a coded depth and an encoding mode for each of the at least one maximum coding unit, and filter coefficient information for performing loop filtering on the current picture, from the bitstream; decoding the encoded image data in units of the at least one maximum coding unit, based on the information relating to the coded depth and the encoding mode for each of the at least one maximum coding unit; and performing deblocking on the decoded image data relating to the current picture, and performing loop filtering on the deblocked data, based on continuous one-dimensional (1D) filtering.