I tried to Fourier decompose my image using FFT and reconstruct it back using IFFT. While I did this, I noticed something peculiar:
The first image is the regular one, and the second is the image I constructed by re-combining the DFT:
[g, map]=imread("skull.png"); gdft=fft2(g); f=ifft2(gdft); subplot(1,2,1) imshow(g,map) subplot(1,2,2) imshow(f)
As you can see, I applied the function and the inverse successively which means there should technically be no change in the image. Why is there such a noticeable change then? I think there is a loss of information on the relative magnitudes of gray values to some extent.
Maybe relevant details:
- The program was written in Matlab
- The image is 16x16 grayscale in nature