Order of the Bath

To those who look carefully, photographs on web pages look dull compared to how they look in photo editors. I always thought it was due to the low resolution but apparently it is all about Colour Management Profiles. These are instructions placed in the image file which tell the receiver how to render the colours and are intended to allow matching on different devices—e.g. Screens on different computers, projectors and printers. However, Firefox has always ignored them; until Firefox 3. IE ignores them as well; Safari does read them but in a different way.

In Firefox, if you go to the about:config page and set gfx.color_management.enabled to True then, after a restart, it will be activated. All the photographs will look just a little bit richer, brighter and more sparkling. The photo purists are wondering why it has not been enabled by default?

Well if you have tried it in Windows you will see—everything else will have taken on a different tinge compared to what it was before, mine went pinkish, others have reported a cream bias. The greys are no longer neutral because in the process of doing it to photographs that come with built-in profiles, they have applied a default profile to everything else on the page and it all looks wrong. The official Mozilla page says that it relies on a properly calibrated monitor. Well mine is as close as I can get it without special hardware but that is not the answer. What you also need to do is set the default profile gfx.color_management.display_profile. You would expect this to be the actual values for your monitor, but that is what Firefox is already doing. What you need to do is set it to C:\WINDOWS\system32\spool\drivers\color\sRGB Color Space Profile.icm to stop Firefox altering it and allow the Windows display driver to make the correction for the screen. Brad Carlile has a good test page—if the greys still look grey and his three test pictures all look the same then you have got it right. The Apple Mac doesn’t seem to have a problem, just set the enabled flag to True and it mostly works. Safari (at least on the Mac) does it like this by default.

Secondly, plugins, particularly Flash, do not compensate, so sites that blend from backgrounds to Flash will no longer be seamless—but my fix seems to solve that as well, unless they are trying to blend Flash with JPG which would be unusual. I haven’t got this working for the Mac yet. and, although Flash blending is ok, apparently Safari falls down for a similar reason; the CSS and GIF backgrounds don’t blend seamlessly with JPG and PNG images. This may also affect my fix but I haven’t had a chance to experiment with it yet. What I need is another comprehensive test page. Update: It is a heavy read, but this page by G. Ballard explains it all and has a lot of test pictures or this excelent article by Jeffrey Friedl.

Finally, it also takes 10–15% more processor power to render the pictures so those on older systems will see a noticeable slow down on picture heavy sites.

I first though that I would be switching it off again until they get this sorted out properly, but having found the profile hack I will leave it, I don’t care about Flash anyway.

This entry was posted on 24 Jun 2008 at 20:37 by Rick and is filed under Browsers, ChurchTech, Mac, Technical, Windows, WordPress. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.