Why zero padding the 2-d DFT interpolates images in spatial domain?

1. Why is it required to do zero padding in DFT analysis?
2. Why zero padding is done prior to filtering?
3. What is zero padding in image processing?
4. What is the effect of zero padding in frequency domain?

Why is it required to do zero padding in DFT analysis?

Zero padding enables you to obtain more accurate amplitude estimates of resolvable signal components. On the other hand, zero padding does not improve the spectral (frequency) resolution of the DFT. The resolution is determined by the number of samples and the sample rate.

Why zero padding is done prior to filtering?

Zero-padding allows space for this wrap-around to occur without contaminating actual output pixels.

What is zero padding in image processing?

Padding is simply a process of adding layers of zeros to our input images so as to avoid the problems mentioned above. This prevents shrinking as, if p = number of layers of zeros added to the border of the image, then our (n x n) image becomes (n + 2p) x (n + 2p) image after padding.

What is the effect of zero padding in frequency domain?

In this case, we can say “zero padding in the frequency domain results in an increased sampling rate in the time domain”.