| Image Processing Toolbox | |
Compute two-dimensional inverse fast Fourier transform
Syntax
B = ifft2(A) B = ifft2(A,m,n)
Description
B = ifft2(A) returns the two-dimensional inverse fast Fourier transform of matrix A. If A is a vector, B has the same orientation as A.
B = ifft(A,m,n) pads matrix A with zeros to size m-by-n. If [m n] < size(A), ifft2 crops A before transforming.
For any A, ifft2(fft2(A)) equals A to within roundoff error. If A is real, ifft2(fft2(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
ifft2 is a function in MATLAB.
Algorithm
The algorithm for ifft2(A) is the same as the algorithm for fft2(A), except for a sign change and scale factors of [m,n] = size(A). Like fft2, the execution time is fastest when m and n are powers of 2 and slowest when they are large prime numbers.
See Also
dftmtx, filter, freqz, specplot, spectrum in the Signal Processing Toolbox User's Guide
fft, ifft in the MATLAB Function Reference
| | idct2 | ifftn | |