[argyllcms] Re: Green Color Cast with LUT profiles

  • From: Pascal de Bruijn <pmjdebruijn@xxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Wed, 16 Sep 2009 08:37:55 +0200

2009/9/16 Nikolay Pokhilchenko <nikolay_po@xxxxxxx>:
> 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 dispread?

I ran dispread with -y l yes, I did not run dispcal, I'm not using the
VideoLUT...

Regards,
Pascal de Bruijn

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