Comparison of image techniques for the detection of graffiti in the cloister of the monastery of San Millán de la Cogolla (Spain)

A study comparing advanced image techniques revealed that graffiti in the cloister of San Millán de Yuso Monastery, previously thought lost after cleaning works, could still be detected using raking light photography, short-distance convergent photogrammetry with image enhancement, Reflectance Transformation Imaging (RTI), and structured-light scanning. These methods, applied in 2018, demonstrated varying effectiveness for identifying graffiti and assessing their conservation status, offering potential for combined use to preserve cultural heritage. The research highlights the importance of non-invasive imaging techniques in documenting at-risk artistic elements before irreversible damage occurs.

Valle Melón, J. M., Rodríguez Miranda, Á., Elorriaga Aguirre, G., Korro Bañuelos, J., Arrúe Ugarte, M. B., & Marchante Ortega, Á. (2019). Comparison of image techniques for the detection of graffiti in the cloister of the monastery of San Millán de la Cogolla (Spain). Science and Digital Technology for Cultural Heritage, 26–30. https://doi.org/10.1201/9780429345470-4