Abstract: A video decoding apparatus for decoding a current block comprised of a plurality of subblocks by using an intra prediction, includes: a prediction mode extractor to extract information on an intra prediction mode of the current block; an inverse quantization unit to inversely quantize transformed and quantized residual subblocks corresponding to the subblocks of the current block to thereby generate transformed residual subblocks; an inverse transform unit to inversely transform the transformed residual subblocks to thereby reconstruct residual subblocks; a prediction unit to sequentially predict each of the subblocks from neighboring pixels selected based on the information on the intra prediction mode of the current block and thereby generate a plurality of predicted subblocks corresponding to the subblocks; and an adder to sequentially reconstruct the subblocks by adding each of the reconstructed residual subblocks to a predicted subblock corresponding thereto.

Abstract: A video decoding apparatus using an intra prediction, includes: a decoder to obtain mode information of a current block and residual sub-blocks corresponding to a plurality of sub-blocks included in the current block, from a bitstream; an intra predictor to select an intra prediction mode of the current block from among a plurality of intra prediction modes, based on the obtained mode information, identify the plurality of sub-blocks of the current block, and sequentially predict the plurality of sub-blocks by using neighboring pixels adjacent to each of the plurality of sub-blocks; an inverse quantization and transform unit configured to inversely quantize and then inversely transform each of the residual subblocks; and an adder configured to sequentially reconstruct the plurality of sub-blocks by adding each of the predicted sub-blocks to an inversely quantized and inversely transformed residual sub-block corresponding thereto.

Abstract: A method for encoding pixels in an image, includes: encoding an offset to be applied to a reference frame; generating predicted pixels of the pixels in the image, based on interpolating pixels in the reference frame and then adding the offset to the interpolated pixels; and encoding residual signals that are differences between the pixels in the image and the predicted pixels, wherein the encoding of the residual signals comprises: skipping both transform and quantization with respect to residual signals of which an encoding scheme corresponds to skipping of both transform and quantization, the encoding scheme related to transform and quantization, skipping transform and performing quantization with respect to residual signals of which the encoding scheme corresponds to skipping of transform, and performing transform and quantization with respect to residual signals of which the encoding scheme corresponds to skipping neither transform nor quantization.

Abstract: A method performed by an apparatus for intra-predicting a current block in the unit of subblocks, comprises: determining an intra prediction mode of the current block among a plurality of intra prediction modes; identifying the subblocks split from the current block; and sequentially reconstructing the identified subblocks using an intra prediction mode identical to the determined intra prediction mode of the current block, wherein a subblock to be reconstructed is predicted using at least one pre-reconstructed neighboring subblock in the current block.

Abstract: An apparatus for reconstructing a current motion vector of a current block in a current frame by determining a predicted motion vector of the current motion vector, includes: a differential motion vector decoder to reconstruct a differential motion vector by decoding an encoded differential motion vector included in a bitstream; and a motion vector reconstructor to derive one or more motion vector prediction candidates to predict the current motion vector, set the predicted motion vector to a motion vector prediction candidate determined among the one or more motion vector prediction candidates, and reconstruct the current motion vector of the current block by adding the predicted motion vector to the differential motion vector.

Abstract: An apparatus of predicting a current motion vector of a current block in a current frame for predictively decoding the current motion vector, the apparatus includes: a prediction candidate selector to select one or more motion vector prediction candidates from among blocks in the current frame and a block in a reference frame other than the current frame to determine a predicted motion vector corresponding to the current motion vector; and a predicted motion vector determiner to determine the predicted motion vector among the one or more motion vector prediction candidates, wherein the prediction candidate selector comprises: means for deriving one or more first motion vector prediction candidates from motion vectors of one or more blocks adjacent to the current block in the current frame, and means for deriving a second motion vector prediction candidate from a motion vector of the block located in the reference frame.

Abstract: An apparatus for reconstructing a current motion vector of a current block in a current frame by determing a predicted motion vector of the current motion vector, includes: a decoder to reconstruct a differential motion vector and a prediction candidate identification flag by decoding a bitstream; and a motion vector reconstructor to derive one or more motion vector prediction candidates to predict the current motion vector, set the predicted motion vector to a motion vector prediction candidate identified by the prediction candidate identification flag among the one or more motion vector prediction candidates, and reconstruct the current motion vector of the current block by adding the predicted motion vector to the differential motion vector.

