`ifft2`

Two-dimensional inverse discrete Fourier transform.

Category: Mathematics > Fourier Analysis and Filtering

Syntax

X = ifft2(Y)

Inverse transform along the first two dimensions.

X = ifft2(Y, m, n)

Pads or truncates Y to m rows and n columns first.

Description

ifft2(fft2(X)) recovers X. Multiplying two spectra element by element and applying ifft2 gives the circular convolution of the original matrices, which is how frequency-domain image filters are applied.

Input arguments

Y: Two-dimensional spectrum, typically from fft2.
m, n: Number of rows and columns of the transform.

Output arguments

X: Spatial-domain matrix, real when Y is conjugate symmetric.

Example

Round trip

X = [1 2; 3 4];
ifft2(fft2(X))

Output

ifft2