Page 191 - Algorithm Collections for Digital Signal Processing Applications using MATLAB

180 Chapter 4
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createdaubinvmatrix.m

function [res]=createdaubinvmatrix(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([b(3) a(2)],1,(m/2));
t2=repmat([a(1) b(2)],1,m/2);
t3=repmat([b(1) 0],1,m/2);
t4=repmat([a(4) 0],1,m/2);
res=diag(repmat([a(3) b(4)],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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9.3 Program Illustration

Figure 4-23. Audio signal before and after watermarking