[argyllcms] Re: Green Color Cast with LUT profiles

  • From: Nikolay Pokhilchenko <nikolay_po@xxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Wed, 16 Sep 2009 10:23:06 +0400

Pascal de Bruijn wrote:

> > I've noticed, that on some generic LCD displays with classical CCFL backlit 
> > get a green cast when calibrated with i1 Display 2 (a colorimeter). It's 
> > because most of consumer colorimeter have far not exact spectral 
> > sensitivity as in described in CIE standard for standard observer. The 
> > correction matrix are applied to colorimeter data for every kind of display 
> > type in software (LCD CCFL, LCD LED, Wide GAMUT LCD, Projectors). If Your 
> > kind of display wasn't corrected by matrix by manufacturer, the results may 
> > be quite far from wanted.
> Does this correction happen in hardware? Anyway I though the Huey was
> a stupid device... As in just a passive sensor... Since it has no
> firmware...

The firmware may mean not only the program code, but the simplest correction 
coefficient for certain device with certain filters and sensors.
The PC software may reads that coefficients from device memory (firmware) and 
use the coefficients to interpret the sensors data. The every type of display 
should have it's own coefficients in a colorimeter.

> Please note that only the single shaper matrix profile looks good on
> my screen... Even the multiple shaper matrix looks a bit greenish..

I'm glad to read it! :) So I'm right.

> I'd appreciate any pointers to what might be the issue...

The problem is in the Huey firmware coefficients, which are non-correct for 
Your display (and may be for other displays too). The device sensor may be just 
dirty. Or the devise may be broken.
Do You insured, that You have select the correct display type while dispcal and 

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