Graeme,
My first thought was to use this (colverify) to compare two printing
workflow, but from what I see below there are a few more possibilities.
Below in #3 you mention using a different set of test values. I assume
we need a "good" set of test values both in quality and in quantity if
we want to obtain meaningful results from this kind of test. How do we
figure this out?
Is there some documentation on the various algorithm you mention in
targen docs?
Thanks,
YG
On 12/1/2018 7:38 AM, Yves Gauvreau wrote:
Sorry for the long delay, my computer crashed.
I have way to many thing to recover so I'll get back some time later on this.
Thanks,
YG
On 11/28/2018 9:58 PM, Graeme Gill wrote:
ygauvreau wrote:
Hi,
I figured out DisplayCal probably used colverify to generate the report. Any suggestion onit depends on what you are trying to do. You could:
how to proceed for prints? I assume I'll need some meaningful target(s) to begin with, how
do I generate that? Black and white prints either RGB or greyscale anything special for
these? I'd like to compare 2 or more workflows, any suggestion for that?
1) Verify the profile colorimetric A2B against the test chart used to make it.
This is a measure of self fit.
- profcheck can be used for this.
2) Verify the profile colorimetric A2B against the test chart used to make it
after printing and measuring it again.
This is a measure of printing and measuring consistency, as well as fit.
3) Verify the profile colorimetric A2B against a test chart with a different set of
test values.
This is a measure of profile interpolation accuracy, as well as printing and
measuring consistency, as well as fit.
4) Test emulation/proofing of another colorspace. The most tricky part of this
is dealing with colors that are out of gamut of the printer, as (naturally)
such colors will be printed inaccurately. This is somewhat complex.
You have to create a set of test values in the emulated space (targen), and then
convert them to CIE reference values (fakeread ?). You then need to convert those
reference values into the printer space, for printing and measurement (xicclu then
manually copy into .ti1 file ?). Print and measure, using colverify with the -L
parameter to ignore out of gamut values between the reference values and the measured
values. You may have to also pay proper attention to the intent - typically absolute
intent is used for the verifications 1-3 above, but this may not be suitable when you
are doing emulation/proofing, given that the white point may be different.
Cheers,
Graeme Gill.
