In the recording, Ren says (0,0) means omega x, omega y, both equal 0. Since omega = 2pi*f, this means the frequency is 0. Honestly the frequency domain part of this lecture was a bit confusing for me. Feel free to correct me explanation of the coordinates.
UPDATE: check out https://web.archive.org/web/20130513181427id_/http://sharp.bu.edu/~slehar/fourier/fourier.html#filtering, it explains (in text) the following slides. Basically, different points in the fourier domain represent different sampling frequencies in the spatial domain. Points closer to the center are lower frequency. If you want to filter out high frequencies then you'd sample a ton of points close to the center of the frequency domain.
In the recording, Ren says (0,0) means omega x, omega y, both equal 0. Since omega = 2pi*f, this means the frequency is 0. Honestly the frequency domain part of this lecture was a bit confusing for me. Feel free to correct me explanation of the coordinates.
UPDATE: check out https://web.archive.org/web/20130513181427id_/http://sharp.bu.edu/~slehar/fourier/fourier.html#filtering, it explains (in text) the following slides. Basically, different points in the fourier domain represent different sampling frequencies in the spatial domain. Points closer to the center are lower frequency. If you want to filter out high frequencies then you'd sample a ton of points close to the center of the frequency domain.