Color management in ubuntu

[Gys van Zyl <gysvanzyl gmail com>]

Hi all,

I have a couple of questions that may be a bit silly due to my beginner level knowledge of color management.

I'm an amateur/hobby photographer and I've been using ubuntu for a while (currently using 10.04).  For a while now I've realized the importance of having a color managed workflow, but have put off getting the hardware as I thought getting everything installed, set up and configured would be tough in linux.  I recently purchased a Pantone Huey monitor calibration device and you could imagine my pleasant surprise when I found how extremely easy everything was to use with gnome color manager.  In no time, with almost zero effort I had everything up and running.  Kudos to the developer(s) - this is excellent software!

So, to test how color management works in a browser, I found this web site: http://www.gballard.net/psd/go_live_page_profile/embeddedJPEGprofiles.html.  Using google chrome (a non color managed browser) this page is a mess of incorrectly rendered photo's - I expected this.  Using Firefox, things are a lot better - imbedded color profiles are now honored and the photos display fine. However, about half-way down the page at the heading "sRGB / Standard RGB 2.2 gamma" I've come across a problem.  This photo is a tagged/untagged rollover of an sRGB image.  It says that "If your monitor is profiled to 2.2 gamma and D65- 6500 kelvin, there should be minimum change in the Un-tagged sRGB rollover."  In my Firefox window, the change is not minor, and I'm trying to figure out why this is.

In my workflow all exif data is stripped from my photo's before I upload to the web.  I thought that this wouldn't matter, as long as my final image was created in an sRGB colorspace.  However, I have now found that my photo's look subtly but definitely different in the software I use (gimp, digikam) and my browsers.

My limited understanding of color management led me to believe that un-tagged sRGB images should look the same in a browser on a color-managed system.  However, on my system they don't and its causing a problem for me - my photo's don't display the way I intended.  How can I resolve this?  Is my understanding wrong, should I educate myself a bit more?  Did I do something wrong when I calibrated my monitor?

Gys