| # Public Domain Check - Confirming the author has died at least 70 years ago | |
| ## Summary | |
| The goal of the check is to avoid uploading non-public domain data. | |
| The digitized documents obtained from the [Danish Royal Library](https://www.kb.dk/en) have a range of publishing dates from 1750 to 1930. | |
| According to [Danish law](https://www.retsinformation.dk/eli/lta/2023/1093) 70 years must pass after the death of the author(s) in order for these documents to become part of the [public domain](https://creativecommons.org/public-domain/). | |
| Based on this, the data can be separated to 3 distinct groups: | |
| - **Published before 1833**: Even if the longest living human in modern history wrote that as soon as they were born, they still died more than 70 years ago | |
| - **Copyright info supplied**: The Danish Royal Library provides meta data on several of these documents, in which they claim the writing is indeed part of the public domain | |
| - **The rest**: Documents where public domain status has to be investigated | |
| To confirm whether a document is part of the public domain or not, the author(s) indicated in the meta data were matched against a database of potential Danish authors. Both their full names and potential abbreviations were used. A document was marked as being in the public domain if: | |
| - All authors were matched to at least one name in the reference database | |
| - All of these matches had complete biographic information in the reference database | |
| - The author(s) died at least 70 years ago | |
| - The author(s) have been born at least 18 years before the publication date | |
| It must be noted, that the digitization took place over the course of several years, the provided meta data mostly follows a standard layout, but some documents might differ in that regard. This can be a potential source of errors. | |
| **IMPORTANT: In case some non-public domain document is found in the dataset, please let us know** | |
| The matched authors and written media is available for reference in .parquet format as [public_domain_data.parquet](./public_domain_data.parquet) | |
| The list of only the filenames of the selected works (used in the extraction process, and is probably less important to outside parties) is available as [public_domain_files.txt](./public_domain_files.txt) | |
| ## Sources | |
| Potential authors were gathered using [Web Scraping](../scrape/scraping.md) | |
| ## Logic | |
| The flowchart is for a broad understanding and is not a fully accurate representation. | |
|  | |
| The whole python script is provided for reference as [select_pd.py](./select_pd.py) | |
| Made with: | |
| - python 3.12.10 | |
| Required libraries for running: | |
| - [PyMuPDF](https://pypi.org/project/PyMuPDF/) 1.26.0 | |
| - [datasets](https://pypi.org/project/datasets/) 3.5.0 |