ABSTRACT
Telepresence and virtual reality systems can both provide high fidelity ‘indirect’ images of a scene. The core principal of these technologies is the same as for photography: projective isomorphism (Gibson, 1971). The indirect image viewed from the station point (SP-the centre of projection) produces a retinal image that is geometrically equivalent to the image produced by direct viewing of the real scene. The principal of retinal equivalence can be extended to moving scenes and to the binocular case. In the former, relative motion within the scene produces equivalent retinal changes to direct viewing, and this additional information can enhance perceptual judgements (Rogers and Graham, 1979) In the latter case, if two cameras view the scene separated by the average
interocular distance and the images are sent separately to the eyes, then viewed from the SP the scene disparities will be equivalent to those generated in direct viewing. Binocular information adds to the sense of immersion in the scene, and enhances accuracy of spatial judgements (Asbery and Pretlove, 1995; Lippert et al, 1982).
