[argyllcms] Re: FWA overcompensation bug in spec2cie

  • From: Alexey Gribunin <Gribunin@xxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Thu, 15 Jul 2010 14:18:03 +0400

Hello Gerhard!

I think you are assuming that the FWA compensated spectral reflectances
would be generic.

Yes, exactly.

So I don't see why it should make sense to
compute FWA compensated spectra for D50_0.0.sp, but then assume a
regular D50 illuminant for converting these compensated reflectance
spectra to XYZ.

Why not??? I want to simulate UV cut measurement device.
Graeme wrote in ArgyllCMS manual the following:
"Note that using the ref/D50_0.0.sp spectrum with -f gives a result that is comparable to that of a U.V. cut filter".

So I consider this feature as a simulation of UV cut filter.
And now the question. How do you use spectral measurements from UV Cut device? Do you create ICC profile with the regular D50 light source or with the "special UV Cut" light source?
I think, you will say "regular D50", right?
Ok, that's why I'm trying to get either filtered spectrals (which simulates UV cut measurements) or Lab values, calculated from that filtered spectrals with STANDARD D50.

Best regards,
Alexey Gribunin,
UNIT Color Technologies,
Moscow, Russia.

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