The Fourier theory of vision.

The historical roots of the Fourier theory of spatial visual perception are traced. The development of the underlying concepts and the psychophysical experiments that led to them, and that they in turn spawned, are examined, as well as their relation to the current knowledge of neural substrates in the retina and primary visual cortex. Allowing nonlinearities or even substituting other types of basis functions does not eliminate the difficulties faced by any theory of visual perception that is built on the notion of fixed spatial filters.