  Based on image moment theory, an approach for space-variant Shack-Hartmann
wavefront reconstruction is presented in this article. The relation between the
moment of a pair of subimages and the local transformation coefficients is
derived. The square guide 'star' is used to obtain a special solution from this
relation. The moment-based wavefront reconstruction has a reduced computational
complexity compared to the iteration-based algorithm. Image restorations are
executed by the tiling strategy with 5 $\times$ 5 PSFs as well as the
conventional strategy with a global average PSF. Visual and quantitative
evaluations support our approach.
