We want to sample the 2-D continuous signal by means of a rectangular sampling scheme t...

We want to sample the 2-D continuous signal by means of a rectangular sampling scheme to obtain 1.5 samples per millimeter. Determine the PSF of an ideal low-pass anti-aliasing filter with the maximum possible frequency content. What percentage of the spectrum energy (see Problem 2.3) of f (x, y) is preserved by this filter? In practice, can we sample f (x, y) alias-free without using an anti-aliasing filter?