CODING: SPREAD SPECTRUM WATERMARKING

CODING: SPREAD SPECTRUM WATERMARKING%&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&%%%spread spectrum watermarking

%&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&%WATERMARK ENCODING%

clc;

clear all;

m=3;

w= [1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1];

j= 1 ;

for i=1:16

wr(j)=w(i);

wr(j+1 )=w(i);

wr(j+2)=w(i);

j=j+m;

end

%****************** Interleaved Matrix Starting *************************%

index=length(wr);

l=5;

m=10;

m1=1;

for j=1:1

for i=1:m

if m1 =0.5

c(i,1)=1;

else

c(i,1)=-1;

end

end

%************************** pseudocode generated" *******************%

s=modulate(d,200,1000,'am');

%s(t)*c(t)

for p=1 :66

for j=1 :60

s1((p-1)*60+j)=s(j);

end

end

for p=3960:3969

s1(p)=0.005;

end

x=c.*s1';

nframe=3; % audio signal framed 3 frames %

n1 =1;

n2=1 ; % 1 frame has 3969 samples %

for i= 1:2:nframe

for j=1 :3969

p(i,j)=(wavread('chimes.wav',[n1 n2]))';

n1=n1+1;

n2=n2+1 ;

end

end

t1 =p';

figure;

plot(t(:, 1 ));title('original frame in time domain');

%************************Audio Signal Read****************************%

clc;

close all;

ham=hamming(3969);

for j=1 :nframe

sW(:,j)=ham.*t1(:,j);

xw(:,j)=ham.*x;

end

fsw=fft(sw, 3969);

fsw=fft(xw,3969);

%************************** FF-T COMPLETE************************* %

for j=1 :nframe

for i=1 :3969

sp(i,j)=abs(fsw(i,j)*fsw(i,j));

end

end

%************************* P S D CO M P L ETE***********************%

%PSYCHOACOUSTIC MODELLING%

clc

for j= 1:nframe

for i=1:1985

f(i,j)=(i-1 )*44100/3969;

z1(i,j)=((26.81 *f(i,j))/(1960+f(i,j)))-0.53;

end

end

for j1 =1:nframe

for z=1:25

sum=0;

sum1 =0;

for i= 1:1985

if (z-1)