Convert Matrix to Standard Form (Periodized,Orthogonal)
S = FSFT_PO(M,L,qmf)
Matrix to be put in standard form
Coarsest Resolution Level of WT
quadrature mirror Filter of Wavelet Transform
The matrix M expressed as a matrix operating in wavelet coefficients.
If x is a vector and M is a matrix, then one can calculate Mx in two ways: (a) Use natural basis: M*x (b) Use Wavelet Basis: IWT[S * FWT[x]] where FWT and IWT are wavelet transforms and SF is the standard form of the matrix. If S is sparse then the second form can be much cheaper to implement.