Space perception in pictures

A "picture" is a at object covered with pigments in a certain pattern. Human observers, when looking "into" a picture (photograph, painting, drawing, . . . say) often report to experience a three dimensional "pictorial space." This space is a mental entity, apparently triggered by so called pictorial cues. The latter are sub-structures of color...

Vision as a user interface

The egg-rolling behavior of the graylag goose is an often quoted example of a fixed-action pattern. The bird will even attempt to roll a brick back to its nest! Despite excellent visual acuity it apparently "takes a brick for an egg." Evolution optimizes utility, not veridicality. Yet textbooks take it for a fact that human vision evolved so as...

Transparency and imaginary colors

Unlike the Metelli monochrome transparencies, when overlays and their backgrounds have chromatic content, the inferred surface colors may not always be physically realizable, and are in some sense “imaginary.” In these cases, the inferred chromatic transmittance or reflectance of the overlay lies outside the RGB spectral boundaries. Using the...