Page 144 - Algorithm Collections for Digital Signal Processing Applications using MATLAB

132 Chapter 3

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createdaubmatrix.m

function [res]=createdaubmatrix(m)
a=[(1+sqrt(3))/(4*sqrt(2)) (3+sqrt(3))/(4*sqrt(2)) (3-sqrt(3))/(4*sqrt(2))
(1-sqrt(3))/(4*sqrt(2))];
b=[(1-sqrt(3))/(4*sqrt(2)) -(3-sqrt(3))/(4*sqrt(2)) (3+sqrt(3))/(4*sqrt(2))
-(1+sqrt(3))/(4*sqrt(2))];
t1=repmat([a(2) b(3)],1,(m/2));
t2=repmat([a(3) b(4)],1,m/2);
t3=repmat([a(4) 0],1,m/2);
t4=repmat([b(1) 0],1,m/2);
res=diag(repmat([a(1) b(2)],1,m/2)) + diag(t1(1:1:m-1),1)
+diag(t2(1:1:m-2),2)+diag(t3(1:1:m-3),3)+diag(t4(1:1:m-1),-1) ;
res=[res [zeros(1,m-2) res(1,3) res(2,3)]' [zeros(1,m-2) res(1,4) res(2,4)]'];
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daub4invtrans.m

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
figure
subplot(2,1,1)
i=0:1/127:1;
a=sin(2*pi*i)+sin(2*pi*100*i);
plot(a)
title('Original signal');
subplot(2,1,2)
plot(app)
title('Reconstructed signal');

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