
attenuated completely. The much lower frequency of the Moire
´
fringes is easily
within the passband, and that component carries information about the pattern
on the right that is unobservable directly. What is needed is a way to extract this
information, which can be done by shifting the phase of the illumination grid
over a few frame captures and solving a set of algebraic equations. This is the
basis of using SIM to extend lateral resolution.
17.6.2 Mathematical Foundation
A deeper understanding of this method follows from its mathematical analysis,
which relies on Fourier theory [20]. By the convolution theorem, the FT of the
convolution of two functions ...