Patent application number | Description | Published |
20080247464 | METHOD AND APPARATUS FOR ENCODING AND DECODING BASED ON INTRA PREDICTION USING DIFFERENTIAL EQUATION - Provided are a method and apparatus for encoding and decoding an image based on intra prediction. The image encoding method comprises determining boundary values of a differential equation that is to be used to intra-predict a current block based on pixel values of pre-encoded pixels adjacent to the current block, predicting the current block using the differential equation and the boundary values and encoding the current block based on the prediction block of the current block. | 10-09-2008 |
20090092330 | METHOD AND APPARATUS FOR CORRECTING QUANTIZED COEFFICIENTS IN DECODER - Provided are a method and apparatus for correcting quantized coefficients. In the method, statistical values of coefficients and quantized coefficients are extracted from a received video data stream, coefficient correction values for each pixel position in blocks are determined by using the statistical distribution of the coefficients depending on the statistical values, and then the coefficients are corrected by respectively adding the coefficient correction values to corresponding coefficients of respective pixel positions. | 04-09-2009 |
20090097768 | METHOD AND APPARATUS FOR ENCODING IMAGE BY EXPONENTIAL GOLOMB BINARIZATION USING OPTIMAL THRESHOLD, AND METHOD AND APPARATUS FOR DECODING IMAGE BY EXPONENTIAL GOLOMB BINARIZATION USING OPTIMAL THRESHOLD - A method and apparatus for coding an image by using exponential Golomb binarization are provided. The method comprises: performing entropy coding on an input image by performing exponential Golomb binarization using a plurality of predetermined thresholds; measuring a bit rate of a bit stream which is generated by performing the entropy coding using each threshold; and determining an optimal threshold by comparing bit rates with regard to the thresholds. | 04-16-2009 |
20090110317 | METHOD AND APPARATUS FOR COMPRESSING IMAGE SIGNAL - A method of compressing image signals, to provide more efficient compression than a discrete cosine transform (DCT) while having the least amount of overhead information is provided. A partial exchange between a row and a column of a transform matrix is performed by applying several values to a parameter, which shows an extent of partial exchange between rows and columns of the transform matrix. When a value of the used angle parameter is stored or transmitted, an overhead increases. Processes generating a random sequence of the angle parameter, generating a compression coefficient matrix regarding each angle parameter of the generated random sequence, and calculating a compression rate are repeated to obtain an angle parameter with the highest compression rate. The angle parameter having the highest compression rate is not stored or transmitted, but a number in the random sequence of the corresponding angle parameter is obtained, and stored or transmitted. | 04-30-2009 |
20110038555 | METHOD AND APPARATUS FOR ENCODING AND DECODING IMAGE BY USING ROTATIONAL TRANSFORM - A method and apparatus for encoding an image is provided. The method and apparatus include quantizing and entropy encoding a second frequency coefficient matrix that is generated by performing a partial exchange of one or more values between rows and between columns of a first frequency coefficient matrix. A method and apparatus for decoding image data that is encoded by using the method and apparatus for encoding the image is also provided. | 02-17-2011 |
20110097003 | METHOD AND APPARATUS FOR ENCODING AND DECODING IMAGE BY USING ROTATIONAL TRANSFORM - An image encoding method includes generating a first frequency coefficient matrix by transforming a predetermined block to a frequency domain; determining whether the first frequency coefficient matrix includes coefficients whose absolute values are greater than a predetermined value; generating a second frequency coefficient matrix by selectively partially switching at least one of rows and columns of the first frequency coefficient matrix according to an angle parameter based on a determination result; and selectively encoding the second frequency coefficient matrix based on the determination result. | 04-28-2011 |
20110103475 | IMAGE ENCODING METHOD AND DEVICE, AND DECODING METHOD AND DEVICE THEREFOR - A video encoding method and apparatus and a video decoding method and apparatus. In the video encoding method, a first predicted coding unit of a current coding unit that is to be encoded is produced, a second predicted coding unit is produced by changing a value of each pixel of the first predicted coding unit by using each pixel of the first predicted coding unit and at least one neighboring pixel of each pixel, and the difference between the current coding unit and the second predicted coding unit is encoded, thereby improving video prediction efficiency. | 05-05-2011 |
20110135000 | METHOD AND APPARATUS FOR ENCODING VIDEO, AND METHOD AND APPARATUS FOR DECODING VIDEO - Disclosed are a video encoding method and apparatus and a video decoding method and apparatus. The method of encoding video includes: producing a first predicted coding unit of a current coding unit, which is to be encoded; determining whether the current coding unit comprises a portion located outside a boundary of a current picture; and producing a second predicted coding unit is produced by changing a value of pixels of the first predicted coding unit by using the pixels of the first predicted coding unit and neighboring pixels of the pixels when the current coding unit does not include a portion located outside a boundary of the current picture. Accordingly, a residual block that is the difference between the current encoding unit and the second predicted encoding unit, can be encoded, thereby improving video prediction efficiency. | 06-09-2011 |
20110135212 | METHOD AND APPARATUS FOR ENCODING AND DECODING IMAGE BY USING ROTATIONAL TRANSFORM - Disclosed are a method and apparatus for encoding and decoding an image. The image encoding method includes: generating a first frequency coefficient matrix by performing spatial transform (e.g. discrete cosine transform (DCT) on a current block; determining an angle parameter based on whether the current block is intra or inter predicted; generating a second frequency coefficient matrix by performing a partial switch between at least one of rows and columns of the first frequency coefficient matrix based on the determined angle parameter; and encoding the second frequency coefficient matrix and information about the angle parameter. | 06-09-2011 |
20110243220 | METHOD AND APPARATUS FOR ENCODING AND DECODING IMAGE AND METHOD AND APPARATUS FOR DECODING IMAGE USING ADAPTIVE COEFFICIENT SCAN ORDER - Provided are a method and apparatus for encoding an image and a method and apparatus for decoding an image using an adaptive coefficient scan order. The method for encoding the image includes: projecting coefficients of a current block to a reference axis, from among a horizontal axis and a vertical axis, along a first straight line perpendicular to a second straight line with a predetermined angle α from the reference axis; scanning the coefficients of the current block in an arrangement order of the projected coefficients projected to the reference axis; and entropy-encoding information about the predetermined angle α and the scanned coefficients. | 10-06-2011 |
20110243436 | METHODS AND APPARATUSES FOR ENCODING AND DECODING IMAGE BASED ON SEGMENTS - Encoding and decoding an image may be performed by setting a plurality of segments of a second color component block based on pixel values of a first color component block. The plurality of segments may be predicted by using different context pixels, and the second color component block may be encoded and decoded based on the predicted plurality of segments. | 10-06-2011 |
20120008690 | METHODS AND APPARATUSES FOR ENCODING AND DECODING MOTION VECTOR - Encoding and decoding a motion vector using a motion vector of a current block of a current picture, which indicates a region corresponding to the current block in a first reference picture and one of generating a motion vector predictor from a motion vector of the adjacent block having a motion vector referring to the first reference picture among adjacent blocks encoded before the current block and a motion vector of an adjacent block referring to a second reference picture other than the first reference picture. | 01-12-2012 |
20120147957 | IMAGE ENCODING METHOD AND DEVICE, AND DECODING METHOD AND DEVICE THEREFOR - A video encoding method and apparatus and a video decoding method and apparatus. In the video encoding method, a first predicted coding unit of a current coding unit that is to be encoded is produced, a second predicted coding unit is produced by changing a value of each pixel of the first predicted coding unit by using each pixel of the first predicted coding unit and at least one neighboring pixel of each pixel, and the difference between the current coding unit and the second predicted coding unit is encoded, thereby improving video prediction efficiency. | 06-14-2012 |
20130077682 | VIDEO ENCODING METHOD AND VIDEO ENCODING APPARATUS AND VIDEO DECODING METHOD AND VIDEO DECODING APPARATUS, WHICH PERFORM DEBLOCKING FILTERING BASED ON TREE-STRUCTURE ENCODING UNITS - A method of encoding a video is provided, the method includes: determining a filtering boundary on which deblocking filtering is to be performed based on at least one data unit from among a plurality of coding units that are hierarchically configured according to depths indicating a number of times at least one maximum coding unit is spatially spilt, and a plurality of prediction units and a plurality of transformation units respectively for prediction and transformation of the plurality of coding units, determining filtering strength at the filtering boundary based on a prediction mode of a coding unit to which pixels adjacent to the filtering belong from among the plurality of coding units, and transformation coefficient values of the pixels adjacent to the filtering boundary, and performing deblocking filtering on the filtering boundary based on the determined filtering strength. | 03-28-2013 |
20130077686 | IMAGE ENCODING METHOD AND DEVICE, AND DECODING METHOD AND DEVICE THEREFOR - A video encoding method and apparatus and a video decoding method and apparatus. In the video encoding method, a first predicted coding unit of a current coding unit that is to be encoded is produced, a second predicted coding unit is produced by changing a value of each pixel of the first predicted coding unit by using each pixel of the first predicted coding unit and at least one neighboring pixel of each pixel, and the difference between the current coding unit and the second predicted coding unit is encoded, thereby improving video prediction efficiency. | 03-28-2013 |
