Telepresence systems should be designed to assist the human operator as much as possible to fulfill his task. In order to support the user concerning the visual modality, a system was designed that presents virtual reality images combined together with camera images captured at the remote teleoperator environment. In this work, two experiments were conducted. In the first, it was shown that presenting a widened field of view to the human operator enhances the human performance and the feeling of telepresence. In the second, it was examined how the transition between video and virtual views has to be designed. Relevant criteria of this transition were chosen and the results show that the operator's rating of quality, feeling of telepresence, and situation awareness are positively affected by variations of the transition parameters. Furthermore, a trade-off between the rating of quality and the situation awareness was observed. A parameter selection scheme is presented which can serve as a design guideline for combining video and virtual views depending on the desired application.

The quality of a teleoperation system is decreased by time delays in the communication channel. Delays as low as a few hundred milliseconds between commanding an action and getting the visual feedback reduce the operator's performance. Predictive displays have proven their suitability to compensate for these delays, but at the expense of image quality when using computer-generated images. A photorealistic predictive display is presented that closes the feedback loop locally at the operator's side of a telepresence system. Photorealism is achieved using delayed camera images for texturing the predicted scene. Consumer graphics hardware is not only used for rendering but also for hardware-accelerated texture extraction. To allow concurrent access to model data, a multibuffer model structure is presented. A model of the teleoperator's environment is automatically acquired and updated by image processing techniques using a stereo camera as the only sensor.