Page 188 - Algorithm Collections for Digital Signal Processing Applications using MATLAB

4. Selected Applications 177

s=256;
signal=[];
for k=1:1:length(I)
approx=col{k}{1};
det=col{k}{2};
app=approx{log2(s)-2};
for i=(log2(s)-2):-1:1
a=[app;det{i}];
a=reshape(a,1,size(a,1)*size(a,2));
a=[ a(length(a)-1:1:length(a)) a];
app=createdaubinvmatrix(length(a)-2)*a';
app=app';
end
signal=[signal app];
end
figure
subplot(3,1,1)
plot(signal(1:1:5520));
title('Original signal')
subplot(3,1,2)
plot(A(1:1:5520),'r');
title('Watermarked signal');
subplot(3,1,3)
plot(signal(1:1:5520)-A(1:1:5520))
title('Difference signal')

save signal signal
_________________________________________________________

daub4water.m

function [res]=daub4water(x)
a=x;
s=length(a);
for i=1:1:log2(s) -2
a=[a a(1:2)];
temp=createdaubmatrix(length(a)-2)*a';
temp=temp(1:1:length(temp));
temp=reshape(temp,2,length(temp)/2);
approx{i}=temp(1,:);
det{i}=temp(2,:);
a=approx{i};