[Tool] ChromIQ – a macOS and Windows GUI for ArgyllCMS printer profiling (v4.3.0)

[itsab1989]

Well I made this whole app with the help of AI because I myself was not able to use Argyll in the commandline. So I trusted Claude to offer every option of every part of Argyll that makes sense for printer profiling so one does not have to remember it. There is the following option in the build profile tabs manual module (= colprof), howeer I think this only applies to true CMYK and CMY+N printers:

 

[AmaDeuSbg]

Thank you for your fast replies. I hope I will find time tonight to install (hopefully successfully Agryll, because I never did) and do a test.

Strangely (or maybe not, I do not really understand how ccstudio engine works), if on profiling chart my black measures 1,7 , 7,2, -0,1, created profile prints black 4,2, 1, 1,1. If with another sub paper printed the black on the profiling chart measures 7,4, 9,4, -9,6, the printed black with that profile measures 3,4, 4,8, 1,8 (which at least visually appears much darker but with a brownish tint?). Both are on white glossy alum. sheets and first test with the L1.7 just looks amazing but the profile it creates is just nothing visually comparable to the black on the profile chart.

 

[MeandmyET18100]

Hi guys,
I'm new here, I just registered because I hope you can help me. Thanks in advance for your help and for creating this software/community etc.
My printer is Epson ET-18100 and I have a Colormunki Photo.
I used to make profiles for my printers with CCStudio and it worked, but even after refining the profiles there was still a slight but noticable color cast.
CCStudio doesn't give much options to get better profiles, so I decided to try ChromIQ. I started usind the guided mode. The first profile created with a chart with 4 pages and 420 patches also showed a minimal color cast. I refined the profile with another chart with 5 pages and 484 patches and now the cast is almost gone.
But the problem with the profiles I get with ChromIQ is, that the blacks are not good. See the attached screenshot of the softproof: every square under "20" in the bottom left is pure black and not visible. That was way better with the profiles from CCStudio.
So what can I do now? I'd love to have both: Good details in the shadows/blacks AND a neutral print without color casts.
I don't know anything about Argyll, so I don't understand anything else than the guided mode in ChromIQ. If you want me to use manual mode, you'd have to give advice like to a 6-year-old ;-)
Maybe I have to use a different test chart? I found one in this thread, "A3+_TC918_extended_greys_1160_patches_Colormunki.zip", but I can't use it, because I can't read those small patches with my Colormunki. I don't have a ruler for it.
Please help!
Thank you so much,
M.
P.S. I didn't mention that I used "relative colorimetric" as the rendering intent and simulated paper and ink in the softproof. With "perceptual" the blacks seem to be better, but I don't like the colors to be shifted at all...

 

[itsab1989]

What kind of paper did you use for your tests? This plays a big role in this.
Also you could look into the presets for charts that the app ships. Those are with a little more care than the automatically created one for example the one in the screenshot which puts more than 600 patches on 2 sheets of A4 paper. I think Knut made it in a way that you can use a regular ruler to align the Colormunki. You have to try and move slow and steady though. That being said I have never tried it with a ruler myself.
And maybe @pharmacist has an idea what might have gone wrong.

A few things that come to my mind:

-After printing you should let the test chart dry a good amount of time.
-for measurement you should place a blank sheet of the same paper underneath the one you are measuring. Especially on thinner paper the surface of a dark table might shine through otherwise and affect the measurement.-
-cheap matte papers won’t give as much shadow details as higher quality glossy papers

 

[pharmacist]

Try to disable BPC in your driver. In the past I posted a particular problem with argyllcms created profiles that doesn't use pure black when you choose BPC as the engine wants linearize the grey step and with a small amount measurement points and pure black is seen as way off from the measured slope and thus argyllcms compensates this by lifting the black paint upwards to a dark grey. Commercial profiling programs keeps the measured maximum black as a absolute black point, but in argyllcms this depends on the chosen intent. So relative colorimetric intent with BPC lifts the black point. So try to disable BPC so the Profile can use pure black....albeit it can give clipping in the area from dark grey toward pure black. In perceptual intent this aspect is already taken into account but can give distortion in the rendering of out of gamut colours.

