Abstract: Disclosed is a moving picture mailing system which comprises a video signal capturing device for capturing digital video signals from video signal information of moving pictures; an audio signal capturing device for capturing digital audio signals from audio signal information of moving pictures; and a moving picture recorder for respectively receiving the video and audio signals from the video and audio signal capturing devices, compressing the video and audio signals using MPEG-4 video and audio compression techniques, multiplexing the compressed signals and transmitting combined bit streams to a moving picture mailing server.

Abstract: There is provided an improved scan interleaving method suitable for multipurpose encoding of binary image data, and for selectively encoding a part or the whole of object image data according to presence or absence of exceptional sampling data (ESD). In the present invention, when the pixel data of base image data and the corresponding pixel data of the object image data to be scan-interleaved are the same (in the case of predictive sampling data), no encoding is performed on the pixels of the object image data which have no ESD, thus simplifying the algorithm and system implementation. As a result, the overall encoding performance can be improved.

Abstract: Correct motion estimation is performed by preventing an adverse effect due to the variation of lighting conditions when a motion estimation is performed in a motion image device.

Abstract: A method for encoding picture data using scan interleaving pixels and an apparatus and method for encoding the picture data includes the steps of determining whether pixels of a present scanning line in a predetermined frame of an image should be encoded according to comparison results between pixels of a previous scanning line and pixels of a next scanning line and between pixels of a previous or next scanning line and pixels of the current scanning line, and encoding pixels of lines of the image excluding pixels that are determined to not be encoded.

Abstract: A discrete cosine transform (DCT) coefficient prediction method and a DCT coefficient encoding method are provided. For the prediction of AC coefficients, location information of the nonzero AC coefficients is used. Then, the AC coefficients are divided into the vertical and horizontal component areas, and a remaining area, and variable modified zigzag scanning is applied for encoding. The performance of the AC coefficient prediction coding is improved as the absolute values of the predicted coefficients are small, and as the number of coefficients of value zero increases. The coefficients of value zero may be predicted as nonzero, so these coefficients are eliminated from the prediction. On the other hand, when using the characteristics of the adjacent blocks in a spatial domain, a larger weighted value is applied to the pixel values which are the nearest to the current block, thereby improving the prediction characteristics for DC/AC coefficients in a discrete cosine transform (DCT) domain.

Abstract: In a moving picture coding method and apparatus for low bit rate systems using dynamic motion estimation, a shape component of the moving object for analysis can be extracted together with a motion component, thereby reducing bit generation and reducing degradation of a reconstructed image. The shape component includes location information for a group of blocks which comprise the object for analysis. The motion component includes a displacement and a rotation angle applicable to the group of blocks.

Abstract: An improved interpolation method in which a threshold value used for determining a pixel value of a pixel generated by interpolation according to a context (state value of adjacent pixels). In the interpolation method, the ambiguity between the interpolation value and the threshold value is removed by using the context (state value of the reference pixels around the interpolated pixel), thereby reducing the blocking and smoothing phenomena in the restored binary image.

Abstract: An interpolation method in which a threshold value used for determining a pixel value of a pixel generated by interpolation according to a context (state value of adjacent pixels). In the interpolation method, the ambiguity between the interpolation value and the threshold value is removed by using the context (state value of the reference pixels around the interpolated pixel), thereby reducing the blocking and smoothing phenomena in the restored binary image.

Abstract: A digital data coding/decoding method and apparatus are provided. The coding method includes the steps of representing respective digital data by digits of a predetermined same number, and coding the digital data represented by digits of the same number by a predetermined coding method from the uppermost significant digit sequence to the least significant digit sequence. The method for decoding digital data coded in the order of significance by rating the significance of digits of the digital data, includes the steps of analyzing significance of coded digital data, and decoding the analyzed digital data from upper significant digits to lower significant digits by a predetermined decoding method. Even if some bitstreams are lost or damaged by coding important information first, deterioration in audio quality can be reduced.

