PERCEIVING THE STRUCTURE OF MOVING-OBJECTS

Motion in the environment can provide the information about depth rela tions. As an object moves with respect to an observer, the image of th is object on the observer's retina changes and observer is able to use the information about 2D transformations to recover the structure of 3D environment. Even when the view contains no information about three -dimensionality, depth can still be perceived. Not every conceivable r elative motion of an object with respect to an observer produces valua ble information about its structure. The most researchers use in their experiments rotation in depth. The author describes current state of knowledge in ''structure from motion'' problem and divides this subjec t of study into the three main issues: 1. properties of the input info rmation in the recovery of structure, 2. effect of different stimulus variables and experimental conditions on the accuracy of perception of 3D stucture, 3. properties of perceived structure. Observer commits m any systematic errors in the course of perception and these errors see m to provide a clue to the understanding of actual processing rules.