X-ray Spectrometry and imaging for ancient handwritten document

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.

Virtual X-ray Reading (VXR) of Ancient Administrative Handwritten Documents

Fauzia Albertin, Frédéric Kaplan, Giorgio Margaritondo, Marco Stampanoni

The study of ancient documents is too often confined to specimens of high artistic value or to official writings. Yet, a wealth of information is often stored in administrative records such as ship records, notary papers, work contract, tax declaration, commercial transactions or demographic accounts. One of the best examples is the Venice Time Machine project that targets a massive digitization and information extraction program of Venetian archives. The Archivio di Stato in Venice holds about 80 kms of archival documents spanning over ten centuries and documenting every aspect of Venetian Mediterranean Empire. If unlocked and transformed in a digital information system, this information could change significantly our understanding of European history. We are exploring new ways to facilitate and speed up this broad task, exploiting x-ray techniques, notably those based on synchrotron light. . Specifically, we 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 bounded administrative registers, reducing the risk of damage and accelerating the process. We present here positive tests of this approach. First, we systematically analyzed the ink composition of a sample of Italian handwritings spanning over several centuries. Then, we performed x-ray imaging with different contrast mechanisms (absorption, scattering and refraction) using the differential phase contrast (DPC) mode of the TOMCAT beamline of the Swiss Light Source (SLS). Finally, we selected cases of high contrast to perform tomographic reconstruction and demonstrate page-by-page handwriting recognition. The experiments concerned both black inks from different centuries and red ink from the 15th century. For the majority of the specimens, we found in the ink areas heavy or medium-heavy elements such as Fe, Ca, Hg, Cu and Zn. This eliminates a major question about our approach, since the documentation on the nature of inks for ancient administrative records is quite scarce. As a byproduct, the approach can produce valuable information on the ink-substrate interaction with the objective to understand and prevent corrosion and deterioration.

2014

X-ray spectrometry and imaging for ancient administrative handwritten documents

Fauzia Albertin, Frédéric Kaplan, Giorgio Margaritondo, Marco Stampanoni

‘Venice Time Machine’ is an international program whose objective is transforming the ‘Archivio di Stato’ – 80 km of archival records documenting every aspect of 1000 years of Venetian history – into an open-access digital information bank. Our study is part of this project: We are exploring new, faster, and safer ways to digitalize manuscripts, without opening them, using X-ray tomography. A fundamental issue is the chemistry of the inks used for administrative documents: Contrary to pieces of high artistic or historical value, for such items, the composition is scarcely documented. We used X-ray fluorescence to investigate the inks of four Italian ordinary handwritten documents from the 15th to the 17th century. The results were correlated to X-ray images acquired with different techniques. In most cases, iron detected in the ‘iron gall’ inks produces image absorption contrast suitable for tomography reconstruction, allowing computer extraction of handwriting information from sets of projections. When absorption is too low, differential phase contrast imaging can reveal the characters from the substrate morphology

Wiley-Blackwell2015

X-ray spectrometry and imaging for ancient administrative handwritten documents

Fauzia Albertin, Frédéric Kaplan, Giorgio Margaritondo, Marco Stampanoni

‘Venice Time Machine’ is an international program whose objective is transforming the ‘Archivio di Stato’ – 80 km of archival records documenting every aspect of 1000 years of Venetian history – into an open‐access digital information bank. Our study is part of this project: We are exploring new, faster, and safer ways to digitalize manuscripts, without opening them, using X‐ray tomography. A fundamental issue is the chemistry of the inks used for administrative documents: Contrary to pieces of high artistic or historical value, for such items, the composition is scarcely documented. We used X‐ray fluorescence to investigate the inks of four Italian ordinary handwritten documents from the 15th to the 17th century. The results were correlated to X‐ray images acquired with different techniques. In most cases, iron detected in the ‘iron gall’ inks produces image absorption contrast suitable for tomography reconstruction, allowing computer extraction of handwriting information from sets of projections. When absorption is too low, differential phase contrast imaging can reveal the characters from the substrate morphology.

2015

Virtual X-ray Reading (VXR) of Ancient Administrative Handwritten Documents

Fauzia Albertin, Frédéric Kaplan, Giorgio Margaritondo, Marco Stampanoni

2014