A real antialias routine

It is antialiasing. The first shot is aliased. The second shot is not.

This isn't a blur effect, it looks for lines, and interpolates edges pixels along the slope of the line.

If you have something like this:

00000000000000000005555
00000000000000055550000
00000000000555500000000
00000005555000000000000
00055550000000000000000
55500000000000000000000

It creates this:
00000000000000012345555
00000000000123455554321
00000001234555543210000
00012345555432100000000
23455554321000000000000
55543210000000000000000