Abstract: Provided are a method and apparatus for interpolating an image. The method includes: selecting a first filter, from among a plurality of different filters, for interpolating between pixel values of integer pixel units, according to an interpolation location; and generating at least one pixel value of at least one fractional pixel unit by interpolating between the pixel values of the integer pixel units by using the selected first filter.

Abstract: A method and apparatus for encoding and decoding motion information. The encoding method includes determining whether motion information of spatial prediction units that are spatially collocated to a current prediction unit and motion information of temporal prediction units that are temporally collocated to the current prediction are available; when the number of the motion information of the spatial prediction units and the motion information of the temporal prediction units is less than a predetermined number, generating additional candidate motion information by using the available motion information of the spatial prediction units and the motion information of the temporal prediction units such that the total number of pieces of candidate motion information is the predetermined number; and decoding motion information of the current prediction unit by using the ‘n’ pieces of motion information.

Abstract: Provided are a method and apparatus for interpolating an image. The method includes: selecting a first filter, from among a plurality of different filters, for interpolating between pixel values of integer pixel units, according to an interpolation location; and generating at least one pixel value of at least one fractional pixel unit by interpolating between the pixel values of the integer pixel units by using the selected first filter.

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.

Abstract: Provided are a method and apparatus for interpolating an image. The method includes: selecting a first filter, from among a plurality of different filters, for interpolating between pixel values of integer pixel units, according to an interpolation location; and generating at least one pixel value of at least one fractional pixel unit by interpolating between the pixel values of the integer pixel units by using the selected first filter.

Abstract: An image decoding apparatus in which a size of at least one transformation unit in a coding unit is determined independently from a size of at least one prediction 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: Provided are a method and apparatus for estimating a motion vector using a plurality of motion vector predictors, an encoder, a decoder, and a decoding method. The method includes calculating spatial similarities between the current block and the plurality of neighboring partitions around the current block, selecting at least one of the neighboring partitions based on the calculated spatial similarities, and estimating a motion vector of the selected partition as the motion vector of the current block.

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: 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.

Abstract: An image interpolation method and apparatus are provided. The image interpolation method includes: selecting different interpolation filters according to locations of sub pixels between integer pixels; and generating sub pixel values at the locations of the sub pixels using the selected interpolation filters.

Abstract: A method and apparatus for encoding and decoding motion information. The encoding method includes determining whether motion information of spatial prediction units that are spatially collocated to a current prediction unit and motion information of temporal prediction units that are temporally collocated to the current prediction are available; when the number of the motion information of the spatial prediction units and the motion information of the temporal prediction units is less than a predetermined number, generating additional candidate motion information by using the available motion information of the spatial prediction units and the motion information of the temporal prediction units such that the total number of pieces of candidate motion information is the predetermined number; and decoding motion information of the current prediction unit by using the ‘n’ pieces of motion information.

Abstract: Provided are a method and apparatus for estimating a motion vector using a plurality of motion vector predictors, an encoder, a decoder, and a decoding method. The method includes calculating spatial similarities between the current block and the plurality of neighboring partitions around the current block, selecting at least one of the neighboring partitions based on the calculated spatial similarities, and estimating a motion vector of the selected partition as the motion vector of the current block.

Abstract: Provided is a video encoding method and an apparatus for performing the same, and a video decoding method and an apparatus for performing the same. The video encoding method for encoding symbols having a hierarchical structure includes: encoding a picture of a video based on data units having a hierarchical structure; determining symbols of the encoded picture based on the data units having the hierarchical structure; determining an encoding method of the symbols based on characteristics of symbols, which are determined based on the data units having the hierarchical structure; and encoding and outputting the symbols according to the determined encoding method.

Abstract: Provided are a video encoding method and apparatus using a low-complexity transformation and a video decoding method and apparatus using a low-complexity inverse transformation. The video encoding method includes: receiving image data of an input picture in predetermined data units; generating coefficients of the predetermined data units by performing a low-complexity transformation on the image data; and outputting the generated coefficients. The low-complexity transformation includes at least one of a selective frequency-domain transformation that uses a transformation basis for a predetermined frequency-domain, a sub data unit transformation that performs a transformation by respectively selecting and applying transformation bases for a plurality of sub data units divided from the image data, and a scale-down transformation that uses a scale-down rectangular transformation basis that is a combination of a rectangular matrix and a square matrix.

Abstract: Encoding and decoding a motion vector using a motion vector of a current block of a current picture, which indicates a region corresponding to the current block in a first reference picture and one of generating a motion vector predictor from a motion vector of the adjacent block having a motion vector referring to the first reference picture among adjacent blocks encoded before the current block and a motion vector of an adjacent block referring to a second reference picture other than the first reference picture.

Abstract: Encoding and decoding a video using transformation index that indicates information that indicates a structure of a transformation unit transforming data of a current coding unit.

Abstract: A method of determining a reference image for inter-prediction includes: determining a slice type of a block; if the determining of the slice type indicates that the slice type is a B-slice type configured for uni-directional prediction or bi-directional prediction, determining an inter-prediction direction of the block to be one of a first direction, a second direction, and a bi-direction; if the determining of the inter-prediction direction indicates that the inter-prediction direction is not the second direction, determining a first direction reference index from a first direction reference picture list as a reference index for the block; and if the determining of the inter-prediction direction indicates that the inter-prediction direction is not the first direction, determining a second direction reference index from a second direction reference picture list as a reference index for the block.