Author: folengo
Description:
This problem was raised on 3 August 2011 at Wikimedia Commons village pump. See description there : http://commons.wikimedia.org/wiki/Commons:Village_pump#Pale_photos
Version: unspecified
Severity: normal
Author: folengo
Description:
This problem was raised on 3 August 2011 at Wikimedia Commons village pump. See description there : http://commons.wikimedia.org/wiki/Commons:Village_pump#Pale_photos
Version: unspecified
Severity: normal
The three images cited there look overly pale in both original and thumbnail in Firefox 5.0.1 / Mac OS X 10.7, and look reasonably pleasant in both forms in Safari 5.1 and saved to disk and loaded in Preview on the same machine.
It looks to me like the color profile *is* being preserved (or it wouldn't get seen by Safari and Preview), whereas Firefox is either ignoring the profile or horribly misinterpreting it.
Pretty sure I've heard about this and this is a known FF problem. Lemme see if I can find it.
http://news.cnet.com/Safari-ushers-in-better-browser-colors/2100-1012_3-6191815.html
Safari supports color profiles, but firefox doesn't.
deletesoftware wrote:
(In reply to comment #3)
http://news.cnet.com/Safari-ushers-in-better-browser-colors/2100-1012_3-6191815.html
That article is too old (2007).
From the links Kevin Brosnan gave me, it is Firefox that supports color profiles, while some other software does not.
http://commons.wikimedia.org/wiki/File:Command_and_control_center_Port_of_Long_Beach_CA.jpg — see file history. The oldest image is pale in Firefox 5.0.1; there is only a small difference between the two oldest images in Firefox trunk nightly 20070103.
http://www.libpng.org/pub/png/png-colortest.html (works as described in Firefox 5.0.1 Linux-x86_64 and 3.5.17 Linux-i686, does not in Firefox trunk nightly 20070103, Konqueror 4.6.5, Geeqie 1.0, Gwenview).
http://www.libpng.org/pub/png/colorcube/colorcube-pngs-iCCP.html (works in Firefox 5.0.1, not in Konqueror) There are links to more tests at the bottom of that page.
deletesoftware wrote:
There is some lack of support for ICC v4 profiles in Firefox though: https://bugzilla.mozilla.org/show_bug.cgi?id=488800
It shouldn't matter what support imagemagick has really, it just needs to pass the profile through to the thumbnail. In all cases I've seen, it does -- the browser then either understands it or doesn't.
I tried disabling color profile management in Firefox -- see http://kb.mozillazine.org/Gfx.color_management.enabled
With this off, the 'too pale' images render relatively reasonably (but darker/less saturated than Safari/Preview show them); this probably indicates that either:
-or-
When I load the image into Gimp (on either OS X or Linux) I'm given the opportunity to either convert the file into sRGB from its native profile, or keep it -- either way it ends up looking decent, unlike in Firefox (again, on either OS).
So I'm a bit inclined that it may be Firefox's color management mishandling the profile.
Ok, on further investigation there were a couple images where the thumbnails had the profile missing (and thus rendered ok in Firefox, while other sizes didn't)...
... because those particular thumbnails had not been re-rendered since bug 19960 was resolved (upgrading ImageMagick on the clusters to a version new enough that it preserves the profiles).
You can do an ?action=purge on any affected page as you find them.
The misrendering seems to be an issue with Firefox's color management system, and is likely the same problem as bug 30249 -- I recommend adding these links over there.