Re: physical colors and Mathematica colors
- To: mathgroup at smc.vnet.net
- Subject: [mg26406] Re: [mg26392] physical colors and Mathematica colors
- From: Ben Jacobson <bjacobson at illumitech.com>
- Date: Wed, 20 Dec 2000 00:21:31 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
Hello Preston, If you just need to display the approximate color in Mathematica, the function Hue[] will get you most of the way there. See the help documentation and "Section 2.9.17 Advanced Topic: Color Output" in The Mathematica Book. If you need the actual equations, life will be more complicated. You should be able to calculate the CIE illuminants X, Y, and Z as integrals over the spectrum, and then convert them to various RGB or other values. Check out the excellent reference at http://vera.inforamp.net/~poynton/notes/colour_and_gamma/ColorFAQ.html Ben Jacobson Illumitech Inc. http://www.illumitech.com At 02:40 AM 12/16/00 -0500, Preston Nichols 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 > > >