The LivePaper system: augmenting paper on an enhanced tabletop

The LivePaper system augments ordinary pieces of paper with projected infor mation. Pages, cards and books are placed on an instrumented tabletop to ac tivate their enhancement. To the user, it appears as if the paper gains new visual and auditory features, Projected annotations track the orientation and location of pages as the user moves them on the desktop. A piece of pap er that is removed, but then returned to the desk, regains the same feature s that it previously exhibited. The LivePaper system accomplishes this by u sing features extracted from written material on the page, not from glyphs or other artificial marks. The paper describes both. the system as a whole, and a number of sample app lications we have developed to illustrate the feasibility of the LivePaper system. These applications include an architectural visualization tool, whi ch projects a 3D hidden-line rendering of walls onto a page. The user may r otate and move the page to view the rendering from different angles. Anothe r application is an audio player, which begins playing when a page (such as a business card) is laid on the desk. The user may control playback with h is or her finger via projected buttons. Other applications include page-sha ring, remote collaboration, and World Wide Web page viewing. From the user' s perspective, all of these applications are attributes of the particular p age, not features of the tabletop. Particular attention is given to the design of interaction: LivePaper is ob ject-oriented, because the individual sheets are treated as computational u nits, but it also provides functions that involve several objects. The desi gn principles applied to handle the different kinds of functionality are ex plained and illustrated in the LivePaper system, but are also proposed for wider use in augmented reality. (C) 2001 Elsevier Science Ltd. All rights r eserved.