Vat. gr. 2228 – Medieval Greek HTR

This manuscript-specific HTR model was developed for Vaticanus graecus 2228 (Vat. gr. 2228), a 14th-century Medieval Greek paper manuscript held by the Biblioteca Apostolica Vaticana. The manuscript contains rhetorical treatises and Byzantine commentaries and is characterized, in the sections targeted by the model, by a comparatively regular layout and consistent scholarly minuscule handwriting. The model is based on manually curated line-level ground truth with expert transcriptions of Medieval Greek. The transcriptions preserve the text closely, including polytonic diacritics and the resolution of abbreviations, tachygraphic signs, ligatures, and other palaeographical features. Text normalization was limited to removing invisible characters, standardizing whitespace, applying Unicode NFC normalization, and mapping visually indistinguishable upper-right tick encodings to U+2019 RIGHT SINGLE QUOTATION MARK (`’`). The model and its training data were developed within the E-Rhetoric project, funded by the Carlsberg Foundation (grant CF24-1999). The work was carried out by Nicklas Sindlev Andersen, Byron MacDougall, Ugo Valori, Tariq Yousef, and Aglae Pizzone. For a more detailed description of the model development, ground truth curation, and evaluation, see Andersen et al. (2026), From Manuscript to Model: Developing HTR for Medieval Greek. (DOI: 10.63317/47tkobv5mgbu)