Here is my realisation of wavefront decomposition and restoration based on
Zernike polynomials (up to 100th order).

The base functions are:

double *zernfunR(int n, int m, int W, int H, double *norm);
	calculates Zernike polynomial of order n and angular order m on 
	equidistance rectangular grid WxH (norm is NULL or value to store
	sum(Z_i^2) for normalisation on decomposition.

double *zernfunNR(int p, int W, int H, double *norm);
	the same but in Noll notation

double *Zdecompose(int Nmax, int W, int H, double *image, int *Zsz, int *lastIdx);
	decompose image by Zernike polynomials with order <= Nmax,
	Zsz is size of returned array (in Noll notation)
	lastidx is last non-zero coefficient

double *Zcompose(int Zsz, double *Zidxs, int W, int H);
	build image based on Zernike coeffs Zidxs
	Zsz - size of array in Noll notation
	W, H - size of future image

void set_prec(double val);
	set precision of Zernike transforms