Chapter 5

Colorimetry 1

5.1. Introduction

Color is an integral part of our daily lives and seems, at first glance, to be a familiar and therefore trivial notion. However, if we reflect carefully on the question, it is not that simple to explain what color is. A classical dictionary definition might state: “Color corresponds to the character of light or of the surface of an object according to the particular visual impression produced”. Unfortunately, such a definition is far from satisfactory, essentially because it emphasizes the physical stimulus which induces a visual impression, and offers no description of the visual impression itself. In addition, this definition would not be very useful to someone who had never experienced color. Furthermore, confusion easily arises, as the word “color” is used both to refer to the physical stimulus and to the feeling of the observer.

We must not lose sight of the fact that color is a visual perception resulting from interactions between three elements: an electromagnetic radiation, the photoreceptors in the eye, and the brain. Thus, color is induced by physical, neural and cognitive phenomena, which must be understood in order to determine its facets, richness and dimensions. Such diversity of phenomena has sparked research efforts the world over. Significant advances have been made modeling the physical aspects and, to a lesser extent, decoding the function of the neural circuits involved in the perception of color.

This chapter presents ...

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