Re: [Gimp-developer] Lanczos algorithm funnyness?
Steve Stavropoulos wrote: On 11/19/05, Dag Rune Sneeggen wrote: John Leach wrote: Looking at the original, I can see what it's accentuating but it looks bad. Other photos look great, much sharper compared with the cubic algorithm. This seems rather too sharp, in the wrong place. But still, its clearly a faulty algorithm... Quite serious as well(?) Am I the only one who sees the lanczos produced image, as a near perfect resize of the original? Yes, actually looks like a very interesting resize result to me too. Guess it's pretty subjective. --adam ___ Gimp-developer mailing list Gimp-developer@lists.xcf.berkeley.edu http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-developer
Re: [Gimp-developer] Lanczos algorithm funnyness?
Hi, John Leach [EMAIL PROTECTED] writes: I just downloaded the 2.3.5 snapshot and had a go with the Lanczos resizing algorithm. It seems to bring out some strange artifacts in one photo (actually, the first I randomly tried). The Lanczos implementation in CVS is buggy and unless someone shows up who fixes it, it will most likely end up being removed before the 2.4 release. Sven ___ Gimp-developer mailing list Gimp-developer@lists.xcf.berkeley.edu http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-developer
[Gimp-developer] Lanczos algorithm funnyness?
Hi all, I just downloaded the 2.3.5 snapshot and had a go with the Lanczos resizing algorithm. It seems to bring out some strange artifacts in one photo (actually, the first I randomly tried). Looking at the original, I can see what it's accentuating but it looks bad. Other photos look great, much sharper compared with the cubic algorithm. This seems rather too sharp, in the wrong place. Is this normal? cubic, lanczos and original examples at: http://johnleach.co.uk/downloads/gimp/ John. P.S: Compiled on ubuntu breezy, on i386. ___ Gimp-developer mailing list Gimp-developer@lists.xcf.berkeley.edu http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-developer
Re: [Gimp-developer] Lanczos algorithm funnyness?
John Leach wrote: Hi all, I just downloaded the 2.3.5 snapshot and had a go with the Lanczos resizing algorithm. It seems to bring out some strange artifacts in one photo (actually, the first I randomly tried). Looking at the original, I can see what it's accentuating but it looks bad. Other photos look great, much sharper compared with the cubic algorithm. This seems rather too sharp, in the wrong place. Is this normal? cubic, lanczos and original examples at: http://johnleach.co.uk/downloads/gimp/ It is odd. But it should be noted that an image like this... Brushed steel, with a very, *very* short field of depth is quite rare ;) Is it the camera's aperature/focus that happens to be just below the power button, or is it blurred the image? But still, its clearly a faulty algorithm... Quite serious as well(?) John. P.S: Compiled on ubuntu breezy, on i386. ___ Gimp-developer mailing list Gimp-developer@lists.xcf.berkeley.edu http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-developer -- Cheers, Dag Rune Sneeggen([EMAIL PROTECTED]) --- Tapper Package Manager (http://sourceforge.net/projects/tapper-pm/) -- Do you want to miss the fun? :o ___ Gimp-developer mailing list Gimp-developer@lists.xcf.berkeley.edu http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-developer
Re: [Gimp-developer] Lanczos algorithm funnyness?
Hi, Dag Rune Sneeggen wrote: But still, its clearly a faulty algorithm... Quite serious as well(?) This might be a silly question, but why is GIMP using interpolation at all when reducing images? Shouldn't it be doing weighted averaging of all the source pixels that contribute to a destination pixel? All the best, -- Alastair M. Robinson ___ Gimp-developer mailing list Gimp-developer@lists.xcf.berkeley.edu http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-developer
Re: [Gimp-developer] Lanczos algorithm funnyness?
On 11/19/05, Dag Rune Sneeggen wrote: John Leach wrote: Looking at the original, I can see what it's accentuating but it looks bad. Other photos look great, much sharper compared with the cubic algorithm. This seems rather too sharp, in the wrong place. But still, its clearly a faulty algorithm... Quite serious as well(?) Am I the only one who sees the lanczos produced image, as a near perfect resize of the original? On the other hand, cubic interpolation has clearly lost the details that you seem to not want but clearly are on the original. ___ Gimp-developer mailing list Gimp-developer@lists.xcf.berkeley.edu http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-developer
Re: [Gimp-developer] Lanczos algorithm funnyness?
On Sat, Nov 19, 2005 at 02:18:03AM +, Alastair M. Robinson [EMAIL PROTECTED] wrote: But still, its clearly a faulty algorithm... Quite serious as well(?) This might be a silly question, but why is GIMP using interpolation at all when reducing images? Shouldn't it be doing weighted averaging of all the source pixels that contribute to a destination pixel? Weighted averaging is a way of interpolation. Regarding the original image, though: at least imagemagick produces a sharp image without any artifacts when using lanczos, so maybe there is a problem. -- The choice of a -==- _GNU_ ==-- _ generation Marc Lehmann ---==---(_)__ __ __ [EMAIL PROTECTED] --==---/ / _ \/ // /\ \/ / http://schmorp.de/ -=/_/_//_/\_,_/ /_/\_\ XX11-RIPE ___ Gimp-developer mailing list Gimp-developer@lists.xcf.berkeley.edu http://lists.xcf.berkeley.edu/mailman/listinfo/gimp-developer
