The Bayerische Staatsbibliothek expands its digital services: Similarity-based image search includes 43 million volumes in search for similar motifs

The Bayerische Staatsbibliothek is expanding its digital services again. Users from the fields of scholarship and research can now include all digital copies produced so far – thus around 1.2 million volumes with around 270 million book pages and 43 million images – in a similarity-based image search for similar motifs and images. The service is available at and can also be used on mobile terminals.

The technology developed in cooperation with the Fraunhofer Heinrich-Hertz Institute in Berlin (HHI) detects and extracts images from digitized works fully automatically. In the course of this process, the images are additionally described with colour and edge features and stored in a database, where they are available for comparative searches. Texts and images without relevant information content are filtered out with the aid of machine-learning methods. Subsequently to the processing step, any desired image can be used as starting point for searching the complete holdings for similar motifs within seconds. The search runs the gamut from illustrations of medieval Bible manuscripts and photographs to boulevard magazines of the 1920s. In this way, the similarity-based image search unearths unknown, unusual and frequently surprising connections between highly different works from different epochs. The integrated upload function further enables users to use their own images for searching the entire holdings of digital copies of the Bayerische Staatsbibliothek for similar motifs, thus including also all digital objects contained in the cultural portal bavarikon.

The Munich Digitization Center of the Bayerische Staatsbibliothek has provided all users with a system for similarity-based image search already since 2013. The technology used for this purpose was developed by the Fraunhofer Heinrich-Hertz Institute in Berlin (HHI) and adjusted specially for the digital holdings of the Bayerische Staatsbibliothek.

Director General Klaus Ceynowa: "The new service of enhanced similarity-based image search opens an alternative, non-textual access to our collections, thus creating new perspectives for digital iconographic research. Once more, this tool bears witness to the propensity to innovate of the Bayerische Staatsbibliothek."

Press release for download
Press release  (in German)  (PDF, 63 KB)


Dr. Markus Brantl
Bayerische Staatsbibliothek
Munich Digitization Center
Ludwigstr. 16, 80539 Munich
Phone:  +49 89 28638-2394

Peter Schnitzlein
Bayerische Staatsbibliothek
Press and Public Relations
Ludwigstr. 16, 80539 Munich
Phone:  +49 89 28638-2429


About the Bayerische Staatsbibliothek:
Founded in 1558 by Duke Albrecht V, the Bayerische Staatsbibliothek is an international research library of world renown. With over 10.3 million volumes, around 59,000 current journals in electronic and printed form and almost 131,000 manuscripts, the library ranks among the world's most important centers of knowledge and heritage institutions. With 1.2 million digitized works, the Bayerische Staatsbibliothek holds the largest digital data stock of all German libraries. The library offers a broad range of services in the field of innovative digital use scenarios.