leitro/Copiale_Lines

Copiale Lines

Copiale Lines is a line-level image-to-text dataset for historical cipher decipherment. It contains cropped line images from the Copiale manuscript paired with plaintext ground truth.

This dataset was presented in the paper Learning to Decipher from Pixels -- A Case Study of Copiale (HistoCrypt 2026).

Code: https://github.com/leitro/Decipher-from-Pixels-Copiale

Dataset Structure

The dataset is split into:

• —train: 1,269 samples
• —valid: 175 samples
• —test: 370 samples

Each split contains:

• —images/*.png: cropped line images
• —metadata.csv: filename and plaintext transcription

The corresponding source split files are train.gt, valid.gt, and test.gt, where each line is:

image_id<TAB>groundtruth

Example

1-2.png,gesetz buchs

corresponds to the image:

train/images/1-2.png

Intended Use

This dataset is intended for research on handwritten cipher recognition, image-to-text modeling, and transcription-free decipherment.

Citation

@inproceedings{kang2026learning,
  title     = {Learning to Decipher from Pixels: A Case Study of Copiale},
  author    = {Kang, Lei and De Gregorio, Giuseppe and Heil, Raphaela and Fornés, Alicia and Megyesi, Beáta},
  booktitle = {International Conference on Historical Cryptology (HistoCrypt)},
  year      = {2026}
}

Acknowledgements

This dataset is derived in part from materials related to Decipherment of Historical Manuscripts, a historical manuscript studied within the project "The Copiale Cipher" at Stockholm University. We acknowledge and thank the original project for making these resources available.

We also gratefully acknowledge financial support from Riksbankens Jubileumsfond under grant M24-0028, "Echoes of History: Analysis and Decipherment of Historical Writings (DESCRYPT)", which supported the development of this dataset.