File:Fourier Lowpass Filter Checkerboard.png - Wikipedia
Digital Signal Processing. Discrete Fourier Transform Inverse Discrete Fourier Transform. - ppt download
MATLAB - Ideal Lowpass Filter in Image Processing - GeeksforGeeks
Sampling and Reconstruction The impulse response of an continuous-time ideal low pass filter is the inverse continuous Fourier transform of its frequency. - ppt download
Digital Image Processing using Fourier Transform in Python | by Craig Chen | Medium