2.11.1.4 ifft2(Pro)

Menu Information

Analysis : Signal Processing : FFT : 2D IFFT

Brief Information

Compute 2D inverse fourier transform of data in matrix

Additional Information

This feature is for OriginPro only.

Command Line Usage

1. ifft2 im:=mat(1);

2. ifft2 sc:=1;

3. ifft2 im:= mat(1) om:= mat(2);

Variables

Display
Name
Variable
Name
I/O
and
Type
Default
Value
Description
Input Matrix im

Input

MatrixObject

<active>

Specifies the input matrix.

Imaginary Matrix im2

Input

MatrixObject

<optional>

Specifies the imaginary matrix.

Undo Shift sc

Input

int

0

Specifies whether to undo the shifting. This variable should be set to 1 if the DC component is in the center of the input matrix.

Output Matrix om

Output

MatrixObject

[<new>]<new>!

Specifies the output matrix.

See the syntax here.

Real Matrix orm

Output

MatrixObject

[<same>]<new>!

Specifies the real part of output matrix.

See the syntax here.

Imaginary Matrix oim

Output

MatrixObject

[<same>]<new>!

Specifies the imaginary part of output matrix.

See the syntax here.

Amplitude Matrix oam

Output

MatrixObject

[<same>]<new>!

Specifies the amplitude matrix.

See the syntax here.

Phase Matrix opm

Output

MatrixObject

[<same>]<new>!

Specifies the phase matrix.

See the syntax here.

Description

2D IFFT is a fast algorithm for two-dimensional discrete Fourier transform (2D IDFT), which can be defined as follows:

Ifft2 help English files image002.jpg

It works on a two dimensional array of data, and is capable of reconstructing a 2D signal from its spectrum. However, the reconstruction is correct only when the Undo Shift variable is set to the same value as the DC Shift Center variable of the 2D FFT which generated the input matrix. Additionally, for large data, the restored 2D signal might have minor differences from the original signal.

Examples

1. To perform 2D IFFT on the active matrix, use the script command:

ifft2

2. To open the dialog of this tool, type in the Command Window:

ifft2 -d

Algorithm

For more information, please refer to our User Guide.


Related X-Functions

fft2, fft1, ifft1


Keywords:amplitude, phase, power