Image Spectrometers, Color High Fidelity, and Fine-Art Paintings

This book chapter presents an introduction to image spectrometers with as example their application to the scanning of fine-art paintings. First of all, the technological aspects necessary to understand a camera as a measuring tool are presented. Thus, CFA-based cameras, Foveon-X, multi-sensors, sequential acquisition systems, and dispersing devices are introduced. Then, the simplest mathematical models of light measurement and light–matter interaction are described. Having presented these models, the so-called spectral reflectance reconstruction problem is presented. This problem is important because its resolution transforms a multi-wideband acquisition system into an image spectrometer. The first part of the chapter seeks to give the reader a grasp of how different technologies are used to generate a color image, and to which extent this image is expected to be high fidelity.