Martin Florek wrote:
> I was able to create a profile with the web server, it works perfectly. 
> But I was unable to create a profile without the VCGT tag (and thus have 
> non-linear gamma). Should I use tone curve with gamma = 1.0 (relative or 
> absolute)? In the mean time I applied the calibration from .cal file 
> with applycal, but I would like to have a profile directly created 
> without this step.

No idea - I'm not sure what web server you are referring to.
It's easy enough using the tools directly - you get a profile
without a VCGT by default.

> Another issue with my profile is that Argyll showed average dE of 0.41 
> and max dE of 1.6 for my profile, but when I displayed L*a*b* of 30, 0, 
> 0, with the same display brightness, my meter (colormunki design) 
> measured L*a*b of approx. 49, 0, -22 

L*a*b* is a white relative measure, and you are (probably) comparing different
white point relative L*a*b* values, ie. display white point relative (typically
about D65) vs. D50 relative L*a*b*, hence the blue of b* -22.
> Another option is that Argyll's spotread does not work correctly with my 
> colormunki meter (or the meter itself is broken). The color looks like a 
> neutral gray color, without a tint compared to my x-rite color checker. 
> I tried to measure a perfectly gray (i.e. "a" and "b" to be as close to 
> the zero as possible), I got to a Lab values of 49.39, -0.16, 0.43 and 
> the color on the display was strongly yellowish/brownish. Any ideas?

Same thing. D50 relative neutral will look yellow brown when displayed
with absolute colorimetry on a D65 display.

Graeme Gill.


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