20130083849 | IMAGE ENCODING METHOD AND DEVICE, AND DECODING METHOD AND DEVICE THEREFOR - A video encoding method and apparatus and a video decoding method and apparatus. In the video encoding method, a first predicted coding unit of a current coding unit that is to be encoded is produced, a second predicted coding unit is produced by changing a value of each pixel of the first predicted coding unit by using each pixel of the first predicted coding unit and at least one neighboring pixel of each pixel, and the difference between the current coding unit and the second predicted coding unit is encoded, thereby improving video prediction efficiency. | 04-04-2013 |
20130083850 | IMAGE ENCODING METHOD AND DEVICE, AND DECODING METHOD AND DEVICE THEREFOR - A video encoding method and apparatus and a video decoding method and apparatus. In the video encoding method, a first predicted coding unit of a current coding unit that is to be encoded is produced, a second predicted coding unit is produced by changing a value of each pixel of the first predicted coding unit by using each pixel of the first predicted coding unit and at least one neighboring pixel of each pixel, and the difference between the current coding unit and the second predicted coding unit is encoded, thereby improving video prediction efficiency. | 04-04-2013 |
20130177081 | METHOD AND APPARATUS FOR ENCODING AND DECODING VIDEO USING EXPANDED BLOCK FILTERING - Methods and apparatuses for encoding and decoding a video are provided. The method of encoding a video includes generating an extended corresponding block by extending a corresponding block of a reference picture; generating a filtered extended corresponding block by using a predetermined first filter; performing interpolation in sub-pixel units by using a predetermined second filter; and performing motion prediction and compensation by using the reference picture that is interpolated in the sub-pixel units. The method of decoding a video includes extracting information of a current block; generating an extended corresponding block by extending a corresponding block of a reference picture; generating a filtered extended corresponding block by applying a predetermined first filter to the extended corresponding block; performing interpolation in sub-pixel units by applying a predetermined second filter to the filtered extended corresponding block; and performing motion compensation by using the reference picture that is interpolated in the sub-pixel units. | 07-11-2013 |
20130182761 | IMAGE INTRA PREDICTION METHOD AND APPARATUS - An apparatus and method for intra-predicting an image are provided. The method includes: obtaining, based on restored neighboring pixels of a chrominance block and restored neighboring pixels of a luminance pixel corresponding to the chrominance block, parameters representing a correlation between the chrominance block that is to be intra-predicted and a luminance block; and predicting, using the parameters, the chrominance block from the luminance block, wherein the obtaining the parameters includes performing a predetermined operation on the restored neighboring pixels of the chrominance block and the restored neighboring pixels of the luminance block, and wherein the predetermined operation comprises an adaptive scaling process of changing bit depths of the parameters to reduce a size of a look-up table and prevent an occurrence of overflow. | 07-18-2013 |
20130182762 | ADAPTIVE FILTERING METHOD AND APPARATUS - A filtering method and apparatus for adaptively performing deblocking filtering are provided. The method includes: obtaining a parameter indicating how close pixel values of pixels adjacent to a block boundary are with respect to a predetermined line; determining a filtering strength at the block boundary based on the parameter; and performing filtering based on the filtering strength. | 07-18-2013 |
20130195177 | METHOD AND DEVICE FOR THE TRANSFORMATION AND METHOD AND DEVICE FOR THE REVERSE TRANSFORMATION OF IMAGES - An image transforming method, an image transforming apparatus, an image inverse-transforming method, and an image inverse-transforming apparatus are provided. The image transforming method includes the operations of selecting a predetermined frequency area for performing a frequency transformation with respect to an M×N (where M and N are positive integers) input block, acquiring a truncated transform matrix by selecting elements to be used for a generation of transformation coefficients which correspond to the selected frequency area from among elements of an M×N transform matrix, and generating the transformation coefficients which correspond to the selected frequency area by performing the frequency transformation by applying the truncated transform matrix to the M×N input block. | 08-01-2013 |
20130272401 | METHOD AND DEVICE FOR ENCODING INTRA PREDICTION MODE FOR IMAGE PREDICTION UNIT, AND METHOD AND DEVICE FOR DECODING INTRA PREDICTION MODE FOR IMAGE PREDICTION UNIT - Methods and apparatuses for encoding and decoding an intra prediction mode of a prediction unit of a chrominance component based on an intra prediction mode of a prediction unit of a luminance component are provided. When an intra prediction mode of a prediction unit of a luminance component is the same as an intra prediction mode in an intra prediction mode candidate group of a prediction unit of a chrominance component, reconstructing the intra prediction mode candidate group of the prediction unit of the chrominance component by excluding or replacing an intra prediction mode of the prediction unit of the chrominance component which is same as an intra prediction mode of the prediction unit of the luminance component from the intra prediction mode candidate group, and encoding the intra prediction mode of the prediction unit of the chrominance component by using the reconstructed intra prediction mode candidate group. | 10-17-2013 |
