In this paper, a new concept for markerless optical tracking called "tracking with reference images" is introduced. This concept provides a flexible and praticable framework and is especially relevant for outdoor augmented-reality applications, for which no tracking solution currently exists.
The implementation is achieved using an image matching technique, which compares the current live video image with one or more of the reference images.
The complete system has been tested outdoor in the context of a mobile AR-application for archeology. The system runs on a laptop at around 10 Hz and provides views of virtual monuments superposed to their ruins.