icc profile intent


(Gabriele ) #1

Hi ,
I created a new ICC profile for my display with ArgyllCMS without gamut mapping switch “-s”.

colprof -v -A"HP" -M"LP2465" -D"5000 °K 100 cd/mq" -aX -qm -cmt -dpp hp_100cd5000k

I have a profile with perceptual table A2B0 and B2A0 only but if I set this profile as monitor profile and switch intents I have light changing. Why if I have only one intent table?? Then I do not understand which source gamut ArgyllCMS takes count.

This is the profile hp_100cd5000k.icc (143.8 KB)

Am I missing something??

Gabriele


(Gabriele ) #2

For investigation,
I add to the profile a gamut mapping from Prophoto profile (-s colprof switch) ; the others relative colorimetric and perceptive tables are created and when I change in RT the monitor profile intent the image changes as aspected: there are the tables for that :face_with_raised_eyebrow:
For me, if there is only one tables the image would not have to change.

Right??


#3

Ciao, @dafrasaga,

Scusi, io stupido I believe is the correct description of myself: I do not understand your question :frowning:

However, it sounds interesting!
Could you please try to re-phrase the question?

Cordiali saluti
Claes a Lund, Svezia


(Gabriele ) #4

Hi Claes, you are not stupid :wink: the fact is I am not clear :face_with_raised_eyebrow:

OK, unfortunately English is not my default language and it’s hard to say what is not clear in my brain :sweat:

I re try…

Why Rawtherapee and Gimp, if I set as display profile an icc profile which has not relative colorimetric and saturation A2B and B2A tables, when I try to visualize relative and saturation intents by the button in the editor preview the image in the preview changes??
Very light but it changes…

I tried to use xiccle Argyll command with the same colorimetric coordinate with all intents and the output does not change…

Would be better if such intents are not present in the gui if such the intents are not in the profile…

Am I clear now??:sweat_smile:

More again,It’s not clear to me why if I create an clut display profile without any gamut mapping I have perceptual intent table only. What is the source gamut which is compressed for? @gwgill


(Graeme W. Gill) #5

What intents are you switching between ?

Note that Absolute Colorimetric intent and Relative Colorimetric intent are always available, since the profile data is Relative, and Absolute is generated by the CMM restoring the white point using the white point tag.


(Graeme W. Gill) #6

Note that many applications use the intent setting for both the source and destination profiles. So even if the destination profile doesn’t have a saturation table, the source profile might.


(Gabriele ) #7

Thanks Graeme for the response,

I switch between perceptual relative and absolute by the widgets under the main preview in RawTherapee…

image

Excuse me again but in this clut dell_20181103-0814-100cd-5000K-g2.2-L38-C42-R98-G89-B77.icc (188.3 KB) profile, are there relative (and absolute) and perceptual ? I only view the A2B0 and B2A0 perceptual table :neutral_face:


(Graeme W. Gill) #8

ICC Examin is misleading you. The profile is a V2.2 profile, and according to the corresponding ICC specifications, Display cLUT profiles up to and including ICC Version 2.3 are assumed to have only one set of cLUT tags, those being AtoB0 and BtoA0 with no interpretation of the intent. This actually implies Colorimetric since that is the only intent possible with a matrix profile, and is the neutral intent (i.e. it is the intent that doesn’t modify the devices characteristics for a particular purpose) .
So the profile only contains Colorimetric information.


(Gabriele ) #9

Graeme, thank a lot :smile: for the explanation,
therefore the changes I have when switch the intents are for the intents in the source profile.
Unfortunately I am no able to find Prophoto icc frofile Rawtherapee uses… I think it’s hardcoded.

Thanks again

Cheers
Gabriele


#10

Ciao, Gabriele!

Will this thread assist you?

/Claes


(Morgan Hardwood) #11

See Large: