•Another
way to think about convolution is in terms of how it changes the frequency
distribution in the image.
•
•Recall
the fourier representation of a function
•
–F(u) = s f(x) e-2p i u x dx
–recall
that e-2p i u x = cos(2p u x) – i sin (2 p u x)
–Also we
have f(x) = s F(u) e-2p i u x du
–F(u) =
|F(u)| ei F(u)
•a
decomposition into magnitude and phase
–|F(u)|^2
is the power spectrum
–
•Questions:
what function takes many many many terms in the Fourier expansion?