Spectral Imaging Method for Reflective Media

Abstract

An imaging process is described which captures spectral reflectance for reflective media. The ultimate target media are prints and photographs within the collection of the Library of Congress. The system is based on a fifteen channel LED source and a monochrome camera. The LED source sequentially illuminated reference and verification targets, with an image captured for each LED channel. From the measured data and images of reference targets, a model was developed to predict spectral reflectance. With that model, the 15 images of a test sample were combined to a single 31-band spectral image. Spectral images can be used to calculate colorimetric data for each pixel, or to better understand material properties. The colorimetric results show that the system predicts good color as compared to the most relevant FADGI guidelines.