Introduction

The reproduction of colors in many imaging applications requires “faithful reproduction” of the color appearances in the original scenes or objects. Since faithfulness is in the eyes of the beholder, the objective of color reproduction needs careful examination.

For some applications, the objective is easy to define in exact, physical terms, but turns out to be very difficult to achieve: for example, a mail-order catalogue has to reproduce the image of merchandise just as it will look when the customer actually holds it in his hand. The only true solution is to reproduce the spectral reflectance of the object, including the fluorescent property of the original material if any. The Lippman method and the microdispersion method [429, pp. 5–8], which come close to reproducing the spectra, are simply too expensive and inconvenient to use.

For some other applications, the objective is very difficult to define in exact, physical terms, and there is no known method of achieving the objective systematically. For example, there is no convenient method of reproducing the wide dynamic luminance range of an outdoor scene on a bright sunny day on a reflection print, which has only a very limited dynamic range. In this case, it is difficult to specify the physical criteria for a good or faithful color reproduction. Furthermore, it is likely that there will not be a reproduction that most people agree to be the best possible reproduction. The subject may well fall into the domain of artistic impression, which is still far beyond our limited understanding.