Evaluating a Shape Retrieval System for Watermark Images

The Conservation Unit and Institute of Image Data Research have been working on a collaborative projectinvolving the design and implementation of shape retrieval system for digital images of historic watermarks from works of art on paper. This database, The Northumbria Watermarks Archive, will be published on the web and aims to provide a freely accessible and highly valuable research tool for art and paper historians, forensic scientists and paper conservators. It is intended to draw together and cross-reference existing records in addition to being the starting point for a progressive andinteractive collation of new and related information. In addition to the provision of identification information for watermarksand paper, the archive will include extensive data on paper technology, paper history, working methods of artists, artists'materials and preservation/conservation issues. The archive will have the unique facility to retrieve watermark images basedsolely or in part on similarity of shape through the implementation of content-based image retrieval (CBIR) software writtenat the University specifically for the purpose (see: http://iidr.unn.ac.uk/shrew). This paper discusses the advantages of CBIRin the context of watermarks, and the results of an initial evaluation of the software.