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

Chapter 6Color and Material‐Appearance Measurement

We have seen—several times by now—that three components are needed for the production of most colors: a light source, an object to be illuminated, and an observer who both detects the light and converts the detected signal into a response that the human brain recognizes as color, shown in Figure 6.1. For colored lights, the three components reduce to two—the light and the observer. We have seen also that, for many reasons, it is useful to assign numbers to this response called color so that it can be described accurately to someone else, somewhere else, and at some other time. Now we come to the question of how this can be done, the subject of color measurement, also shown in Figure 6.1.

Figure 6.1 (a) “Color” results from the interaction of a light source, an object, and the eye and brain, or visual system. (b) “Color” also results from the interaction of a light source, an object, a detector, and signal processor.

A. BASIC PRINCIPLES OF MEASURING COLOR AND MATERIAL APPEARANCE

An injection‐molded plastic was produced having different surface properties, shown in Figure 6.2. Its backside matches the smooth surface. There is only a single body color (Shafer 1985). The different surfaces have changed the plastic's material appearance. The change from smooth to rough occurs at a microscopic level. The change from flat to textured ...