| Visual perception studies typically focus either on optic flow structure or image structure, but not on the combination and interaction of these two sources of information. Nevertheless, the two are both available in vision and each offers unique strengths in contrast to the other's weaknesses. Optic flow yields intrinsically powerful information about 3D structure, but is ephemeral. It ceases when motion stops. Image structure is less powerful in specifying 3D structure, but is stable. It remains when motion stops. Optic flow and image structure are intrinsically related in vision because optic flow carries one image to the next. This relation is especially important in the context of progressive occlusion and camouflage, where optic flow provides information about the location of targets hidden in surrounding image structures respectively. In the first two parts of this work, I showed that the combination of optic flow and image structure specified locations of hidden and camouflaged objects, allowing them to be reliably identified after some time delay. The findings support J.J. Gibson's (1979/1986) insights about progressive occlusion and the embodied nature of perception and memory. Finally, this theoretical development was applied to understanding event perception with simulated low vision. In the third part, I showed that videotaped daily events were perceptible when images were blurry but motion was continuous. Optic flow calibrates low quality image structure to allow accurate event perception during and after motion. This implied that low vision observers should perform much better than allowed by weakened image structure information alone. |
