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The FFT can be computed/visualised with a lens [0]. Quite cool [0] https://youtu.be/Y9FZ4igNxNA?t=567 https://youtu.be/Y9FZ4igNxNA?t=567
by secondcoming 5y ago
The FFT can be computed/visualised with a lens [0]. Quite cool
[0] https://youtu.be/Y9FZ4igNxNA?t=567 https://youtu.be/Y9FZ4igNxNA?t=567
- kergonath 5y agoPhysicist’s nitpick: this is Fourier transform (or its discrete equivalent DFT, not to be confused with density functional theory). FFT (fast Fourier transform) is just an algorithm to calculate DFTs. They are used interchangeably by computer people, but they really are not the same thing. That aside, yes, it is amazing to play with this sort of things and produce Fourier transforms by shining a light through a physical object. I remember a lab assignment from undergrad where we de-noised a picture by blocking some parts of its transform before transforming it back. We could remove the noise or the image itself (keeping almost only the noise) by blocking different parts of the beam. It makes the concept of frequency filtering very intuitive.
- kergonath 5y agoI guess it would be equally jarring if someone were using “quick sort” in every context where they mean “sort”.
- dotancohen 5y agoOr if one were to "Google" every time they mean search. "Honey, Google the pantry for the maple syrup please!".
- secondcoming 5y agoOk, I'll edit it! Edit: Oops, too late to edit. It's there forever.
- kergonath 5y agoNo need to anyway. Sorry, it wasn’t meant to be personal, or even criticism really. As I said, just a nit (the video was quite good).