The amount of information available to humankind today is increasing steadily and exponentially. Never before has any individual had as much information at his/her fingertips as the common user of modern information technology. In addition to the problems involved in searching and accessing the required information ("data minining"), another important issue is finding the most efficient way to use the information once it has been found. The easy access to huge amounts of data and information has already revolutionized the way in which many professions are being conducted: architects can use digital blueprints to create, on the fly, arbitrary views of buildings that do not yet exist, and physicians have access to their patients' records, including digital Magnetic Resonance Imaging (MRI) and Computer Tomography (CT) data. Since these data are associated with real-world objects (and subjects), the most intuitive way of showing these graphical data would be to place them into the real world: this way, the architect could see the building he designs, integrated into the real environment, and the physician could see the 3D MRI and CT images overlaid directly onto the patients' body. For this approach to information presentation, the term "augmented reality" (AR) was coined by Tom Caudell in the context of a pilot project in which AR technology was used to simplify an industrial manufacturing process in a Boeing airplane factory. Other industrial applications of AR include virtual prototyping, where the product being developed can be visualized in its real-world surroundings and can be tested for design flaws. Besides those applications, AR technology is useful in error diagnostics and maintenance of complex machinery, where status information and instructions can be overlaid directly on the critical machinery component. In the long term, such systems will reduce maintenance cost, because they will be able to replace expensive printed manuals. Research in AR has emerged from various other research areas such as virtual reality (VR), wearable and ubiquitous computing, and human-computer interaction (HCI). By exploiting technologies and methods developed in the VR-domain, AR bridges the gap between virtual reality and the real world, occupying an intermediate position in the reality-virtuality continuum [Milgram 94]. Although AR is often associated with visualization (starting with the first head-mounted display by Sutherland [Sutherland 68]), augmentation can also be provided in the aural domain [Cohen 93] [Mynatt 97]. AR technology provides a means for intuitive information presentation which enhances perceivers' situational awareness and perception of the real world. This enhancement is achieved by placing virtual objects or information cues into the real world. These techniques can also be used to exploit the natural and familiar modalities for human interaction with the environment, e.g., augmenting paper drawings [Mackay 95], a desk environment [Rauterberg 96], or the pen and notebook paradigm [Szalavari 97]. AR is more than a simple integration of existing technologies, however, although several techniques of various research fields, such as computer vision, virtual reality, sound, AI, and ergonomics, are integrated into AR applications. AR has generated a few new research areas - for example, affine projection. Specific requirements of AR in many areas (tracking, interaction between users and objects or information) also trigger new research efforts in those "integration" fields, greatly expanding the scope of those fields.     «

The amount of information available to humankind today is increasing steadily and exponentially. Never before has any individual had as much information at his/her fingertips as the common user of modern information technology. In addition to the problems involved in searching and accessing the required information ("data minining"), another important issue is finding the most efficient way to use the information once it has been found. The easy access to huge amounts of data and information has...     »