Method of reducing a blocking artifact when coding moving picture
View Patent ↗A method of coding a moving picture is provided that reduces blocking artifacts. The method can include defining a plurality of defining pixels S 0 , S 1 , and S 2 , which are centered around a block boundary. If a default mode is selected then frequency information of the surroundings of the block boundary is obtained. A magnitude of a discontinuous component in a frequency domain belonging to the block boundary is adjusted based on a magnitude of a corresponding discontinuous component selected from a pixel contained entirely within a block adjacent the block boundary. The frequency domain adjustment is then applied to a spatial domain. Or, a DC offset mode can be selected to reduce blocking artifacts in smooth regions where there is little motion.
1. A computer-implemented method comprising:
obtaining, from image data and by a coding system, blocks that each include multiple pixels, a first boundary pixel of a first block being separated from a second boundary pixel of a neighboring second block by a block boundary;
selecting a correction mode of the coding system from amongst at least two correction modes based on information from the first boundary pixel and information from the second boundary pixel; and
modifying, by the coding system, the image data corresponding to the first boundary pixel using the information from the first boundary pixel and the information from the second boundary pixel, using the selected correction mode,
wherein, when a first of the at least two correction modes is selected, modifying the image data corresponding to the first boundary pixel comprises altering the image data corresponding to the first boundary pixel within the first block without altering the image data corresponding to a third pixel adjacent to the first boundary pixel and separated from the second boundary pixel by no pixels other than the first boundary pixel, and
wherein, when a second of the at least two correction modes is selected, modifying the image data corresponding to the first boundary pixel comprises altering image data corresponding to three successive pixels, including the first boundary pixel, within the first block.
2. A device comprising a blocking artifact reducer configured to:
obtain, from image data and by a coding system, blocks that each include multiple pixels, a first boundary pixel of a first block being separated from a second boundary pixel of a neighboring second block by a block boundary,
select a correction mode of the coding system from amongst at least two correction modes based on information from the first boundary pixel and information from the second boundary pixel, and
modify, by the coding system, the image data corresponding to the first boundary pixel using the information from the first boundary pixel and the information from the second boundary pixel, using the selected correction mode,
wherein, when a first of the at least two correction modes is selected, modifying the image data corresponding to the first boundary pixel comprises altering the image data corresponding to the first boundary pixel within the first block without altering the image data corresponding to a third pixel adjacent to the first boundary pixel and separated from the second boundary pixel by no pixels other than the first boundary pixel, and
wherein, when a second of the at least two correction modes is selected, modifying the image data corresponding to the first boundary pixel comprises altering the image data corresponding to three successive pixels, including the first boundary pixel, within the first block.
3. The computer-implemented method of claim 1 , wherein modifying the image data comprises processing the image data by a processor of the coding system.
4. The computer-implemented method of claim 1 , wherein modifying the image data comprises modifying the image data for output on a display.
5. The device of claim 2 , wherein the blocking artifact reducer is configured to modify the image data by processing the image data by a processor of the coding system.
6. The device of claim 2 , wherein the blocking artifact reducer is configured to modify the image data for output on a display.