Abstract: An apparatus and method for encoding and decoding an image are provided. The image decoding method includes (a) decoding luma blocks according to a predetermined decoding mode of each of the luma blocks, and (b) decoding chroma blocks according to the predetermined decoding mode of each of the luma blocks.

Abstract: An apparatus and method for encoding and decoding an image are provided. The image decoding method includes decoding luma blocks according to a predetermined decoding mode of each of the luma blocks, and decoding chroma blocks according to the predetermined decoding mode of each of the luma blocks.

Abstract: An apparatus and a method for encoding and/or decoding an image containing a gray alpha channel image. The apparatus for encoding an image includes a block data reception unit receiving image data of a block currently being input to the apparatus and classifies the current block either as a foreground image portion or as a background image portion according to values of gray alpha components in the current block; a foreground image encoding unit sequentially encoding the gray alpha components and brightness and hue components of the current block if the current block is classified as the foreground image portion; and a background image encoding unit encoding the gray alpha components of the current block if the current block is classified as the background image portion.

Abstract: A method for operating a portable terminal so as to reduce power consumption during the support of a communication service and a portable terminal supporting the same is provided. The method includes activating a Radio Frequency (RF) communication unit, downloading a part of data of predetermined contents through the RF communication unit, buffering the downloaded part of the data in a buffer so as to output the buffered downloaded part of the data, and executing an idle time for terminating or reducing a power supply of the RF communication unit when the downloading of the part of the data of the predetermined contents is completed.

Abstract: An image encoding and decoding apparatus and method, the image encoding and decoding apparatus includes: an encoding unit adjusting at least one weight value adaptively to the number of bits expressing each pixel of a current image, predicting a pixel value of a block of interest by performing an operation on a pixel value of at least one block having a pixel value similar to the pixel value of the block of interest among blocks included in a previous image and the at least one adjusted weight value, and encoding the pixel value of the block of interest using the predicted pixel value of the block of interest; and a decoding unit adjusting the at least one weight value adaptively to the number of bits, restoring the predicted pixel value of the block of interest by performing an operation on the pixel value of the at least one block having the pixel value similar to the pixel value of the block of interest among blocks included in the restored previous image and the at least one adjusted weight value, and dec

Abstract: Provided are a method and apparatus for encoding/decoding a moving picture by using the diffusion properties of the image. In the method, a value of a current pixel is predicted from the values of neighboring pixels of the current pixel, based on the variations between the values of the neighboring pixels present in directions toward the current pixel; a correction value of the predicted value is calculated from at least one variation from among the variations; the value of the current pixel is determined by reflecting the correction value into the predicted value; and then, the original image is reconstructed using the determined value of the current pixel.

Abstract: An apparatus and method for encoding and decoding an image are provided. The image decoding method includes (a) decoding luma blocks according to a predetermined decoding mode of each of the luma blocks, and (b) decoding chroma blocks according to the predetermined decoding mode of each of the luma blocks.

Abstract: Provided are a scalable video coding method and apparatus, and a scalable video decoding method and apparatus. The coding method generates a base layer bitstream of video by using one of a plurality of codecs, determines whether the used codec supports enhancement layer coding, decodes the base layer bitstream according to the result of the determination in order to extract coded information used for the generation of the base layer bitstream, and generates an enhancement layer bitstream of the original video based on the extracted information. Accordingly, it is possible to provide high-quality video and increase coding efficiency while using the various existing codecs.

Abstract: A method, medium, and system encoding and/or decoding a moving picture. The moving picture encoding method may include selecting a prediction mode that is optimal for the macro blocks, which correspond to each other, of the color components of a current image based on the characteristics of a predetermined image, generating a predicted image for the current image according to the selected prediction mode, and encoding a moving picture using the predicted image. An optimal prediction mode can be adaptively applied to the macro blocks, which correspond to each other, of the color components, thereby increasing the moving picture's encoding and decoding efficiencies.

Abstract: An apparatus and a method generate a coded block pattern (CBP) of an alpha channel image. An apparatus and a method encode or decode the alpha channel image using the method. The alpha channel image encoding apparatus includes a CBP generator generating a CBP of a first block corresponding to an encoding unit in the alpha channel image by allocating CBPs to a plurality of second blocks that includes the first block; and a bitstream generator generating a bitstream by encoding the CBP or the CBP and pixel values of the second blocks based on the CBP of each of second blocks.

Abstract: Provided are a scalable video coding method and apparatus, and a scalable video decoding method and apparatus. The coding method generates a base layer bitstream of video by using one of a plurality of codecs, determines whether the used codec supports enhancement layer coding, decodes the base layer bitstream according to the result of the determination in order to extract coded information used for the generation of the base layer bitstream, and generates an enhancement layer bitstream of the original video based on the extracted information. Accordingly, it is possible to provide high-quality video and increase coding efficiency while using the various existing codecs.

