Thanks for the answer Andrew.
I will try to explain the commands that I am using with ArgyllCMS, you can for sure find a better and probably more correct description in the very good ArgyllCMS online documentation here: http://www.argyllcms.com/doc/Scenarios.html#PP1
targen -v -d2 -G -f2232 -g128 nameI am making target test values optimized for an RGB printer (-d2) with 2232 patches and asking to have 128 patches with R=G=B (“nominally grey, of course they are not, otherwise the printer would probably need no calibration). I saw that a good number of patches with same RGB values allows to get a neutral BW later.
printtarg -v -ii1 -t360 -p310x450 name
I am using the previously generated patches to make an i1Pro-compatibile(-ii1) 360dpi 8bit TIFF image file (-t360) whit all the patches. This file will measure 310x450 mm. This is the file that I will print with PhotoshopCS5 (making myself sure to disable colour management, I personally use the “double-assign” method using 2 times the AdobeRGB profile to have as result a null transform).
chartread -v -H -B -T0.4 name
This is to read the previously printed test chard made with printtarg and printed with no colour management applied. I am using high resolution (-H) spectral mode to read it and I am asking for a very low tolerance (-T less than 1). So if the instruments gets big DeltaE 2000 errors while reading I will be asked to read again. I don’t exactly know (I have asked but I received no answer) what tolerance is –T 0.4, but I think that it should be something around max 5 DeltaE2000.
colprof -v -qu -i D50 -o 1931_2 -S AdobeRGB1998.icc -cmt -dpp -f -D A-E7900-Bamboo-2880dpi-i1Pro nameHere I am making the ICC profile. Quality is set to “Ultra”, illumination spectrum is D50, observer is the second , I am asking for OBA compensation (-f) and it will work for the selected illumination spectrum (D50 in this case, but I can use the actual illuminant if I want, there is the specific illumread utilty:
http://www.argyllcms.com/doc/illumread.html) . Here:
http://www.argyllcms.com/doc/FWA.html you can find more about how ArgyllCMS works with OBAs.
-cmt is telling Argyll to use as “input profile” a “standard monitor” and –dpp is telling to Argyll to use as “output” a “print observed under about 500lux”.
-S AdobeRGB indicates that I want the AdobeRGB profile to be used to manage the perceptual and saturation rendering intents.
Now the profile is ready to use. A very interesting function in ArgyllCMS is that I can check how the profile behaves using a validation process (comparing the Lab values to generate the profile to the Lab values that the profile is using). This is the command:
profcheck -v2 -k -i D50 -o 1931_2 -w profile.ti3 profile.icm > logfile.log
As output I will have a 3D graph with vectors (the more the length, the more the DeltaE is) so that I can have an immediate “idea” of how the profile performs and I will also have a log file called “logfile.log” that I can export to Excel (or other similar program) to read all the worst DeltaE patches. In this way I can decide to re-read the patches with the high DeltaE errors. You can locate the patch and read it again. You will have to run charread with –r parameter (re-read) and you can read again in spot mode just the patchs that you want to.
After this step you can get results like this:
Profile check complete, errors(CIEDE2000): max. = 0.925663, avg. = 0.200191, RMS = 0.228265This is for an Epson 7900 with Hahnemuhle FineArt Baryta paper, patch used were about 2500.
Notice that there are many other interesting tools and possibilities in ArgyllCMS.
For example:
1) The mailing list is very active, you get fast answer to your questions.
2) All the files that you generate are text files that you can open and edit. For example you can add new patches to a previously generated test chart.
3) You can use the average tool to average measurements files.
4) Graeme Gill (software author) is always listening, adds new functions and corrects previous bugs or weakness according to users’ needs and reports. Look this discussion (and all the mailing list
:
http://www.freelists.org/post/argyllcms/PurpleBlue-shift-problem-with-Epson-printer