Terahertz Identification of Characters Written in Iron-Gall Ink on Stacked Paper

Haolian Shi, Leor Jacobi, Alexandre Locquet, David Citrin
Abstract:
Iron-gall ink has been widely used ink in the production of documents and artworks since the fifth century C.E. Terahertz imaging is used to read characters written in such ink on stacked sheets of paper. Several contrast mechanisms including maximum/minimum of the reflected terahertz signal, signature frequency, Gaussian mixture model, and short-time Fourier transform are tested to compare the image quality of the buried text. The results show that the short-time Fourier transform mechanism outperforms other contrast mechanism and has the ability to extract clear images of buried text within paper stacks.
Download:
IMEKO-MetroArchaeo-2023-106.pdf
DOI:
10.21014/tc4-ARC-2023.106
Event details
IMEKO TC:
TC4
Event name:
TC4 MetroArchaeo 2023
Title:

IMEKO TC4 International Conference on Metrology for Archaeology and Cultural Heritage

Place:
Rome, ITALY
Time:
19 October 2023 - 21 October 2023