[Digikam-users] Was: problems with ICC profiles (Daniel, Gilles and Gerhard thread)

[Francisco J. Cruz]

I've read the thread about Color Management at the users ML. I'd like
to give my point of view:

- A Color Management workflow is useless if we are working with an
uncalibrated monitor. We can apply all the color profiles we want to,
but if the monitor is showing us a false color gamut, then all the
corrections we make to the image are wrong too. As Daniel said in one
mail, to get an accurated calibration, you need an expesive hardware
(and software), but we can get a "visual calibrated monitor" which is
enough for us, working on gamma and color correction in ours monitors.
There are a lot of tutorials in internet about this.

- I get dark images too when I convert from NEF files using nikon icc
profiles. As far I know this is dued to the gamma and linearity values
for the profiles we are using. The problem is that these values,
usually, are not published, so we have to guess them. In anycase,
digiKam can't use them because the conversion from RAW files is not
interactive, as in ufraw. To get similar results in digikam I follow
this workflow:

           1. I apply the profile when open the image in I.E..
           2. Correct gamma and, if needed, contrast.
           3. Apply some curve that I get from cinepaint (if neede, of course)
           4. If needed, I do some fine adjust with levels tool.

The first step could change: I can decide to make some auto-exposition
adjust before apply any color profile.

In any case, I recommend to have a look at color management page at
ufraw homepage (http://ufraw.sourceforge.net/Colors.html).

- In my modest opinnion, the best software to make conversions from
RAW files is ufraw and, as I said some time ago, if we want digikam
has a powerfull tool for this work, we have to look at ufraw as model.
In any case I think ufraw lacks from something like a graphic tool to
batch processing images.

- We have to take in account that manufacturers software could use
features that don't carry out with standards icc, so this software
seems to get the best results, but be aware that this could be false.
Look for tests with this apps and dcraw and you'll know what i'm
talking about.

Paco