Panasonic Corporation

Godo Kaisha IP Bridge 1

Matsushita Electric Industrial Co., Ltd.

Panasonic Intellectual Property Corporation of America

Zhong Xue

Shinya Kadono Kadono

Sheng Mei Shen

Teck Wee Foo

Chak Joo Lee

A coding distortion removing method is provided for removing coding distortion in two adjacent blocks located on both sides of a block boundary between the two adjacent blocks in a reconstructed image. The method includes deriving a difference of pixel values between a pixel in a first block of the reconstructed image and a pixel in a second block of the reconstructed image adjacent to the first block, deriving an average value of the first quantization parameter and the second quantization parameter, and setting a threshold value to the average value of the first quantization parameter and the second quantization parameter. The method also includes comparing the difference of pixel values with the threshold value, and removing a coding distortion in an area disposed on both sides of the block boundary between the first block and the second block, by applying a filter for coding distortion removal.

Image coding and decoding method for removal of coding distortion by comparing pixel difference values with threshold

A picture coding and decoding method includes a picture coding method for coding an input picture and a picture decoding method for decoding coded picture data. The picture coding method includes dividing the input picture into blocks, coding the input picture on a block basis, decoding the coded data of each block on a block basis, removing coding distortion in an area disposed on both sides of a block boundary, each block being adaptively decoded either as a field structure block or a frame structure block, and storing the reconstructed picture as a reference picture. The picture decoding method includes decoding the coded picture data to obtain a reconstructed picture, removing coding distortion in an area disposed on both sides of a block boundary, each block being adaptively decoded either as a field structure block or a frame structure block, and storing the reconstructed picture as a reference picture.

Picture decoding method for decoding coded picture data and performing distortion removal by comparing pixel difference values with threshold

An image decoding apparatus is provided that decodes a coded image, the coded image being generated by coding an image segmented into a plurality of blocks on a block basis. The image decoding apparatus includes a quantization parameter obtaining unit that obtains a quantization parameter for each block of the plurality of blocks, a decoding unit that decodes the coded image to obtain a reconstructed image, and a pixel difference value obtaining unit that obtains a pixel difference value. The image decoding apparatus also includes a comparing unit that compares the pixel difference value with a threshold value, and a removing unit that removes a coding distortion in an area disposed on both sides of a block boundary between the first block and the second block, by applying a filter for coding distortion removal.

Image decoding apparatus for removal of coding distortion by comparing pixel difference value with threshold

A picture coding method provides coding an input picture. The method includes dividing the input picture into a plurality of blocks, coding the input picture on a block basis to obtain coded data of each block, and decoding the coded data of each block on a block basis to obtain a reconstructed picture having a plurality of blocks. The method also includes removing coding distortion in an area disposed on both sides of a block boundary between a first block and an adjacent second block in the reconstructed picture having the plurality of blocks. Each block is adaptively decoded either as a field structure block, including only even field pixels or only odd field pixels, or a frame structure block, including odd field pixels and even field pixels. The method further includes storing the reconstructed picture, for which coding distortion is removed, as a reference picture.

A picture decoding method is provided for decoding coded picture data. The method includes decoding the coded picture data to obtain a reconstructed picture. The method also includes removing coding distortion in an area disposed on both sides of a block boundary between a first block and an adjacent second block in the reconstructed picture having a plurality of blocks, each block being adaptively decoded either as a field structure block, comprising only even field pixels or comprising only odd field pixels, or a frame structure block, comprising odd field pixels and even field pixels. The method further includes storing the reconstructed picture, for which coding distortion is removed, as a reference picture.

A coding distortion removal method is provided for removing coding distortion in an area disposed on both sides of a block boundary between a first block and an adjacent second block in a picture having a plurality of blocks, each block being adaptively coded either as a field structure block, comprising only even field pixels or comprising only odd field pixels, or a frame structure block, comprising odd field pixels and even field pixels. The method includes detecting whether the block boundary between the first block and the adjacent second block is a block boundary between a field structure block and a frame structure block, and performing a coding distortion removal process on the first block and the adjacent second block. The coding distortion removal process includes determining whether coding distortion removal is needed, determining the number of pixels to be processed, and removing coding distortion.

A picture decoding method is provided for decoding coded picture data. The decoding method includes decoding coded picture data to obtain a first transform block and an adjacent second transform block in a reconstructed picture having a plurality of blocks forming a moving picture image. The decoding method also includes determining whether the first transform block is located inside a motion-compensation block in which the second transform block is located. The decoding method further includes performing a filtering on pixels in a block boundary between the first and second transform blocks when the first transform block is located outside the motion-compensation block in which the second transform block is located, and performing no filtering on the pixels in the block boundary between the first and second transform blocks when the first transform block is located inside the motion-compensation block in which the second transform block is located.

