Bad image interpolation !!

Message

Gabriel_Blake · Post by **Gabriel_Blake** » Sun Jul 26, 2009 8:47 pm

I've had this problem for quite some time.

All .jpg and .png files are interpolated improperly when either stretching the image or squeezing it.

Some sort of blur is always expected, but this is far beyond that :/

error.jpg shows some images when zoomed in, while browsing in Firefox. You can see the distortion, no anti-aliasing.
error2.png shows some images when 64x64 pixel icons are squeezed to fit the fluxbox menu. For example the Skype icon should be a round bubble, and the Kadu icon should have two eyes and a smile.

Since the problem is more or less everywhere and I can't be sure for how long, I think it's a problem with some libraries.

Any ideas ??

I'm using:
xorg-server 1.5.3-r6
fluxbox 1.1.1-r1
nvidia-drivers 180.60

erik258 · Post by **erik258** » Tue Jul 28, 2009 6:32 am

I'd agree. aren't there some libraries for jpeg and png images?

Gabriel_Blake · Post by **Gabriel_Blake** » Thu Jul 30, 2009 8:22 pm

Anyone.... any ideas ??

erik258 · Post by **erik258** » Fri Jul 31, 2009 10:39 pm

hi again,

on this fresh install I'm using, which by the way appears to be rendering jpeg images just fine, I have this installed:

emerge -s jpeg (clipped)

media-libs/jpeg
Latest version available: 6b-r8
Latest version installed: 6b-r8
Size of files: 620 kB
Homepage: http://www.ijg.org/
Description: Library to load, handle and manipulate images in the JPEG format
License: as-is

* media-libs/openjpeg
Latest version available: 1.3-r2
Latest version installed: 1.3-r2
Size of files: 981 kB
Homepage: http://www.openjpeg.org/
Description: An open-source JPEG 2000 codec written in C
License: BSD-2

and emerge -s png (clipped) provides:

* media-libs/libpng
Latest version available: 1.2.37
Latest version installed: 1.2.37
Size of files: 507 kB
Homepage: http://www.libpng.org/
Description: Portable Network Graphics library
License: as-is

do you have these isntalled? And do you have 'jpg', 'jpeg', and 'png' in your USE flags?

erik258 · Post by **erik258** » Sat Aug 01, 2009 1:39 am

hi,

i take that back. my images look bad too, in firefox at least. still building the system so I don't know in what else.

so, i'm looking for ideas too.

Gabriel_Blake · Post by **Gabriel_Blake** » Sun Aug 02, 2009 11:15 am

Thank you for your interest in this subject and sorry for my late reply... I lost all hope :/

The problem is quite complex.

I do have the jpeg and png use flags, therefore I have those libs installed. When I had a fresh install the images were rendered correctly. Maybe I'll try downgrading them.

erik258 · Post by **erik258** » Sun Aug 02, 2009 6:39 pm

I've been looking at the output on ldd on firefox, which doesn't render properly. maybe if we can find the library its using to interpolate, we can find a version that works.

by the way, did you by chance just upgrade your firefox when this started happening? I'm running 3.5.1.

boerKrelis · Post by **boerKrelis** » Sun Aug 02, 2009 6:44 pm

Firefox uses x11-libs/cairo to do its resizing. I had a quick look and I couldn't find further image library deps for cairo, so I assume the resizing happens in the cairo code. If you want to look for solutions, start there. media-libs/jpeg and media-libs/libpng are irrelevant afaik.
Btw, resizes look just as bad here too - but only for resizing upwards.
I just remerged cairo with the 'cleartype' useflag and fonts look prettier than previously. Can't remember whether downsizes look prettier.

erik258 · Post by **erik258** » Thu Aug 13, 2009 9:56 pm

hi again,

still having this problem in firefox, at least. Here's the gentoo forum image from the forums site:

http://spore.ath.cx/~dan/bad-interp.jpg

but the weird thing is that if I brink up the image itself (firefox's right-click=>view image)

http://spore.ath.cx/~dan/good-interp.jpg

just the image looks fine, but the page with the image in it looks horrible. the smileys to the left of the post area also look terrible - but only as a part of the page:

http://spore.ath.cx/~dan/smile-interp.jpg

erik258 · Post by **erik258** » Thu Aug 13, 2009 10:01 pm

FWIW, upgrading cairo to 1.8.8 (~amd64) did nothing.

erik258 · Post by **erik258** » Sat Aug 15, 2009 12:36 am

neither did updating to 3.5.1-rc1 from gentoo. Previously I had been running 3.5.2 from mozilla's sources ("shiretoko").

Nothing changed...

Gabriel_Blake · Post by **Gabriel_Blake** » Sun Aug 23, 2009 4:09 pm

erik258 wrote: just the image looks fine, but the page with the image in it looks horrible. the smileys to the left of the post area also look terrible - but only as a part of the page:

http://spore.ath.cx/~dan/smile-interp.jpg

The answer to your problem may the zoom in firefox.

Try "Ctrl +" and "Ctrl -" and adjust it to the proper size. You can also set "View -> Zoom -> Zoom Text Only".

This isn't a solution since the image resizing is still bad :/ And in my case it's not only in Firefox.

PaulBredbury · Post by **PaulBredbury** » Sun Aug 23, 2009 6:35 pm

Are you using jpeg-7? I'm thinking about blurriness patch for gtk+-2.

Gabriel_Blake · Post by **Gabriel_Blake** » Mon Aug 24, 2009 9:15 am

NO... I'm using 6b-r8 so this bug is probably irrelevant :/ But I'll look into it anyway. Thanks for the link... this still may be the issue.

askoff · Post by **askoff** » Sun Sep 27, 2009 1:15 pm

I've found interesting blog post on the firefox zoom quality issue. I suggest all of you to read it. http://blog.vlad1.com/2008/03/18/a-litt ... t-for-you/