abeles@mhuxm.UUCP (abeles) (08/10/84)
The discussion on color vision has been very interesting. In my observation, pigments available for creating colored objects or film have not always been perfect. For example, the older color motion pictures clearly have poorer color, with overemphasis on the primary colors. Also color television, in my opinion, does not create the same quality of color as do modern motion pictures; I can tell when a projection TV system is being used on an airplane movie that it isn't as good as the actual film. The question is whether the color quality is simply due to poor control on the mixing of the primary pigments. I do take issue with those who have claimed in this newsgroup that a simplistic interpretation of color is possible, based on the biological evidence that we are only sensitive to three color ranges. I don't take issue with the biological evidence, but I do think that an error can be make in the evaluation of that evidence: If it is true that our eyes only can collect data on three color components of the color spectrum, then is it true that any three color components are adequate for "simulating" for our protoplasmic optical receptors (eyes) the sensation that would be caused by any visible wavelength monochromatic source? Clearly, the answer is "no", since the three components could be chosen so that none of them contained any red, for example, and red would not then be possible. It doesn't seem to me to be quite as simple as choosing three basis vectors for a three-dimensional space, since two of the three components need not be completely the same (degenerate; or, if you prefer, parallel in the three dimensional space) in order to prevent all color "vectors" from being achievable. Obviously, however, eyes are not capable of fourier transforms in the way ears are. Artists using oil paints identify many pigments by their origin, as in "titanium white", as do at least some house paints. I assume that artistic tastes in such matters are determined from experience, and could not be justified entirely deductively but rather somewhat subjectively. One of the reasons, however, for specifying titanium dioxide as a pigment could be its color--maybe artists feel that it is not quite the same as other white pigments! That difference could be more than just the mixing of three primaries. I believe that my argument above does indicate that the mixing "theory" is, in fact, incomplete. Finally, the existence of poor pigments as mentioned in the first section above implies the existence of superior pigments. Viewing the colors of the late model GM cars, I would say that Detroit is competing with the Japanese by painting their cars with "high-tech" paints which create colors never before available. If colors are really just a linear combination of three basis vectors, would this be possible? --J. Abeles