Re: [Gimp-developer] need help with bug #464466 (downscaling quality)

2008-08-07 Thread Sven Neumann
Hi, On Mon, 2008-08-04 at 22:09 +0200, Sven Neumann wrote: Since the test results are looking good, I think we should commit the changes then so that they get more testing. Does anyone disagree with this? Otherwise I will commit the changes later this week. The changes are in trunk for some

Re: [Gimp-developer] need help with bug #464466 (downscaling quality)

2008-08-04 Thread gg
On Fri, 01 Aug 2008 13:51:02 +0200, David Gowers [EMAIL PROTECTED] wrote: Pixel art ('block graphics'?) is a pathological case for most scaling algorithyms, and no algorithym old or new performed very well on upscaling image #8. David yes, this is a good test for scaling alorithms. I had

Re: [Gimp-developer] need help with bug #464466 (downscaling quality)

2008-08-04 Thread Sven Neumann
Hi, On Fri, 2008-08-01 at 17:22 -0400, Liam R E Quin wrote: So far it feels noticeably slower on mediumsized or large images (e.g. a 13899x8497-pixel 2400dpi grayscale scan, which Gimp reports as 230MBytes) but the results are outstandingly better. Since the test results are looking good, I

Re: [Gimp-developer] need help with bug #464466 (downscaling quality)

2008-08-01 Thread David Gowers
Hi solar, On Fri, Aug 1, 2008 at 6:58 AM, [EMAIL PROTECTED] wrote: On Wed, 30 Jul 2008 15:53:36 +0200, David Gowers [EMAIL PROTECTED] wrote: I've finished checking, and am just sending off the results and webpage to Sven now. David Thanks for all the hard work on this. A very interesting

Re: [Gimp-developer] need help with bug #464466 (downscaling quality)

2008-08-01 Thread Liam R E Quin
On Wed, 2008-07-30 at 23:54 +0200, Sven Neumann wrote: I've put your results online at http://svenfoo.org/scaletest/ I've tried the patch out a little. So far it feels noticeably slower on mediumsized or large images (e.g. a 13899x8497-pixel 2400dpi grayscale scan, which Gimp reports as

Re: [Gimp-developer] need help with bug #464466 (downscaling quality)

2008-07-31 Thread David Gowers
Hi, On Thu, Jul 31, 2008 at 3:39 PM, [EMAIL PROTECTED] wrote: I olso get the top+left pixel error but only when scaling using a script-fu. Any idea? No, sorry, all the scaling was done manually using GIMP's Image-Scale Image dialog, and that's how I got the problematic results. David.

Re: [Gimp-developer] need help with bug #464466 (downscaling quality)

2008-07-30 Thread David Gowers
The webpages are nearly finished, I'm checking them now. Some observations on the results of scaling: * The old code mistreated the left and top edges, resulting in a duplication of up to 1 pixel on the left and top edge (and corresponding omittal of a row of pixels on the right and bottom

Re: [Gimp-developer] need help with bug #464466 (downscaling quality)

2008-07-30 Thread David Gowers
Hi, On Wed, Jul 30, 2008 at 10:23 PM, David Gowers [EMAIL PROTECTED] wrote: The webpages are nearly finished, I'm checking them now. Some observations on the results of scaling: * The old code mistreated the left and top edges, resulting in a duplication of up to 1 pixel on the left and top

Re: [Gimp-developer] need help with bug #464466 (downscaling quality)

2008-07-30 Thread Sven Neumann
Hi, On Wed, 2008-07-30 at 23:23 +0930, David Gowers wrote: I've finished checking, and am just sending off the results and webpage to Sven now. Thanks a lot. I've put your results online at http://svenfoo.org/scaletest/ Sven ___ Gimp-developer

Re: [Gimp-developer] need help with bug #464466 (downscaling quality)

2008-07-29 Thread David Gowers
Hi, On Sat, Jul 26, 2008 at 7:08 PM, Geert Jordaens [EMAIL PROTECTED] wrote: David Gowers wrote: Hello. I've just completed the first half of the set (all specified results before the patch). Currently image files total 66mb, I'm guessing after adding the results after-patch this will come up

Re: [Gimp-developer] need help with bug #464466 (downscaling quality)

2008-07-26 Thread Geert Jordaens
David Gowers wrote: Hello. I've just completed the first half of the set (all specified results before the patch). Currently image files total 66mb, I'm guessing after adding the results after-patch this will come up to ~110mb. During this testing I found one obvious bug, it remains to be

Re: [Gimp-developer] need help with bug #464466 (downscaling quality)

2008-07-25 Thread David Gowers
Hello. I've just completed the first half of the set (all specified results before the patch). Currently image files total 66mb, I'm guessing after adding the results after-patch this will come up to ~110mb. During this testing I found one obvious bug, it remains to be seen whether the patch fixes

Re: [Gimp-developer] need help with bug #464466 (downscaling quality)

2008-07-17 Thread Sven Neumann
Hi, On Thu, 2008-07-17 at 09:19 +0930, David Gowers wrote: Personally I think the test is being run under flawed conditions (using nonlinear sRGB rather than linear RGB, which produces errors of up to 50% because interpolation is done linearly despite the colorspace being nonlinear.).

