How to perform 2-D image FFT in Simulink?

Trying to perform 2-D image FFT of 3-channel "RGB" image in Simulink (converted from grayscale using: cat(3, im, im,im)).

Also how to visualise Frequency domain output in Simulink?

Thank you.

Answer 1

[Gowtham]

Hello George Paul,

I understand that you want to perform 2D FFT (Fast Fourier Transformation) on a RGB image in Simulink and to visualise frequency domain output in Simulink.

To perform 1D FFT in Simulink, the FFT block (as mentioned in documentation [2]) in the library DSP System Toolbox / Transforms can be used.

To perform 2D FFT in Simulink, the same FFT block can be used 2 times by applying 1D FFT on the rows and columns as mentioned in documentation [1]. An alternate way is to use a MATLAB function block which calls fft2 as mentioned in documentation [1].

To visualise frequency domain output in Simulink, the Spectrum Analyzer block can be used as mentioned in documentation [3].

Feel free to refer to the following documentation for further understanding:

1. https://www.mathworks.com/help/matlab/ref/fft2.html
2. https://www.mathworks.com/help/dsp/ref/fft.html
3. https://www.mathworks.com/help/simulink/slref/spectrumanalyzerblock.html

Hope it helps!