The image is the record - similarity-based image search for visual materials in digitized library collections: The approach of the Bavarian State Library

With 96,000 manuscripts, 20,000 incunabula, and more than 160,000 rare books of the 16th century, the Bavarian State Library is one of the major institutions for written cultural heritage worldwide. Huge parts of these unique collections are digitized and freely available for research and study. They contain vast amounts of images of immense value to researchers and students in arts and humanities. To make these treasures more visible, the Bavarian State Library, in cooperation with the Fraunhofer Heinrich-Hertz-Institute, has developed a similarity based image retrieval tool that operates directly on the level of the digital content. The colours and edges of the images themselves are used as metadata to explore related and similar images in a rich content-repository of rare books and manuscripts.