Super-resolution in computational imaging.

Super-resolution is a word used in different contexts but mainly in the case of methods aimed at improving the resolution of an optical instrument beyond the diffraction limit. Such a result may be achieved by means of specific instrumental techniques (such as, for instance, interferometry) or by means of a suitable processing of a digital image; in the latter case we will use the expression computational super-resolution (CSR). In this paper we describe the basic concepts underlying CSR without using the mathematics required for establishing its theoretical validity. The aim is to introduce a wide audience to this topic, to specify the situations where CSR is feasible and to emphasize the point that unlimited CSR is not possible.