imm_dwt.sci

小波分解源代码

function f = IMM_DWT(maxima);
// MaxRecons - Inverse Reconstruction of signals from Modulus
//	      Maxima of a Dyadic Wavelet Transform
// Usage f = MaxRecons(maxima);
// Inputs 
//	maxima 		n times b matrix storing the positions
//			and values of a dyadic wavelet transform
// Outputs
//	f		signal, size n
// References
//   Mallat's book, section 6.3.2
//  Copyright Aldo I Maalouf

[n,b] = size(maxima);

//u = (abs(maxima) > 0);
u=zeros(maxima);
u(find(abs(maxima) > 0))=1;
//

J     = log2(n);
D     = b-1;
J0    = J-D;

p     = WaveL(maxima);

f     = zeros(n,1);
pold  = zeros(n,1);
r     = p;
Lpold = zeros(n,1);
flag  = 1;
i = 1;
imax = 10;
while (flag==1) & (i<imax),
  i = i+1;
  [fnew,pnew,rnew,Lp] = ConjGrad(f,p,pold,r,u,J0,Lpold);
  f     = fnew;
  pold  = p;
  p     = pnew;
  r     = rnew;
  Lpold = Lp;
end
endfunction