Abstract: Video coding and decoding methods using interlayer filtering and a video encoder and decoder using the same are provided. Multi-layer video coding employing a plurality of video coding algorithms can improve video coding efficiency by using interlayer filtering. The video coding method includes encoding video frames using a first video coding scheme, performing interlayer filtering on the frames encoded by the first video coding scheme, encoding the video frames using a second video coding scheme by referring to the frames subjected to the interlayer filtering, and generating a bitstream containing the frames encoded by the first and second video coding schemes.

Abstract: A method and apparatus for efficiently predecoding a hybrid bitstream generated by a plurality of coding schemes are provided. The method includes obtaining a first bit-rate for a boundary between the lower layer bitstream and the upper layer bitstream and a second bit-rate for a boundary between motion information and texture information of the upper layer bitstream from the input hybrid bitstream, determining the target bit-rate according to variable network circumstances, and when the target bit-rate is between the first and second bit-rates, skipping the motion information of the upper layer bitstream and truncating all bits of the texture information of the upper layer bitstream from the tail, except bits corresponding to the difference between the target bit-rate and the first bit-rate.

Abstract: Disclosed are a method and an apparatus for realizing signal to noise ratio (SNR) scalability in a video stream server in order to transmit a video stream in a variable network environment. An apparatus for adapting a bitrate of a coded scalable bit-stream based on multi-layers to a variable network environment, comprising a bit-stream parsing unit to parse an input bit-stream, a pre-decoding condition determining unit to determine a target transmission bitrate according to the variable network environment, a pre-decoding unit to skip at least one frame among the frames included in the parsed bit-stream according to the determined target transmission bitrate, and a bit-stream transmission unit to transmit to a client device the bit-stream that has been restructured due to frame skipping.

Abstract: Video coding and decoding methods and video encoder and decoder are provided. The video encoding method includes determining one of inter predictive coding and intra predictive coding mode as a coding mode for each block in an input video frame, generating a predicted frame for the input video frame based on predicted blocks obtained according to the determined coding mode, and encoding the input video frame based on the predicted frame. When the intra predictive coding mode is determined as the coding mode, an intra basis block composed of representative values of a block is generated for a block and the intra basis block is interpolated to generate an intra predicted block for the block.

Abstract: An inter-frame prediction method in video coding, a video encoder using the same, a bitstream structure, a video decoding method, and a video decoder are provided. The inter-frame prediction method in video encoding includes estimating a motion vector between a current block in an input frame and a reference block in a reference frame corresponding to the current block and a filtering mode defining a spatial effect to be applied to at least one of the current block and the reference block, and interceding the input frame according to the estimated motion vector and the filtering mode.

Abstract: A method and apparatus for supporting scalability for motion vectors in scalable video coding are provided. The motion estimation apparatus includes a motion estimation module searching for a variable block size and a motion vector that minimize a cost function for each layer according to predetermined pixel accuracy, a sampling module upsampling an original frame when the pixel accuracy is less than a pixel size, and before searching for a motion vector in a layer having a lower resolution than the original frame downsampling the original frame into the low resolution, a motion residual module calculating a residual between motion vectors found in the respective layers, and a rearrangement module rearranging the residuals between the found motion vectors and the found variable block size information using significance obtained from a searched lower layer. Accordingly, true motion scalability can be achieved to improve adaptability to changing network circumstances.

Abstract: A method and an apparatus for elevating compression efficiency of a motion vector by effectively predicting a motion vector of an enhanced layer by means of a motion vector of a base layer in a video coding method employing a multi-layer structure are disclosed. A motion vector compression apparatus includes: a down-sampling module for down-sampling an original frame to have a size of a frame in each layer; a motion vector search module for obtaining a motion vector in which an error or a cost function is minimized with respect to the down-sampled frame; a reference vector generation module for generating a reference motion vector in a predetermined enhanced layer by means of a block of a lower layer corresponding to a predetermined block in the predetermined enhanced layer, and motion vectors in blocks around the block; and a motion difference module for calculating a difference between the obtained motion vector and the reference motion vector.

