[argyllcms] Re: Green Color Cast with LUT profiles

  • From: Florian Höch <lists+argyllcms@xxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Wed, 16 Sep 2009 17:17:35 +0200


just looked at some of the profiles, and the first thing I thought was "wow, is the gamut of that display limited" :) (way smaller than even sRGB, I've seen that on alot of TN panel displays, mostly Laptop/Notebook screens) - but I think that's maybe another issue altogether.

Regarding the green cast problem, how do you view the images (e.g. which OS, viewer application and setup)?

Also, just out of interest, why no dispcal (as mentioned in your other message)?


Florian Höch

Pascal de Bruijn schrieb:
2009/9/15 Nikolay Pokhilchenko <nikolay_po@xxxxxxx>:
Pascal de Bruijn wrote:

What instrument You have use?
A huey :)

If You have try a colorimeter, it may have a shift itself, because colorimeter 
matrix may be not optimized for your certain display(s).
I do not have a funky LED backlit display or something like that, so
that should be no issue...

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

And it _does_ work with single shaper matrix profiles.
Yes, It may work because of very restricted fitting capabilities of single 
shaper matrix. In general, there are rotary dispersion effect in the subpixels 
of LCD. The light spectrum, which passes through a liquid crysrals, are depend 
of crystals rotation angle. The effect is more distinctive at a maximum 
subpixel transparency level. So the averaged by gamut volume shaper data may 
not to be greenish, but fitted LUT data in certain transparencies levels can.
Do You try a shaper matrix, not a single shaper?

I've uploaded some sample files here:


It's the original ti3, all the generated profiles, the profiles are
named as the options used for colprof. I also converted some JPEGs
using jpegicc from lcms...

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

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

Pascal de Bruijn

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