Image Processing Toolbox | ![]() ![]() |
Compute N-dimensional inverse fast Fourier transform
Syntax
B = ifftn(A) B = ifftn(A,siz)
Description
B = ifftn(A)
performs the N-dimensional inverse fast Fourier transform. The result B
is the same size as A
.
B = ifftn(A,siz)
pads A
with zeros (or truncates A
) to create an N-dimensional array of size siz
before doing the inverse transform.
For any A
, ifftn(fftn(A))
equals A
within roundoff error. If A
is real, ifftn(fftn(A))
may have small imaginary parts.
Class Support
The input matrix A
can be of class double
or of any integer class. The output matrix B
is of class double
.
Remarks
ifftn
is a function in MATLAB.
Algorithm
B = A; for p = 1:length(size(A)) B = ifft(B,[],p); end
This code computes the one-dimensional inverse fast Fourier transform along each dimension of A
. The time required to compute ifftn(A)
depends most on the number of prime factors of the dimensions of A
. It is fastest when all of the dimensions are powers of 2.
See Also
![]() | ifft2 | im2bw | ![]() |