Unveiling hidden text in Frisian historic manuscripts by fused reflectance and transmittance imaging spectroscopy
A.D.B. Di Benedetto (Politecnico di Milano, TU Delft - Team Matthias Alfeld)
L.M. de Almeida Nieto (TU Delft - Team Matthias Alfeld)
Daniel Marsh (Student TU Delft)
Janneke Zwetsloot (Student TU Delft)
Riemer Janssen (Pastei Research Group for Book History)
Anne Tjerk Popkema (Pastei Research Group for Book History)
Herre de Vries (Pastei Research Group for Book History)
Daniela Comelli (Politecnico di Milano)
M.W.E.M. Alfeld (TU Delft - Team Matthias Alfeld)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
In several manuscripts, text is obscured due to glued together leaves, making it difficult or impossible to read. In this context, this study explores the use of reflectance and transmittance imaging spectroscopy (RIS and TIS) in the visible and near-infrared range (400–1000 nm) to recover hidden texts. The method is applied to two cases of medieval Frisian legal codes from the Richthofen Collection, where we employed Non-Negative Matrix Factorization (NMF) for the analysis of single and spectrally fused datasets integrating both RIS and TIS. We further integrated spatial stitching of adjacent areas to enhance spatial resolution of the images. Our results demonstrate that factorization algorithms perform well on fused datasets, with spectral fusion proving essential in complex cases where individual analyses fail to clearly reveal hidden text.