Abstract: The present invention relates to an image encoding and decoding technique, and more particularly, to an image encoder and decoder using unidirectional prediction. The image encoder includes a dividing unit to divide a macro block into a plurality of sub-blocks, a unidirectional application determining unit to determine whether an identical prediction mode is applied to each of the plurality of sub-blocks, and a prediction mode determining unit to determine a prediction mode with respect to each of the plurality of sub-blocks based on a determined result of the unidirectional application determining unit.

Abstract: In embodiments of the present invention, an ultrasound system includes an ultrasound machine, which may be located in a hospital, clinic, vehicle, home, etc., coupled to a remotely located diagnosis station via a communication network. For some embodiments, the ultrasound machine includes an application-specific scan head that has identification information that allows the home ultrasound machine to notify a user whether the attached scan head is appropriate for the type of examination to be performed. For other embodiments, a first stage of beamforming is conducted in reconfigurable hardware and a second stage of beamforming is conducted in programmable software digital signal processor.

Abstract: A moving picture encoding/decoding apparatus and method for processing a moving picture, which is divided in units of slices are provided. The encoding method includes: dividing a moving picture in units of slices when the moving picture is received; determining an encoding order of moving pictures divided in units of slices; and generating a bitstream by encoding moving pictures, which are divided in units of slices, according to a corresponding order when the encoding order had been determined.

Abstract: Provided is a method and apparatus for adaptively performing deblocking filtering using a quantization parameter, based on a video block unit in a boundary between macroblocks including an intra macroblock. The filter and filtering method may enhance a compression rate of a high resolution video and enhance a video compression environment.

Abstract: An apparatus and method for assessing image quality in real-time in consideration of both a coding error generated in an image processing process and a packet error generated in an image transmission process are provided. The apparatus for assessing image quality in real-time includes: an image quality measurement unit measuring image degradation generated in processing an image; a packet degradation detection unit detecting a packet error generated in transmitting the image; and final outcome drawing unit finally assessing the quality of the image in consideration of both a degradation degree of the image measured by the image quality measurement unit and the packet error measured by the packet degradation detection unit.

Abstract: A deblocking filtering apparatus and method for removing block distortion of a decoded image, and a video decoding apparatus and method using the same. The deblocking filtering method includes extracting parameter information for a plurality of unit blocks in a macro block, from a header of an input current frame, determining whether to perform deblocking filtering, based on the extracted parameter information, and performing deblocking filtering on the macro block according to the determination result.

Abstract: An in-loop filtering method and apparatus for video encoding, the in-loop filtering method including: determining a type of a boundary of an image block to be filtered by using context information of the image block; adaptively creating a filter for filtering the boundary of the image block according to the determined type; selecting a filter for filtering the image block between the created filter and a previously stored filter; and filtering the image block by using the selected filter.

Abstract: An in-loop filtering apparatus for eliminating an error of deblocking-filtered image data in an encoder of image data, the apparatus including: an in-loop filter generator which generates in-loop filters using different filter coefficients for a block boundary and a block inside of the deblocking-filtered image; an in-loop filter applier which performs selective filtering on at least one of the block boundary and the block inside using the generated in-loop filters; and an in-loop filter information generator which generates in-loop filter information including at least one of coefficients of the generated in-loop filters, information indicating an area to which in-loop filtering is applied between the block boundary and the block inside, a size of a block to which in-loop filtering is applied, and a flag indicating whether to use an in-loop filter generated for a current frame or an in-loop filter generated for a previous frame.

Abstract: The present invention discloses an encoding apparatus using a Discrete Cosine Transform (DCT) scanning, which includes: a mode selection means for selecting an optimal mode for intra prediction; an intra prediction means for performing intra prediction onto video inputted based on the mode selected in the mode selection means; a DCT and quantization means for performing DCT and quantization onto residual coefficients of a block outputted from the intra prediction means; and an entropy encoding means for performing entropy encoding onto DCT coefficients acquired from the DCT and quantization by using a scanning mode decided based on pixel similarity of the residual coefficients.

Abstract: A method of and apparatus for encoding and decoding a signal by illumination change compensated motion estimation are provided. The apparatus for encoding a signal by illumination change compensated motion estimation includes: an illumination change compensation unit performing compensation for an illumination change by performing a differential calculation between each pixel value of a current block and the means pixel value of a reference block indicated by a motion vector of the current block and the mean pixel value of the reference block; a residual signals generation unit generating residual signals based on the blocks in which illumination change compensation is performed; and an illumination changed amount prediction unit performing differential pulse code modulation (DPCM) based on the illumination change amount prediction value by reflecting the closeness between neighboring blocks in which illumination change occurs.

Abstract: An apparatus and method for deciding an adaptive noise level for bandwidth extension are provided. The apparatus includes a noise level decider for deciding a high-band noise level for bandwidth extension according to tonality of an input signal, a pitch frequency analyzer for detecting a pitch frequency of the input signal and analyzing correlation between the detected pitch frequency and a frequency channel, and a noise level controller for adaptively controlling the decided high-band noise level based on the analyzed correlation of the pitch frequency and the frequency channel.

