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 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: Provided is an apparatus for decoding an image. The apparatus restores a plurality of sub-blocks by applying a scan pattern determined according to the intra prediction mode of the current block on the quantization coefficient sequence and restores the quantized transform block by applying a scan pattern determined according to the intra prediction mode of the current block on the plurality of sub-blocks. Therefore, it is possible to reduce the amount of coding bits and computing resources required to decode a current prediction block.

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.

Abstract: Provided is an apparatus for decoding a moving picture that determines a quantization step size of a previous coding block according to scan order as the quantization step size predictor of the current coding block when a quantization step size of a left coding block of a current coding block and a quantization step size of an above coding block of the current coding block are unavailable and determines an available motion vector encountered first when retrieving motion vectors in the order of motion vector of a first predetermined position and motion vector of a second predetermined position in a reference picture as a temporal motion vector candidate. Therefore, it is possible to reduce the amount of coding bits required to decode motion information and the quantization step size of the current prediction block.

Abstract: Provided is a method that de-multiplexes a bit stream to extract intra prediction mode information and residual signals, restores an intra prediction mode of a current prediction unit using the intra prediction information and intra prediction modes of prediction units adjacent to the current prediction unit, generates reference pixels using one or more available reference pixel if there exist unavailable reference pixels of the prediction unit, adaptively filters the reference pixels based on the restored intra prediction mode, generates a prediction block using the restored intra prediction mode and the reference pixels, decodes the residual signal to generating a residual block, and generates a reconstructed block using the prediction block and the residual block. Accordingly, additional bits resulted from increase of a number of intra prediction mode are effectively reduced. Also, an image compression ratio can be improved by generating a prediction block similar to an original block.

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: 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 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: 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: An apparatus is provided for decoding video data in a merge mode. The apparatus comprises an inter prediction unit configured to derive motion information of a current coding unit and generate a prediction block using the motion information, wherein the motion information is derived using a merge index and a merge candidate list constructed using available spatial and temporal merge candidates. The apparatus further comprises an inverse-quantizing unit configured to inverse-quantize a quantized block by using a quantization parameter, an inverse transform unit configured to generate a residual block by inverse-transforming the inverse-quantized block, and an adder configured to generate a reconstruct block by adding the residual block and the prediction block.

Abstract: An image decoding method using a merge mode can include constructing a merge candidate list using available spatial and temporal merge candidates, obtaining motion information using a merge index and the merge candidate list, deriving a prediction block using the motion information, inverse-quantizing a quantized block using a quantization parameter and a quantization matrix to generate a transform block, and inverse-transforming the transform block to generate a residual block, and generating a reconstructed block using the prediction block and the residual 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: Provided is a method that de-multiplexes a bit stream to extract intra prediction mode information and residual signals, restores an intra prediction mode of a current prediction unit using the intra prediction information and intra prediction modes of prediction units adjacent to the current prediction unit, generates reference pixels using one or more available reference pixel if there exist unavailable reference pixels of the prediction unit, adaptively filters the reference pixels based on the restored intra prediction mode, generates a prediction block using the restored intra prediction mode and the reference pixels, decodes the residual signal to generating a residual block, and generates a reconstructed block using the prediction block and the residual block. Accordingly, additional bits resulted from increase of a number of intra prediction mode are effectively reduced. Also, an image compression ratio can be improved by generating a prediction block similar to an original block.