Abstract: A method for decoding an image in intra prediction, includes generating two-dimensional quantized block by applying an inverse scan pattern to significant coefficients, sign flags and levels respectively; generating a quantization parameter predictor; adding the quantization parameter predictor and a differential quantization parameter to generate quantization parameter; inversely quantizing the quantized block using the quantization parameter; inversely transforming the inversely quantized block to restore a residual block; generating a prediction block; and generating a reconstructed block using the residual block and the prediction block.

Abstract: A method of encoding an image can include determining an intra prediction mode and generating one or more prediction blocks using the intra prediction mode; determining motion information and generating a prediction block using the motion information; transforming residual signals generated using an original block and the prediction block to generate a transformed block; determining a quantization parameter and quantizing the transformed block using a quantization matrix and the quantization parameter to generate a quantized block; determining a scan pattern and applying the scan pattern to the quantized block to generate one-dimensional coefficient information; and entropy-coding the one-dimensional coefficient information, information on the intra prediction mode, the motion information, and a differential quantization parameter, in which the differential quantization parameter is generated by subtracting a quantization parameter predictor from the quantization parameter.

Abstract: A method of reconstructing video data using a merge mode can include constructing a merge list using available spatial and temporal merge candidates; determining a merge candidate on the merge list corresponding to a merge index as motion information of a current prediction unit; generating a predicted block of the current prediction unit using the motion information; generating a transformed block by inverse-quantizing a block of quantized coefficients using a quantization parameter; generating a residual block by inverse-transforming the transformed block; and generating a reconstructed block using the predicted block and the residual block, in which when the current prediction unit is a second prediction unit partitioned by asymmetric partitioning, the spatial merge candidate corresponding to a first prediction unit partitioned by the asymmetric partitioning is excluded from the merge list, and a motion vector of the temporal merge candidate is determined depending on a position of the current prediction u

Abstract: An image decoding method using a merge mode, can include constructing a merge candidate list by using available spatial merge candidates and an available temporal merge candidate; generating a prediction block based on motion information derived by using the merge candidate list; inversely quantizing a quantization block by using a quantization parameter generated per quantization unit, wherein the quantization block is generated with quantization coefficient components; generating a residual block by inversely transforming the inversely quantized quantization block; deriving a reconstructed block by using the prediction block and the residual block, in which the spatial merge candidates are motion information of spatial merge candidate blocks, and the spatial merge candidate blocks are a left block, an above block, an above-right block, a left-below block or an above-left block of a current block, and a reference picture index of the temporal merge candidate is 0.

Abstract: A method for decoding chroma image can include deriving a chroma intra prediction mode of a prediction unit using a corresponding luma intra prediction mode; determining a size of a current chroma block using luma transform size information; generating a chroma prediction block of the current chroma block; generating a chroma residual block of the current chroma block using the chroma intra prediction mode and a chroma quantization parameter; and generating a chroma reconstructed block adding the chroma prediction block and the chroma residual block, in which the chroma quantization parameter is generated using a luma quantization parameter determined per quantization unit and information indicating the relationship between the luma quantization parameter and the chroma quantization parameter, the size of the quantization unit is one of allowable sizes of a coding unit, and a minimum size of the quantization unit is determined per picture and a parameter for specifying the minimum size of the quantization uni

Abstract: A method for decoding image, includes generating a residual block; reconstructing an intra prediction mode group indicator and a prediction mode index of a current block, wherein the indicator indicates whether the intra prediction mode of the current block belongs to which intra prediction mode group among a first or second group, and the prediction mode index specifies intra prediction mode in an intra prediction mode group indicated by the indicator; constructing the first group including three intra prediction modes using valid intra prediction modes of left and top blocks of the current block; determining the intra prediction mode corresponding to the prediction mode index in the first group as the intra prediction mode of the current block when the indicator indicates the first group; generating a prediction block based on the determined intra prediction mode of the current block; generating a reconstructed block using the residual block and the prediction block; and performing deblocking filtering on a

Abstract: An image coding method includes generating a prediction block using intra prediction mode or motion information, transforming residual signals generated using an original block and the prediction block to generate a transformed block, quantizing the transformed block using a quantization parameter to generate a quantized block, determining a scan pattern and applying the scan pattern to the quantized block to generate one-dimensional coefficient information, and entropy-coding the one-dimensional coefficient information, wherein a transform type used for transforming the residual signals of luma components is DCT-based integer transform if prediction mode is inter prediction, and a transform type used for transforming the residual signals of chroma components is a DCT-based integer transform.

