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Hi,
You may use lcms to do that
programmatically:
hSrc = cmsCreateLabProfile(&D50);
hDest = cmsCreateLabProfile(&D65);
xform = cmsCreateTransform(hSrc, TYPE_Lab_DBL,
hDest, TYPE_Lab_DBL, INTENT_ABSOLUTE_COLORIMETRIC, 0);
...
Or, if you are sure all your data is inside sRGB
gamut, use following trick:
- Load Lab image in Photoshop, it is using D50
- Image-mode-convert to profile-sRGB USING ABSOLUTE
COLORIMETRIC. You have now D50 data as seen by an D65 adapted observer
(yellowish)
- Image-mode-convert to profile-Lab USING RELATIVE
COLORIMETRIC intent.
Voila. But this will only work for values inside
sRGB gamut.
Regards,
Marti.
----- Original Message -----
Sent: Friday, January 30, 2004 12:44
PM
Subject: [Lcms-user] Re: Convert a lot of
Lab measurements to a different observer temperature?
Um - typo - Photoshop only supports D50, of
course.
----- Original Message -----
Sent: Friday, January 30, 2004 10:41
PM
Subject: Convert a lot of Lab
measurements to a different observer temperature?
Hi,
I need to convert many D50 Lab measurements
over to D65 illuminant. I.e, I need the new measurements to be
equivalent to
the measurements I *would* have measured, had I
set my colorimeter to D65.
Any ideas how I could do this? Unfortunately,
Photoshop only supports D65 Lab, otherwise I could have used
it.
(I can definitely bring the measurements into
Photoshop, though, if you think there is a way to use
Photoshop)
Thanks,
Greg.
p.s I really don't want to take all the
measurements again. ;^)
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