Mathematically, real space and Fourier space are equivalent (via the Fourier transform). The Fourier domain also has some useful properties, such as efficiency in representing large objects and multi-resolution capabilities. I propose the use of Fourier goggles to automatically perform a Fourier transform on normal visual input. They could be used for... well, I don't know what.
-- lubbit, May 05 2001

(???) Optical Fourier transform lab experiment http://www.ee.bilke...al/html/node10.html
Here's a student lab experiment on doing the Fourier transform optically. [td, May 05 2001]

Err... FFT then. Probably.
-- lubbit, May 05 2001


Possibly surprisingly, this is baked. An ordinary lens does a Fourier transform. This is routinely used to do spatial filtering optically -- you transform into Fourier space, use an ordinary neutral density filter to block selected frequencies and transform back. See the link.

At work we have an optical gadget set up to measure the resolution of the images we put on film.
-- td, May 05 2001


Of course, it wasn't really specified whether the Fourier transform was with spatial or temporal. (Spatial is probably a better approximation; a temporal Fourier transform would just be a spectrogram of some sort, I guess.)
-- egnor, May 05 2001


Yes, we learned about optical transforms in image processing class. (You just focus a lens in a certain way, and the 2D transform of the intensity of the image appears.) But goggles! That is genius! I want to try it. Would it give us any information we can't glean with our plain 'ol eyes?
-- omegatron, Nov 24 2004


If I remember right, holography works on somewhat related principles, but the interference patterns for different wavelengths of light do not coincide in any useful way.
-- supercat, Nov 24 2004



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