iwt_po.sci

小波分解源代码

function x = IWT_PO(wc,L,qmf)
// IWT_PO -- Inverse Wavelet Transform (periodized, orthogonal)
//  Usage
//    x = IWT_PO(wc,L,qmf)
//  Inputs
//    wc     1-d wavelet transform: length(wc) = 2^J.
//    L      Coarsest scale (2^(-L) = scale of V_0); L << J;
//    qmf    quadrature mirror filter
//  Outputs
//    x      1-d signal reconstructed from wc
//
//  Description
//    Suppose wc = FWT_PO(x,L,qmf) where qmf is an orthonormal quad. mirror
//    filter, e.g. one made by MakeONFilter. Then x can be reconstructed by
//      x = IWT_PO(wc,L,qmf)
//
//  See Also
//    FWT_PO, MakeONFilter
//
//  Copyright Aldo I Maalouf

  wcoef = ShapeAsRow(wc);
	x = wcoef(1:2^L);
	[n,J] = dyadlength(wcoef);
	for j=L:J-1
		x = UpDyadLo(x,qmf) + UpDyadHi(wcoef(dyad(j)),qmf)  ;
	end
    x = ShapeLike(x,wc);

 endfunction