Luminous Landscape Forum

Raw & Post Processing, Printing => Colour Management => Topic started by: Ryan Mack on February 01, 2020, 06:47:45 pm

Title: Perceptual profiles from ArgyllCMS lightening the image?
Post by: Ryan Mack on February 01, 2020, 06:47:45 pm
I donít understand why the perceptual profiles generated by Argyll CMS significantly lighten the image. None of my profiles made by other tools or provided by my rip or the paper manufacturer do that. Argyll CMS relative colorimetric is more or less is equivalent to my other profile sources. Itís only the perceptual profiles that have this behavior. Itís like it has baked in strong black point compensation and thereís no way to disable it. Anyone know how to turn this off when generating the profiles or can explain why I would want this?
Title: Re: Perceptual profiles from ArgyllCMS lightening the image?
Post by: Doug Gray on February 01, 2020, 07:02:22 pm
I donít understand why the perceptual profiles generated by Argyll CMS significantly lighten the image. None of my profiles made by other tools or provided by my rip or the paper manufacturer do that. Argyll CMS relative colorimetric is more or less is equivalent to my other profile sources. Itís only the perceptual profiles that have this behavior. Itís like it has baked in strong black point compensation and thereís no way to disable it. Anyone know how to turn this off when generating the profiles or can explain why I would want this?
Argyll's colprof normally creates a Perc. that is the same as Rel. There are multiple options for making different Perc. tables. What options are you using?
Title: Re: Perceptual profiles from ArgyllCMS lightening the image?
Post by: Ryan Mack on February 01, 2020, 07:04:38 pm
Argyll's colprof normally creates a Perc. that is the same as Rel. There are multiple options for making different Perc. tables. What options are you using?

./colprof -v -qh -r1.0 -S AdobeRGB1998.icc -cmd -dpp -D"Canon PRO-4000 / Harman by Hahnemuhle Gloss Baryta" glossbaryta
Title: Re: Perceptual profiles from ArgyllCMS lightening the image?
Post by: Doug Gray on February 01, 2020, 09:18:21 pm
./colprof -v -qh -r1.0 -S AdobeRGB1998.icc -cmd -dpp -D"Canon PRO-4000 / Harman by Hahnemuhle Gloss Baryta" glossbaryta

You might try -cmt or -cmb instead of -cmd. Also you could try percentages like -S 20. Personally, I don't usually use Perc. tables preferring to adjust things in Photoshop using Rel. Col. To me Perc. is just an unknown. There's no standards for it. I sometimes use it (with XRite profiles)  in Photoshop for non critical stuff. XRite's Perc.'s default doesn't distort things much. But it's never been clear to me exactly how Argyll's various options map Perc. and I really haven't dug into it. Perhaps others here have specific experience with Argyll's Perc.
Title: Re: Perceptual profiles from ArgyllCMS lightening the image?
Post by: Ryan Mack on February 02, 2020, 07:29:38 am
You might try -cmt or -cmb instead of -cmd. Also you could try percentages like -S 20. Personally, I don't usually use Perc. tables preferring to adjust things in Photoshop using Rel. Col. To me Perc. is just an unknown. There's no standards for it. I sometimes use it (with XRite profiles)  in Photoshop for non critical stuff. XRite's Perc.'s default doesn't distort things much. But it's never been clear to me exactly how Argyll's various options map Perc. and I really haven't dug into it. Perhaps others here have specific experience with Argyll's Perc.

Ah, thank you for that! Using -cmt made the issue go away! I guess my thinking was backwards here. I thought setting the viewing conditions to a dark room would make the image darker because my monitor likely appeared too bright. But instead it made the print brighter to match the monitor appearing too bright. That makes more sense but just isn't how I was thinking about it before.