Perceptual Effects in Aligning Virtual and Real Objects in Augmented Reality Displays

The concept of Augmented Reality (AR) displays is defined, in relation to the amount of real (unmodelled) and virtual (modelled) data presented in an image, as those displays in which real images, such as video, are enhanced with computer generated graphics. For the important class of stereoscopic AR displays, several factors may cause potential perceptual ambiguities, however, which manifest themselves in terms of decreased accuracy and precision whenever virtual objects must be aligned with real ones. A review is given of research conducted to assess both the magnitude of these perceptual effects and the effectiveness of a computer assisted Virtual Tape Measure (VTM), which has been developed for performing quantitative 3D measurements on realworld stereo images.