2-d Refinement based on Average-Interpolation
fine = AIRefine2d(coarse,L,D,Filter,Efil)
2-d image at a coarse scale: length(coarse)=n
integer >=1. number of generations to refine by
D degree of polynomials used for interpolation
interpolating filter from MakeAIFilter(D)
Boundary filter from MakeAIBdryFilter(D)
2-d image at a fine scale: size(fine) = 2^L * size(coarse)
Average-Interpolating Refinement scheme is used to refine boxcar averages on a grid of n*n points, imputing averages on a finer grid of 2^L n * 2^L n points.