[Radiance-general] color calculations in mgfilt

[Greg Ward]

Hi Lars,

I'm pretty sure mgfilt does its calculation with an equal-energy white, not D65 or any of the other standard illuminants.  Try repeating it with EE white to see what you get.

Cheers,
-Greg

Sent from my iPad

> On Nov 15, 2013, at 3:27 PM, "Lars O. Grobe" <grobe at gmx.net> wrote:
> 
> Hi,
> 
> mgfilt is not really part of the core Radiance package, but typically
> used with Radiance. So I hope this is not entirely off-topic.
> 
> I have been using mgfilt from time to time as a convenient tool for
> getting color coordinates from measured reflection spectra. However some
> results appeared a bit strange, and thus I did a comparision with what I
> get from mgfilt and the results of using the CIE formulae with rcalc
> instead. To make it short, the results I got from mgfilt were quite off,
> and I am wondering wether I did something wrong or the accuracy
> implemented in mgfilt is really that much worse.
> 
> I uploaded a short report on the comparison here:
> 
> http://static.larsgrobe.de/spec2Yxy-20131115.pdf
> 
> Cheers, Lars.