[argyllcms] dispwin vs xcalib loading LUT

  • From: Frédéric <frederic.mantegazza@xxxxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Sun, 31 Dec 2006 11:36:18 +0100

Hello there,

I have a strange behaviour with xcalib vs dispwin when loading LUT. They do 
not seem to read the vcgtag the same way, depending of the profile.

Let me try to explain...

I attached a profile coming with xcalib package. This profile has a 2.2 
gamma. When loaded with xcalib, it does not change anything to my 
uncalibrated screen (no previous profile loaded). But when loaded with 
dispwin, the screen becomes very bright.

*But*, when I load an Argyll generated profile (also attached), they both 
give the same result!

I had a look in the profiles, with iccexamin, and I saw differences; it 
seems that the vcgtag is linear in Argyll generated profile, even if it is 
a 2.2 gamma profile. But I also see that the [rgb]TRC tags are, in both 
cases, the same (2.2 gamma curved).

Graeme, can you explain me how exaclty dispwin loads LUT? Do you know why 
xcalib does not give the same results only on its sample file?

Thanks,

-- 
   Frédéric

   http://www.gbiloba.org

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