Re: physical colors and Mathematica colors

*To*: mathgroup at smc.vnet.net*Subject*: [mg26414] Re: physical colors and Mathematica colors*From*: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>*Date*: Wed, 20 Dec 2000 00:21:37 -0500 (EST)*Organization*: Universitaet Leipzig*References*: <91f7u4$55k@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Hi, a) the conversion in a nice FORTRAN program can be found at http://www.physics.sfasu.edu/astro/color.html b) You can dwonload a Mathematica package ColorFuntions.m form http://phong.informatik.uni-leipzig.de/~kuska/visualsupp/ColorFunctions.m with a function SpectralColor[h] that returns the RGB colors for h in [0,1] (or lambda in [380,700] nm) the scalung for h in [0,1] is done to use it as value for the ColorFunction option. Regards Jens PNichols at cornell-iowa.edu wrote: > > Dear Group, > > 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? > > Of course, it is not essential that the result be RGBColor; any other > standard computer-graphics color model would do the job (HSB, HLS, CMY, > CMYK, etc.), because the conversions are standard. It's only the conversion > between one of these and physical wavelengths which I don't know. > > 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"? > > I shall be grateful for even the smallest suggestions. > > Preston Nichols > Visiting Assistant Professor of Mathematics > Cornell College >