Abstract: A digital data coding/decoding method and apparatus are provided. The coding method includes the steps of representing respective digital data by digits of a predetermined same number, and coding the digital data represented by digits of the same number by a predetermined coding method from the uppermost significant digit sequence to the least significant digit sequence. The method for decoding digital data coded in the order of significance by rating the significance of digits of the digital data, includes the steps of analyzing significance of coded digital data, and decoding the analyzed digital data from upper significant digits to lower significant digits by a predetermined decoding method. Even if some bitstreams are lost or damaged by coding important information first, deterioration in audio quality can be reduced.

Abstract: An improved interpolation method in which a threshold value used for determining a pixel value of a pixel generated by interpolation according to a context which is a state value of adjacent pixels. In the interpolation method, the ambiguity between the interpolation value and the threshold value is removed by using the context, thereby reducing the blocking and smoothing phenomena in the restored binary image.

Abstract: An improved interpolation method in which a threshold value used for determining a pixel value of a pixel generated by interpolation according to a context which is a state value of adjacent pixels. In the interpolation method, the ambiguity between the interpolation value and the threshold value is removed by using the context, thereby reducing the blocking and smoothing phenomena in the restored binary image.

Abstract: A video signal encoding and/or decoding method based on adaptive lattice quantization. An input frame of a video sequence is partitioned into blocks of pixel data called vectors. The set of the vectors is partitioned into blocks called macroblocks. The vectors in each macroblock are subjected to lattice vector quantization which examines the range of vector components in multiple dimensions and adjusts the density of lattice vectors in accordance with the range of vector components. Quantization unit replaces each input vector for a nearest lattice vector in multidimensional space. Each quantized vector in the macroblock is converted into an index of a lattice vector. An overhead information about the range in a macroblock and set of indices with or without subsequent Huffman or Arithmetic coding is transmitted to or stored in the receiver end.

Abstract: A resolution-variable adaptive picture compression method and the apparatus therefor varies the resolution of the currently compressed picture while adjusting its frame structure which is compressed according to the picture's condition, to thereby enhance picture quality with respect to the compression ratio.

Abstract: An image compression method employing a conditional quadtree split method includes inputting image data in frame or field units as blocks having a predetermined size; generating an average value for all of the pixels in each block and a sub-block code value for determining whether to perform sequential quad-splitting operations on the block into a suitable sub-block according to image type; and outputting a quadtree map drawn according to the sub-block code value and the average value of each block, as a bit stream. An apparatus employing the method can transmit good quality image data having no distortion at a high transmission rate.

Abstract: A method for encoding a motion image and an apparatus therefor includes first and second buffers, a motion estimator/compensator, an MC error generator/divider, first and second quadtree processors, a multiplexer, a quantizer, a variable length coder, a bit rate controller, an inverse quantizer, first and second inverse quadtree processors, and an adder/filter. Here, MC errors generated after motion compensation are divided into accumulated and compensation errors according to the characteristics, and then encoded. Thus, bit generation can be reduced compared with the conventional method, picture quality can be improved, and a process structure can be simplified.

Abstract: A bi-directional motion estimation method and apparatus thereof in a low bit-rate moving video codec system, for filtering motion vectors by performing a bi-directional motion estimation in units of objects having the same motion in a constant domain and for compensating the motion using the motion vectors generated as the result of forward or backward motion prediction in accordance with the motion prediction mode of previously set frames, can determine the precise motion vector compared to the existing block matching algorithm and depict the inter-frame motion with a smaller amount of information. Therefore, markedly less data (for compression) is used and reconstructed picture quality is improved.

Abstract: An interpolation method in which a threshold value used for determining a pixel value of a pixel generated by interpolation according to a context (state value of adjacent pixels). In the interpolation method, the ambiguity between the interpolation value and the threshold value is removed by using the context (state value of the reference pixels around the interpolated pixel), thereby reducing the blocking and smoothing phenomena in the restored binary image.