 

[MeandmyET18100]

@itsab1989 Thanks for your input. But those things are not the problem. I let the test charts dry for several hours and I always put about 10 sheets of the same paper beneath a chart while measuring. I'm using Epson Matte Paper Heavyweight. And it can give deep blacks and good separation in the dark tones! I know this because the profiles from CCStudio show this! But those profiles always have color casts.
I don't want to fiddle with narrow patches, I don't mind printing them big and splurging on sheets of paper, because I'd like to read them easily with the colormunki. The question is: which charts will me help to get better separation in the blacks? (With the relative colorimetric intent, of course. I really don't like perceptual, because it shifts colors too much, I almost always get color casts with it.)
@pharmacist Thanks for your answer! I think maybe you have a point... So why is there no option in Argyll to have the same behaviour with the maximum black as absolute black point? There seem to be an almost infinite number of options, why not this one? I don't get it. Is there a workaround for this in Chromiq? Anything?
I printed some pictures with the profile from Chromiq and BPC set to off - and what a difference this made!!! Thanks for the hint! Seems like my printer uses full color for the first time! It puts more ink onto the paper, alle colors have more punch. (And no, it's not the same as cranking up the saturation before printing.)
So for now I get the best prints by using the profile I made/refined with ChromIQ and sending them to the printer with BPC off. Best prints in many years.
What I really don't get wrapped my head around: for so long I made profiles and fiddled around with softproofs and settings etc. but nobody told me that it can make a big difference to turn off BPC???!! And in Lightroom there isn't even an option to do so, it's always on by default and almost everbody on the internet tells you "yeah you want it that way"??!! (At least that's what I found in the past.)
Conclusion: profiles from ChromIQ/Argyll have better colors (more neutral, less color cast), but have a bad black point when using relative colorimetric for my prints. Unless I turn off BPC.
Is there another solution to this problem? I think this should be adressed in ChromIQ/Argyll somehow!
Thanks again,
M.

 

[pharmacist]

Some information from Google Gemini:

AI-overzicht


When using Relative Colorimetric intent with Black Point Compensation (BPC) enabled on an ArgyllCMS-generated profile, pure black (RGB 0,0,0 or CMYK rich/k-only setup) may not print as a flat or maximum-density "pure" black due to how ArgyllCMS handles device black points, neutrality, and colorimetric mapping:

• True Media Black vs. Pure Digital Black: In strict Relative Colorimetric mode without BPC, RGB 0,0,0 maps directly to the printer and media's measured black point (the maximum density the printer can physically achieve on that specific paper, which often has an \(L^{*}\) greater than 0 and a slight chromatic tint like warm or cool gray). [1, 2]
• • Black Point Compensation (BPC) Scaling: BPC does not force an RGB 0,0,0 input to output a arbitrary "pitch black" or 100% K ink dump; instead, it scales and compresses the shadow tonal range so that the source space's black point matches the destination (printer/paper) black point. If your paper's maximum black point is elevated or non-neutral, BPC preserves shadow graduation rather than clipping everything to a single heavy ink dump. [1, 2, 3]
  • ArgyllCMS Neutral-Axis Steering: ArgyllCMS’s profiler (colprof) tends to steer toward smooth, natural, and neutral near-black behavior rather than arbitrarily forcing a composite or non-neutral maximum ink mix that could cause bronzing, hue shifts, or blocked-up shadow detail. If the printer/ink combination has a non-neutral black point (e.g., brownish or cool gray shades at maximum density), ArgyllCMS honors the measured colorimetric behavior rather than faking a neutral "super black" in the relative colorimetric table. [1, 2]
  • Perceptual vs. Colorimetric Intent: If you want a deeper or re-mapped black that alters the shadow/neutral axis for visual depth rather than strict colorimetric accuracy, using ArgyllCMS’s perceptual options (such as -t la for luminance-axis matched appearance) or adjusting your source file's tone curves is typically required. [1, 2, 3]

 

[pharmacist]

@itsab1989: Maybe chromiq must change the standard colprof setting in order to accommodate maximum black level for pure black in the relative colorimetric intent with BPC on to prevent these problems in the future.