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 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: A method of encoding an image in an advanced motion vector prediction (AMVP) mode can include determining motion information of a current block, and generating a prediction block of the current block using the motion information; transforming the residual block to generate a transformed block; quantizing the transformed block using a quantization parameter and a quantization matrix to generate a quantized block; scanning quantized coefficient components of the quantized block; and entropy-coding the scanned coefficient components of the quantized block, in which the motion information is encoded by performing the sub-steps of constructing an AMVP list using available motion vector candidates of a left motion vector candidate, an above motion vector candidate and a temporal motion vector candidate; selecting a motion vector predictor among motion vector candidates of the AMVP candidate list; and generating a differential motion vector by subtracting the motion vector predictor from the motion vector.

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 reconstructed block creating method in a decoder can include obtaining an intra prediction mode group indicator and a prediction mode index from a received bitstream; decoding an intra prediction mode using the intra prediction mode group indicator, the prediction mode index and a MPM group, in which the MPM group is generated using intra prediction modes of left and top blocks of a current block, and the MPM group includes three intra prediction modes; constructing a prediction block using the intra prediction mode and reference pixels; inversely quantizing a received residual signal using a quantization parameter to create a quantized block and inversely transforming the quantized block to create a residual block; and adding the prediction block and the residual block to create a reconstructed block.

Abstract: An apparatus of encoding an image in an advanced motion vector prediction (AMVP) mode 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 quantized coefficient components of the quantized block; and an entropy coding module for entropy-coding the scanned quantized coefficient components of the quantized block; in which the motion information is encoded by performing the sub-steps of: constructing an AMVP list using available motion vector candidates of a left motion vector candidate, an above motion vector candidate and a temporal motion vector candidate; selecting a motion vector predictor among motion vector candidates of

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: An image decoding method includes deriving an intra prediction mode using three intra prediction modes which are determined by left and above intra prediction modes of a current prediction unit; generating a prediction block according to the intra prediction mode; generating a residual block using the intra prediction mode; and generating a reconstructed block using the prediction block and the residual block, wherein the intra prediction mode is derived by constructing a Most Probable Mode (MPM) group including three intra prediction modes determined based on the left intra prediction mode and the above intra prediction mode, by setting an intra prediction mode of the MPM group specified by a prediction mode index as the intra prediction mode of the current prediction unit if a mode group indicator indicates the MPM group, and by determining the intra prediction mode of the current prediction unit if the mode group indicator does not indicate the MPM group.

Abstract: An apparatus for decoding an image in intra prediction can include an inverse scanning module generating a quantized block by applying an inverse scan pattern to significant flags, coefficient signs and coefficient levels; 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 adder generating a reconstructed block using the residual block and the prediction block, in which 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

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 encoding method can include determining an intra prediction mode of a current prediction unit; constructing a mode group including three intra prediction modes using valid intra prediction modes of left and top blocks of the current prediction unit; determining a mode group indicator and a prediction mode index of the current prediction unit; and encoding the mode group indicator and the prediction mode index, in which the mode group indicator indicates whether or not the intra prediction mode of the current prediction unit belongs to the mode group, when the mode group indicator indicates that the intra prediction mode of the current prediction unit belongs to the mode group, the prediction mode index specifies the intra prediction mode of the current prediction unit in the mode group, when the mode group indicator indicates that the intra prediction mode of the current prediction unit does not belong to the mode group, the prediction mode index specifies the intra prediction mode of the current pre

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: An apparatus for encoding an image in intra prediction can include an intra prediction unit generating a prediction block using an intra prediction mode; a transform unit transforming residual signals generated using an original block and the prediction block to generate a transformed block; a quantization unit determining a quantization parameter and quantizing the transformed block using a quantization matrix and the quantization parameter to generate a quantized block; a scanning unit determining a scan pattern and applying the scan pattern to the quantized block to generate one-dimensional coefficient information; and an entropy coding unit entropy-coding the one-dimensional coefficient information and the intra prediction mode, in which the residual signals are transformed in a transform unit, DST-based integer transforms are used for transforming the residual signals if the size of the transform unit is smaller than a predetermined size, and DCT-based transforms are used if the size of the transform uni

Abstract: Provided is a method determines a boundary strength for each 4-sample edge lying on 8×8 sample grid, determines whether deblocking filtering is performed on the 4-sample edge or not if the boundary strength is not equal to zero, selects a deblocking filter if the deblocking filtering is performed on the 4-sample edge, and filters the 4-sample edge using the selected filter. Accordingly, the computational complexity required to determine the boundary strength according to the present invention is reduced by 50% or more when compared with the HEVC under development. Also, the memory capacity and bandwidth required to determine the boundary strength are reduced by 50% or more without deterioration of image quality.

Abstract: An image decoding device includes a processor, and a non-transitory computer-readable medium having stored thereon instructions that, when executed, cause the processor to perform a method that use quantization parameters of left and above coding units to derive a quantization parameter predictor used for generating a residual block.

Abstract: An image decoding device includes a processor, and a non-transitory computer-readable medium having stored thereon instructions that, when executed, cause the processor to perform a method that use quantization parameters of left and above coding units to derive a quantization parameter predictor used for generating a residual block.

Abstract: An image decoding device includes a processor, and a non-transitory computer-readable medium having stored thereon instructions that, when executed, cause the processor to perform a method that use quantization parameters of left and above coding units to derive a quantization parameter predictor used for generating a residual block.

Abstract: An image decoding device includes a processor, and a non-transitory computer-readable medium having stored thereon instructions that, when executed, cause the processor to perform a method that use quantization parameters of left and above coding units to derive a quantization parameter predictor used for generating a residual block.

Abstract: An image decoding method can include deriving luma intra prediction mode and chroma intra prediction mode, wherein the luma intra prediction mode is derived by using a prediction mode index, a mode group indicator, and an MPM (Most Probable Mode) group including three intra prediction modes; determining a size of a luma transform unit and a size of a chroma transform unit; generating a reference pixel when at least one of reference pixels is unavailable; adaptively filtering a reference pixel of a current luma block based on the luma intra prediction mode and the size of luma transform unit; generating prediction blocks of a current chroma block and the current luma block using the adaptively filtered reference pixel; generating residual blocks of the current chroma block and the current luma block; and generating a reconstructed block by adding the residual blocks and the prediction blocks.

Abstract: Provided is a method determines a boundary strength for each 4-sample edge lying on 8×8 sample grid, determines whether deblocking filtering is performed on the 4-sample edge or not if the boundary strength is not equal to zero, selects a deblocking filter if the deblocking filtering is performed on the 4-sample edge, and filters the 4-sample edge using the selected filter. Accordingly, the computational complexity required to determine the boundary strength according to the present invention is reduced by 50% or more when compared with the HEVC under development. Also, the memory capacity and bandwidth required to determine the boundary strength are reduced by 50% or more without deterioration of image quality.