Radiometric Characterization of Spectral Imaging for Textual Pigment Identification

Abstract  Digital imaging of cultural heritage artifacts has become a standard practice. Typically, standard commercial cameras, often commodity rather than scientific grade cameras, are used for this purpose. Commercial cameras are optimized for plausible visual reproduction of a physical scene with respect to trichromatic human vision. However, visual reproduction is just one application of digital images in heritage. In this paper, we discuss the selection and characterization of an alternative imaging system that can be used for the physical analysis of artifacts as well as visually reproducing their appearance. The hardware and method we describe offers a middle ground between the low cost and ease of commodity cameras and the high cost and complexity of hyperspectral imaging systems. We describe the selection of a system, a protocol for characterizing the system and provide a case study using the system in the physical analysis of a medieval manuscript.