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Re: PLI: property standards

"Steven M. Belknap" <sbelknap@UIC.EDU> writes on 951129:
> This implies that color *could* (not *must*, *could*!!) be defined by an
> external, objective standard, which would be potentially quantifiable on an
> interval or ratio scale in intensity and purity...

If you're on a UNIX system with X Window System, /usr/lib/X11/rgb.txt contains
the definitions of all colors known to X, numerically.  In principle the
can be set up so that if everyone put a patch of Peach Puff 3 on their screens,
all would be getting the same color of light.  (But it's hard to set up and
some parts are broken, too bad.)

The Pantone Book of Color is very useful in non-computer applications as the
of standard you describe.

Also, in humans there are variable numbers of copies of the receptor gene for
(I think it was).  0 copies -> color blind in that channel, but the people doing
the research were able to correlate sensitivity variations with copy number even
when it was nonzero.  Green and blue have one copy each.

James F. Carter        Voice 310 825 2897       FAX 310 206 6673
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