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: A method for decoding chroma image is discussed. The method includes 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.

Abstract: An apparatus of decoding an image is discussed. The apparatus can include an intra prediction unit for generating a prediction block using an intra prediction mode of a current prediction unit; an inverse scanning unit for inversely scanning significant flags, coefficient signs and coefficient levels according to an inverse scan pattern which is selected based on the intra prediction mode and a size of a transform unit to generate a quantized block; an inverse quantization unit for inversely quantizing the quantized block using a quantization parameter and a quantization matrix to generate a transform block; an inverse transform unit for inversely transform the transform block to generate a residual block; and an adder for adding the prediction block and the residual block to generate a reconstructed block.

Abstract: An image decoding method in a merge mode, can include constructing a merge candidate list using available spatial and temporal merge candidates, and deriving motion information using a merge index and the merge candidate list; generating a prediction block using the motion information; generating a quantization block by inverse-scanning quantized coefficient components according to a diagonal scan, inverse-quantizing the quantization block using a quantization parameter and a quantization matrix, and inverse transforming the inversely-quantized quantization block to generate a residual block; and deriving a reconstructed block using the prediction block and the residual block.

Abstract: A method for decoding an image is discussed. The method can include generating a residual block; reconstructing an intra prediction mode group indicator and a prediction mode index of a prediction unit; constructing a first group including three intra prediction modes using available intra prediction modes of left and top blocks of the prediction unit; determining the intra prediction mode corresponding to the prediction mode index in the first group as the intra prediction mode of the prediction unit 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 prediction unit; generating a reconstructed block using the residual block and the prediction block; and performing deblocking filtering on a reconstructed picture.

Abstract: Provided is a method extracts a merge index from a bit stream, constructs a merge candidate list using available spatial and temporal merge candidates, selects a merge predictor among merge candidates using the merge index, and sets motion information of the merge predictor as motion information of the current prediction unit. The temporal merge candidate includes a reference picture index and a motion vector, and a motion vector of a temporal merge candidate block of a temporal merge candidate picture is set as the motion vector of the temporal merge candidate. Accordingly, the coding efficiency of the motion information is improved by including various merge candidates. Also, the computational complexity of an encoder and a decoder is reduced maintaining improvement of coding efficiency by adaptively storing motion information of reference picture and adaptively generating a temporal merge candidate.

Abstract: A method of decoding video data, the method including deriving a luma intra prediction mode and chroma intra prediction mode; determining a size of a luma transform unit and a size of a chroma transform unit; generating a reference pixel if at least one reference pixel is unavailable; generating prediction blocks of the current luma block and a current chroma block using the adaptively filtered reference pixels; and generating reconstructed block adding the prediction blocks with residual blocks, further the luma intra prediction mode is derived using a most probable mode (MPM) group including three intra prediction modes, a mode group indicator and a luma prediction mode index, also the luma prediction mode index indicates one of the three intra prediction mode in the MPM group as the luma intra prediction mode when the mode group indicator indicates the MPM group.

Abstract: A method of decoding video data using motion information, the method includes extracting quantized coefficient components and inter prediction information from bitstream; generating a quantization block having a size of transform unit by inverse-scanning the quantized coefficient components; generating quantization parameter, and inverse-quantizing the quantization block using the quantization parameter; generating a residual block by inverse-transforming the inverse-quantized quantization block; deriving the motion information, and generating a prediction block using the motion information; generating a reconstructed block using the residual block and the prediction block; and applying deblocking filtering on a picture which is reconstructed using the reconstructed block, wherein the step of generating the quantization block includes: generating a plurality of subsets by inverse-scanning the quantized coefficient components when the size of the transform unit is larger than 4×4; and generating the quantizati

Abstract: An image coding apparatus according to an embodiment includes an intra prediction unit configured to generate a prediction block using an intra prediction mode; an inter prediction unit configured to generate a prediction block using motion information; a transform unit configured to transform residual signals generated an original block and the prediction block to generate a transformed block; a quantization unit configured to quantize the transformed block using a quantization parameter to generate a quantized block; a scanning unit configured to determine a scan pattern and applying the scan pattern to the quantized block to generate one-dimensional coefficient information; and an entropy coding unit configured to entropy-code the one-dimensional coefficient information.

Abstract: A method for encoding an intra prediction mode according to the present invention selects an intra prediction mode for a current block, determines the number of valid MPM candidates by checking the validity of MPM candidates of the current block, and if the number of valid MPM candidates is less than a previously set number, adds additional intra prediction modes as MPM candidates. MPM candidates can be adaptively added on the basis of the directionality of valid MPM candidates. Additionally, during the encoding of residual intra prediction modes, residual intra prediction modes are realigned on the basis of the directionality of valid MPM candidates. Accordingly, the present invention allows the information for encoding the intra prediction mode of the current block to be minimized by adding MPM candidates or realigning the residual intra prediction modes on the basis of the directionality of valid MPM candidates.

Abstract: Provided is an apparatus that includes an inverse scanning unit configured to an inverse scan pattern to the quantized coefficient components to generate a quantized block, an inverse quantization unit configured to generate a quantization parameter and to inverse-quantize the quantized block to generate a transformed block, an inter prediction unit configured to derive motion information and to generate a prediction block, and an adder configured to generate a reconstructed block. The transform unit is larger than a 4×4 block, each of the quantized coefficient components are inversely scanned in the unit of subset to generate multiple subsets, and the multiple subsets are inversely scanned to generate the quantized block. Accordingly, the coding efficiency of the motion information is improved by including various motion vector candidates. Also, the amount of coding bits of the residual block is reduced by applying diagonal scan pattern to each subset.