20130279574 | METHODS AND APPARATUSES FOR ENCODING AND DECODING IMAGE BASED ON SEGMENTS - Encoding and decoding an image may be performed by setting a plurality of segments of a second color component block based on pixel values of a first color component block. The plurality of segments may be predicted by using different context pixels, and the second color component block may be encoded and decoded based on the predicted plurality of segments. | 10-24-2013 |
20130279580 | METHOD AND APPARATUS FOR ENCODING AND DECODING IMAGE BY USING ROTATIONAL TRANSFORM - An image encoding method includes generating a first frequency coefficient matrix by transforming a predetermined block to a frequency domain; determining whether the first frequency coefficient matrix includes coefficients whose absolute values are greater than a predetermined value; generating a second frequency coefficient matrix by selectively partially switching at least one of rows and columns of the first frequency coefficient matrix according to an angle parameter based on a determination result; and selectively encoding the second frequency coefficient matrix based on the determination result. | 10-24-2013 |
20130301705 | VIDEO-ENCODING METHOD AND APPARATUS FOR SAME AND VIDEO-DECODING METHOD AND APPARATUS FOR SAME USING A SELECTIVE SCAN MODE - Provided are encoding and decoding methods and apparatuses for a video by selectively determining and using a scan mode. The video encoding method includes: generating transformation coefficients by performing transformation based on a transformation unit to encode an image; determining a scan mode, from among a plurality of scan modes, indicating a scanning direction of the generated transformation coefficients, based on characteristics of the transformation coefficients; and determining and outputting an encoding order of the generated transformation coefficients based on the scanning direction of the determined scan mode. | 11-14-2013 |
20140105287 | IMAGE ENCODING METHOD AND DEVICE, AND DECODING METHOD AND DEVICE THEREFOR - A video encoding method and apparatus and a video decoding method and apparatus. In the video encoding method, a first predicted coding unit of a current coding unit that is to be encoded is produced, a second predicted coding unit is produced by changing a value of each pixel of the first predicted coding unit by using each pixel of the first predicted coding unit and at least one neighboring pixel of each pixel, and the difference between the current coding unit and the second predicted coding unit is encoded, thereby improving video prediction efficiency. | 04-17-2014 |
20140105296 | IMAGE ENCODING METHOD AND DEVICE, AND DECODING METHOD AND DEVICE THEREFOR - A video encoding method and apparatus and a video decoding method and apparatus. In the video encoding method, a first predicted coding unit of a current coding unit that is to be encoded is produced, a second predicted coding unit is produced by changing a value of each pixel of the first predicted coding unit by using each pixel of the first predicted coding unit and at least one neighboring pixel of each pixel, and the difference between the current coding unit and the second predicted coding unit is encoded, thereby improving video prediction efficiency. | 04-17-2014 |
20140133558 | METHOD AND APPARATUS FOR CODING VIDEO AND METHOD AND APPARATUS FOR DECODING VIDEO, USING INTRA PREDICTION - A video decoding method involving intra prediction includes: parsing a most probable mode (MPM) flag of a block while parsing symbols of the block of an encoded video from a received bitstream; determining whether a predetermined number of a plurality of candidate intra prediction modes are used to predict an intra prediction mode of the block based on the MPM flag; when it is determined that the plurality of candidate intra prediction modes are used based on the MPM flag, determining the plurality of candidate intra prediction modes based on intra prediction modes of a left block and an upper block that are adjacent to the block while restoring the intra prediction mode of the block by using the parsed symbols. | 05-15-2014 |
20140140401 | PREDICTION METHOD AND APPARATUS FOR CHROMA COMPONENT OF IMAGE USING LUMA COMPONENT OF IMAGE - Provided are a method and an apparatus for predicting a chrominance signal from a luminance signal by using a correlation between the luminance and chrominance signals. A method of predicting a chrominance component image generates a down-sampled luminance signal matching a chrominance signal by independently applying various down-sampling methods according to a location of a luminance signal, and predicts a chrominance signal from the down-sampled luminance signal, while considering a size of a luminance prediction unit and a size of a chrominance prediction unit corresponding to each other according to a color format. | 05-22-2014 |
20150016525 | IMAGE ENCODING METHOD AND DEVICE, AND DECODING METHOD AND DEVICE THEREFOR - A video encoding method and apparatus and a video decoding method and apparatus. In the video encoding method, a first predicted coding unit of a current coding unit that is to be encoded is produced, a second predicted coding unit is produced by changing a value of each pixel of the first predicted coding unit by using each pixel of the first predicted coding unit and at least one neighboring pixel of each pixel, and the difference between the current coding unit and the second predicted coding unit is encoded, thereby improving video prediction efficiency. | 01-15-2015 |