Quote Originally Posted by SilverWarior View Post
Now I don't want to discourage you but doing simple transformation from slanted rectangle to regular rectangle will never return you nice results. Why? Because in order to render a smooth diagonal line you actually go and perform anti-aliasing in order to smooth that rough edges. So when you do transformation from slanted rectangle to regular rectangle those anti-aliased pixels are causing your lines to appear wavy instead of straight. In order to avoid this you will actually have to undo anti-aliasing of your picture which I'm not sure if it is even possible.
You see doing transformation from regular rectangle to slanted rectangle is much easier because you first do direct transformation of each individual pixel and then apply anti-aliasing filter to the result in order to smooth out the rough edges.

Any way what I recommend you is that you first try to vectorize your image so that you extract most of the shapes from your image. Then do the transformation of that vectorized image so shapes are now nicely transformed. And finally try transferring of individual pixels to those transformed shapes.
Surely this approach will cause you to lose some of teh finest detail but result should be still much better than the result with your current approach.
Never thought of that
Do you think that a high quality scale algorithm (such as xBR, xBRZ ect) could help before making the transformation ?