Capturing the Color of Black and White

One of the first and iconic imaging targets to be developed for color photography was described by McCamy, Marcus, and Davidson. That was more than thirty years ago and, for better or for worse, the Macbeth ColorChecker ™ continues to be a de-facto target standard in imaging circles. The target was designed to simulate the spectral nature of critical or problematic colors for consumer photography so that color calibrations and color reproduction evaluations could be made that were consistent with scene content. However, for digital collections with limited colorgamut, or where detection of small differences in material properties is important, adopting collection-specific color test targets is often advisable. This can reduce metamerism, and sample the device signal space in the most important regions. As an example of such content, the spectral-reflectance characteristics of a collection of early photographic prints were measured. The underlying structure of the data set was investigated in terms of principal components, and a spectral reconstruction based on two principal components was demonstrated