Abstract
We have discovered a new type of optical illusion in which a single solid generates impressions of two quite different cylinders when it is seen from two special viewpoints. By positioning a solid and a mirror in such a way that the two special viewpoints can be experienced simultaneously, the viewer sees both the solid itself and its mirror image, but as apparently different objects. From this, the viewer understands logically that what he/she is perceiving is different from the real shape of the solid, but the visual system of the viewer does not correct the misperception of the solid’s shape. In this sense, this anomalous perception belongs to the class of optical illusions, and we are naming it the ambiguous cylinder illusion. The ambiguous cylinder illusion can be explained as the result of an interaction between depth ambiguity in a single image and a human preference for a rectangular structure. From a mathematical point of view, a single image cannot uniquely specify the three-dimensional shape of an object appearing in the image, because the image does not convey depth information, and hence there is ambiguity in the object. From a psychological point of view, on the other hand, the human visual system prefers certain interpretations more strongly than other interpretations. In particular, if the solid is composed of planar faces, then the system seems to prefer the interpretation of a rectangular structure to other interpretations. In the case of an image of a cylindrical object, the human visual system seems to consider that the object is generated by cutting a cylinder with a plane perpendicular to the axis of the cylinder. We will show that ambiguous cylinders can be created successfully on the basis of this hypothesis.
Meeting abstract presented at VSS 2015