Gimp quality problem when I curve an image

[SO•Audiojack]

That's what the program does. The algorithm for bending an image works like that, it must multiply pixels at some places to make it look stretched and subtract some in the places where they don't fit anymore. This will cause some aliasing in the final result.

My advice is to try and sliiightly blur the aliased parts (not around them) to make it kind of a "pseudo-antialiasing" OR just re-do the lines by hand, which may also help. I use both methods in my skins, but usually I just try to avoid unnecessary curving and cut and stretch little pieces instead and then put them back together for a final result.