Abstract: An apparatus for decoding an image can include an inverse scanning module generating a quantized block; an inverse quantization module generating a quantization parameter predictor, adding the quantization parameter predictor to a differential quantization parameter to generate a quantization parameter and inversely quantizing the quantized block using the quantization parameter; an inverse transform module inversely transforming the inversely quantized block to restore a residual block; an intra prediction module generating a prediction block; and an of generating a reconstructed block using the residual block and the prediction block, wherein when a size of a transform unit is equal to or smaller than 8×8, the inverse scan pattern is a horizontal scan for a vertical mode and a predetermined number of intra prediction modes having closest direction to the vertical mode, the inverse scan pattern is a vertical scan for a horizontal mode and the predetermined number of the intra prediction modes having closest

Abstract: A method for generating a prediction block in intra prediction, includes restoring a mode group indicator and a prediction mode index; constructing a most probable mode (MPM) group including three intra prediction modes of a current block; determining an intra prediction mode specified by the intra prediction mode index in the MPM group as the intra prediction mode of the current block if the mode group indicator indicates the MPM group, and deriving the intra prediction mode of the current block using the prediction mode index and the three intra prediction modes of the MPM group if the mode group indicator does not indicate the MPM group; determining a size of the prediction block based on transform size information; determining whether all reference pixels of the current block are available; generating reference pixels if one or more reference pixels of the current block are unavailable; adaptively filtering the reference pixels based on the intra prediction mode and the size of the current block; and gene

Abstract: A method of decoding an intra prediction mode, can include reconstructing an intra prediction mode group indicator and a prediction mode index; constructing an MPM group including three intra prediction modes using present intra prediction modes of left and top blocks of the current block; determining an intra prediction mode of the MPM group corresponding to the prediction mode index as the intra prediction mode of the current block when the intra prediction mode group indicator indicates the MPM group; and determining the intra prediction mode of the current block using the prediction mode index and the three intra prediction modes of the MPM group when the intra prediction mode group indicator does not indicate the MPM group, in which a DC mode and a planar mode are two non-directional intra prediction mode, and a mode number of the planar mode is lower than mode numbers of the other intra prediction modes.

Abstract: An image encoding apparatus is presented. A differential quantization parameter is generated by subtracting a quantization parameter predictor from a quantization parameter, and is entropy-coded. If two or more quantization parameters are available among a left quantization parameter, an above quantization parameter and a previous quantization parameter of a current coding unit, the quantization parameter predictor is generated using two available quantization parameters determined according a predetermined order, and if only one quantization parameter is available, the available quantization parameter is set as the quantization parameter predictor. A transform type for inversely transforming the residual signals is selected among a discrete cosine transform (DCT)-based integer transform and a discrete sign transform (DST)-based integer transform based on a prediction mode and a size of a transform unit.

Abstract: An image encoding apparatus can include an inter prediction module for determining motion information of a current block, and generating a prediction block of the current block using the motion information; a transform module for transforming the residual block to generate a transformed block; a quantization module for quantizing the transformed block using a quantization parameter and a quantization matrix to generate a quantized block; a scanning module for scanning coefficient components of the quantized block using a diagonal scan; and an entropy coding module for entropy-coding the scanned coefficient components of the quantized block; in which the motion information is encoded by performing the sub-steps of: constructing a merge list using available spatial and temporal merge candidates; selecting a merge predictor among merge candidates of the merge list; and encoding a merge index specifying the merge predictor, in which if the current block is a second prediction unit partitioned by asymmetric partit

Abstract: A method of decoding video data using a merge mode can include constructing a merge list using available spatial and temporal merge candidates; determining a merge candidate on the merge list corresponding to a merge index as motion information of a current prediction unit; generating a predicted block of the current prediction unit using the motion information; generating a transformed block by inverse-quantizing a block of quantized coefficients using a quantization parameter; generating a residual block by inverse-transforming the transformed block; and generating a reconstructed block using the predicted block and the residual block, in which the merge list contains a predetermined number of merge candidates among the available spatial and temporal merge candidates, the quantization parameter is derived per a quantization unit, a minimum size of the quantization unit is adjusted per picture, and the quantization parameter is derived using a differential quantization parameter and a quantization parameter

Abstract: A method of image decoding can include generating a quantization block by inversely scanning quantization coefficient information; generating a transform block by inversely quantizing the quantization block using a quantization step size; generating a residual block by inversely transforming the transform block; reconstructing an intra prediction mode group indicator and a prediction mode index of a current block; constructing a first group including three intra prediction modes using valid intra prediction modes of left and top blocks of the current block; determining the intra prediction mode corresponding to the prediction mode index in the first group as the intra prediction mode of the current block when the intra prediction mode group indicator indicates the first group; generating a prediction block on the basis of the determined intra prediction mode of the current block; and generating a reconstructed block using the residual block and the prediction block.

