[Digikam-users] image resizing - digikam CIMG is GREAT! and icc profile problem

[elle stone]

Hi all,

It has been a while since I've used digikam.  Recently I decided to take the
leap from monitor to paper and actually have a print made from one of my
digital images.  My digital image needs to be enlarged x4 (x2 in length and
width).  So I've been testing various (windows and linux) programs for image
resizing.  Amongst the "ordinary" image resizing programs, ImageMagick's
default "Mitchell" seems to me to be quite better than those supplied by
that "900 pound gorilla" of imaging programs.  However, I wanted to try CIMG
and look there! - digikam 9.3 (installed per Debian Lenny) has a REALLY nice
interface to CIMG!  The progress bar really helps, too - I still don't know
if my command line attempt to use greycstoration actually was doing anything
or not.  And look there again! digikam 9.4 beta 4 (installed from source
today by yours truly) has the latest and greatest CIMG!  Too, too cool, and
the results are stellar!  Yeah!!! digikam!!!  Yeah!!! CIMG!!!  

Now, if I could just figure out what all those CIMG options mean - I've just
been using the defaults so far.  But that is a topic for another post and
if/when I get some experience with or info about modifying the defaults,
I'll post what I find.

In the meantime, I have a question about icc profiles.  I use argyll to
calibrate my monitor.  I do most of my image processing using linear
(gamma=1) prophoto as my workspace icc profile (though I've been thinking
about switching to ***linear*** wide gamut).  I put my linear prophoto icc
profile in /usr/share/color/icc.  But neither digikam, nor krita for that
matter, seem to recognize that the linear prophoto profile is in the icc
folder.   

When I open an image for resizing purposes in digikam, digikam correctly
reports the image profile and offers to convert or assign wide gamut.  But I
don't want to convert to a nonlinear space.  Image resizing is more accurate
when done in a linear space (see
http://www.4p8.com/eric.brasseur/gamma.html).  So I just tell digikam to "do
nothing".  The CIMG image resizing works perfectly anyway.  However, digikam
displays all my linear image files as very, very dark - it doesn't seem to
be applying the icc transform or whatever it is, that tells how to properly
interpret and display on the monitor the rgb numbers in the image file.   

I don't really mind the dark display because at this point I'm not using
digikam for anything other than image resizing, and after resizing, the
resized images display perfectly when opened by the "900-pound gorilla". 
However, if digikam COULD properly display my images using the embedded icc
profile (that digikam obviously detects when I open the image), then I would
love to start using other editing features offered by digikam.  And I'd like
to start using digikam to keep track of my edited images.  But that dark
display is a bit of a downer.

Is there a solution?  Have I failed to read the manual sufficiently
carefully?  Is there a configuration setting that I could modify to enable
digikam to use my linear workspace profiles?  Would a linear wide gamut
profile fare better than the linear prophoto profile? 

Thanks in advance for any suggestions and again, digikam's CIMG interface is
just great!

Elle

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