Infobridge Pte. Ltd.

M&k Holdings Inc.

Gensquare LLC

Infobridgepte. Ltd.

Infobridge Ptd. Ltd.

Innotive Corporation

Moonock Yang

Soo Mi Oh

A method of decoding an image can include constructing an amvp candidate list using available motion vector candidates of a left, an above and a temporal motion vector candidate, selecting a motion vector predictor among motion vector candidates of the amvp candidates list using the amvp index, and generating a motion vector using the motion vector predictor and a differential motion vector. The method further includes generating a prediction block using the motion vector and a reference picture index, inversely quantizing a quantized block using a quantization parameter to generate a transformed block and inversely transforming the transformed block to generate a residual block, and generating a reconstructed block. Also, the quantization parameter is generated per quantization unit, a minimum size of the quantization unit is adjusted per picture, and the quantization parameter is generated using a differential quantization parameter and a quantization parameter predictor.

Method of decoding motion vector

A method for encoding an image using intra prediction can include determining an intra prediction mode of a current block, generating a mode group indicator and a prediction mode index specifying the intra prediction mode of the current block, constructing a most probable mode (MPM) group including three intra prediction modes determined using a left and an above intra prediction mode of the current block. The method can further include generating a prediction block based on the intra prediction mode of the current block specified by the mode group indicator and the prediction mode index, generating a residual block of the current block, generating a quantization block by transforming and quantizing the residual block. The method can include scanning the quantized block using a scan pattern determined based on the intra prediction mode and the size of a transform unit, and entropy-encoding the scanned information of the quantized block.

Method of deriving quantization parameter with differential and predicted quantization parameters

An apparatus of decoding video data can include a prediction mode decoding module to derive a luma intra prediction mode and a chroma intra prediction mode; a prediction size determining module to determine a size of a luma transform unit and a size of a chroma transform unit using transform size information; a reference pixel generating module to generate referential pixels if at least one reference pixel is unavailable; and a reference pixel filtering module adaptively filter the reference pixels of a current luma block based on the luma intra prediction mode and the size of the luma transform unit. The apparatus can further include a prediction block generating module to generate prediction blocks of the current luma block and the current chroma block; and a residual bock generating module to generate residual blocks of the current luma block and the current chroma block.

Apparatus of decoding video data

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, and the quantization parameter is generated using a quantization parameter predictor and a differential quantization parameter.

Apparatus for decoding video data

A method of decoding an image can includes constructing an advanced motion vector predication (AMVP) candidate 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 candidates list using an AMVP index, and generating a motion vector using the motion vector predictor and a differential motion vector, generating a prediction block using the motion vector and a reference picture index; inversely quantizing a quantized block using a quantization parameter to generate a transformed block and inversely transforming the transformed block to generate a residual block; and generating a reconstructed block using the prediction block and the residual block, in which the quantization parameter is generated per quantization unit, and a minimum size of the quantization unit is adjusted per picture.

A method for encoding an image using intra prediction can include determining an intra prediction mode of a current block; generating a mode group indicator and a prediction mode index; constructing a most probable mode (MPM) group including three intra prediction modes determined using a left and an above intra prediction mode of the current block; 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, wherein if the size of the current block is 4&#xd7;4, the reference pixels are not filtered, and if the size of the current block is larger than 4&#xd7;4, the number of intra prediction mode where the reference pixels are filtered increases as the current block becomes larger; generating the prediction block using the reference pixels.

Method of deriving quantization parameter with differental and predicted quantization parameters

Provided is an apparatus forencoding anddecoding an image that adaptively filters reference pixels according to an intra prediction mode and a size of a prediction block, and generates the prediction block according to the intra prediction mode. When the reference pixels for a second directional intra prediction mode are filtered, the reference pixels for a first directional intra prediction mode, that is closer to an intra prediction mode having a direction of 45&#xb0; with reference to a horizontal mode than the second directional intra prediction mode is, are also filtered. The first and the second intra prediction modes exist between the horizontal mode and the intra prediction mode having the direction of 45&#xb0; with reference to the horizontal mode. The number of intra prediction modes in which the filter is applied increases as the size of the prediction block increases.

Apparatus for encoding an image

A method can include decoding residual signals to generate quantized coefficient components; determining an inverse scan pattern and generating a quantized block using the inverse scan pattern; deriving a quantization parameter and inversely quantizing the quantized block using the quantization parameter to generate a transformed block; and inversely transforming the transformed block to generate a residual block, in which when the quantization parameter is a chroma quantization parameter, the chroma quantization parameter is generated using a luma quantization parameter and an offset parameter indicating a relationship between the luma quantization parameter and the chroma quantization parameter, the luma quantization parameter is derived using a differential quantization parameter and a quantization parameter predictor, and the differential quantization parameter is generated by entropy decoding, and parameters are set according to certain conditions.

An apparatus can include a prediction mode decoding module configured to derive a luma intra prediction mode and a chroma intra prediction mode; a prediction size determining module configured to determine a size of a luma transform unit and a size of a chroma transform unit using transform size information; a reference pixel generating module configured to generate referential pixels if at least one reference pixel is unavailable; a reference pixel filtering module configured to adaptively filter the reference pixels of a current luma block based on the luma intra prediction mode and the size of the luma transform unit, and not to filter the reference pixels of a current chroma block; a prediction block generating module configured to generate prediction blocks of the current luma block and the current chroma block; a residual bock generating module configured to generate a luma residual block and a chroma residual block; and an adder.

An image decoding apparatus can include a prediction mode decoding module for deriving luma intra prediction mode and chroma intra prediction mode; a prediction size determining module for determining a size of a luma transform unit and a size of a chroma transform unit; a reference pixel generating module for generating a reference pixel when at least one reference pixel is unavailable; a reference pixel filtering module for adaptively filtering a reference pixel of a current luma block based on the luma intra prediction mode and the size of the luma transform unit, wherein a reference pixel of a current chroma block is not filtered; a prediction block generating module for generating prediction blocks of the current luma block and the current chroma block; and a residual block generating module for generating a luma residual block and a chroma residual block.

An image coding method can include generating a prediction block using an intra prediction mode; generating a prediction block using 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, in which the residual signals are transformed in transform unit, a transform type used for transforming the residual signals of luma component is determined by a prediction mode and a size of the transform unit, and a transform type used for transforming the residual signals of chroma components is a DCT-based integer transform, and the quantization parameter is a luma quantization parameter, and a differential quantization parameter is generated by subtracting a quantization parameter predictor from the quantization parameter, and is entropy-coded.

An apparatus for decoding an image can include an inverse scanning module for generating a quantized block by applying an inverse scan pattern to significant flags, coefficient sign and coefficient levels respectively; an inverse quantization module for 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 for inversely transforming the inversely quantized block to restore a residual block; an intra prediction module for generating a prediction block; an adder for generating a reconstructed block using the residual block and the prediction block, in which certain types of scans are used based on a size of a transform unit and various parameters are set according to availability conditions.

Method and apparatus for encoding an image

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 generating the prediction block using the reference pixels based on the restored intra prediction mode.

Method for generating intra prediction block with most probable mode

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.

Apparatus for decoding an image

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.

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Singapore, Singapore

Moonock Yang