chcaa/kb-books

open-rdl-books

Dataset Description

Language	dan, dansk, Danish
License	Public Domain, cc0-1.0

Dataset Summary

Documents from the Royal Danish Library published between 1750 and 1930.

The dataset has each page of each document in image and text format. The text was extracted with OCR.

The documents (books of various genres) were obtained from the library. The dataset was assembled to make these public domain Danish texts more accessible.

Dataset Structure

Data Instances

{
  "doc_id": "unique document identifier",
  "page_id": "unique page identifier",
  "page_image":"image of the page, extracted from a pdf",
  "page_text": "OCRed text of the page, extracted from a pdf",
  "author" : "name of the author. If more than one, separated by ';' ",
  "title" : "document title",
  "published" : "year of publishing",
  "digitalized" : "year of processing the physical document by the library",
  "file_name" : "file_name of the original PDF"
}

The "page_text" was obtained through OCR, and is therefore likely to contain noisy data, especially in older documents, where the original text is either handwritten or printed in fonts, which are not commonly used today, such as Fraktur.

"author" and "title" may be missing, especially in documents published before 1833. Those are considered public domain, as there is no probable way the authors could be dead less than 70 years, and no in-depth metadata collection was done.

"digitalized" may be missing.

Data Splits

All data is in the "train" split.
Data is organized by year of publication, and is segmented into <5GB chunks.

Dataset Creation

Curation Rationale

The dataset makes public domain text data more accessible to whomever may wish to view it or use it.

The dataset was created for the projects:

• Danish Foundation Models
• Golden Matrix

The documents were filtered to make sure no non-public domain data is added. See pd_check.md for the confirming of public domain status and scraping.md for collecting possible Danish authors in detail.

Source Data

Data consists of OCRed documents from the Royal Danish Library published between 1750 and 1930. These documents are mostly books of various genres. No distinction was made among the documents based on genre. Additional to the text, the original PDF pages are also added as images for potentially improving the quality of text.

The source data was made by humans, chiefly danish speaking authors, poets and playwrights.

Data Extraction

Logic

The initial dataset was downloaded using the scripts located in this folder

The whole python script is provided for reference as extract_data.py
For more detailed information the other scripts see pd_check and scraping

General Data Extraction

flowchart is for a broad understanding and is not a fully accurate representation.

Confirming Public Domain Status

flowchart is for a broad understanding and is not a fully accurate representation.

Additional Information

Citation

If you use this work please cite:

@report{open-rdl-books,
 title={Public domain books from the Danish Royal Library},
 author={Szabo, Balazs and Vahlstrup, Peter and Møldrup-Dalum, Per and Nielbo, Kristoffer L. and Enevoldsen, Kenneth},
 year={2025}
}

Personal and Sensitive Information

This dataset is under the public domain and, to our knowledge, does not contain personally sensitive information.

Bias, Risks, and Limitations

The works in this collection are historical, and thus they reflect the linguistic, cultural, and ideological norms of their respective times. As such, it includes perspectives, assumptions, and biases characteristic of the period, likely including stances that we would now deem inappropriate.

Notice and takedown policy

We redistribute files under the public domain or with a license permitting redistribution.
If you have concerns about the licensing of these files, please contact us. If you consider that the data contains material that infringes your copyright, please:

Clearly identify yourself with detailed contact information, such as an address, a telephone number, or an email address at which you can be contacted.
Clearly reference the original work claimed to be infringed
Clearly identify the material claimed to be infringing and information reasonably sufficient to allow us to locate the material.
We will comply with legitimate requests by removing the affected sources from the next release of the dataset.

Dataset Curators

The dataset was created for use in these projects by the Center for Humanities Computing at Aarhus University:

• Danish Foundation Models
• Golden Matrix

License

The documents in the dataset are part of the public domain