A Dataset of Wolof Ajami Manuscripts for HTR and OCR

Oreen Yousuf, Elhadji Djibril Diagne, Christian Høgel, Beata Megyesi, Joakim Nivre


Abstract
We present the first ever dataset of manually segmented and transcribed Ajami manuscripts written in Wolof. The term Ajami refers to modified Arabic-script orthographies used to transcribe African languages. Handwritten text recognition (HTR) and optical character recognition (OCR) models for Arabic-script languages perform poorly on African languages written in Ajami orthographies because these languages are not represented in the pre-training data of the models. This leads to recognition models being unable to extract unique Arabic-script letters and ubiquitous diacritics used in African languages, and struggling to adapt to various calligraphy styles used across Africa. We release the following as an open-source dataset: an ALTO formatting of high-quality images of handwritten and printed, 20th–century Wolof manuscripts; manual segmentation (region and line); and manual transcriptions. We extend our contribution by evaluating several Arabic-script recognition models intended for historical manuscripts and find they produce character error rates (CER) of 61–81%. Transcriptions produced by the evaluated recognition models, as well as a keyboard to transcribe Wolof Ajami manuscripts, are released as well. The digitally transcribed text in the dataset can also be utilized for various natural language processing (NLP) and historical linguistic tasks.
Anthology ID:
2026.lrec-1.253
Volume:
Proceedings of the Fifteenth Language Resources and Evaluation Conference
Month:
May
Year:
2026
Address:
Palma de Mallorca, Spain
Editors:
Stelios Piperidis, Núria Bel, Henk van den Heuvel, Nancy Ide, Simon Krek, Antonio Toral
Venue:
LREC
SIG:
Publisher:
ELRA Language Resource Association
Note:
Pages:
3234–3239
Language:
External URL:
https://lrec.elra.info/lrec2026-main-253
DOI:
10.63317/4pz98ojeeqpw
Bibkey:
Cite (ACL):
Oreen Yousuf, Elhadji Djibril Diagne, Christian Høgel, Beata Megyesi, and Joakim Nivre. 2026. A Dataset of Wolof Ajami Manuscripts for HTR and OCR. In Proceedings of the Fifteenth Language Resources and Evaluation Conference, pages 3234–3239, Palma de Mallorca, Spain. ELRA Language Resource Association.
Cite (Informal):
A Dataset of Wolof Ajami Manuscripts for HTR and OCR (Yousuf et al., LREC 2026)
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