F = round(fftshift(abs(fft2(A))))
where A is the image.
I am studying contrast stretching in Digital Image Processing. I don't understand zero frequency component. I searched for it but I couldn't understand it, kindly refer some documentation about zero frequency component.
The zero-frequency is shifted to the center in both audio and image spectrums, simply because this is how people normally expect to see a spectrum. I.e. it is per convention. The spectrum content is not changed in any way, and everything you can derive after the shift, you can derive before the shift.
And Oliver is right - all frequencies are shifted and the zero-frequency (DC) just is the one ending up in the center.
Regards
