A Methodological Framework for Digital Enhancement and Text Recognition in Palimpsests

Authors

  • Katia Rasheva-Yordanova University of Library Studies and Information Technologies, Sofia, Bulgaria
  • Georgi P. Dimitrov University of Library Studies and Information Technologies, Sofia, Bulgaria
  • Inna Dimitrova University of Library Studies and Information Technologies, Sofia, Bulgaria

DOI:

https://doi.org/10.55630/dipp.2025.15.14

Keywords:

Palimpsest, Image Processing, Optical Character Recognition (OCR), Contrast Enhancement, Digital Preservation

Abstract

This paper presents a methodology for enhancing palimpsest readability using image processing. Applying CLAHE, noise reduction, and adaptive thresholding enables the extraction of hidden text layers. The results show effective separation of scriptio inferior and superior, supporting further analysis through digital reconstruction and OCR.

References

Brenner, S., & Miklas, H. (2019). Multispectral imaging of degraded manuscripts in the Ivan Vazov National Library in Plovdiv. Godišnik na Narodna biblioteka „Ivan Vazov“ (2014–2018) [Yearbook of the Ivan Vazov National Library (2014–2018)], 32–48.

Brenner, S., Sablatnig, R., Cappa, F., Vetter, W., Frühmann, B., Schreiner, M., & Miklas, H. (2020). Virtual conservation and restoration via multispectral imaging and spectroscopy. In M. V. Korogodina (Ed.), Issledovanie i restavraciâ rukopisej: Materialy konferencii - 2019 [Manuscript research and restoration: Conference materials - 2019, St. Petersburg, September 17–18, 2019] (pp. 15–26). SPb.: BAN. https://spbiiran.ru/issledovanie-i-restavracziya-rukopisej-sbornik-materialovnauchnoj-konferenczii-2019-goda/

Christova-Shomova, I. (2018). Dragotin minej. Bulgarski rukopis ot nachaloto na XII vek [Dragotin Menaion. A Bulgarian manuscript from the beginning of the 12th century]. Univ. izd. “Sv. Kliment Ohridski.”

Dimitrov, V. (2019). And everybody leaves something so the next could ruin it. Along Via Diagonalis through Istria and Friuli. Sledva: Journal for University Culture, 39, 67–81. https://doi.org/10.33919/sledva.19.39.9

Easton, R. L. Jr., Knox, K. T., Christens-Barry, W. A., & Boydston, K. (2018). Spectral imaging methods applied to the Syriac Galen Palimpsest. Manuscript Studies: A Journal of the Schoenberg Institute for Manuscript Studies, 3 (1), 69–82.

Fischer, C., & Kakoulli, I. (2006). Multispectral and hyperspectral imaging technologies in conservation: Current research and potential applications. Studies in Conservation, 51 (sup1), 3–16. https://doi.org/10.1179/sic.2006.51.supplement-1.3

Grusková, J., & Gregorio, G. D. (2023). Neue paläographische Einblicke in einige palimpsestierte Handschriften aus den griechischen Beständen der Österreichischen Nationalbibliothek [New palaeographic insights into palimpsested manuscripts from the Greek holdings of the Austrian National Library]. Veröffentlichungen zur Byzanzforschung, 2023, 317–341. https://doi.org/10.1553/978oeaw91575s317

Grotans, A. A., Hendrix, J., & Kaczynski, B. M. (2009). Understanding medieval manuscripts: St. Gall's virtual library. History Compass, 7 (3), 955–980. https://doi.org/10.1111/j.1478-0542.2009.00603.x

Kasso, T., Kytökari, M., Oinonen, M., Mizohata, K., Tahkokallio, J., & Heikkilä, T. (2022). A glance to the Fragmenta Membranea manuscript collection through FTIR and radiocarbon analyses. Radiocarbon, 65 (1), 155–171. https://doi.org/10.1017/rdc.2022.81

Namicheva-Todorovska, E., & Namichev, P. (2021). Cultural sustainability and architectural heritage. Palimpsest, 6 (11), 227–239. https://doi.org/10.46763/palim21116227n

Perino, M., Ginolfi, M., Felici, A. C., & Rosellini, M. (2023). A deep learning experiment for semantic segmentation of overlapping characters in palimpsests. In Proceedings of the 2022 IMEKO TC4 International Conference on Metrology for Archaeology and Cultural Heritage. https://doi.org/10.21014/10.21014/tc4-arc-2023.153

Rachman, Y. B. (2017). The use of traditional conservation methods in the preservation of ancient manuscripts: A case study from Indonesia. Preservation, Digital Technology & Culture, 46 (3), 109–115. https://doi.org/10.1515/pdtc-2017-0006

Rasheva-Yordanova, K., Dimitrov, P. G., Tsvetkova, P. T., Bankovska, M., & Petrov, P. S. (2024). Improving palimpsest readability via image preprocessing: An investigation into adjustment techniques. Digital Presentation and Preservation of Cultural and Scientific Heritage, 14, 107–116. https://doi.org/10.55630/dipp.2024.14.9

Şahin, C. D., Coşkun, T., Arsan, Z. D., & Akkurt, G. G. (2017). Investigation of indoor microclimate of historic libraries for preventive conservation of manuscripts: Case study: Tire Necip Paşa Library, İzmir -Turkey. Sustainable Cities and Society, 30, 66–78. https://doi.org/10.1016/j.scs.2016.11.002

Starynska, A., Messinger, D., & Kong, Y. (2021). Revealing a history: Palimpsest text separation with generative networks. International Journal on Document Analysis and Recognition, 24 (3), 181–195. https://doi.org/10.1007/s10032-021-00379-z

Teasdale, M. D., Fiddyment, S., Vnouček, J., Mattiangeli, V., Speller, C., Binois, A., & Collins, M. J. (2017). The York Gospels: A 1000-year biological palimpsest. Royal Society Open Science, 4 (10), 170988. https://doi.org/10.1098/rsos.170988

Downloads

Published

2025-09-05

How to Cite

Rasheva-Yordanova, K., P. Dimitrov, G., & Dimitrova, I. (2025). A Methodological Framework for Digital Enhancement and Text Recognition in Palimpsests. Digital Presentation and Preservation of Cultural and Scientific Heritage, 15, 147–158. https://doi.org/10.55630/dipp.2025.15.14