Hi
I’m making profiles (for RGB-interface inkjet printer/driver settings/paper/ink
combinations) using targen, printarg, chartread, measuring with an unfiltered
i1Pro and finally colprof.
Evaluating the colprof check report for abnormal errors, and using Gamutvision
looking at several displays (liking the black and white density, 3D L*a*b and
ColorChecker simulation).
I also do subjective tests, both on monitor and print, with familiar test
images and synthetic ball gradients etc. That is seemingly going pretty well.
But non of those post profile creation tests are looking at new measurement
analysis from an actual print using the profiles.
What I would like now is a procedure for printing a chart for a measured
control test from physical print using the profile (no simulation) - confirming
how close or not I am to achieving color matching. It is unclear to me how best
to accomplish this. Please advice.
Background: I have previously trying to determine which target printing method
was correct, as I saw obvious visual differences between two recommended
approaches (Adobe Color Printer Utility and ColorSync vs Canon Print Studio Pro
with color management). But who was right? I though Canon might have their own
profiles roughly right, so I preconditioned the target with their profile, and
after printing with various methods, read them all with chartread. Then I did a
colverify between the .ti2 target and the .ti3 measurements - and the Canon
method was showing many and big errors, while the others were within reason.
That’s the closest I’ve been to validating something - but not validating
created profiles as of yet.
I’d like to be able to evaluate two different kinds of patch sets:
1) Fixed set of patches
Like ColorChecker Classic or SG. I see files under /ref, but haven’t figured
out how to make them into a .ti1 for use with printtarg, or making my own. Have
seen image files with attempts to match the reference CIE values with a given
color workspace. But would like to have a .ti1 and .ti2 generated with those
values.
2) Adaptive set of patches
By adaptive, I mean they sample the printer gamut well, so I think the
procedure from my background story above might be useful, or something thereof.
Using preconditioning, with the just created profile, to make a patchset of
chosen count size (perhaps just a small strip or two, like 32-64), where targen
samples the gamut well (default OFPS, all still inside) and registeres expected
CIE values, I can later colverify after printting chart with the new profile.
Smarter way of creating such a set?
Question is then, how exactly I should print and compare. I assign the
printtarg with the new profile, so RGB values get the right CIE meaning
(matching the preconditioned data using same profile). I now see multiple
routes and need feedback. I can print without color management. I can print
with the profile, but then absolute or relative colorimetric and no BPC? Should
I after profile assignment convert to working space (ProPhoto) and then print
with profile, again abs or rel intent?
Should colverify have any options about whitepoint matching or anything else of
interest?
Appreciate any input on this. Thanks.
Regards
Henrik
