Fauzia Albertin, Frédéric Kaplan, Giorgio Margaritondo, Marco Stampanoni
We detected handwritten characters in ancient documents from several centuries with different synchrotron x-ray imaging techniques. The results were correlated to those of x-ray fluorescence analysis. In most cases, heavy elements produced high image quality suitable for tomography reconstruction leading to virtual page-by-page “reading”. When absorption is too low, differential phase contrast (DPC) imaging can reveal the characters from the substrate morphology. This paves the way to new strategies for information harvesting during mass digitization programs. This study is part of the Venice Time Machine project, an international research program aiming at transforming the immense venetian archival records into an open access digital information system. The Archivio di Stato in Venice holds about 80 kms of archival records documenting every aspects of a 1000 years of Venetian history. A large part of these records take the form of ancient bounded registers that can only be digitize through cautious manual operations. Each page must be turned manually in order to be photographed. Our project explore new ways to virtually “read” manuscripts, without opening them,. We specifically plan to use x-ray tomography to computer-extract page-by-page information from sets of projection images. The raw data can be obtained without opening or manipulating the manuscripts, reducing the risk of damage and speeding up the process. The present tests demonstrate that the approach is feasible. Furthermore, they show that over a very long period of time the common recipes used in Europe for inks in “normal” handwritings - ship records, notary papers, commercial transactions, demographic accounts, etc. – very often produced a high concentration of heavy or medium-heavy elements such as Fe, Hg and Ca. This opens the way in general to x-ray analysis and imaging. Furthermore, it could lead to a better understanding of the deterioration mechanisms in the search for remedies. The most important among the results that we will present is tomographic reconstruction. We simulated books with stacks of manuscript fragments and obtained from sets of projection images individual views -- that correspond indeed to a virtual page-by-page “reading” without opening the volume.
2014
