Hypertext is an appealing interface for digital libraries, but using existing paper documents to build such a library poses several challenges. We describe a system for creating hypertext links on the fly in a library composed of bitmapped images of paper documents and text derived from those images by optical-character recognition.
We present two simple ideas: text-image maps coordinate text and image representations of a document, and our probabilistic search heuristics generate hypertext links from the text of citations. Using the World-Wide Web, we built an interface that lets readers move from a bibliography entry to the cited document with a mouse click. Similarly, readers can click on entries in the table of contents and move directly to them.