Hi All,
I’m new to color management and I hope you excuse me if I repeat things are
said ..
I’m in a pure opensource flow from image raw decoding to print hence I have
to make my own icc profiles because those I can download fro OEM cant match
to my flow..
I want share this with you and if someone sees wrong please tell me ..
I have a EPSON Stylus PRO 3800 and I print from GIMP, hence RGB color space.
Ok the first trouble I encoutered was I need to change the ink density
because with default 1.00 on density I have too much ink on the paper :
sometimes ink go underside and bleed.I need to find the correct value and
I thought I can use Argyll capacities
I created a color patch with
targen -d2 -f400
printtarg -ii1 -T300 -pA4
and I printed it by GIMP without convert to any profile ( therefore the RGB
value of targen are unchanged) with different Gutenprint ink densities
Hence I inspect the patches with a magnifier (45x) to see how the ink
bleeds or goes underside.
Found the correct density I create the
patches for printer calibration
targen -G -d2 -e0 -B0 -g51 -s51 -f0
printtarg -ii1 -T300 -pA4
print with GIMP with not values change
chartread -H
printcal calib.cal
Now I have the calibration curve for my combination
driver+printer+ink+paper.
Now I create color patches
targen -G -d2 -f442
printtarg -ii1 -T300 -k calib.cal -pA4
The file tiff is now corrected with che curves from the calibration.
For now I want create a profile for a paper with OBA therefore I need to
make FWA compensation. Let's say I want create e profile for a D50
environment therefore:
print with GIMP as before
chartread -H
colprof -qh -f -i D50
Now I have a profile which would have in it values which can compensate the
UV for a D50 illuminant. OK?
I converted the image from its profile to this printer profile and printed
the image.
If I view It under warm led lamps it was more yellow than what I see on the
monitor ( calibrated and profiled) because until now I could not view under
sun light.
I thing this is correct because the FWA correction has moved down blue
wavelenghts, isn't it?
However for what I can read into the documentation if I did a profile with
custom illuminant I couldn't convert the image from its profile which was
for D50. OK?
For now I stop here....I have a lot other question I'll tell you later if
it's not too mutch disturb.
Cheers
Gabriele
