Abstract
In the case of the visual angle of a visual object is sufficiently large, usually almost constant shape perception is yielded in spite of the change of fixation point which is optionaly selected on the object. In this paper, this problem of stable perception, besides with the problem of constancy as the meaning of regression to the real object were investigated by the application of ⊿-transformed figure II⊿. First, some trials of measurement of shape stableness on the perception of a obliquely viewed square were considered. Second, the stableness of perspective declination of vertical sides of a obliquely viewed rectangle which stands upright was investigated by means of II⊿, in conditions of fixation point variated on the center line of object. Third, the invers perspective which is a kind of overconstancy was investigated, in was found that the conditions exist that yield a upward divergence about vertical parallel sides of a rectangle in II⊿. Moreover, the characters of the overconstancy under the detailed conditions on arrangement of object were shown. Further, some results of previous experiment under the similar situation were also considered.
