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 method of reducing blocking artifacts when coding a picture including a collection of points, the method comprising:
dividing the picture into blocks that each include multiple points, wherein points of a first block are separated from points of a neighboring second block by a block boundary;
selecting a correction mode from amongst at least two correction modes, the selected correction mode using information from the firs block and information from the second block;
determining a quantity N of points to modify based on the selected correction mode; and
modifying N points from the first block using information from at least one point of the second block.
2. The method of claim 1 , wherein the modified N points include a first point, and wherein the at least one point of the second block includes a second point.
3. The method of claim 2 , wherein the first point is modified in a first way when a first correction mode is selected, and
wherein the first point is modified in a second way when a second correction mode is selected.
4. The method of claim 2 , further comprising modifying the second point using information from the first point.
5. The method of claim 4 , wherein the first point is disposed adjacent to the block boundary with no points separating the first point from the second point.
6. The method of claim 5 , further comprising generating a modification value using information from the second point, wherein modifying the first point further comprises subtracting the modification value from a value associated with the first point.
7. The method of claim 6 , wherein modifying the second point comprises adding the modification value to a value associated with the second point.
8. The method of claim 7 , wherein generating the modification value further comprises using information from the first point.
9. The method of claim 8 , wherein generating the modification value comprises determining a difference between the value associated with the first point and the value associated with the second point.
10. The method of claim 9 , wherein generating the modification value comprises using a clipping function that constrains the modification value to be no greater than half of the difference between the value associated with the first point and the value associated with the second point.
11. The method of claim 4 , further comprising generating a modification value using information from the seconds point, wherein modifying the first point comprises subtracting the modification value from a value associated with the first point.
12. The method of claim 11 , wherein modifying the second point comprises adding the modification value to a value associated with the second point.
13. The method of claim 12 , wherein generating the modification value further comprises using a clipping function that constrains the modification value to be no greater than half of the difference between the value associated with the first point and the value associated with the second point.
14. The method of claim 2 , further comprising generating a modification value using information from the second point, wherein modifying the first point comprises subtracting the modification value from a value associated with the first point.
15. The method of claim 14 , wherein generating the modification value further comprises using a clipping function that constrains the modification value to be no greater than half of difference between the value associated with the first point and the value associated with the second point.