Imagine I have the following profile for gray intensity along a known curve:
I got the following from Fourier transform:
1. I wonder how I can obtain frequency from spatial coordinates? I read all of fft examples, but I am really confused!
The first image above is the gray intensity in terms of "number of the points" along a path. I can also plot it vs. the points x or y values. Now how can I find the frequency from them? I mean to find the dominant frequency from fft? while now it is still the number of the points.
2. Why is the fft symmetric while the original profile is not? I feel something's terribly wrong about fft or fft2, but I do not know what!
Note: What I want finally, is the main frequency and then wavelength of an image.
Thanks so much in advance