Figure 1

Image and spectrum of a point source. Top row: the ideal image of a point source and its frequency spectrum. Second row: noise-free blurred image of the point source and the corresponding frequency spectrum. Third row: blurred and (Poisson) noisy image of the point source and the corresponding frequency spectrum. The gray line is the spectrum of the noise, and the black line is the spectrum of the noisy image of the point source. Last row: The result of a (hypothetical) recovery procedure, restoring all non-zero frequency amplitudes.