Re: physical colors and Mathematica colors
- To: mathgroup at smc.vnet.net
- Subject: [mg26394] Re: physical colors and Mathematica colors
- From: "Borut L" <justmyname at email.si>
- Date: Wed, 20 Dec 2000 00:21:23 -0500 (EST)
- References: <91f7u4$55k@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
> I am working on a package for which I need a function which takes a
> wavelength of light (in nanometers, for example) and returns an RGBColor
> specification. Has anyone made such a function for Mathematica?
>
> I understand that human color perception is a complicated matter, and so
is
> rendering of color on computer display devices. (The brightness dimension
> is perhaps the most obvious ambiguity.) It's probably nonsense to ask
for
> a "perfect" correspondence between wavelength and RGB. But is there a
> "standard" mapping? Or one that you think is "pretty good"?
Hi,
I don't think that will be much help to you. I hope at least a bit.
Anyway, I guess linear mapping from wavelength to hue percentage domain is a
good first order approximation.
hueValue[lambda_] := Fit[{{380, 0.8}, {750, 0}}, {1, lambda}, lambda]
Where 380nm corresponds to violet and 750nm to red, and correspondig hue
values are 0.8 and 0.
I don't know if binaries are permitted in this newsgroup (if not, they
should be!), but I even made an image collaged from 'true' (above) specter
and Mathematica Hue (below) linear specter. [no binaries - contact the
author to get this - moderator]
Usage of Hue[h] is equivalent to Hue[h,1,1] where saturation and brightness
are taken to be 1, i.e. 100%.
Well, bye
Borut Levart
a physics student