[argyllcms] Re: A possible problem with Colorprof and XYZ LUT profiles
- From: Kai-Uwe Behrmann <ku.b@xxxxxx>
- To: ArgyllCMS <argyllcms@xxxxxxxxxxxxx>
- Date: Thu, 16 Dec 2010 08:15:38 +0100 (MET)
Date: Wed, 15 Dec 2010 17:37:46 +0100
From: =?ISO-8859-1?B?SuFub3MsIFTzdGggRi4=?= <janos666@xxxxxxxxxx>
I had a conversation with Marti Maria about a possible lcms2 bug (possibly
broken absolute colorimetric rendering intent).
He asked me to send my profile. Here is the package:
http://www.tar.hu/janos666/abstest.rar
It includes my spectral measurement data (and a spec2cie converted version
from the ti3 file), my colorprof settings and the resulted ICM file.
The profile is indeed ~D64. As well I tested the conversion with lcms2
actual git and its behaves like D64 with a absolute colorimetric intent.
I found no visible whitepoint adaption for D65[e.g. sRGB]->D64[your_profile]
conversions, as expected.
He inspected my problem and his judge was that lcms2 works fine because my
display has D93 white point. (And the very brownish result is correct for my
display.)
For D93 that assumtion would be correct. But with the profiles from the
rar archive, I do not see a D93. So it might be a renderer issue.
But it's impossible, because this is is a factory calibrated display. It
can't be so far from D65.
According to the spec2cie converted measurement data, my white point is:
X=93.943
Y=100.00
Z=105.17
So, why does it look like that my WP is D93?
Can you make sure to use lcms from actual git in your renderer? tificc
would be helpful to track things down.
I have no idea, except that there is a bug in ArgyllCMS / colorprof. (I am
using v1.3.2)
As you can see, I used my original ti3 file, the spec2cie result stands for
debugging purposes only. And I didn't use any tricky or strange build
settings, I think.
kind regards
Kai-Uwe Behrmann
--
developing for colour management
www.behrmann.name + www.oyranos.org
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