Abstract: Provided is an image decoding apparatus that receives an intra prediction mode and one-dimensional (1D) quantized coefficients, restores a quantized transform block by inversely scanning the 1D quantized coefficients, inversely quantizes the quantized transform block using a quantization step size to generate a transform block, inversely transforms the transform block to generate a residual block, and generates a prediction block according to the intra prediction mode. When a size of the transform block is 8×8, the quantized transform block is divided into a plurality of sub-blocks, and the plurality of sub-blocks and coefficients of each sub-block are scanned using a same scan pattern determined according to the intra prediction mode.

Abstract: Provided is an image encoding apparatus that generates a prediction block according to an intra prediction mode, generates a residual block, transforms the residual block to generate a transform block, quantizes the transform block to generate a quantized transform block, scans the quantized transform block to generate one-dimensional (1D) quantized coefficients, and entropy-codes the 1D quantized coefficients. When a size of the transform block is 8×8, the quantized transform block is divided into a plurality of sub-blocks, the plurality of sub-blocks and coefficients of each sub-block are scanned using a same scan pattern determined according to the intra prediction mode. When the intra prediction mode is a horizontal mode, the scan pattern is a vertical scan. The intra prediction mode is coded using an upper and a left intra prediction modes.

Abstract: Provided is an image encoding apparatus that generates a prediction block according to an intra prediction mode, generates a residual block, transforms the residual block to generate a transform block, quantizes the transform block to generate a quantized transform block, scans the quantized transform block to generate one-dimensional (1D) quantized coefficients, and entropy-codes the 1D quantized coefficients. When a size of the transform block is 8×8, the quantized transform block is divided into a plurality of sub-blocks after quantization of the transform block, the plurality of sub-blocks are scanned using a first scan pattern determined according to the intra prediction mode, and coefficients of each sub-block are scanned using a second scan pattern determined according to the intra prediction mode. The first scan pattern is a scan order applied to the plurality of sub-blocks. The second scan pattern is a scan order applied to the coefficients of each sub-block.

Abstract: Provided is an image encoding apparatus that generates a prediction block according to an intra prediction mode, generates a residual block, transforms the residual block to generate a transform block, quantizes the transform block to generate a quantized transform block, scans the quantized transform block to generate one-dimensional (1D) quantized coefficients, and entropy-codes the 1D quantized coefficients. When a size of the transform block is 8×8, the quantized transform block is divided into a plurality of sub-blocks, the plurality of sub-blocks are scanned and coefficients of each sub-block are scanned using a scan pattern determined according to the intra prediction mode. The scan pattern for scanning the plurality of sub-blocks is the same as the scan pattern for scanning the coefficients of each sub-block and when the intra prediction mode is a horizontal mode, the scan pattern is a vertical scan.

Abstract: Provided is an image decoding apparatus that receives an intra prediction mode and one-dimensional (1D) quantized coefficients, restores a quantized transform block by inversely scanning the 1D quantized coefficients, inversely quantizes the quantized transform block using a quantization step size to generate a transform block, inversely transforms the transform block to generate a residual block, and generates a prediction block according to the intra prediction mode. When a size of the transform block is 8×8, the quantized transform block is divided into a plurality of sub-blocks, and the plurality of sub-blocks and coefficients of each sub-block are scanned using a same scan pattern determined according to the intra prediction mode. When the intra prediction mode is a horizontal mode, the scan pattern is a vertical scan.

Abstract: Provided is an apparatus for encoding a moving picture. When the current block is coded in intra prediction and a size of the transform block is larger than 4×4, the quantized transform coefficients of the quantized transform block are divided into a plurality of sub-blocks. The plurality of sub-blocks are scanned according to a first scan pattern determined by the intra prediction mode of the current block and the quantized transform coefficients of each sub-block are scanned according to a second scan pattern determined by the intra prediction mode of the current block. The first scan pattern for scanning the plurality of sub-blocks is the same as the second scan pattern for scanning the quantized transform coefficients of each sub-block.

Abstract: Provided is an image encoding apparatus that generates a prediction block according to an intra prediction mode, generates a residual block, transforms the residual block to generate a transform block, quantizes the transform block to generate a quantized transform block, scans the quantized transform block to generate one-dimensional (1D) quantized coefficients, and entropy-codes the 1D quantized coefficients. When a size of the transform block is 8×8, the quantized transform block is divided into a plurality of sub-blocks, the plurality of sub-blocks and coefficients of each sub-block are scanned using a same scan pattern determined according to the intra prediction mode. A scan pattern for scanning flags indicating non-zero coefficients of each sub-block is the same as the scan pattern for scanning non-zero coefficients of each sub-block.

