| Subjects observe a horizontal random-dot surface through a transparent board on which stripes of vertical lines are printed. Under this condition, the surface is illusory perceived as a sequence of wave-like three-dimensional surface that does not exist. This phenomenon has not been known so far, and is related to depth perception by stereo-disparity information because the wave-like surface does not appear by monocular viewing.|
In this paper, we conducted a psychophysical experiment to measure frequencies and locations of those waves. Results of the experiment showed that a frequency of waves increased as an Interval between vertical lines were decreased and as the subject observed the nearer region of the surface. Then we conducted computer simulations based on a computational theory: in that when neighboring two points on the surface are hidden by vertical lines from either left or right retina, they were matched as a congruent point. This algorithm predicted that the stereo matching of those points resulted in a wave-like three-dimension surface. The results of the simulation corresponded to that of the psychophysical experiment with respect to a frequency of waves. It is needed for future investigations to manipulate experimental parameters as widths of vertical lines or density of the random-dot surface, and to onstruct the better computational model explaining how the wave-like surface are constructed by the gross of matched points.