Re: [Gimp-developer] need help with bug #464466 (downscaling quality)

2008-07-17 Thread David Gowers
On Thu, Jul 17, 2008 at 2:32 PM, Guillermo Espertino [EMAIL PROTECTED] wrote: Please consider adding typographic elements (logos, text) and icons/diagrams to the test images. One of the most critic use cases where downscaling shows issues is with high contrast such as dark typography on light

Re: [Gimp-developer] need help with bug #464466 (downscaling quality)

2008-07-16 Thread David Gowers
I can do at least half of this task, possibly most of it. * decide on test images: 2 landscapes http://www.flickr.com/photos/hapal/2292885459/sizes/l/ http://www.flickr.com/photos/[EMAIL PROTECTED]/2432037855/sizes/l/ (or size o/ ) 3 portraits

Re: [Gimp-developer] need help with bug #464466 (downscaling quality)

2008-07-16 Thread David Gowers
Hi, I've just completed producing images without the patch (using old scaling code) for None and Linear methods. This amounts to 2*77 = 154 images totalling 110 MB. Some of these I plan to discard, for the cases where the old and new code produce the same result. One of the photos had

Re: [Gimp-developer] need help with bug #464466 (downscaling quality)

2008-07-16 Thread Liam R E Quin
On Wed, 2008-07-16 at 22:14 +0930, David Gowers wrote: The one thing I definitely can't do is * Host webpage. I can do that if you want, although gimp.org would be better. As long as it's under a gigabyte or so. Here are some images that may help show some problems -- colour photos tend to

Re: [Gimp-developer] need help with bug #464466 (downscaling quality)

2008-07-16 Thread Sven Neumann
Hi, On Wed, 2008-07-16 at 18:30 +0930, David Gowers wrote: The one thing I definitely can't do is * Host webpage. I don't think we have enough space currently on gimp.org to host this. But it doesn't really matter where it is hosted. I can put the stuff online if you give me a tarball that I

Re: [Gimp-developer] need help with bug #464466 (downscaling quality)

2008-07-16 Thread gg
On Wed, 16 Jul 2008 17:15:38 +0200, Liam R E Quin [EMAIL PROTECTED] wrote: On Wed, 2008-07-16 at 22:14 +0930, David Gowers wrote: The one thing I definitely can't do is * Host webpage. I can do that if you want, although gimp.org would be better. As long as it's under a gigabyte or so.

Re: [Gimp-developer] need help with bug #464466 (downscaling quality)

2008-07-16 Thread David Gowers
Here are some images that may help show some problems -- colour photos tend to hide problems, partly because the eye sees the subject more easily and auto-corrects flaws, and partly because the hardest thing for rescaling is often preserving both texture and sharpness. Of course, most people

Re: [Gimp-developer] need help with bug #464466 (downscaling quality)

2008-07-16 Thread Guillermo Espertino
Please consider adding typographic elements (logos, text) and icons/diagrams to the test images. One of the most critic use cases where downscaling shows issues is with high contrast such as dark typography on light backgrounds. This is particularly important when working with small designs for

Re: [Gimp-developer] need help with bug #464466 (downscaling quality)

2008-07-15 Thread Liam R E Quin
On Tue, 2008-07-15 at 00:32 +0200, Sven Neumann wrote: Since no one has offered to help with this bug so far, I see two options: (1) postpone this change for 2.8 (2) commit the changes and release them with 2.5.2, revert if needed I can certainly offer images, I'm maxed out with work

Re: [Gimp-developer] need help with bug #464466 (downscaling quality)

2008-07-15 Thread Sven Neumann
Hi, On Tue, 2008-07-15 at 09:49 -0400, Liam R E Quin wrote: I can certainly offer images, I'm maxed out with work meetings stuff this month though, so apart from that I don't have spare cycles probably until the end of the month. Sorry for not replying first time round. I don't think

Re: [Gimp-developer] need help with bug #464466 (downscaling quality)

2008-07-14 Thread Sven Neumann
Hi, On Tue, 2008-07-08 at 08:25 +0200, Sven Neumann wrote: Geert has made some progress on the patch to improve downscaling quality in GIMP (http://bugzilla.gnome.org/show_bug.cgi?id=464466) and we would like to include this change for GIMP 2.6. But in order to do this, we need to know if