90 PERVASIVE computing Published by the IEEE CS n 1536-1268/08/$25.00 © 2008 IEEE Conferences Editor: Jason Hong n Carnegie Mellon University n jasonh@cs.cmu.edu n n n n n n n n n n n n n SUPPORTING AUGMENTED REALITY IN UBIQUITOUS COMPUTING ENVIRONMENTS Dongpyo Hong, Tobias Höllerer, Michael Haller, Haruo Takemura, Adrian David Cheok, Gerard Jounghyun Kim, Mark Billinghurst, and Woontack Woo R ecent augmented-reality (AR) sys- tems often use auxiliary sensory information to enhance the accuracy of context recognition and tracking and registration, especially in mobile settings, where computer vision alone is insuf fcient. As AR systems become increasingly commercial- ized, there have been many attempts to improve their design and usability. Here we report on context-sensitive AR research presented at the 2007 International Symposium on Ubiqui- tous Virtual Reality, held in Gwangju, Korea, on 15–16 July 2007. ISUVR 07 explored the use of contextual infor- mation, design principles, and effec- tive user evaluation for developing AR applications for ubiquitous computing environments. MOBILE AR: ANYWHERE AUGMENTATION As mobile platforms have become suf- fciently powerful, AR systems are shift- ing from desktop to mobile computers. In ubiquitous computing environments, mobile AR systems have several advan- tages over desktop-based platforms. On the symposium’s frst day, Tobias Höllerer (University of California, Santa Barbara) discussed the central goals and requirements of “anywhere aug- mentation”—making virtual content overlays readily and directly available in any situation and location. Current approaches rely on user-worn sensors and the availability of a 3D model of the environment or on active or passive markers in the environment. However, AR will become truly ubiquitous only if these requirements are relaxed. For example, research on vision- based AR systems in unprepared envi- ronments is yielding initial results, but a general and robust automatic solu- tion for this exceedingly hard prob- lem is still out of reach. So, Höllerer also focused on exploiting various Geographic Information System data sources, such as aerial photographs, to aid outdoor tracking. He proposed to better empower the human in the loop by providing tools to easily set up initial registration frames, issue simple correc- tions to registration errors, and model scene geometry. Current real-time com- puter vision techniques and algorithms are far from being able to facilitate fully automatic scene understanding for general scenes. However, they’re well suited to constrain and guide a user’s informed input for scene analysis and augmentation, delivered in the form of a few simple point selections, stroke gestures, and common classifcations. DESIGNING AR SYSTEMS Michael Haller (Upper Austria Univer- sity of Applied Sciences) talked about particular challenges and solutions for designing interactive tabletops and walls. Such devices are becoming increasingly popular, and large aug- mented surfaces are already part of our physical environment. These newly emerging form factors require novel HCI techniques. A tabletop or wall provides a large interactive visual sur- face for groups to interact. It encour- ages collaboration, coordination, and simultaneous and parallel problem solving. Haller explained how to design a nontraditional user interface for large EDITOR’S INTRO This issue we have a special treat for readers, presenting reports on two different con- ferences instead of just one. The first summary reports on the 2007 International Sym- posium on Ubiquitous Virtual Reality, describing some of the latest results in developing useful, usable, and desirable augmented-reality systems. The second summary reports on the International Conference on Tangible and Embedded Interaction, highlighting some of the latest results in this first conference devoted to tangible user interfaces. — Jason Hong Advances in Tangible Interaction and Ubiquitous Virtual Reality