Clear Filters
Clear Filters

What do "fftshift" do exactly for an image ?

31 views (last 30 days)
What do "fftshift" do exactly for an image ?

Accepted Answer

Image Analyst
Image Analyst on 16 Feb 2015
Normally the "center" or the 0 frequency location of the spectrum is at the first and last element, and the "ends" of the spectrum (highest frequencies) are at the center of the array. That's just how the fft works. But that's confusing for display because the low frequencies are appearing in two disconnected locations. So fftshift() moves the zero frequency location to the middle of the array so that when you display it with imshow() or plot(), it looks like you'd expect.
  5 Comments
bh dhouha
bh dhouha on 17 Feb 2015
Image analyst you said: "Normally the "center" or the 0 frequency location of the spectrum is at the first and last element, and the "ends" of the spectrum (highest frequencies) are at the center of the array. That's just how the fft works", i would like to understand the location of each frequency in the spectrum, is there a document on this or something that explains this point?

Sign in to comment.

More Answers (0)

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!