I am having trouble identifying the frequency components of an image,
Here I simply generated, 256x256 binary-image.
a = [zeros(256,128) ones(256,128)]; imshow(a);
Taking the image FFT and shifting the Zero-frequency to the center,
f = fft2(a) shft = fftshift(f); imshow(log(shft)) %stretching
How do I identify how many frequency components are there and what are those frequencies?
Also if I calculate FFT of any 1-D sequence and plot that sequence there are certain values on negative, what does that mean? How could there be negative frequencies?