Lei, Q.Q.LeiZhang, H.H.ZhangSfarra, S.S.SfarraOsman, AhmadAhmadOsmanIbarra-Castanedo, C.C.Ibarra-CastanedoMaldague, X.P.V.X.P.V.Maldague2022-09-292022-09-292022https://publica.fraunhofer.de/handle/publica/42714010.1007/978-3-031-03795-5_52-s2.0-85131785297This work presents a comparative study for the inspection of an old book, which was bound in the XIXth century. Infrared thermography (IRT), terahertz time-domain spectroscopy (THz-TDS) and air-coupled ultrasonic C-scan (ACU) were used to retrieve the damages and defects in the book cover. Image processing techniques including Fast Fourier Transform (FFT), peak-to-peak and time-delay analysis in time domain were applied in order to highlight the shapes of subsurface features. X-ray radiography was used to anticipate the inspection results. Overall, this work appears useful to investigate the feasibility of different non-invasive inspection (NII) techniques applied to ancient books.enHand-bound bookInfraredNDTTerahertzUltrasoundconference paper