Abstract: 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.

Abstract: 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.

Abstract: 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×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.

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 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.

Abstract: 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.

Abstract: A video encoding/decoding method and apparatus using arbitrary pixels in each sub-block are disclosed. The present disclosure comprises an extractor, a first predictor, a first subtractor, a first transformer, a first quantizer, a first inverse quantizer, a first inverse transformer, a first adder, a second predictor, a second subtractor, a combiner for combining arbitrary residual pixels, a second transformer, a second quantizer, and an encoder whereby arbitrary pixels may be extracted from the respective sub-blocks of a current block and then encoded and decoded into reconstructed arbitrary pixels, which are used to predict and encode the remaining pixels of the respective sub-blocks. According to the disclosed encoding and decoding of a video, an intra prediction of pixels in a block to currently encode or decode is improved in accuracy to increase the video coding efficiency.