Abstract: A method and an apparatus for image encoding/decoding are disclosed. The apparatus includes: a block decomposer for decomposing a current block into a plurality of sub-blocks; and an intra prediction encoder for performing an intra prediction encoding by referring to already encoded and decoded adjacent pixel information of each sub-block, based on an intra prediction mode equal to an intra prediction mode of the current block, thereby generating a bit stream for the current block. In image encoding and image decoding, when a current block to be encoded or decoded is predicted, the disclosed method and apparatus can improve the accuracy of the prediction, which can provide an image with a satisfactory reproduction quality by improved coding efficiency.

Abstract: Disclosed are a method and apparatus for determining an intra prediction mode, and for encoding/decoding video using the same. An apparatus for determining an intra prediction mode is provided, the apparatus comprising a calculator to calculate a variation of adjacent pixels to a current block; a threshold setter to set a threshold to evaluate the pixel variation; a comparator to compare between the variation and the threshold; a first prediction mode determination unit to determine a single predetermined prediction mode to be an optimal prediction mode if the variation is below the threshold; and a second prediction mode determination unit to determine a particular prediction mode from a plurality of prediction modes to be the optimal prediction mode through a rate-distortion optimization by performing intra predictions in the plurality of prediction modes if the variation is greater than or equal to the threshold.

Abstract: A motion vector encoding apparatus includes: an optimum motion vector determiner for determining optimum motion vectors for multiple reference pictures with respect to a current motion vector of a current block; a motion vector encoding mode determiner for determining a motion vector encoding mode according to whether a motion vector decoding apparatus can predict the optimum motion vectors for the multiple reference pictures; and a motion vector encoder for generating and encoding motion information on the multiple reference pictures by using the optimum motion vectors for the multiple reference pictures or preset default motion vectors for the multiple reference pictures according to the motion vector encoding mode, and generating motion vector encoded data by encoding the motion vector encoding mode. The motion vector encoding apparatus can more accurately predict a predicted motion vector of the current motion vector for multiple reference pictures, so as to improve the compression efficiency.

Abstract: Disclosed is a method for decoding a video using an inter prediction. The method identifies one or more conditions for enabling an inverse quantization and an inverse transform, and selectively performs, based on the identified conditions, at least one of: skipping both of the inverse quantization and the inverse transform for the obtained residual data; inversely quantizing the obtained residual data and skipping the inverse transform for the inversely quantized residual data; and inversely quantizing and then inversely transforming the obtained residual data.

Abstract: An apparatus for decoding a video, includes: a mode information extractor to extract mode information on an intra-prediction mode of a current block from encoded data; a prediction mode determiner to determine a candidate intra-prediction mode selected from a plurality of candidate intra-prediction modes as the intra-prediction mode of the current block, when the mode information indicates a first encoding mode; a prediction mode extractor to determine the intra-prediction mode of the current block by using a prediction mode identifier, when the mode information indicates a second encoding mode and includes the prediction mode identifier; and a decoder to decode the encoded data to produce a residual block, and reconstruct the current block by adding the produced residual block to a prediction block predicted based on the intra-prediction mode of the current block determined by either the prediction mode determiner or the prediction mode extractor.

Abstract: An apparatus for decoding a video includes: a mode information extractor to extract mode information on an intra-prediction mode of a current block from encoded data; a prediction mode determiner to determine a candidate intra-prediction mode selected from a plurality of candidate intra-prediction modes as the intra-prediction mode of the current block, when the mode information indicates a first encoding mode; a prediction mode extractor to determine the intra-prediction mode of the current block by using a prediction mode identifier, when the mode information indicates a second encoding mode and includes the prediction mode identifier; and a decoder to decode the encoded data to produce a residual block, and reconstruct the current block by adding the produced residual block to a prediction block predicted based on the intra-prediction mode of the current block determined by either the prediction mode determiner or the prediction mode extractor.

Abstract: An apparatus and method for video encoding/decoding considering impulse signal are disclosed. The method for video encoding includes generating a predicted block from predicting a current block and subtracting the predicted block from the current block to generate an M×N residual block, and encoding an A×B residual block containing residual signals of an impulsive component in the M×N residual block to generate a bitstream. The apparatus and the method of the present disclosure improve coding efficiency by efficiently encoding or decoding the residual signals of the impulse component in encoding or decoding videos.

