Hi, de@xxxxxxxxxx (2005-03-01 at 2248.36 +0100): > > Supersampling is to avoid aliasing, which is not caused only by those > > discontinuities but high frequency data (IIRC abrupt change is like > > infinite frequency). You can have aliasing with a square wave > > (segments that do not match) but also with a sine wave (segments that > > match). > Right. But where in reality can this happen using a gradient blend? Yes, "radial rainbow hoop" gradient (linear 6 pixel to right sawtooth) without supersampling it paints mostly red and with it shows the muddy colour mix you would get if you render big and scale down: http://www.infernal-iceberg.com/gimp/tmp/gradient-supersampling-03-crop.png > I just played around with the blend tool on a 100x100px image and > looked very closely for any artifacts with and without > supersampling. The result was that I couldn't produce any visible > aliasing effects no matter how hard I try other than by using > a sawtooth repeat pattern. That seems like a *huge* price to pay > for something that can be easily done by accident. The price is an user decision, and default is supersampling off, right? If it is removed, the price you impose is not so low: render into a big version then scale down and copy. Which means fucked up workflow and no adaptive algorithm, so even slower computing and user working a lot more. > What does the commercial counterpart offer here? Dunno... but should GIMP care and target a worse solution cos someone else is behind? What I know is those other commercial apps implement better things in other fronts, like dithering in some operations to avoid histrogram holes or 16/32 bit buffers to edit high dynamic range images or whatever, and we are talking about giving crappy results always cos the computer takes some seconds more when asked to be more precise. GSR
