An American academic is creating a searchable database of 12 million historical copyright-free images, according to BBC.

Kalev Leetaru has already uploaded 2.6 million pictures to the popular website Flickr.

The images are searchable thanks to tags that have been automatically added.

“For all these years all the libraries have been digitising their books, but they have been putting them up as PDFs or text searchable works,” he told the BBC, adding that “They have been focusing on the books as a collection of words. This inverts that”.

“Most of the images that are in the books are not in any of the art galleries of the world – the original copies have long ago been lost,” he explained.

The pictures in his collection range from 1500 to 1922, when copyright restrictions kick in.