ifft2 (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.