[Radiance-general] Color appearance and color temperature

Thu, 07 Feb 2002 11:59:14 +0200

Hello,

Does anybody know tools that might help in tuning chromaticity (color 
temperature) adaptation for Radiance renderings? For example, if you define 
a tungsten source (2856 K), the result is far too reddish to be plausible. 
This question arises when mixing sources of different temperatures, such as 
daylight and incandescent light. (When this is not the case, I suppose it 
is reasonable to use neutral source color, which in the Radiance RGB system 
is near 5500 K).

In pcond you have an opportunity to define, besides the RGB primaries, also 
the white point, with the -d option. Does it include any "color appearance 
model" or something of a kind which could be useful? Any other ideas? In 
photography there are filters defined in "mired" units, which mean 
reciprocals of megakelvins. They shift the overall color temperature range. 
So, at least in the spectral domain a feasible transformation might be 
quite straightforward.

Regards,
Markku N.

Markku_Norvasuo
Technical_Research_Centre_of_Finland