Signal Processing Toolbox

fft2

Compute the two-dimensional fast Fourier transform.

Syntax

Y = fft2(X)
Y = fft2(X,m,n)

Description

Y = fft2(X) performs a two-dimensional FFT, producing a result Y with the same size as X. If X is a vector, Y has the same orientation as X.

Y = fft2(X,m,n) truncates or zero pads X, if necessary, to create an m-by-n array before performing the FFT. The result Y is also m-by-n.

The fft2 function is part of the standard MATLAB language.

Algorithm

fft2(x) is simply

fft(fft(x).').'

This computes the one-dimensional fft of each column of x, then of each row of the result. The time required to compute fft2(x) depends on the number of prime factors in [m,n] = size(x). fft2 is fastest when m and n are powers of 2.

See Also

fft	One-dimensional fast Fourier transform.
fftshift	Rearrange the outputs of fft and fft2.
ifft	One-dimensional inverse fast Fourier transform.
ifft2	Two-dimensional inverse fast Fourier transform.

fft

fftfilt