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Generalised, multilingual, optical Braille recognition models
Thesis (MSc)--Stellenbosch University, 2026.
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| Format: | Thesis |
| Language: | English |
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Stellenbosch : Stellenbosch University
2026
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| _version_ | 1867613769742417920 |
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| access_status_str | Open Access |
| author | Van der Linden, Wicus Jan |
| author2 | Grobler, T. L. |
| author_browse | Grobler, T. L. Van der Linden, Wicus Jan |
| author_facet | Grobler, T. L. Van der Linden, Wicus Jan |
| author_sort | Van der Linden, Wicus Jan |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MSc)--Stellenbosch University, 2026. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/135695 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:41:24.431Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2026 |
| publishDateRange | 2026 |
| publishDateSort | 2026 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/135695 Generalised, multilingual, optical Braille recognition models Van der Linden, Wicus Jan Grobler, T. L. Van Zijl, L. Stellenbosch University. Faculty of Science. Dept. of Computer Science. Thesis (MSc)--Stellenbosch University, 2026. Van der Linden, W. J. 2026. Generalised, multilingual, optical Braille recognition models. Unpublished masters thesis. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/1933f16b-1744-416c-8dc3-dc17ae39d157 Optical Braille recognition (OBR) is the computer vision task of extracting and classifying character cells from a Braille document. This study investigates the impact of class imbalance and adverse data quality conditions on OBR performance, by training standard multiclass (well adopted methodology) and novel multilabel (proposed in this work) models on different scenarios with resampled training data. These models are evaluated on unseen test data, both in-distribution and out-of-distribution, as well as on simulated adverse conditions. The results show that the proposed multilabel modelling approach outperforms the current standard multiclass approach across different evaluations. Multilabel models further generalise better than multiclass models to severe adverse data quality conditions, and achieve more stable performance across both majority and minority classes. Additionally, the use of data resampling to reduce imbalance in training data leads to improved performance generalisation, for both modelling approaches. In particular, a multi-objective resampling strategy minimising both the imbalance in character classes and the correlations between Braille dots, yields exceptionally stable performance across different conditions. In contrast, multiclass models trained on imbalanced, non-resampled data consistently exhibit poor generalisation to adverse conditions and minority Braille characters. In summary, these findings strongly support the conclusion that the application of the multilabel classification approach, in combination with strategic data resampling, yields robust OBR models exhibiting generalised performance across diverse Braille datasets. Masters 2026-04-08T07:53:44Z 2026-04-08T07:53:44Z 2026-03 Thesis https://scholar.sun.ac.za/handle/10019.1/135695 en Stellenbosch University 199 pages application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Van der Linden, Wicus Jan Generalised, multilingual, optical Braille recognition models |
| title | Generalised, multilingual, optical Braille recognition models |
| title_full | Generalised, multilingual, optical Braille recognition models |
| title_fullStr | Generalised, multilingual, optical Braille recognition models |
| title_full_unstemmed | Generalised, multilingual, optical Braille recognition models |
| title_short | Generalised, multilingual, optical Braille recognition models |
| title_sort | generalised multilingual optical braille recognition models |
| url | https://scholar.sun.ac.za/handle/10019.1/135695 |
| work_keys_str_mv | AT vanderlindenwicusjan generalisedmultilingualopticalbraillerecognitionmodels |