[Digikam-users] Color management behaviour

[Milan Knížek]

Hi,

Francesco Scaglioni píše v So 20. 06. 2009 v 10:28 +0100:

> Any thoughts on how one might determine or obtain profiles
> that are more suited.  I too have been using those supplied
> by canon and am always looking for ways to improve my setup.
> 
No simple answer here.

One approach is to obtain a colorimetric target (like IT8.7) and prepare
own profile for the particular workflow (using argyllcms, lprof - the
process is similar to profiling a scanner).

Another approach is to rely on vendor of the software - like Bibble with
its own profiles or UFRaw with colour matrix.

I am using both and while for some pictures I find more pleasing results
are from my own profile, for others I prefer UFRaw's colour matrix
(actually, these come from dcraw and are probably comparable to those
used by Adobe raw converter). Note that I am saying "pleasing" results
since I do not do a colour reproduction work.

The critical points with own profiles are: changing type and colour of
light (sun, shade, bulb, etc.), material from which the target is made
(metamerism, different colour reproduction when compared to a real
scene), number of colours of the target (the rest is
inter/extrapolated), camera sensor linearity (any error means the
extra/interpolation may be wrong), adjustments to raw/rgb data before
application of the profile (white-balancing, EV or tonal adjustment).
Definitely not an easy thing.

You may want to look at argyllcms list archive - these topics are
occasionally discussed there.

Also a good reading is "ICC White Paper #17" (use google to find it)

Hope it helps,

Milan Knizek
knizek (dot) confy (at) volny (dot) cz
http://www.milan-knizek.net - About linux and photography (Czech
language only)