Abstract: Provided are an image encoding apparatus and an image decoding apparatus. The image encoding apparatus includes a compression unit compressing a reference image by reducing a resolution of the reference image in a resolution adjustment mode determined from among at least two resolution adjustment modes according to a distribution of values of pixels of the reference image, and providing the compressed reference image to a memory, a reconstruction unit reconstructing the reference image by increasing a resolution of the compressed reference image stored in the memory to an original resolution, a predictive encoding unit performing predictive encoding on a current image by using the reconstructed reference image, and a predictive decoding unit generating the reference image by performing decoding on the predictive encoded current image, and providing the generated reference image to the compression unit.

Abstract: A color image and video encoding and/or decoding apparatus, method, and medium using inter-color-component prediction in accordance with an encoding mode are provided.

Abstract: A color image residue transform and/or inverse transform method and apparatus, and a color image encoding and/or decoding method and apparatus using the same are provided. The residue transform method includes: obtaining a residue corresponding to the difference of an original image and a predicted image; and transforming the residue by using a relation between residues of color image components. The residue inverse transform method includes: generating a residue for each component by performing residue inverse transform of the residue transformed original image; and restoring the original image by adding a predicted image to the residue of each component. Also, the color image lossless encoding method using the residue transform includes: obtaining a residue corresponding to the difference of an original image and a predicted image; and performing encoding by transforming the residue by using the relation between residues of predetermined components.

Abstract: An image encoding and decoding apparatus and method, the image encoding and decoding apparatus includes: an encoding unit adjusting at least one weight value adaptively to the number of bits expressing each pixel of a current image, predicting a pixel value of a block of interest by performing an operation on a pixel value of at least one block having a pixel value similar to the pixel value of the block of interest among blocks included in a previous image and the at least one adjusted weight value, and encoding the pixel value of the block of interest using the predicted pixel value of the block of interest; and a decoding unit adjusting the at least one weight value adaptively to the number of bits, restoring the predicted pixel value of the block of interest by performing an operation on the pixel value of the at least one block having the pixel value similar to the pixel value of the block of interest among blocks included in the restored previous image and the at least one adjusted weight value, and dec

Abstract: An image encoding and decoding apparatus and method, the image encoding and decoding apparatus includes: an encoding unit adjusting at least one weight value adaptively to the number of bits expressing each pixel of a current image, predicting a pixel value of a block of interest by performing an operation on a pixel value of at least one block having a pixel value similar to the pixel value of the block of interest among blocks included in a previous image and the at least one adjusted weight value, and encoding the pixel value of the block of interest using the predicted pixel value of the block of interest; and a decoding unit adjusting the at least one weight value adaptively to the number of bits, restoring the predicted pixel value of the block of interest by performing an operation on the pixel value of the at least one block having the pixel value similar to the pixel value of the block of interest among blocks included in the restored previous image and the at least one adjusted weight value, and dec

Abstract: A prediction image generation method and apparatus using a single coding mode for all color components and image and video encoding and decoding methods and apparatuses using the same are provided.

Abstract: A method of coding a moving picture reduces blocking artifacts. The method includes defining pixel sets S0, S1, S2 around a block boundary, selectively determining a deblocking mode as a default mode or a DC offset mode depending on the degree of blocking artifacts. If the default mode is selected, frequency information is obtained around the block boundary per pixel using a 4-point DCT kernel, for example, a magnitude of a discontinuous component belonging to the block boundary is replaced with a minimum magnitude of discontinuous components belonging to the surroundings of the block boundary in the frequency domain and the replacing step is applied to the spatial domain. If the DC offset mode is selected and a determination is made to perform DC offset mode, the blocking artifacts in a smooth region are removed in the DC offset mode.

Abstract: A method of coding a moving picture reduces blocking artifacts. The method includes defining pixel sets S0, S1, S2 around a block boundary, selectively determining a deblocking mode as a default mode or a DC offset mode depending on the degree of blocking artifacts. If the default mode is selected, frequency information is obtained around the block boundary per pixel using a 4-point DCT kernel, for example, a magnitude of a discontinuous component belonging to the block boundary is replaced with a minimum magnitude of discontinuous components belonging to the surroundings of the block boundary in the frequency domain and the replacing step is applied to the spatial domain. If the DC offset mode is selected and a determination is made to perform DC offset mode, the blocking artifacts in a smooth region are removed in the DC offset mode.

Abstract: A method of coding a moving picture reduces blocking artifacts. The method includes defining pixel sets S0, S1, S2 around a block boundary, selectively determining a deblocking mode as a default mode or a DC offset mode depending on the degree of blocking artifacts. If the default mode is selected, frequency information is obtained around the block boundary per pixel using a 4-point DCT kernel, for example, a magnitude of a discontinuous component belonging to the block boundary is replaced with a minimum magnitude of discontinuous components belonging to the surroundings of the block boundary in the frequency domain and the replacing step is applied to the spatial domain. If the DC offset mode is selected and a determination is made to perform DC offset mode, the blocking artifacts in a smooth region are removed in the DC offset mode.