This week, the Internet Archive announced that they have joined Flickr Commons and will be uploading over 14 million copyright-free images over the next months. These images have been extracted from the Internet Archive’s collection of public domain eBooks (spanning a time period between 1500 – 1922) by research fellow Kalev Leetaru. At the moment, over 2.5 million images are already available. What makes this resource specifically valuable is that for each image a detailed description, the subject tags of the originating book and 500 words of surrounding text have been added – which makes it possible to search through them based on topics and keywords.
The image collection can be found and used through this Flickr page: more background information on the release is also available from the Flickr announcement, as well as from this background article by the BBC.