Evaluating a Printer Profile

[KeithM]

I have been on quite a journey for the last month trying to create my own ICC profiles for my printers. I had a Spyder instrument, but just could not get a decent profile with it. So, I managed to find a new ColorMunki on eBay. I have been using Argyll to calibrate my monitors for several years, and I have been so happy with the results that I thought I would learn how to use it for creating my printer profiles. I've done a ton of reading to learn how to use it, and what settings to use in order to achieve the profiles that I am looking for. I am now getting profiles that I am very happy with. I have downloaded a test image from Keith Cooper's site and have been using that to evaluate the results. Both the test images and my prints look great with my Argyll profiles.

I only have one unresolved curiosity. Argyll has a function (profcheck) for testing the profile. I can use the function, but I don't know how to interpret the results. Following is a graph showing the results of a recently generated profile for Moab Lasal Lustre on a Canon Pro-2000 printer, using 836patches:

View: original size

Profcheck tells me that the test results shows errors (CIE94): max. = 0.841293, avg. = 0.251627, RMS = 0.288972

Are these results good, bad, or average? Can I tell if the largest errors relate to a particular color? If so, can I improve the profile by using additional target patches from that color range?

I noticed while trying to find an answer on this site before posting, that people are using Gamutvision to examine their profiles. I've downloaded and installed it, but really don't know that it is telling me. Is there a "Gamutvision for Dummies" somewhere? I'm working through their instructions, but finding it a bit overwhelming. For example, these two plots do not look anything like what I see posted elsewhere on this site.

If I am going to go through the effort of producing my own profiles, I want to make sure they are better than what I can download from the paper manufacturers or it is not worth doing. That is why I am keep to learn how to judge a good profile from a bad one. It would also help me to spot a problem profile before I try to use it and waste a lot of ink and paper.

Any and all help appreciated!!

 

[marco565]

Tu be honest profites from the manufacturer a good one like Hahnemuhle will probably better than the profiles created with argy for the perspective rendering intent. I all not ultra convinced about the profiles from argy compared the one made by manufacturers. It comme useful if you have a different ink set or a printer that you can not find profiles. There is a huge topic in this form about how to make profiles with argy (more than 40 pages) read though there is good information. Basically you need to make sure the measurements are correct. A low deltaE is necessary.
Hope that helps a bit.

 

[Ink stained Fingers]

Gamutvision is not supported anymore since a long time by Imatest, you have to use it on an 'as is' basis including the available documentation - tutorials etc

https://www.imatest.com/gamutvision/

I'm not aware on other software for the private user - basically for free - which would allow you to analyse profile performance beyond the display of gamuts.

But what is the aim of all that - what is a 'better' profile created with ArgyllCMS or ColorMunki or i1Profiler or ???

 

[KeithM]

Yes, I guess that is what I was asking. I know I can create a profile, but how do I know it is any good. I know I can create bad ones since all of the ones I created with Spyder were bad. I guess my test prints tell the tale, and they certainly look good.

 

[Ink stained Fingers]

A method to evaluate a profile is described here

http://marcelpatek.com/imatest.html

But keep in mind that this article covers only displays but not printers - printer profiling is left for a future update but the posting is already very old - from 2008 , and the method could be transferred to printer profile evaluation as well.

The overall approach should be simple - you print your target sheet again - now with the profile you created for that ink/paper combination, and you compare the findings with the original color values of the original patch sheet you printed w/o profile. Keep in mind that this only works with the abs. colorimetric rendering mode, all other modes introduce significant color changes - compress colors in relation to the gamut etc , or look to black point compensation. And you always have to exclude out of gamut colors - they by definition cannot be printed correctly with whatever profile and rendering intent.

Comparing the printed colors with the reference target is exactly what color control methods for print production do - like FOGRA - a German industry standard and method for this purpose.

 

[KeithM]

I like this approach, perhaps because I can understand the principle at work here. Thank you. I will try doing this with one of my profiles and see what I can learn.

 

[Smile]

PM me I will send you a certification target, print and mail me the target, I'll send you the report.

 

[jejes]

Hello, I'm creating the printer profiles with IProfiler and argyll. I would like to know if it exists a program like Oris Certified Proof but for RGB. I used this app in the past to certify my proof was ok with ISO standards. Is there any app? Oc can i do with IProfiler or argyll ?

Thank You

Is there a better way than doing like this? This is my theorethical proof, but i would like to use with a printed chart.

Here's details on my calls to ArgyllCMS:

targen -v -d2 -G -e2 -B 2 -g64 -f210 validate
printtarg -v -i CM -h -T300 -pA4 validate
cctiff -ia .\sRGB.icm .\i1_1xa4.icm .\validate.tif validate_abscol.tif
(or use -r for relative colorimetric)
chartread -v -T "0.4" validate
profcheck -v -k -s -I r .\validate.ti3 .\printerprofile.icm