Abstract: A video decoding method using an intra prediction, includes: predicting a current block from a plurality of neighboring blocks of the current block; decoding a bitstream to thereby extract residual signals; inversely quantizing the residual signals; inversely transforming the inversely quantized residual signals; and adding the inversely transformed residual signals to the predicted pixels in the predicted block, wherein the prediction of the current block comprises: calculating a plurality of weighted pixel values of pixels selected in the neighboring blocks by applying weights to the pixels selected in the neighboring blocks, wherein the weights are decided variably based on a position of a current pixel to be predicted in the current block; and deriving a predicted pixel value of the current pixel using the weighted pixel values.

Abstract: A video decoding apparatus for decoding a current block comprised of a plurality of subblocks by using an intra prediction, includes: an inverse quantization unit to inversely quantize transformed and quantized residual subblocks corresponding to the subblocks of the current block to thereby generate transformed residual subblocks; an inverse transform unit to inversely transform the transformed residual subblocks to thereby reconstruct residual subblocks; a prediction unit to sequentially predict the subblocks from neighboring pixels which have been already reconstructed to thereby generate a plurality of predicted subblocks corresponding to the subblocks; and an adder to sequentially reconstruct the subblocks by adding each of the reconstructed residual subblocks to a predicted subblock corresponding thereto, wherein the prediction unit uses one or more pixels of at least one previously reconstructed subblock within the current block as the neighboring pixels.

Abstract: A video decoding method using an inter prediction, includes: obtaining a differential motion vector and residual data from encoded data; determining a predicted motion vector; generating a predicted block by performing the inter prediction based on the differential motion vector and the predicted motion vector; identifying one or more conditions for enabling an inverse quantization and an inverse transform; skipping both of the inverse quantization and the inverse transform for the obtained residual data to thereby reconstruct a residual block directly from the obtained residual data, when the one or more identified conditions indicate skipping of both the inverse quantization and the inverse transform; and inversely quantizing the obtained residual data and skipping the inverse transform for the inversely quantized residual data to thereby reconstruct a residual block using the inverse-quantized residual data, when the one or more identified conditions indicate skipping of the inverse transform.

Abstract: A video encoding apparatus using an intra prediction, includes: an intra predictor to predict a current block from a plurality of neighboring blocks of the current block; a subtractor to generate residual signals by subtracting predicted pixels in the predicted block from pixels in the current block; a transformer to transform the residual signals into a frequency domain; a quantizer to quantize the transformed residual signals; and an encoder to encode the quantized residual signals into a bitstream, wherein the intra predictor includes: a weighted pixel calculator configured to calculate a plurality of weighted pixel values of pixels selected in the neighboring blocks by applying weights to the pixels selected in the neighboring blocks.

Abstract: A video decoding method using an inter prediction, includes: reconstructing a first differential motion vector and a second differential motion vector of a current block by decoding encoded data; deriving a first predicted motion vector and a second predicted motion vector of the current block from one or more neighboring blocks of the current block; generating a first motion vector of the current block by adding the first candidate motion vector to the first differential motion vector, and a second motion vector of the current block by adding the second candidate motion vector to the second differential motion vector; generating a predicted block of the current block by using the first and second motion vectors; reconstructing a residual block by decoding residual signals included in the encoded data; and adding each pixel value of the predicted block to a corresponding pixel value of the residual block.

Abstract: A video decoding method using an inter prediction, includes: obtaining block mode information and residual data from encoded data; generating a predicted block by performing the inter prediction in the unit of a block identified by the block mode information; identifying one or more conditions for enabling an inverse quantization and an inverse transform; skipping both of the inverse quantization and the inverse transform for the obtained residual data to thereby reconstruct a residual block directly from the obtained residual data, when the one or more identified conditions indicate skipping of both the inverse quantization and the inverse transform; inversely quantizing the obtained residual data and skipping the inverse transform for the inversely quantized residual data to thereby reconstruct a residual block using the inverse-quantized residual data, when the one or more identified conditions indicate skipping of the inverse transform.