extract 64 lowest frequency components of fft

How to extract 64 lowest frequency components using fourier transform of an image

fft2 or fftn which function to use, and how to get the 64 feature vector as fft2 and fftn returns a matrix ouput

Answer 1

[Sulaymon Eshkabilov]

Hi,

For image analysis, fft2 is to be used and that is quite straightforward.

Here is an additional help discussion on this:

https://www.mathworks.com/matlabcentral/answers/24965-fft2-function-in-matlab

Good luck.