Hello...
@Eric P: Upscaling image: 500px -> 5000px (bicubic): Gimp 2.6.1: 35,21 sec Gimp 2.4.7: 6,9 sec Downscaling layer: Image is 5000x5000 px, 2 white layers Scaling top layer to 2500x2500px (bicubic): Gimp 2.6.1: 7,85 sec Gimp 2.4.7: 4,78 sec @Sven Neumann: Thanks for your hint on the related bugthread. I will read it carefully to better understand the whole thing. Claus Eric P wrote: > > Claus Berghammer wrote: >> Hello Gimp Users and Developers, >> >> This is a follow up of Bug 557950 (which in fact isn't a bug, according >> to >> Sven Neumann ;-) >> http://bugzilla.gnome.org/show_bug.cgi?id=557950 >> >> As described in the “Bug”, scaling in Gimp 2.6 series is far slower, than >> it >> was in 2.4. Sven Neumann commented: >> >> “We have completely changed the scaling implementation. The new algorithm >> is >> slower for some cases, but that is not a bug.” >> >> Since there is no explanation WHY the algorithm was rewritten, I guess 2 >> possible reasons: >> >> 1.)The old code did something wrong in some cases >> 2.)The new code was necessary due to GEGL integration >> >> For the first point, I compared scaling results from 2.4 and 2.6, and >> they >> are (ignoring some harmless alignment issues) 100% identical (using >> difference blend mode). I also cannot remember, that in the past years, >> the >> scaling routine in Gimp produced noticeable wrong results. (Beside the >> lanczos interpolation, that didn't work right, when it was introduced) >> >> So my question is, isn't it possible, to have both algorithms in Gimp, >> and >> let the user decide which one he wants to use? (Option in Scale Dialog) >> >> If it was due to point 2, the GEGL integration, than can we expect a >> faster >> version of the new scaling routine? Or will it be automatically faster, >> when >> GEGL is integrated more/better? >> >> The current situation draws some users (not myself) to not use Gimp 2.6, >> and >> stick with 2.4 instead, because the difference in speed is so >> dramatically. >> >> Sincerely, Claus Berghammer >> > > I'd be curious to see some benchmarks comparing 2.4 and 2.6 in this regard > so that we know just how dramatically > different the speed is. > > Eric P. > _______________________________________________ > Gimp-user mailing list > Gimp-user@lists.XCF.Berkeley.EDU > https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user > > -- View this message in context: http://www.nabble.com/Scaling-in-Gimp-2.6-is-much-slower-than-in-Gimp-2.4-tp20185528p20202924.html Sent from the Gimp User mailing list archive at Nabble.com. _______________________________________________ Gimp-user mailing list Gimp-user@lists.XCF.Berkeley.EDU https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-user
