Re: physical colors and Mathematica colors

*To*: mathgroup at smc.vnet.net*Subject*: [mg26416] Re: physical colors and Mathematica colors*From*: malakm at rpi.edu (Michael Jay Malak)*Date*: Wed, 20 Dec 2000 00:21:39 -0500 (EST)*Organization*: Rensselaer Polytechnic Institute, Troy NY, USA*References*: <91f7u4$55k@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

PNichols at cornell-iowa.edu writes: >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 > Preston, There are a number of references listed at http://www.physics.sfasu.edu/astro/color.html although I think that none of them is written in Mathematica. There is actually a well-defined correspondence between wavelength and RGB (see http://www.physics.sfasu.edu/astro/color/cie_xyz1964.html), although I'm not sure how brightness figures in. Of course, translating it to the screen also involves issues like gamma correction. Mike -- Michael Malak | 1. All syllogisms have three parts. Wolfram Research, Inc. | 2. Therefore, this is not a syllogism. malak at wolfram.com