iwt_pb.sci

小波分解源代码

function x = IWT_PB(wc,L,qmf,dqmf)
// IWT_PB -- Inverse Wavelet Transform (periodized, biorthogonal)
//  Usage
//    x = IWT_PB(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
//    dqmf    dual quadrature mirror filter (symmetric, dual of qmf)
//  Outputs
//    x       1-d signal reconstructed from wc
//
//  Description
//    Suppose 
//          wc = FWT_PB(x,L,qmf,dqmf);
//
//    where analysis_qmf is a biorthogonal symmetric quadrature
//    mirror filter as made by 
//          [qmf,dqmf] = MakeBSFilter(Request,par);
//
//    Then x can be reconstructed by
//          x = IWT_PBS(wc,L,qmf,dqmf);
//
//  See Also
//    FWT_PBS, MakeBSFilter
//
//  Copyright Aldo I Maalouf

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

  endfunction