A demonstration of the visual importance and flexibility of spatial-frequency amplitude and phase.

To establish how little information the human visual system requires for recognition, common objects were digitally manipulated in the Fourier domain. The results demonstrate that it is not only possible, but also quite efficient, for a (biological) visual system to exist with very few phase relationships among the component spatial frequencies of the (retinal) image. A visual example is then presented which illustrates how certain phase relationships can hinder, or completely eliminate, the recognition of visual scenes.