Abstract: An apparatus for generating a residual block according to an embodiment includes an entropy decoding unit configured to decode residual signals to generate quantized coefficient components; an inverse scanning unit configured to determine an inverse scan pattern and generate a quantized block using the inverse scan pattern; an inverse quantization unit configured to derive a quantization parameter and inversely quantize the quantized block using the quantization parameter to generate a transformed block; and an inverse transform unit configured to inversely transform the transformed block to generate a residual block.

Abstract: An image decoding device is provided which reconstructs an intra prediction mode of a current prediction unit using a prediction mode group indicator and a prediction mode index, determines a size of a sub block when intra prediction is performed on each sub block of the current prediction unit, and creates reference pixels and a prediction block per sub block. Therefore, by causing the first group to include modes having a high possibility of being equal to the prediction mode of the current block and determining the intra prediction mode group indicator and the prediction mode index, it is possible to reduce an amount of information of the intra prediction mode to be encoded. Also, by creating a prediction block very similar to the current block, the number of bits to be encoded and to be decoded are reduced.

Abstract: A method is provided for encoding video data in uni-directional prediction by a coding apparatus. The coding apparatus determines a reference picture index and a motion vector of a current block, generates a prediction block of the current block using the reference picture index and the motion vector, generates a residual block using the current block and the prediction block, transforms the residual block to generated a transformed block, quantizes the transformed block using a quantization parameter and a quantization matrix to generate a quantized block, scans coefficient components of the quantized block using a diagonal scan, and entropy-codes the scanned coefficient components of the quantized block. Prediction pixels of the prediction block are generated using an interpolation filter selected based on the motion vector.

Abstract: A method of inversely quantizing a quantized block is discussed. The method according to an embodiment includes restoring a differential quantization parameter, generating a quantization parameter predictor, generating a quantization parameter using the differential quantization parameter and the quantization parameter predictor, and inversely quantizing the quantized block using the quantization parameter and a quantization matrix.

Abstract: An apparatus of decoding an image is discussed. The apparatus can include an intra prediction unit for generating a prediction block using an intra prediction mode of a current prediction unit; an inverse scanning unit for inversely scanning significant flags, coefficient signs and coefficient levels according to an inverse scan pattern which is selected based on the intra prediction mode and a size of a transform unit to generate a quantized block; an inverse quantization unit for inversely quantizing the quantized block using a quantization parameter and a quantization matrix to generate a transform block; an inverse transform unit for inversely transform the transform block to generate a residual block; and an adder for adding the prediction block and the residual block to generate a reconstructed block.

Abstract: An apparatus of decoding an image is discussed. The apparatus can include an intra prediction unit for generating a prediction block using an intra prediction mode of a current prediction unit; an inverse scanning unit for inversely scanning significant flags, coefficient signs and coefficient levels according to an inverse scan pattern which is selected based on the intra prediction mode and a size of a transform unit to generate a quantized block; an inverse quantization unit for inversely quantizing the quantized block using a quantization parameter and a quantization matrix to generate a transform block; an inverse transform unit for inversely transform the transform block to generate a residual block; and an adder for adding the prediction block and the residual block to generate a reconstructed block.

Abstract: An apparatus of encoding an image can include an intra prediction unit that determines an intra prediction mode of a current prediction unit and generates one or more prediction blocks using the intra prediction mode, an inter prediction unit that determines motion information and generates a prediction block using the motion information, a transform unit that transforms residual signals generated using an original block and the prediction block to generate a transformed block, a quantization unit that determines a quantization parameter and quantizes the transformed block using a quantization matrix and the quantization parameter to generate a quantized block, a scanning unit that determines a scan pattern and applies the scan pattern to the quantized block to generate one-dimensional coefficient information, and an entropy coding unit the entropy-codes one-dimensional coefficient information from the scanning unit, intra prediction information from the intra prediction unit, and motion information from the

Abstract: Provided is a method derives a reference picture index and a motion vector of a current prediction unit, generates a prediction block of the current prediction unit using the reference picture index and the motion vector, generating a residual block by inverse-scan, inverse-quantization and inverse transform, and generates reconstructed pixels using the prediction block and the residual block. Prediction pixels of the prediction block is generated using an interpolation filter selected based on the motion vector. Accordingly, the coding efficiency of the motion information is improved by including various merge candidates. Also, the computational complexity of an encoder and a decoder is reduced by selecting different filter according to location of the prediction pixels determined by the motion vector.

Abstract: Provided is a method derives a reference picture index and a motion vector of a current prediction unit, generates a prediction block of the current prediction unit using the reference picture index and the motion vector, generating a residual block by inverse-scan, inverse-quantization and inverse transform, and generates reconstructed pixels using the prediction block and the residual block. Prediction pixels of the prediction block is generated using an interpolation filter selected based on the motion vector. Accordingly, the coding efficiency of the motion information is improved by including various merge candidates. Also, the computational complexity of an encoder and a decoder is reduced by selecting different filter according to location of the prediction pixels determined by the motion vector.