🚀 go-pugleaf

In article <1993Jan8.110908.484@otago.ac.nz> athomson@otago.ac.nz (Alastair Thomson) writes:
>In article <C0HM2E.Grx@cs.dal.ca>, legrady@ug.cs.dal.ca (Tom Legrady) writes:
>> 
>> If you have white light light and remove the red, you wind up with
>> cyan.  No two ways about it. Remove the green from white and the
>> remainder is magenta. Take out the blue and the result is yellow.
>
>The question here is what do you mean by "white light", or "green", do you mean
>the entire visible spectrum?, do you mean what you see as white on a CRT?, is
>green one wave length?, is green a range of wavelengths?, what range?  
>
>The real difficulty is that we are talking about the perception of colour, not
>some mathematical model of it. If the original poster could specifiy exactly
>why they want to do the conversion I may be able to help some more

"White light" is any spectrum that looks white to the human visual system.
This includes a flat spectrum among many other shapes.  Likewise, green
light can be monochromatic or consist of a spectrum with most of the
energy concentrated in the green wavelength band.

Since we're talking about the perception of color, the important thing
to remember is that (under the opponent-process theory) we have three
types of receptors (Red, Blue, Green), which are combined into three
opponent processes: Red-Green, Blue-Yellow, and Black-White.  So given
any light that looks white, if you remove a part of the spectra that
would look "greenish", the remainder will look "reddish".

Ed