4 possible intensities off, level 1, level2, full (or level3) 2 1 3 1 1 3 1 2 1 3 x x x x x x x x x x x x x x x The
slope is 2/4 or m=½.
Therefore yk+1 = yk + m. Since we are anti-aliasing, we need to
supersample. Instead of running the
algorithm from x=0 to 4 (5 pixels of data), we need to run the algorithm
from x=0 to 14 (15 pixels of
data. 3 times as many times) 0
0 1
½ 2
1 3
1-1/2 4
2 5
2-1/2 6
3 7
3-1/2 8
4 9
4-1/2 10 5 11 5-1/2 12 6 13 6-1/2 14 7 7 1 3 1 7 3 5
|
1 |
2 |
1 |
|
2 |
4 |
2 |
|
1 |
2 |
1 |
Use the same data and supersampling as in 1a. But this time use the weighted 3x3 matrix. There are several pixel intensities: ranging from 0, and then 1 to 8.