Re: color profiles in gnome color manager and in applications

[Pascal de Bruijn <pmjdebruijn pcode nl>]

On Thu, Aug 4, 2011 at 1:15 AM, Matthew Miller <mattdm mattdm org> wrote:
> I've finally gotten around to color-calibrating my display in Linux. I'm
> thankful that there's all this great software for doing so.
>
> However, one thing makes me confused, and I wanted some clarification. This
> message
> <http://mail.gnome.org/archives/gnome-color-manager-list/2011-January/msg00002.html>
> suggests that the corrections applied by loading the device profiles at
> session startup are just color temperture (and perhaps gamma -- the above
> message isn't sure, but it seems to from my experience), and that to really
> _use_ the profiles, they should be enabled in each application.
>
> This makes sense to me but I want to make sure it's correct -- color
> management is so complicated that it seems easy to inadvertently do
> something wrong and end up with _worse_ results than uncalibrated.

gcm-apply applies the videolut part of the profile at login, which
gets loaded into Xorg, this is mostly a correction for color
temperature (you should see your display gets warmer/colder when you
login), en indeed gamma.

Then your application loads the XYZ matrix from the profile to do
final corrections, applications do this by using liblcms. So you need
both parts active for actually accuracy.

Regards,
Pascal de Bruijn