FFT (DFT) of 2D Images

1. How do you calculate 2D FFT?
2. What does a 2D FFT tell you?
3. What is 2D Fourier transform on an image?
4. What is 2D discrete Fourier transform in image processing?

How do you calculate 2D FFT?

Y = fft2( X ) returns the two-dimensional Fourier transform of a matrix using a fast Fourier transform algorithm, which is equivalent to computing fft(fft(X). '). ' . If X is a multidimensional array, then fft2 takes the 2-D transform of each dimension higher than 2.

What does a 2D FFT tell you?

2D FFT (2-dimensional Fast Fourier Transform) can be used to analyze the frequency spectrum of 2D signal (matrix) data. Conversely, 2D IFFT (2-dimension Inverse Fast Fourier Transform) is able to reconstruct a 2D signal from a 2D frequency spectrum.

What is 2D Fourier transform on an image?

The Fourier Transform ( in this case, the 2D Fourier Transform ) is the series expansion of an image function ( over the 2D space domain ) in terms of "cosine" image (orthonormal) basis functions.

What is 2D discrete Fourier transform in image processing?

The (2D) Fourier transform is a very classical tool in image processing. It is the extension of the well known Fourier transform for signals which decomposes a signal into a sum of sinusoids. So, the Fourier transform gives information about the frequency content of the image.