Nepal Script Text Recognition from Ancient Artifacts: Challenges and Opportunities
Summary
Nepal Script, historically used for Nepal Bhasa, Sanskrit and other languages, is now considered endangered. Many inscriptions and manuscripts written in it remain undigitized, and there was no OCR ground truth for stone inscriptions. Building on their earlier CRNN-based recognizer for handwritten and printed text, the authors assembled a line-level dataset from several sources. They photographed stone inscriptions at 85 sites around the Kathmandu Valley. They added archival material from Tribhuvan University and the National Archives of Nepal, and included modern handwritten and typed documents. Experts verified the transcriptions, which use the Newa Unicode block. The recognition pipeline first finds text lines with YOLOv8, converts them to grayscale, and then transcribes them with a CRNN trained using CTC loss. After augmentation, the model reached a character error rate of 12.61%. It also produced usable output on unseen inscriptions and manuscripts, and even on wooden and copper plates. This makes the work a practical starting point for digitizing heritage material in Nepal Script and related Nepalese scripts.
Key points
- The dataset contains 5,219 text-line images: 2,371 from stone inscriptions, 1,758 from religious manuscripts, and the rest from modern handwritten and typed documents. Augmentation expanded it to 41,752 samples.
- The pipeline combines YOLOv8 for line detection with CRNN + CTC for recognition, achieving a CER of 12.61%. The authors' earlier system scored 6.65% CER and 13.11% WER, but only on handwritten and printed text.
- The script is hard to recognize for several reasons: ancient texts rarely separate words, conjuncts are numerous, and many characters have variant forms. The header line also affects which vowel modifiers are used.
- The released resources are the Nepal Script Stone Inscription Dataset on Kaggle (CC BY-NC-SA 4.0) and the source code on GitHub (GPLv3). The secondary archival data cannot be redistributed because of licensing.
- Related resources cited include the manuscript ground truth of O'Neill and Hill (2022), built with Transkribus HTR, and a Ranjana script character dataset. HTR-VT is noted as a promising approach for settings with little data.
Cite
@inproceedings{nakarmi2026nepal,
title = {{Nepal Script Text Recognition from Ancient Artifacts: Challenges and Opportunities}},
author = {Nakarmi, Swornim and Sthapit, Sarin and Tuladhar, Sahil Ratna and Shakya, Arya and Bal, Bal Krishna and Chulyadyo, Rajani},
booktitle = {Proceedings of the Fifteenth Language Resources and Evaluation Conference},
year = {2026},
doi = {10.63317/427yvm8biop7},
url = {https://doi.org/10.63317/427yvm8biop7}
}References
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