Abstract: A method for decoding chroma image can include deriving a chroma intra prediction mode of a prediction unit; determining a size of a current chroma block using luma transform size information; generating a chroma prediction block of the current chroma block using the chroma intra prediction mode; generating a chroma residual block of the current chroma block using the chroma intra prediction mode and a chroma quantization parameter; and generating a chroma reconstructed block adding the chroma prediction block and the chroma residual block, in which the chroma quantization parameter is generated using a luma quantization parameter determined per quantization unit and information indicating the relationship between the luma quantization parameter and the chroma quantization parameter, the size of the quantization unit is one of allowable sizes of a coding unit, and a minimum size of the quantization unit is determined per picture and a parameter for specifying the minimum size of the quantization unit is inclu

Abstract: A method for generating a prediction block in intra prediction can include restoring a mode group indicator and a prediction mode index; constructing a most probable mode (MPM) group including three intra prediction modes of a current block; determining an intra prediction mode specified by the intra prediction mode index in the MPM group as the intra prediction mode of the current block if the mode group indicator indicates the MPM group, and deriving the intra prediction mode of the current block using the prediction mode index and the three intra prediction modes of the MPM group if the mode group indicator does not indicate the MPM group; determining a size of the prediction block based on transform size information; determining whether all reference pixels of the current block are available; generating reference pixels if one or more reference pixels of the current block are unavailable; adaptively filtering the reference pixels based on the intra prediction mode and the size of the current block; and ge

Abstract: A method of decoding video data using quantized coefficient components and inter prediction information can include extracting quantized coefficient components and inter prediction information from a received bit stream; applying an inverse scan pattern to the quantized coefficient components to generate a quantized block having a size of a transform unit; generating a quantization parameter per quantization unit which is a unit for deriving a quantization parameter and inverse-quantizing the quantized block to generate a transformed block; generating a residual block by inverse-transforming the transformed block; deriving motion information and generating a prediction block; and generating a reconstructed block by using the residual block and the prediction block.

Abstract: A method of decoding video data in uni-directional prediction by a decoding apparatus can include deriving, by the decoding apparatus, a reference picture index and a motion vector of a current prediction unit; generating, by the decoding apparatus, a prediction block of the current prediction unit using the reference picture index and the motion vector; generating, by the decoding apparatus, a quantized block by inversely scanning quantized coefficient components; generating, by the decoding apparatus, a transformed block by inversely quantizing the quantized block using a quantization parameter; generating, by the decoding apparatus, a residual block by inversely transforming the transformed block; and generating, by the decoding apparatus, reconstructed pixels using the prediction block and the residual block, in which prediction pixels of the prediction block are generated using an interpolation filter selected based on the motion vector, the interpolation filter being a 7-tap filter if the motion vector

Abstract: An apparatus for decoding an image can include an inverse scanning module generating a quantized block; an inverse quantization module generating a quantization parameter predictor, adding the quantization parameter predictor to a differential quantization parameter to generate a quantization parameter and inversely quantizing the quantized block using the quantization parameter; an inverse transform module inversely transforming the inversely quantized block to restore a residual block; an intra prediction module generating a prediction block; and an of generating a reconstructed block using the residual block and the prediction block, wherein when a size of a transform unit is equal to or smaller than 8×8, the inverse scan pattern is a horizontal scan for a vertical mode and a predetermined number of intra prediction modes having closest direction to the vertical mode, the inverse scan pattern is a vertical scan for a horizontal mode and the predetermined number of the intra prediction modes having closest

Abstract: A method of decoding video data in merge mode can include constructing a merge candidate list using available spatial and temporal merge candidates; deriving motion information using a merge index and the merge candidate list; generating a prediction block using the motion information; generating a residual block by inverse-quantizing a quantized block using a quantization parameter and a quantization matrix and by inverse-transforming the inverse quantized block; and generating a reconstructed block using the residual block and the prediction block, wherein the quantization parameter is generated per quantization unit and a minimum size of the quantization unit is adjusted per picture by using a parameter which specifies the depth between the quantization unit having the minimum size and a largest coding unit, and the quantization parameter is generated using a quantization parameter predictor and a differential quantization parameter.