[argyllcms] Re: Black point gamut

  • From: Klaus Kompatscher <kkompatscher@xxxxxxxx>
  • To: <argyllcms@xxxxxxxxxxxxx>
  • Date: Sat, 19 Sep 2009 18:52:10 +0200

Hi Martin

Thanks for the advise.
I carried out your steps and got a similar black value as yours
if I check the value in colorsync.
Colorthink still shows me the L41....
Also by looking at the 3D Gamut in Colorthink I get a kind of a
small secondary color space starting from the black point going
side wards  .

Any ideas?

Klaus Kompatscher



On 19.09.2009 16:05 Uhr, "Martin Weberg" <martin.weberg@xxxxxxxxx> wrote:

> Hi Klaus!
> 
> 2009/9/19 Klaus Kompatscher <kkompatscher@xxxxxxxx>:
>> I get a black point of approx L41 a 17 b 37.
>> K black is L23 a 3 b 2.
> 
> I did make a profile from your data:
> colprof -v -kp 0 .15 .9 .9 .5 -L100 SapphireGloss
> [...]
> Find black point
> K only value (Lab) = 24.004226 0.869899 -1.800685
> Black point XYZ = 0.158615 0.163662 0.138984, Lab = 47.451325 0.468539
> -1.064285
> [...]
> This output is similar to your findings.
> 
> Then I tried sending Lab 0 0 0 abs col through SapphireGloss.icm:
> icclu -fb -ia SapphireGloss.icm
> 0 0 0
> 0.000000 0.000000 0.000000 [Lab] -> Lut -> 0.997033 0.077146 0.008354
> 1.000000 [CMYK]
> and back again:
> icclu -ff -ia SapphireGloss.icm
> 0.997033 0.077146 0.008354 1.000000
> 0.997033 0.077146 0.008354 1.000000 [CMYK] -> Lut -> 18.511783
> -1.502135 1.800392 [Lab]
> 
> And we end up with Lab 19 -2 2 which seem resonable.
> 
> Martin Weberg
> 


Other related posts: