How to change screen saturation?

[Kai-Uwe Behrmann]

Am 02.01.11, 15:45 -0800 schrieb Hal V. Engel:
> On Sunday, January 02, 2011 01:02:37 pm Alberto Gonzalez wrote:
>> On Sunday 02 January 2011 21:16:01 Hal V. Engel wrote:
>>> Because the monitor has a large gamut you will get higher than normal
>>> saturation unless you color manage the display system wide (IE. not just
>>> in CM aware software).  The reason that this is happening is that
>>> currently most software other than a few color management aware apps
>>> (GIMP, Scribus, CinePaint...) is assuming that displays have approx.

The three applications can see the basic monitor ICC profile as well as 
many other colour managed ones.

>>> sRGB characteristics (IE. gamut, primaries, gamma and so on) but your
>>> monitor is near AdobeRGB in gamut and likely has primaries that are
>>> significantly different from sRGB and that assumption fails apart under
>>> those conditions.
>>
>> Ah, yes, you are right. I thought about this, but because The GIMP also
>> showed the saturation I discarded it. However, it's because I needed to
>> actually feed it with an ICC profile. Once I did it, pictures in it show
>> correct colors.
>>
>>> If you are using  compiz there is a CM plug-in named Compicc (see
>>> http://sourceforge.net/apps/mediawiki/compicc/index.php?title=Main_Page)
>>> available that will allow you to color manage your display system wide.
>>> But to really use this correctly you will need to create (or get if one
>>> is available) an ICC profile specific to your monitor(s).
>>
>> I'm using Kwin now, but I seem to remember reading about some way of using
>> monitor color profiles in Linux via xorg. I'll investigate that option and
>> if it fails I'll take your suggestion and use Compiz with that plugin.
>>
>> Thank you very much for the hint!
>> Alberto
>
> Currently the only way to use icc profiles system wide is to use the compiz
> plug-in.  X11 does not have direct support for color management other than
> allowing for setting of ICC_PROFILE atoms for monitors.  There have been a
> number of threads about this on the list over the last few years.
>
> My understanding is that compiz plays nice with newer versions of KDE but I
> have not tested this.

It looks good. Typical not all customisations are available in compiz from 
kwin.

> The plug-in requires that the xorg ICC_PROFILE atoms be set for each monitor.

The CompIcc plug-in uses the Colour Management System (CMS) Oyranos to 
create ICC profiles on the fly from the typical available monitor EDID 
data. So the saturation of your monitor should be coverd nicely. All 
untagged content is converted to sRGB CompIcc. The only exception 
currently is CinePaint with the net_color patch applied. It can utilise 
the whole gamut, while the other desktop regions are converted to sRGB by 
CompIcc. Packages are available on openSUSE's build service.

> Currently the only apps that support this on KDE are oyranos (command line),
> kolor-manager (in KDE svn playground but currently needs work. It is a
> settings module that provides a nice GUI for oyranos in KDE4) and ArgyllCMS
> (command-line).  For gnome users there is gnome color manager.

gnome color manager must be ignored by CompIcc once monitors are switched,
like during hotplug.

> Hal

kind regards
Kai-Uwe Behrmann
-- 
developing for colour management 
www.behrmann.name + www.oyranos.org