wt08fig02.m

一些关于小波的去噪算法

% CAPTION :
fprintf('\n');
disp('Figure 8.2')
disp('Wavelet packets at the depth j=3 of the wavelet packet tree,') 
disp('calculated with a Daubechies 5 filter. They are ordered from')
disp('left to right and up to down, from low to high frequencies.')

close all;
n = 2048;
J = log2(n);
j = 7;
p = 10;
k = 2^(J-j-1);
figure(1);clf
for b = 0:7,
	w = MakeWaveletPacket(j,b,k,'Daubechies',p,n)*2^((j-3)/2);
	x = (abs(w)>1.e-6);
    x=double(x);
    length = x*x';
	m = find(abs(w) >0.0000001);
	minm = min(m);
	maxm = max(m);
	i = (((1:n)-n/2)./2^(j-3)); 
	subplot(3,4,b+1)
	plot(i(minm:maxm),w(minm:maxm))
	axis([i(minm) i(maxm) min(w)-.05 max(w)+.05])
end;

% Written by Maureen Clerc and Jerome Kalifa, 1997
% [e-mail], [e-mail]

%Revision History
% 10/1/05        AM        logical vector x is converted to a double vector

    
 
 
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