University of Washington researchers are working to more closely integrate the paper world with the world of electronic data.

Their system uses a computer and overhead video camera to track physical documents on a desk and automatically link them to appropriate electronic documents.

The paper-tracking system allows users to pinpoint the location of a given document within a stack of documents on the desktop. Users can find documents by using keywords, appearance, or by how recently a paper was moved. The photo-sorting application also allows users to sort digital photographs using printouts of the photos.

The system could be taken further to allow for querying the history of documents, lifting written annotations from document surfaces, recognizing text, and attaching reminders to documents.