Billmeyer and Saltzman's Principles of Color Technology, 4th Edition

Chapter 2Color and Spatial Vision

So far, we have limited our discussion about color to the physical stimulus, producing light which, when detected and interpreted through our visual system, results in the stimulus having a particular color. The conversion from light energy to color names such as red, green, and brown is exceedingly complex. It requires an understanding of physiology, optics, detectors, neural processing, and cognition. Every year, vision scientists fill in more pieces of the puzzle. The comprehensive textbooks of Backhaus, Kliegl, and Werner (1998), Gegenfurtner and Sharpe (1999), Palmer (1999), Valberg (2005), Daw (2012), and Livingstone (2014) are suggested for more in‐depth study. Fortunately, it is not essential for our purposes in this book to know in detail how the visual system works; knowledge of a few basic principles will suffice.

A. TRICHROMACY

A cross section of the eye is shown in Figure 2.1. Light entering our eyes is imaged onto the back of the eyeball, the retina. The cornea and lens focus the image by changing their shape. The iris modulates how much light enters the eye. The retina contains photoreceptors that absorb a portion of the incident light and generate a signal that is eventually interpreted by the brain. In many respects, the image formation is similar to that in a camera. The quality of the retinal image depends on the absorption, scattering, and focusing properties of the cornea, lens, and fluids filling the eyeball (aqueous and ...