Introduction - If you have any usage issues, please Google them yourself
Generating shown bright block image F1 (x, y) (128128 size dark = 0, light at = 255), the FFT, the same screen display Original f1 and FFT (f1) of the amplitude spectrum FIG Let f2 (x, y) = (-1) x+y f1 (x, y), the above process is repeated. And rotated by 45 degrees to transform