Sk Telecom Company, Ltd.

Hayoon Kim

Byeungwoo Jeon

Haekwang Kim

Yunglyul Lee

Joohee Moon

Yoonsik Choe

Yonggoo Kim

Yungho Choi

Jinwoo Jung

Daeyeon Kim

Kwanghyun Won

Jungyoup Yang

Byongho Kim

Sungjei Kim

Kihun Han

Dongkyun Kim

Hyoungmee Park

Mincheol Park

Kibaek Kim

Hyemin Jun

Jie Jia

Video encoding/decoding method and apparatus using a block transformation are disclosed. The apparatus encodes the video through predicting each pixel in a current block of the video by using one or more adjacent pixels, which are encoded prior to encoding the current block and have the closest proximity to the pixels respectively in a predetermined prediction direction, and wherein the current block is sized L&#xd7;M with L being unequal to M. It has become possible to predict the pixels in the block starting from closest one of the pixels in the prediction direction in order to provide more accurate block predictions and then raise the compression efficiency that leaps to more efficient video encoding/decoding performance.

Image encoding/decoding method and apparatus using block transformation

A method for encoding/decoding a motion vector and an apparatus thereof are disclosed. The method includes defining a candidate motion vector set with respect to a current motion vector; selecting a predicted motion vector from the candidate motion vector set; determining a predictability of the predicted motion vector in a decoding apparatus; encoding the current motion vector by using a motion vector prediction mode for indicating the predicted motion vector and the predictability, if the predictability is determined positive; and encoding the current motion vector by using a motion vector prediction mode for indicating a default predicted motion vector and an unpredictability, if the predictability is determined negative. According to the disclosure, it becomes unnecessary to directly notify of the predicted motion vector of the current motion vector to the decoding apparatus, and instead a predetermined shared function is provided to inform of or search the predicted motion vector.

Method for encoding/decoding motion vector and apparatus thereof

Video encoding and its corresponding decoding are disclosed. The video encoding incorporates: a predictor for predicting a pixel value of each pixel in a current block of the video to generate a predicted pixel value; a subtractor for calculating a difference between an original pixel value of the pixel in the current block and the predicted pixel value of the pixel in the current block to generate a residual signal; a transformer for transforming the residual signal into frequency coefficients; a quantizer for quantizing the transformed frequency coefficients; and an encoder for encoding the quantized frequency coefficients by using one of different variable length coding tables.

Video encoding and decoding apparatus and method

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.

Method and apparatus for determining intra prediction mode, and method and apparatus for encoding/decoding video using same

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.

Method and an apparatus for inter prediction decoding with selective use of inverse quantization and inverse transform

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&#xd7;N residual block, and encoding an A&#xd7;B residual block containing residual signals of an impulsive component in the M&#xd7;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.

Apparatus and method for image encoding/decoding considering impulse signal

The present disclosure relates to an apparatus and method for encoding/decoding videos using prediction direction change and selective encoding. The present disclosure provides a video encoding apparatus that encodes the current block of a video, comprising a rectangle encoder for dividing and then successively encoding the current block at input into rectangular block units to output a rectangularly encoded bitstream; a square encoder for encoding the current block at input in square block units to output a squarely encoded bitstream; and an encoding selector for calculating the encoding costs of the rectangularly encoded bitstream and the squarely encoded bitstream so as to output the bitstream with a minimum encoding cost. According to the present disclosure, the prediction accuracy may be increased when encoding or decoding videos so that video encoding efficiency can be improved.

Device and method for image encoding/decoding using prediction direction conversion and selective encoding

The present disclosure relates to an intra prediction method and apparatus and an image encoding/decoding method and apparatus using the same. The disclosure provides the intra prediction apparatus that predicts the pixel values of respective pixels in a current block by weight-averaging the pixel values of one or more adjacent pixels in neighboring blocks to the current block according to the distances between each pixel in the current block and the adjacent pixel(s). According to the disclosure, the current block to be encoded can be predicted more accurately so that the encoding efficiency is improved by reducing the difference between the original block and the predicted block, and thereby video compression efficiency can be improved.

Intra prediction method and apparatus, and image encoding/decoding method and apparatus using same

The present disclosure relates to a video encoding/decoding apparatus, and apparatus and method for adaptive overlapped block motion compensation by variable units for same. The apparatus and the method for adaptive overlapped block motion compensation by variable units, according to the present disclosure, when conducting a motion compensation, enable an encoder to perform an adaptive overlapped block motion compensation for a plurality of predetermined scan modes and sampling modes, and enable the encoder to calculate the computation volume occurring in said compensation and residual pixel energy, estimate the performance for each mode based on the calculation, determine an optimum scan mode and an optimum sampling mode, thus enabling a decoder to perform a motion compensation with optimum performance and less computing volume based on the determined mode.

Motion picture encoding/decoding apparatus, and apparatus and method for adaptive overlapped block motion compensation by variable unit for same

The present disclosure relates to an apparatus and method for determining an adaptive filter tap to encode a wavelet transform coefficient, a wavelet transform apparatus and a method using the same, and a recording medium for the same, wherein the filter tap is determined rendering the high-band energy to be minimized, based not only on whether an edge is present but also on the edge location so as to adaptively determine the filter tap for an efficient coding of the wavelet transform coefficient. Therefore, the disclosure is able to prevent ringing artifacts and increase coding efficiency while maintaining clear definition on the edges.

Apparatus and method for determining adaptive filter tap to encode wavelet transform coefficient, wavelet transform apparatus and method using the same, and recording medium for the same

The present disclosure relates to a wavelet transform apparatus and method based on a prediction-update lifting scheme, and an adaptive prediction apparatus and method and a recording medium for the same. The disclosure comprises the steps of: setting first updated even polyphase samples influenced when being updated from corresponding odd polyphase samples, setting plural candidate groups for prediction direction based on the set first updated even polyphase samples, selecting a first prediction direction from the candidate groups to minimize the energy in a high band, obtaining a first prediction value based on the first prediction direction and the updated even polyphase samples corresponding to the first prediction direction, and obtaining residual odd polyphase samples by deducting the first prediction value from the corresponding odd polyphase samples. Therefore, the present disclosure is able to increase encoding efficiency by minimizing energy transfer to a high band signal when removing the spatial correlation within an image using a directional wavelet transform designed based on the prediction-update lifting scheme.

Wavelet transform apparatus and method based on prediction-update lifting scheme, and adaptive prediction apparatus and method and recording medium for the same

An encoding method and encoding apparatus for B-transform, and encoded data for same are provided. The apparatus is for encoding input data and includes: a B-transform unit for performing a B-transform on the input data to generate a binary expression; and an encoder for removing one or more binary symbols from the binary expression and scanning the binary expression with the one or more binary symbols removed to generate a bitstream. According to the method and apparatus, it is possible to encode uniform distribution data efficiently, and using the B-transform by its characteristics for reducing the bit number in the generation of the binary expressions from the B-transform operation on the uniform distribution data enhances the data compression performance.

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Gyeonggi-do, South Korea

Hayoon Kim