Signal processing techniques for enhancing multispectral images of ancient documents

Digital multispectral imaging (MSI) has been widely adopted to aid in the study of ancient artefacts including paintings and documents. MSI is able to capture views of the subject at multiple narrowband wavelengths ranging from the ultraviolet through the infrared. Stacking the imagery data in three dimensions creates a large image data cube which can be processed using statistical signal and image processing techniques. This paper is a brief review of how signal processing can aid in reducing three general problem areas that may be present in MSI data sets of ancient documents, namely: image fusion, ink identification, and bleed-through removal.