Abstract: Provided is an apparatus for decoding a moving picture. An inverse quantization/transformation unit generates a quantized block by inversely scanning a quantized coefficient sequence, generates a transform unit by inversely quantizing the quantized block using a quantization step size, and generates a residual block by inversely transforming the transform block. An inter prediction unit generates a prediction block of a current prediction unit based on motion vector information. An adding unit generates a restored block using the residual block and the prediction block. When a motion information coding mode is a skip mode, the inter prediction unit restores motion information of the current prediction block using an available spatial or temporal skip candidate.

Abstract: Provided is a method that determines a reference picture index and a motion vector of a current prediction unit, derives spatial motion vector candidates using valid motion vectors of neighboring prediction units each of which exists at a predetermined position, derives temporal motion vector candidate of the current prediction unit, determines one of the spatial and temporal motions vector candidates as a motion vector predictor, calculates a motion vector difference between the motion vector of the current prediction unit and the motion vector predictor and encodes the motion vector difference and the reference picture index. Therefore, a motion vector is effectively predicted not only when motion of image is ordinary but also when the motion of image is little or steady or the image to be encoded is a background image.

Abstract: Provided is an apparatus for encoding 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° 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° with reference to the horizontal mode. The plurality of sub-blocks and non-zero coefficients of each sub-block are scanned according to a scan pattern determined by the intra prediction mode of the 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: Provided is an apparatus for decoding a moving picture. An entropy decoding unit restores a quantization coefficient sequence from a bitstream. An inverse quantization/transform unit generates a residual block. An inter prediction unit generates a prediction block of a current block based on motion vector information. When the prediction block is encoded in skip mode, motion information of the current block is restored using an available spatial or temporal skip candidate and the prediction block of the current block is generated using the motion information. The temporal skip candidate includes a reference picture index and a motion vector, the reference picture index of the temporal skip candidate is set to 0, and a motion vector of the temporal skip candidate is a motion vector of the temporal skip candidate in a temporal skip candidate picture. A scan pattern for inversely scanning the plurality of subsets is the same as a scan pattern for inversely scanning coefficients of each subset.

Abstract: Provided is an apparatus for encoding 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 the direction of 45° with reference to a horizontal mode than the second directional intra prediction mode is, are also filtered. The first and the second directional intra prediction mode exist between the horizontal mode and the intra prediction mode having the direction of 45° with reference to the horizontal mode. The plurality of sub-blocks and non-zero coefficients of each sub-block are scanned according to a scan pattern determined by the intra prediction mode.

Abstract: Provided is an apparatus for decoding a moving picture. An entropy decoding unit restores a quantization coefficient sequence from a bitstream. An inverse quantization/transform unit generates a quantized block by inversely scanning the quantization coefficient sequence in a unit of subset when a size of a transform unit is larger than 4×4 and generates a residual block. An inter prediction unit generates a prediction block of a current block based on motion vector information. When the prediction block is encoded in merge mode, motion information is restored using an available spatial or temporal merge candidate and the prediction block is generated using the motion information. The temporal merge candidate includes a reference picture index and a motion vector, the reference picture index of the temporal merge candidate is set to 0, and a motion vector of the temporal merge candidate is a motion vector of the temporal merge candidate in a temporal merge candidate picture.

Abstract: Provided is an apparatus for encoding 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° 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° with reference to the horizontal mode. The plurality of sub-blocks and non-zero coefficients of each sub-block are scanned according to a scan pattern determined by the intra prediction mode of the prediction block.

Abstract: Provided is a method for decoding a moving picture. The method has the steps of generating a prediction block of a current block and generating a residual block of the current block. To generate the prediction block, a reference picture index and motion vector difference of the current block are obtained from a received bit stream, and spatial and temporal motion vector candidates are derived to construct a motion vector candidate list. A motion vector candidate corresponding to a motion vector index is determined as a motion vector predictor, and a motion vector of the current prediction unit is restored to generate a prediction block or the current block. Therefore, the motion vector encoded effectively using spatial and temporal motion vector candidates is correctly recovered and the complexity of a decoder is reduced.

Abstract: Provided is an intra prediction apparatus that adaptively filters reference pixels according to an intra prediction mode and a size of a prediction block, and generates the prediction block using reference pixels determined by the intra prediction mode. The reference pixels are adaptively filtered according to the size of the prediction block for intra prediction modes existing between a horizontal mode and an intra prediction mode having a direction of 45° with reference to the horizontal 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 the intra prediction mode having the direction of 45° with reference to the horizontal mode than the second directional intra prediction mode is, are also filtered. Accordingly, an image compression ratio can be improved.

Abstract: Provided is an apparatus for encoding 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° 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° with reference to the horizontal mode. The plurality of sub-blocks and non-zero coefficients of each sub-block are scanned according to a scan pattern determined by the intra prediction mode of the prediction block.

Abstract: Provided is an apparatus for encoding 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° 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° with reference to the horizontal mode. The plurality of sub-blocks and non-zero coefficients of each sub-block are scanned according to a scan pattern determined by the intra prediction mode of the prediction block.

Abstract: Provided is an intra prediction apparatus 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° 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° 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.