Jul 04

Firefox 3.5 and color management

Firefox 3.5 was released a few days ago and no doubt a few people are anxious to upgrade.  The most notable change is Firefox 3.5 is now color managed by default resulting in accurate colors for images saved in color profiles other than sRGB. The other feature some may find useful is private browsing (aka: porn mode). When this feature is enabled, you won’t leave a single browsing fingerprint behind for others to discover. You can slip in and out of private browsing mode quickly, so it’s easy to return to what you were doing before as if nothing ever happened (you can also browse privately all the time).

Beyond that, the biggest reason to upgrade is speed. Firefox 3.5 is significantly faster than all previous version of Firefox.

Windows users can upgrade by going here.

Linux users will not see Firefox 3.5 included in the distribution until it has been vetted by the distributor and users.  Ubuntu users anxious to upgrade should follow these instructions.

Existing FF users should be aware that lots of add on are still incompatible with 3.5. The following is a list of add ons that are known to be incompatible with Firefox 3.5.

Add N Edit Cookies
CookieSwap 0.5.165b
Ctrl Tab Preview 0.2.1
deli.icio.us. 1.2
Exif Viewer 1.45
Google Gears
Opanda iExif 2.3
Pagemark 0.1
Paste and Go 2 0.8
Restore Scroll Position
Richscrollbar 0.1
Tab Mix Plus

TinEye, Xmarks, Stylish, Adblock Plus, Lazarus: Forms Recovery, FireFTP, Cooliris are all compatible.

When you upgrade to Firefox 3.5, it will initially test your existing add ons for compatibility. It’s a good idea to update all your add ons first by going to Tools-Add Ons-Find Updates. Any add ons it finds incompatible will be disabled. After Firefox 3.5 upgrades, check for add on updates again and it will update to the latest versions.

You can disable update checks by taking the following steps:

* Type about:config into Firefox’s address bar and click the “I’ll be careful, I promise!” button.
* Right-click anywhere. Choose New>Boolean. Make the name of your new config value extensions.checkCompatibility and set it to false.
* Make another new boolean pair called extensions.checkUpdateSecurity and set the value to false.
* Restart Firefox.

Color management in Firefox 3.5

All browsers with the exception of Safari and Firefox 3 (with modifications) were not color managed. That meant only pictures saved in sRGB color profile will display close to the intended colors. Images tagged with any other color profiles will render incorrectly resulting often in muted colors. In Firefox 3, users could turn on color management at the expense of a performance hit. Firefox 3.5 now has color management turned on by default as they have improved performance 5x faster than 3.0.

There are three modes for color management which can be verified/changed by typing about:config in the url bar.

Filter for: gfx.color_management.mode

The values are:

0=Color management disabled. (Default in Firefox 3.)
1=Full color management
2=Color management applied only to tagged images.  (Default in Firefox 3.5.)

Looking at the image below, non managed browsers and mode 1 will see one purple box. Mode 2 will see a lighter purple box to the right unless your system profile is sRGB.

Why are the images now darker?


The new QCMS color management system introduced in Firefox 3.5 currently only supports ICC version 2 color profiles, not version 4. This bug occurs both in Windows and Mac OS. This bug is more likely to present itself to advanced users as they are more likely to have monitor calibration software that creates ICC v4 profiles. This may result in images being too dark. See bug 488800 and the ICC version 4 profile test.

Firefox 3.5.1 was released on July 17, 2009 but it does not address the color management bug with ICC V4.

Is your system ICC v4 ready?

If you want to use Firefox 3.5 but you are getting dark images, you can fix this by simply changing the color management mode to 0, 1, or 2. There is no need to downgrade back to Firefox 3 unless you need to do it for some other reason.

Check here for more information regarding color management on the web.