Figure Properties - SERC

2fft2
Purpose Two-dimensional discrete Fourier transform
Syntax Y = fft2(X)
Y = fft2(X,m,n)
Description Y = fft2(X) returns the two-dimensional discrete Fourier transform (DFT) of
X, computed with a fast Fourier transform (FFT) algorithm. The result Y is the
same size as X.
Y = fft2(X,m,n) truncates X, or pads X with zeros to create an m-by-n array
before doing the transform. The result is m-by-n.
Algorithm fft2(X) can be simply computed as
Data Type
Support
fft(fft(X).').'
This computes the one-dimensional DFT of each column X, then of each row of
the result. The execution time for fft depends on the length of the transform.
It is fastest for powers of two. It is almost as fast for lengths that have only
small prime factors. It is typically several times slower for lengths that are
prime or which have large prime factors.
Note You might be able to increase the speed of fft2 using the utility
function fftw, which controls how MATLAB optimizes the algorithm used to
compute an FFT of a particular size and dimension.
fft2 supports inputs of data types double and single. If you call fft2 with
the syntax y = fft2(X, ...), the output y has the same data type as the input
X.
See Also fft, fftn, fftw, fftshift, ifft2
fft2
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