[Digikam-users] Re: if system monitor profile set, can't override in color management settings

[Elle Stone]

Remco Viëtor wrote:
> 
> on Thursday 24 February 2011, Elle Stone wrote: 
> (snip)
>> 
>> Feature? or Bug? Gimp allows to use or not use system monitor, if one has
>> been set. Personally, I like the option of being able to overriding the
>> system monitor profile.
> 
> Why would you want to override one profile with another?
> 
> 'Overriding' the profile set by dispwin could be a bad idea:
> dispwin can install a profile that modifies the LUT for the graphicd card, 
> which corrects all output to the graphics card from all applications. This
> can 
> be completely transparent to the applications (as in, "they don't have to
> know 
> what happens")
> The profiles used by digikam are (I suppose) more like translation tables, 
> where the program using the profile translates the image data before
> sending 
> them to the graphics system. 
> 
> So, 'overriding' the profile set by dispwin could have one of two effects:
> - the LUT profile is disabled, meaning that images from Digikam display 
> correctly, and everything else will be uncorrected (not what the one 
> installing the LUT profile wanted, presumably)
> 
> - the LUT profile is NOT disabled; then what should Digikam do? Knowing
> that 
> both profiles correct assume an uncorrected display, applying the
> 'digikam' 
> profile before the LUT profile would give wrong colours on the image, and 
> correct colours everywhere else (not what the digikam user wants).
> 
> This assumes of course that both profiles do their job. If one of them is 
> wrong, get rid of it...
> 
> Remco
> 
> _______________________________________________
> Digikam-users mailing list
> Digikam-users at kde.org
> https://mail.kde.org/mailman/listinfo/digikam-users
> 
> 

I use ArgyllCMS to profile my NEC 2190uxi monitor in its "native",
completely uncalibrated state - the graphic card LUTs are not altered and
the hardware controls were not used to alter the native color temperature or
transfer curves. Loaded or unloaded, the graphic card LUTs are not modified
at all.

I made three profiles, a shaper-matrix (-as) for general use, a
single-shaper (-aS) for any programs that might choke on a shaper-matrix,
and a Lab cLUT profile (-al - not the same thing as altering the graphics
card LUTs - the profile itself contains lookup tables). All of my profiles
are "good" profiles.

I can't be the only person who profiles their LCD monitor in its native
state or has more than one "good" monitor profile.

The only reason I even stumbled over this issue is that somehow yesterday
sRGB got set as my system default profile - I have no idea how. I used to
use a script to set the atom thingy every time I start my computer, but that
was when I was using an ArgyllCMS profile that DID require modifying the
graphics card LUTs.

It is an easy enough "feature" to work around, just drop to the command line
and issue "dispwin -U nameofprofile" to unload an unwanted profile. So no
biggie. But it does mean going in and altering the digiKam/showFoto color
management settings every time the wrong system default might get set. And
it means keeping a constant lookout for suddenly being shown "the wrong
colors".

I like the way Gimp and UFRaw do it - they both give you the option of using
or not using the "system monitor profile". And they DON'T alter your
previous choice, if a system default was set in the meantime. 

That's the real problem, once a system default has been set,
digiKam/showFoto don't give you the option of not using that system default.
It gets used automatically, regardless of what you might have previously
chosen as the monitor profile. So all of a sudden digiKam was using sRGB as
the monitor profile and all my colors were off. That behavior -
automatically altering the monitor profile regardless of previous choice,
and then graying out your option to change it back - seems to me to be
undesirable. Especially when some rude program goes and sets a system
default behind your back. (I'm thinking cinepaint/oryanos might have been
the culprit.)

Elle

-- 
View this message in context: http://digikam.1695700.n4.nabble.com/if-system-monitor-profile-set-can-t-override-in-color-management-settings-tp3321956p3322395.html
Sent from the digikam-users mailing list archive at Nabble.com.