Colormunki/ArgyllCMS profile lacking dark tones (compared to ccStudio)

[pharmacist]

Did you use perceptual intent or relative colorimetric ? ArgyllCMS profiles have a particular behaviour that for relative colorimetric intent you will have to disable black point compensation to achieve the deepest black.

 

[Ink stained Fingers]

I don't have problems with posting comments in this thread - everything appears to be normal for me.

Here is the patch distribution in the Lab space



There are quite some more control points in the lower - darker range of the sRGB space, but I overall would not expect this the main cause for the missing blacks in the profiles.

Please post one of your erratic profiles - Gamutvision may reveal some other details in this respect. I remember the case of the missing blacks @pharmacist is referring to, it was related to the rendering intent BPC on or off .
(But since I'm not an active ArgyllCMS user I didn't follow it to the last detail. )

 

[pharmacist]

Please upload the generated *.ti3 file, so we can look at it and I can regenerate the profile and look for some crulpits in it. The 480 patch target is proven to be a very good target and should be even better compared to the 50 + 50 method of X-rite/Calibrite even with 2 extra optimization scans.

 

[lmylm]

Did you use perceptual intent or relative colorimetric ? ArgyllCMS profiles have a particular behaviour that for relative colorimetric intent you will have to disable black point compensation to achieve the deepest black.

I actually used both and all. With perceptual rendering intent it is a bit better, still not as good as with the 50+50-patch profile by ccStudio.

Please post one of your erratic profiles

Please upload the generated *.ti3 file

Sure! I attached a zip file with both the ti3 and the icc file.

 

[Ink stained Fingers]

Thanks for the data - what is the type of paper you profiled in this case ? Do you have a profile created with ColorMunki or ccStudio which can be used for comparison and the readout of the blacklevel .?

@pharmacist is referring to some issues with the BPC option , here is a plot of the graylevel curve without BPC, it shows a blacklevel of 20 at L*=0 and some spikes in the lower L-range



and here below with BPC=on , the level at the left L-axis with BPC=on is up by about 5 vs. the curve above which is apparently one of the overall problems. The other issue could be that the black level is too high in both cases , a profile generated a different way should clarify tlhis by comparison.

 

[Ink stained Fingers]

You may review this thread which is quite lengthy and from about a year ago - it deals with about the same problem as yours

https://www.printerknowledge.com/th...e-black-when-checked.15740/page-5#post-138240

 

[Ink stained Fingers]

@lmylm - I think we can conclude your inquiry at tlhis state , there are some issues with ArgyllCMS which you got into. They relate to the use of the BPC - black point compensation - function which interferes to a degree with the perceptual rendering intent, and as well profiling of papers with a weak black level - uncoated - Fineart - normal papers can lead to some erroneous black levels in the rel col rendering mode, and both effects together can make it worse.
These issues are not that well published and may not effect most of the ArgyllCMS users at all or their effect ist not directly visible.

 

[lmylm]

@Ink stained Fingers

Thank you for all your replies. I have read them all. Sorry for not getting back to the subject though. This week was a nightmare. I had a medical emergency with a short stay at the hospital. Recovering slowly. That’s why I heavy-heartedly have to postpone taking care for my printer problem. Even though there are so many things I would like to mention.

I also read the beginning of the thread you linked. I am sure the BPC is not my problem. No matter if I turn BPC on or off, the problem persists.

Also I am sure that the rendering intent is not the problem: no matter if I used relative colorimetric or perceptual the problem existed with both intents.

I am also sure the matte paper is not the problem. I also profiled satin and pearl paper getting similar results. They have much much stronger black levels and definitely are coated. The pearl paper isn’t even cheap at 2.40 Euros per A3 sheet. Only for demonstration purposes I uploaded samples for the matte paper (because there you could see the effects the strongest).

As soon as I have a little more time on hand I would like to add some more data to this thread. I can also add profiles for the pearl paper. And maybe @pharmacist will find out something has they offered to regenerate the profile with the .ti3 file I supplied. Still hoping to find out how to correctly use ArgyllCMS as everyone using it seems to be so happy with it.

 

[Ink stained Fingers]

Let me first wish you a quick recovery from your sickness; please be aware that ArgyllCMS is raising the blacklevel for a profile with rel. col. intent and BPC on, exactly tlhis was already discussed in the thread a year ago, and as well with the author of ArgyllCMS, and there is a related problem with the use of the perceptual intent; these are deviations of the ArgyllCMS behaviour vs. other profiling packages , particular combinations of BPC and coloring intents should not be used. And these are effects you cannot test away. I haven't seen this with quite some other profiling packages besides XRite/i1, MonacoProfiler, ProfileMaker 5, EFI profiler, PrintProfiler by ColorConfidence

 

[Ink stained Fingers]

Here is my last curve - the gray level response for the 480target profile - it reads out a blacklevel of 18.7 as embedded in the profile header data. The diagram with the perceptual rendering intent with BPC on shows this - the curve starts at a black level of about 34 - a dramatic increase of almost 16 . Lots of programs turn on BPC by default with the perc. rendering intent since BPC is part of the attempt of a perceptually appealing color reproduction - these are this Gamutvision program or the Thumbsplus editor or Photoshop Elements and probably some more. Issues are most likely identical on a Mac computer.



I must admit I don't like an icc-profile which changes the black level that much; I don't think it's the job of an icc-profile at all to manipulate the blacklevel. But if that is not known to the user the softproof function of some programs deliver you a distorted image and may lead the user to some suboptimal changes to his image.