Abstract: Provided are an apparatus for multi-stage transforming a plurality of unit blocks in multi-dimension that can improve compression efficiency of video data by collecting Discrete Cosine Transforming (DCT) coefficients of neighboring blocks and performing an additional transformation based on the DCT coefficients of an original picture and a differential picture. The method includes the steps of: performing a Discrete Cosine Transform (DCT) on inputted picture data and selecting R blocks of a predetermined size from DCT picture data, where R is a natural number equal to or greater than 2; arranging DCT coefficients of each of the selected R blocks according to each frequency in one-dimension; and performing one-dimensional transformation again on the DCT coefficients arranged in one-dimension.

Abstract: A method and apparatus for encoding an image based on a video sensor structure are provided. The method includes acquiring an image to be encoded; separating the acquired image into respective color components; creating a predicted image for each of the color components, and creating a residual image between the predicted image and the acquired image; and performing transform encoding on each of the color components individually by applying the residual image to a transformation formula.

Abstract: Provided is a method of compressing a reference frame in encoding or decoding moving images. A reference frame to be compressed is divided into basic processing blocks. The basic processing blocks are divided into sub-blocks. A maximum value and a minimum value of pixels within each sub-block are calculated. A necessary bit length needed for compression of each sub-block is obtained based on a difference between the maximum value and the minimum value. An average bit length of the sub-blocks within the basic processing block is calculated based on the calculated necessary bit lengths of the sub-blocks. Bits are variably allocated to each sub-block by adjusting the necessary bit length of each sub-block so that the average bit length of the sub-blocks within a corresponding basic processing block is less than or equal to a preset required bit length. Each sub-block is compressed to the allocated bits.

Abstract: Provided is an apparatus and method for encoding and decoding using alternative transform units according to the correlation of residual signals. The video encoding apparatus includes a first transforming unit for performing discrete cosine transform (DCT), first quantization, first inverse quantization, and inverse DCT on a block basis onto residual coefficients generated after intra frame prediction or inter frame prediction; a second transforming unit for performing discrete sine transform (DST), second quantization, second inverse quantization, and inverse DST on a block basis onto the residual coefficients; a selecting unit for selecting one having a high compression rate between the first and second transforming units for each block through performing rate-distortion optimization; and a flag marking unit for recording information about the selected transforming unit at a flag bit provided on a macroblock basis.

Abstract: Provided is a multiple camera system, and more particularly, a method and apparatus for processing hopping default views in an apparatus for encoding/decoding video streams of multiple view positions. The encoding apparatus for the multiple camera system includes an encoder for receiving video signals of multiple view positions, and encoding the video signals based on a predetermined default Group of Pictures (GoP); a default GoP selector for providing the default GoP information to the encoder; and a multiplexer for multiplexing the encoded video signals and sequentially outputting only the default GoP.

Abstract: Provided is a video encoding and decoding method and apparatus using pixel-based prediction. A pixel-based video encoding apparatus includes a block prediction unit, a residual image generation unit, a pixel prediction unit, and an entropy-coding unit. The block prediction unit performs temporal or spatial prediction between a reference image and a current image in order to generate a prediction block corresponding to a current block to be encoded. The residual image generation unit generates a residual image block composed of a residual signal corresponding to a difference between pixels of the prediction block and pixels of the current block.

Abstract: Video data encoding and decoding methods and apparatuses are provided. In the video data encoding and decoding methods, codes books are provided to an encoder and a decoder. In the encoder, an index corresponding to a vector that is most similar to a current vector of an input moving picture among the vectors of the code book is encoded. In the decoder, the index is decoded. Accordingly, it is possible to increase compression ratio and reduce calculation complexity.

Abstract: Provided is an apparatus and method for encoding/decoding moving pictures based on adaptive scanning. The moving picture apparatus and method can increase a compression rate based on adaptive scanning by performing intra prediction onto blocks of a predetermined size, and scanning coefficients acquired from Discrete Cosine Transform (DCT) of a residue signal and quantization differently according to the intra prediction mode. The moving picture encoding apparatus includes: a mode selector for selecting and outputting a prediction mode; a predictor for predicting pixel values of pixels to be encoded of an input video based on the prediction mode to thereby output a residue signal block; a transform/quantization unit for performing DCT onto the residue signal block and quantizing the transformed residue signal block; and an encoder for adaptively scanning and encoding the quantized residue signal block based on the prediction mode.

Abstract: In embodiments of the present invention, an ultrasound system includes an ultrasound machine, which may be located in a hospital, clinic, vehicle, home, etc., coupled to a remotely located diagnosis station via a communication network. For some embodiments, the ultrasound machine includes an application-specific scan head that has identification information that allows the home ultrasound machine to notify a user whether the attached scan head is appropriate for the type of examination to be performed. For other embodiments, a first stage of beamforming is conducted in reconfigurable hardware and a second stage of beamforming is conducted in programmable software digital signal processor.