iwt_ti.sci

小波分解源代码

function x = IWT_TI(pkt,qmf)
// IWT_TI -- Invert translation invariant wavelet transform
//  Usage
//    x = IWT_TI(TIWT,qmf)
//  Inputs
//    TIWT     translation-invariant wavelet transform table
//    qmf      quadrature mirror filter
//  Outputs
//    x        1-d signal reconstructed from translation-invariant
//             transform TIWT
//
//  See Also
//    FWT_TI
//
//  Copyright Aldo I Maalouf

	[n,D1] = size(pkt); 
	D = D1-1;
	J = log2(n);
	L = J-D;
//
	wp = pkt;
//
	sig = wp(:,1)'; 
	for d= D-1:-1:0,  
		for b=0:(2^d-1)
			hsr = wp(packet(d+1,2*b  ,n),d+2)';
		    hsl = wp(packet(d+1,2*b+1,n),d+2)';
		    lsr = sig(packet(d+1,2*b  ,n) );
		    lsl = sig(packet(d+1,2*b+1,n) );		   
			loterm = (UpDyadLo(lsr,qmf) + lshift(UpDyadLo(lsl,qmf)))/2;
			hiterm = (UpDyadHi(hsr,qmf) + lshift(UpDyadHi(hsl,qmf)))/2;
			sig(packet(d,b,n)) = loterm+hiterm;
		end
	end
	x = sig;

endfunction