Abstract: A method and apparatus for encoding a moving picture using a fast motion estimation algorithm are provided. The method includes motion estimation performed by obtaining motion vectors of representative sub-blocks of macroblocks each containing a plurality of sub-blocks, respectively, and by estimating motion vectors of all sub-blocks other than the representative sub-blocks using relationships among the motion vectors of the representative sub-blocks. In the method and apparatus, motion estimation requiring a large amount of computation in encoding a moving picture can be performed quickly and accurately.

Abstract: A video coding method supporting a variable group of pictures (GOP) size, a video encoder, and the structure of an encoded bitstream are provided. The coding method includes receiving a video sequence, and encoding the received video sequence into a bitstream with a variable GOP size. The video encoder includes a determiner determining a GOP size variably according to a predetermined criterion, and a scalable video coding unit encoding an input video sequence into a bitstream with the determined GOP size.

Abstract: Provided are a method and apparatus for scalable video coding and decoding. The scalable video coding method performs video coding separately at each resolution, and coding results are incorporated into one resolution level for compression. The scalable video coding combines images with the respective images into a single one while providing high image quality across all resolution levels.

Abstract: An economically viable process for the microwave destruction of contaminated water-based liquids, such as by chemical and biological agents, employs carbonaceous materials to enhance the efficiency of the microwaves while keeping the bulk temperature down to only a modest rise. A second absorption reactor is used not employing microwaves. The cyclic microwave use of both reactors allows high efficiency for the total process of destruction—adsorption.

Abstract: Disclosed is a method and apparatus for picture compression using a variable block of an arbitrary size, the method comprising: a first step of calculating motion vectors of desired variable blocks; a second step of dividing a screen into a plurality of blocks of arbitrary sizes according to the calculated motion vectors of the variable blocks; and a third step of determining motion vectors with respect to each of the plurality of blocks of the arbitrary sizes constructing the divided screen. Also, the method comprises a first step of compensating motion with respect to blocks of arbitrary sizes from which the motion vectors are decided; and a second step of transmitting block information of an arbitrary size for which the motion is compensated, in order, from a block disposed on the upper left of the screen to a block disposed on the lower right of the screen.

Abstract: Disclosed is a method and apparatus for a motion estimation using a variable block size of a hierarchy structure. The method includes: calculating each of a motion vector of a desired minimum unit variable block; determining a similarity of the calculated motion vectors between the minimum unit variable blocks in a higher hierarchy including the minimum unit variable block; establishing a mode of the variable block according to the determined similarity; and deciding a motion vector with respect to the mode established variable block. The complexity of the method of compressing a motion picture of a hierarchy structure having a plurality of block sizes can be reduced by selecting a mode of the optimal block size on the basis of a motion vector with respect to the minimum unit and the cost occurred at that time without performing the motion estimation with respect to each mode each time.

Abstract: A high-speed inverse discrete cosine transformation method and apparatus are provided. All elements of a discrete cosine transformation (DCT) matrix for elements having a value other than 0 are searched for in a predetermined order when a total number of elements having a value other than 0 is not greater than a predetermined critical value. Two-dimensional (2D) IDCT is performed on the elements having a value other than 0. 2D IDCT is performed on the DCT matrix when the total number of elements having a value other than 0 is greater than the predetermined critical value.

Abstract: An MPEG video decoding method and an MPEG video decoder are provided. The method includes determining whether to perform motion compensation on motion-vector-decoded data or not depending on a value of a decoded motion vector, determining whether to perform inverse discrete cosine transformation (IDCT) on motion-compensated data or not depending on values of decoded DCT coefficients, and generating a decoded image based on the results of the two determinations.

Abstract: A method and apparatus for fast inverse discrete cosine transform (IDCT) are provided. The fast IDCT method includes: (a) searching all elements of a discrete cosine transform (DCT) matrix in a predetermined order for non-zero elements; and (b) calculating the restored value of each element of a restoration matrix, by 2 dimensional-inverse DCT (2D-IDCT) transforming the non-zero elements of the DCT matrix by using the symmetry of an IDCT formula. According to the method and apparatus, unnecessary computation for 0's that are the majority of elements in a DCT matrix can be reduced to the minimum in performing the IDCT transform. In addition, even when the number of elements having effective values is large in a DCT matrix, the amount of computation is greatly reduced by using the symmetry of a DCT formula such that the method shows an excellent performance when statistically compared to the conventional fast DCT algorithms.