Shader implementation of the NEDI algorithm

[Shiandow]

Originally Posted by foxyshadis

I find the "broken" version was slightly more pleasant thanks to the extra sharpness. The aliasing had already been reduced enough that further reduction in the fixed didn't quite balance the sharpness loss, but either way, it's a very subtle difference. It might be a worthwhile trade if it speeds things up. Would be interesting to make the sharpness/aliasing tunable, if that's possible.

Using the "broken" method is only faster because I have very little control over the output size, I think the "correct" method could be made almost as fast.

Ironically the difference in sharpness was caused because I was trying to make the sharpness easier to configure. You can tune it by using the "softness" parameter, but more sharpness does tend to lead to more ringing. It's somewhat harder to tune aliasing, as far as I can tell you can avoid it by either making the edges softer (by raising the "baseline" parameter), or you need to lower the "strength" parameter, which means that you may need more iterations to get a good result.