[argyllcms] i1Profiler vs Argyll ICC profiles -- Part 1 A2B1 (Device to PCS direction)
- From: <graxx@xxxxxxxxxxxx>
- To: <argyllcms@xxxxxxxxxxxxx>
- Date: Sat, 21 Dec 2019 19:46:22 -0500
I wanted to share some "new" results about my humble efforts at using
Argyll, to create ICC profiles for my Epson printer in RGB mode.
I confess I stuck with the "Dark side of the Force", using the old
ProfileMakerPro TC918 chart. Had to import TC918.txt into my Minolta FD-S2w
application, first, in order to generate a TIFF document for printing that I
can later measure with my FD-9.
I ran the target from Photoshop CC 2020 with the "Nul" conversion trick and,
of course, with CMS turned off in the print driver.
I saved the data in CGATS format and later converted with "txt2ti3.exe" to
ti3 format with the following command :
txt2ti3 -v P5M_TC918_Paint.txt P5M_TC918_de_Paint
(Had to add extra underscore characters, is there a way to 'work around'
that?)
I used this line to generate the ICC profile :
colprof -v -D"P5M TC918 de Paint de Argyll en M0 sur E240 (2019 12 20)" -P
P5M_TC918_Argyll_de_Paint_en_M0_sur_E240
I know, I have not figured the 'Assumed source profile' option yet - I'm
only starting, here, you'll have to give me a break.
In parallel, I created an ICC profile with X-Rite i1Profiler from the same
TC918 data.
Then I opened up the original TIFF characterization chart (generated out of
FD-S2w) in Photoshop, twice, once for the Argyll profile and once for the
i1Profiler profile.
I then converted both document to CIE Lab, using Absolute Colorimetry, and
combine them into one 16 bit document, on two separate layers, for
comparison.
Conclusion : I don't see the difference between the two 'profiles'.
The Photoshop file is here, in case you want to take a look at it.
https://1drv.ms/u/s!AkD78CVR1NBqkoc-nFEoTi7qV_9WOQ?e=9LpGc5
I also enclose, below, the output of 'colprof' which I need to study to
better understand the result of this profiling session.
/ Roger
-------------------------------------------------------------------------
colprof: Warning - No gamut mapping called for, so -P will produce nothing
No total ink limit being used
No black ink limit being used
No of test patches = 918
Estimating white point
Approximate White point XYZ = 0.82517383 0.85667498 0.72094536, Lab =
94.170000 -0.160000 -1.270000
Creating optimised per channel curves
Initial White Point XYZ 0.825174 0.856675 0.720945, Lab 94.170000 -0.160000
-1.270000
About to optimise temporary matrix
100%
About to optimise a common ord 0 input curve and matrix
100%
About to optimise a common input curve and matrix
100%
About to optimise input curves and matrix
100%
About to optimise output curves and matrix
100%
About to optimise input curves and matrix again
100%
About to optimise input, matrix and output together
100%
About to adjust a and b output curves for white point
About to create grid position input curves
Create final clut from scattered data
****************************************************************************
****************************************************************************
****************************************************************************
*******************
Doing White point fine tune:
Before fine tune, rel WP = XYZ 0.962034 0.997763 0.825194, Lab 99.913422
-0.001949 -0.172559
After fine tune, rel WP = XYZ 0.964203 1.000000 0.824905, Lab 100.000000
0.000000 0.000000
abs WP = XYZ 0.82332528 0.85476070 0.72119841, Lab
94.087879 -0.160776 -1.433958
Creating fast inverse input lookups
White point XYZ = 0.82332528 0.85476070 0.72119841, Lab = 94.087879
-0.160776 -1.433958
Find black point
Black point XYZ = 0.00246701 0.00252386 0.00266306, Lab = 2.279797 0.135227
-1.097135
Done A to B table creation
Setting up B to A table lookup
Creating B to A tables
Rev cache RAM = 670 Mbytes
Initializing nnrev arrays...
There is 1 rev cache instance with 670 Mbytes limit
nnrev initialization done
Initializing nnrev arrays...
There are 2 rev cache instances with 2482 Mbytes limit
nnrev initialization done
55%
Done B to A tables
Creating gamut boundary table
100%
Done gamut boundary table
There is 1 rev cache instance with 670 Mbytes limit
Profile check complete, peak err = 2.591521, avg err = 0.390598, RMS =
0.498853
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