[argyllcms] black generation drives me nuts

  • From: Klaus Karcher <lists@xxxxxxxxxxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Mon, 17 Sep 2007 00:26:38 +0200

Hi Graeme,

you know that I am sold on argyllcms, but to puzzle out the right black generation parameters sometimes drives me nuts.

I tried to generate a profile from the data set

with a black generation comparable to to this profile:

here is a screenshot of "xicclu -g -fb -ir SC_paper_bas.ICC":

I attended the instructions at

and literally tried hundreds of different parameters.

E.g. I create a preliminary profile with
"profile -v -ql -b -no -ni -l250 F40"
and tested several black generation parameters, see

To bar the curves from gamboling around I tried to generate a bigger data set with fakeread:

targen -d4 -l300 -c SC_paper_eci.icc -A0.5 -f3000 -v3 F40fakeread
fakeread -v SC_paper_eci.icc F40fakeread
profile -v -ql -b -no -ni -l300 F40fakeread
mv F40fakeread.icc F40fake300.icc

and decided to use it with the following black generation parameters:
kp 0 0.15 1 1 0.65 -l300
as the curves looked smooth an reasonable to some extent, see

but when I created the profile with
"profile -qm -k p 0.0 0.15 1 1 .65 -l300 -L100 -S sRGB.icc -cmt -dpp F40fakeread"

I got this:

What am I doing wrong?


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