Augmented Reality: An Overview

We define Augmented Reality (AR) as a real-time direct or indirect view of a physical real-world environment that has been enhanced/augmented by adding virtual computer-generated information to it [1]. AR is both interactive and registered in 3D as well as combines real and virtual objects. Milgram’s Reality-Virtuality Continuum is defined by Paul Milgram and Fumio Kishino as a continuum that spans between the real environment and the virtual environment comprise Augmented Reality and Augmented Virtuality (AV) in between, where AR is closer to the real world and AV is closer to a pure virtual environment, as seen in Fig. 1.1 [2]. Augmented Reality aims at simplifying the user’s life by bringing virtual information not only to his immediate surroundings, but also to any indirect view of the real-world environment, such as live-video stream. AR enhances the user’s perception of and interaction with the real world. While Virtual Reality (VR) technology or Virtual Environment as called by Milgram, completely immerses users in a synthetic world without seeing the real world, AR technology augments the sense of reality by superimposing virtual objects and cues upon the real world in real time. Note that, as Azuma et al. [3], we do not consider AR to be restricted to a particular type of display technologies such as head-mounted display (HMD), nor do we consider it to be limited to the sense of sight. AR can potentially apply to all senses, augmenting smell, touch and hearing as well. AR can also be used to augment or substitute users’ missing senses by sensory substitution, such as augmenting the sight of blind users or users with poor vision by the use of audio cues, or augmenting hearing for deaf users by the use of visual cues.