From Photon to Pixel

5Color

On the one hand, the concept of color is the result of a subtle operation between the physics of electromagnetic radiations and on the other hand, the psycho-physiology of perception. This double inheritance justifies the complexity of the explanatory mechanisms of color. It is also not surprising to learn that color, since the antiquity, has caught the attention of both the greatest philosophers and physicists. We will quote, in particular, Aristotle, Plato, Pythagoras, Locke, Young, Newton, Goethe, Dalton, Rayleigh, Helmholtz, Lorentz, Maxwell, Schopenhauer, Husserl, Land and many others¹.

Is is therefore a difficult task to expose in a few lines the main elements of the reproduction of colors by the photographic camera, and we can be certain that we will miss important developments. This is all the more true as the field continues to unravel many unknown as modern techniques for examining biological structures and of perception mechanisms are beginning to appear. A number of excellent books are fully dedicated to color to which we gladly refer the reader who wishes a comprehensive approach of the field [HUN 95, KOW 99, WYS 82].

Faced with the immensity of the topic, what are the objectives of this chapter?

They could be reduced to two formulas:

• – How can a colored field be effectively and accurately acquired?
• – How can this recorded information be restored to account for the perception that the photographer had thereof?

In order to fulfill these objectives, we should ...