An image coding and decoding system is provided that includes an image coding apparatus and an image decoding apparatus. The image coding apparatus includes a coder that codes an input image, a first decoder that decodes the coded image to obtain a first reconstructed image, a first pixel difference value obtainer, a first average deriver, a first threshold value setter, a first comparator, and a first remover that removes a coding distortion. The image decoding apparatus includes an obtainer that obtains the first quantization parameter of the first block and the second quantization parameter of the second block, a second decoder that decodes the coded image, a second pixel difference value obtainer, a second average deriver, a second comparator, and a second remover that removes a coding distortion in an area disposed on both sides of a block boundary between the first block and the second block.

Image coding and decoding system for removal of coding distortion by comparing pixel difference values with thresholds

An image encoding and decoding apparatus includes an image encoder for encoding an input image and an image decoder for decoding a variable length coded signal. The image encoder includes a coding unit, a first decoding unit, a first coding distortion removing unit, a first storage unit, and a variable length coding unit. The image decoder includes a variable length decoding unit, a second coding distortion removing unit, and a second storage unit. In the encoding and decoding apparatus, a block size of a motion compensation block is smaller than a block size of the macroblock, a block size of a motion compensation block is larger than a block size of a transform block, and a coded motion compensation error of each of two adjacent motion compensation blocks located inside the same macroblock is zero.

Selective coding distortion removal between two adjacent transform blocks based on their locations

A semiconductor for decoding coded image and audio data, which includes an audio processor that decodes coded audio data, and an image decoder that decodes image data. The image decoder removes coding distortion in pixels of two adjacent transform blocks which are motion-compensated, having a coded motion compensation error equal to zero, and are located inside a same macroblock. The image decoder includes a motion compensation block boundary detector that determines whether the motion compensation error of the two adjacent transform blocks located inside the macroblock is zero, and determines whether a boundary of two adjacent transform block is also a boundary of two adjacent motion-compensation blocks. The image decoder also includes a filter that removes coding distortion in pixels of the two adjacent transform blocks, and a selector that selects whether or not the filter removes the coding distortion based on the determination of the motion compensation block boundary detector.

Selective filtering based on the motion compensation error of two adjacent transform blocks

Mosaic-shaped block noise occurs when a compressed video signal is reproduced. This block noise is removed, but removing block noise from every block using a deblocking filter imposes a significant load on the deblocking filter. This load is therefore reduced by determining whether coding distortion removal (deblocking) is necessary, and applying a deblocking filter only when needed.

Coding distortion removal method by selectively filtering based on a pixel difference

A method for coding a picture segmented into a plurality of blocks. The method decodes the coded blocks to produce a reproduced image. A filter selection parameter determines a threshold value for each quantization parameter, so as to change between a mode to effect coding distortion removal by a filter and a mode not to effect the coding distortion removal. The determined filter selection parameter is coded. A difference between pixel values of pixels in the adjacent blocks on both sides of a boundary between adjacent blocks forming the reproduced image is compared with the determined threshold value determined by the filter selection parameter, and the coding distortion is removed using the filter when the difference is smaller than the threshold value, and not removed when the difference is larger than the threshold value.

Video coding and decoding method for selective coding distortion removal using a filter

A coding distortion removal method for removing coding distortion in an image which was has been divided in to a plurality of macroblocks. The method operates under the following conditions such that: (i) a size of a pixel in a motion compensation block is smaller than a size of a pixel in said macroblock; (ii) a size of a pixel in a motion compensation block is larger than a size of a pixel in a coding unit; and (iii) a pixel difference between two adjacent motion compensation blocks located inside the macroblock is zero. The method disables the coding distortion removal at a boundary between blocks located inside each of the two adjacent motion compensation blocks, and enables the coding distortion removal at a boundary between the two adjacent motion compensation blocks.

Video coding distortion removal method and apparatus using a filter

An LSI device for decoding a coded image segmented and coded in a plurality of blocks. The LSI device includes a section which receives a filter selection parameter that determines a threshold value for each quantization parameter, for changing between conducting and non-conducting a coding distortion removal by the use of a filter. A decoder, decodes a coded block to obtain a reproduced image. A remover, removes a coding distortion from a region including both sides of a block boundary between adjacent decoded blocks that form the reproduced image, in accordance with a comparison of a difference value of the pixels in adjacent decoded blocks with the threshold value determined based on the filter selection parameter, such that the coding distortion removal is not conducted when the difference value is greater than the threshold value. The coding distortion removal is conducted by the use of the filter when the difference value is smaller than the threshold value.

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Zhong Xue