---
library_name: PyLaia
license: mit
tags:
- PyLaia
- PyTorch
- atr
- htr
- ocr
- historical
- handwritten
metrics:
- CER
- WER
language:
- 'no'
pipeline_tag: image-to-text
---

# PyLaia - NorHand v1 (post-processed)

This model performs Handwritten Text Recognition in Norwegian. It was developed during the [HUGIN-MUNIN project](https://hugin-munin-project.github.io/).

## Model description

The model has been trained using the PyLaia library on the [NorHand](https://zenodo.org/record/6542056) document images. 
Line bounding boxes were improved using a post-processing step.

Training images were resized with a fixed height of 128 pixels, keeping the original aspect ratio.

## Evaluation results

The model achieves the following results:

| set   | CER (%)    | WER (%)   |
| ----- | ---------: | --------: | 
| train | 2.33       | 5.62      |
| val   | 8.20       | 24.75     |
| test  | 7.81       | 23.30     |

Results improve on validation and test sets when PyLaia is combined with a 6-gram language model. 
The language model is trained on [this text corpus](https://www.nb.no/sprakbanken/en/resource-catalogue/oai-nb-no-sbr-73/) published by the National Library of Norway.

| set   | CER (%)    | WER (%)   |
| ----- | ---------: | --------: | 
| train | 2.62       | 6.13      |
| val   | 7.01       | 19.75     |
| test  | 6.75       | 18.22     |

## How to use?

Please refer to the [documentation](https://atr.pages.teklia.com/pylaia/).

# Cite us!

```bibtex
@inproceedings{pylaia-lib,
    author = "Tarride, Solène and Schneider, Yoann and Generali, Marie and Boillet, Melodie and Abadie, Bastien and Kermorvant, Christopher",
    title = "Improving Automatic Text Recognition with Language Models in the PyLaia Open-Source Library",
    booktitle = "Submitted at ICDAR2024",
    year = "2024"
}
```

```bibtex
@inproceedings{10.1007/978-3-031-06555-2_27,
author = {Maarand, Martin and Beyer, Yngvil and K\r{a}sen, Andre and Fosseide, Knut T. and Kermorvant, Christopher},
title = {A Comprehensive Comparison of Open-Source Libraries for Handwritten Text Recognition in Norwegian},
year = {2022},
isbn = {978-3-031-06554-5},
publisher = {Springer-Verlag},
address = {Berlin, Heidelberg},
url = {https://doi.org/10.1007/978-3-031-06555-2_27},
doi = {10.1007/978-3-031-06555-2_27},
booktitle = {Document Analysis Systems: 15th IAPR International Workshop, DAS 2022, La Rochelle, France, May 22–25, 2022, Proceedings},
pages = {399–413},
numpages = {15},
keywords = {Norwegian language, Open-source, Handwriting recognition},
location = {La Rochelle, France}
}
```