Mid-wave Infrared Reflectography and Thermography for the Study of Ancient Books: A Review

Abstract

In this paper an overview of recent applications of mid-wave infrared imaging techniques to the study of books is presented. Studies performed by thermography and mid-wave infrared reflectography are reviewed to demonstrate how they can be used to investigate the main features of books. The capability of these techniques is exploited in the analysis of structural elements of the bookbindings and writing supports as well as in the characterization of the writings and illuminations. Thermographic and reflectographic results are compared with results obtained using other imaging techniques operating in different spectral regions, thus pointing out how mid-wave infrared imaging techniques can help in examining many aspects of books. Finally, it is shown that the obtained information can also be used to evaluate the condition of the book and, when required, to properly plan conservation treatments.

Comparison of Auger Coefficients in Type I and Type II Quantum Well Midwave Infrared Lasers

“…ngoing advances in semiconductor laser and detector technologies for the midwave infrared (mid-IR, loosely defined here as 2-6 µm) have substantially expanded their use in systems addressing such commercial and military applications as chemical sensing [1]- [3], infrared countermeasures [4], and thermal imaging [5], [6]. For interband lasers operating in the mid-IR, threshold current densities are nearly always limited by the non-radiative Auger process, in which electron-hole recombination is accompanied by the excitation of a third carrier (either electron or hole) to an excited state that conserves energy and momentum [7], [8].…”

Study of the edge distortion effect in thermographic detection in semi-transparent Cultural Heritage

“…The ancient manufacturing of a book was a long process requiring expert skills in materials preparation and decoration. Since the support material such as paper and parchment were often scarce in quantity in the workshops, they were reused very often, disassembling older manuscripts [7]. In such complex structures, the possibility of discovering hidden texts by means of non-destructive imaging techniques is of strong relevance for both conservators and books researchers, since it allows to reveal the stratigraphy of the artefact and, consequently, to achieve a better understanding of the book history and manufacturing.…”

“…For this reason, non-destructive analyses are crucial for the identification and characterisation of such hidden precious elements, without compromising the book structure, aimed to the comprehension of the manuscript and for palaeographic purposes. Such an issue has been successfully investigates by the use of several imaging techniques [1][2][3], among which Pulsed Thermography (PT) has proven to be an efficient tool for the investigation of multi-layers structures [4][5][6], such as ancient manuscripts [7][8][9]. In particular, PT allows the detection of sub-surface features beneath the end papers of ancient book-bindings, providing the in-depth mapping of the investigated object and also indications of reused manuscripts.…”

Structural feature investigation of wooden artifacts through imaging techniques: a step forward in the preservation of historical musical instruments

“…To overcome the limits highlighted above, we propose to combine the traditional RX analysis with Infrared Thermography (IRT). IRT is a photo-thermal noninvasive methodology that has been recently employed for the investigation of Cultural Heritage to identify and characterize structural defects and subsurface features in several items, such as painted artefact [11], [12], bronzes [13] and librarian heritage [14].…”