How do i manually edit the whitepoint of a profile (after profile creation)

[Adnan Cesko]

I need The profiles to Specify that the WP is D65 even if it’s actually not due to me using the windows ACM feature which will do unwanted WP correction to D65. since i’m perceptually matching my WCG displays WP instead.

[Vincent]

Hex editor

+
ICC Profile inspector (https://www.color.org/profileinspector.xalter)to get the offset

+

format spec
https://www.color.org/icc34.pdf
wtpt -> XYZType -> XYZNumber -> s15Fixed16Number

but if your source profile has PCS white with actual white encoded in CHAD (not DisplayCAL’s) it may be too complex.

[Adnan Cesko]

Hmm i see so it’s not possible to do this with argytll/displaycal command line?

[Vincent]

AFAIK you can’t. You can extract info. or you can create an idealized matrix profile and attach VCGT cxalibration to it, but hacking individual tags no… its not meant to be used that way.

[Dadido3]

On the assumption that you are using github.com/dantmnf/MHC2 to generate ACM compatible profiles from your DisplayCal profiles:

There is a new option to do a chromatic adaption to the device whitepoint: You have to use the --chromatic-adaptationflag when you convert the profile.

[Adnan Cesko]

On the assumption that you are using github.com/dantmnf/MHC2 to generate ACM compatible profiles from your DisplayCal profiles:

There is a new option to do a chromatic adaption to the device whitepoint: You have to use the --chromatic-adaptationflag when you convert the profile.

Ohhh yeah that seems to be a option now didn’t know they added it, hopefully MS adds option for custom WP and maybe higher accuracy clamping since there still seems to be some over coverage of gamut.

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