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Inverse two-dimensional fast Fourier transform
Y = ifft2(X) Y = ifft2(X,m,n)
Y = ifft2(X)
returns the two-dimensional inverse fast Fourier transform of matrix X.
Y = ifft2(X,m,n)
returns the m-by-n inverse fast Fourier transform of matrix X.
For any X, ifft2(fft2(X)) equals X to within roundoff error. If X is real, ifft2(fft2(X)) may have small imaginary parts.
The algorithm for ifft2(X) is the same as the algorithm for fft2(X), except for a sign change and scale factors of [m,n] = size(X). The execution time is fastest when m and n are powers of 2 and slowest when they are large primes.
dftmtx, freqz, specplot, and spectrum in the Signal Processing Toolbox, and:
fft2 Two-dimensional fast Fourier transform
fftshift Shift DC component of fast Fourier transform to center
of spectrum
ifft Inverse one-dimensional fast Fourier transform