Perceptual steps along color scales

Color scales are commonly used to represent numerical information visually. Most scales are derived from some physical or mathematical behavior; even worse, sometimes they are selected based solely on hardware capabilities. In most known cases, no consideration is made to the perceptual capabilities of the human observer, who is ultimately the “consumer” of the information to be delivered by the scale. This article presents a method and an algorithm for the derivation of color scales, such that their perceptual properties—in particular, the perceptual steps between colors along the scale—can be controlled by the scale designer. This approach has been used for the design of the linearized gray scale and the linearized optimized color scale (LOCS). These scales are demonstrated and are also compared to the linearized heated-object scale.