2d fourier transform in matlab

To compute the 2D Fourier transform of an image in MATLAB, you can use the built-in function fft2. Here's an example code snippet:

main.m
% Read in image file
im = imread('lena.jpg');

% Convert image to grayscale
im = rgb2gray(im);

% Compute the 2D Fourier transform
im_fft = fft2(im);

% Shift zero-frequency component to center of spectrum
im_fft = fftshift(im_fft);

% Visualize the magnitude of the Fourier transform
im_fft_mag = abs(im_fft);
imshow(log(1 + im_fft_mag), []);
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This code reads in an image, converts it to grayscale, and computes the 2D Fourier transform using fft2. The fftshift function is then used to shift the zero-frequency component to the center of the spectrum. Finally, the magnitude of the Fourier transform is visualized using imshow. Note that we take the logarithm of the magnitude array to better visualize the spectrum.