Color Charts under two illuminant

[Saeideh Gorji]

Hi,

I search for the rgb data of a specific chart such as macbeth captured
by a specified camera under 2 illuminants (for instance: A & D65). Is
there anyone who can help me please?

Thanks,

Saeideh

[Gernot Hoffmann]

Post by Saeideh Gorji
Hi,
I search for the rgb data of a specific chart such as macbeth captured
by a specified camera under 2 illuminants (for instance: A & D65). Is
there anyone who can help me please?
Thanks,
Saeideh

The spectral reflectance factor data of the GretagMacbeth ColorChecker
are available, for me in a file which came with ProfileMaker5.
See p.16 here:
http://www.fho-emden.de/~hoffmann/camcal17122006.pdf

Multiply the reflectance spectrum by the spectrum of your illuminant.
Then multiply by x-bar and integrate (sum up). This delivers X.
Similarly by y-bar for Y and by z-bar for Z.
Apply a normalization: Y=1 or 100 for the perfect diffusor under the
illuminant.
Calculate (R,G,B)^T = Crx*(X,Y,Z)^T
using the appropriate matrix Crx, e.g. for sRGB, AdobeRGB,
ProPhotoRGB.

Best regards --Gernot Hoffmann