Color gamut measurements and mapping: the role of color spaces

Before embarking on an extensive set of color gamut mapping experiments, we were distracted by wanting to understand uniform color spaces. The CIE L*a*b* is almost universally used for a colorimetric uniform color space. It is found most often in the literature and is used by many instrument makers as colorimetric output. There are a wide variety of papers that imply small errors in L*a*b*. Nevertheless, the sense of these articles is that the errors are small local perturbations about an average response that is essentially correct. Many papers describe small improvements using modified equations. This paper will present measurements and literature data that show surprisingly large discrepancies between CIE L*a*b* and isotropic observation based Color Spaces such as Munsell.