The geometric relational expression of horizontal disparity, viewing distance, and depth magnitude between objects in stereopsis suggests that, for a given viewing distance, the magnitude of perceived depth of objects would be the same as long as the disparity magnitudes are the same. However, we found that this is not necessarily the case for random dot stereograms that depict parallel-overlapping-transparent-stereoscopic-surfaces (POTS). Data from three experiments indicated that, when the stimulus size is relatively large (e.g., 13 x 20 arc deg), the magnitude of reproduced depth between two POTS is larger by 6% than that for an identical pair of stereo-surfaces but with an additional stereo-surface located between the pair. The results are discussed in terms of global stereopsis which "operates" for relatively large stimulus sizes.

Date Published: 17 February 2012
PDF: 9 pages
Proc. SPIE 8291, Human Vision and Electronic Imaging XVII, 82910O (17 February 2012); doi: 10.1117/12.909788

Published in SPIE Proceedings Vol. 8291:
Human Vision and Electronic Imaging XVII
Bernice E. Rogowitz; Thrasyvoulos N. Pappas; Huib de Ridder, Editor(s)