[argyllcms] Re: spec2cie feature request: CAT and cie2rgb parameters
- From: Graeme Gill <graeme@xxxxxxxxxxxxx>
- To: argyllcms@xxxxxxxxxxxxx
- Date: Sun, 17 Jan 2010 00:59:46 +1100
darkbasic wrote:
and I can also create my custom spectrum file with spotread, but I have to
manually chromatic adapte the XYZ/Lab coordinates from the illuminant
temperature to D50 and then convert the adaptated XYZ/Lab coordinates to RGB
Prophoto.
Hi, I guess I'm not following what you are after here. Are you attempting
to convert the absolute (ie. illuminant relative) to relative (ie. media
white point relative) readings ? Normally this is done inside the profiler
as it creates the relative colorimetric ICC table.
Note also that you can't have both a spectral and chromatically adapted
to D50 output at the same time, since there's no way to transform
the spectrum in the same way as the XYZ values, and the idea of
converting the spectral reflectance to XYZ under a certain
illumination spectrum and then chromatically adapting using
a matrix to D50 is a little odd anyway - why is this preferred
over directly converting to the spectral appearance under D50 illuminant ?
Where is the illuminant spectrum coming from that you're using ? (ie.
what illuminant situation are you making the chart appear as
if it was viewed in ?)
Why do you need to convert to ProPhoto ? If you're doing calibration,
don't you want CIE values ?
Graeme Gill.
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