Two-dimensional Fourier transformation utility

It provides some utility functions for the two-dimensional Fourier transform.

It provides some utility functions for the two-dimensional Fourier transform.

run demo_fourier2.m

Textbooks usually show the Fourier spectrum which the DC component is located at the center of the graph. However, matlab function of fft2 provides the Fourier transform whose DC component is top-left. It is not convenient for us. Then, it provides simple warp function to generate a texbook like Fourier spectrum.

Fourier transform implicitly assumes an input image is cyclic.

This implicit assumption produces an artifact in the Fourier domain because the border of an image usually has strong edges.

In order to reduce this artifact, the window is usually applied to the image before the Fourier transformation.

But, if we want to operate in the Fourier domain, the window is not suitable. Then, it also provides the padding function for the Fourier transform.

demo_fourier2 : sample program

fourier2, ifourier2 : wrap functions of fft2 and ifft2

FourierSpectrum2: warp function to estimate Fourier spectrum

fbourder2, ifboruder2: padding functions for Fourier transform

fblackman2: window function

demo_fourier2 : sample program

fourier2, ifourier2 : wrap functions of fft2 and ifft2

FourierSpectrum2: warp function to estimate Fourier spectrum

fbourder2, ifboruder2: padding functions for Fourier transform

fblackman2: window function