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Error in getting output

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kash
kash on 21 Dec 2012
clc
clear all
close all
[y,Fs,nbits] = wavread('bird.wav');
[cA,cH,cL,cD] = dwt2(y,'haar');%wavelet decomposition
C1=int16(cA*32768);C2=int16(cH*32768);%%%%convertibg to 16 bit
[y1, Fs, nbits] = wavread('wov.wav');
[sA,sH,sL,sD] = dwt2(y1,'haar');
S1=max(min(round(2^13*sA),2^13),-2^13);%%%%%convertibg to 14 bit
S2=max(min(round(2^13*sH),2^13),-2^13);
Cw=C1;
Sw=S1;
%%%%%%applying threshold
for i=1:length(Cw)
if (Cw(i)<7 && Cw(i)>-7)
Cw(i)=0;
end
end
for i=1:length(Sw)
if (Sw(i)<7 && Sw(i)>-7)
Sw(i)=0;
end
end
A=Cw;
B=Sw;
if length(A)<length(B)
S=length(B)-length(A);
S1=zeros(S,1);
A=[A;S1];B;
elseif length(A)>length(B)
S=length(A)-length(B);
S1=zeros(S,1);
B=[B;S1];A;
else
A;B;
end
Cw=A;
Sw=B;
%%%%%SORTING
[~,J] = sort(A);
BSA = sort(B);
J(J) = 1:length(A);
BSA = BSA(J);
[J1,ke] = ismember(BSA,Sw);
key=ke;
Ew=double(BSA)./double(Cw);
Ew=ceil(Ew*100);
Ew(~isfinite(Ew))=0;
nn=16;
n=15;
Cw=double(Cw);
Cw1 = dec2bin(mod(2^n+Cw,2^n));
Ew1 = dec2bin(mod(2^5+Ew,2^5),5);
%%%%%%%%%%%%%%%%%%%%%%EMBEDDED%%%%%%%%%%%%%%%%%%%%%%%
n=[];
CC = Cw1;
DD = Ew1;
n=11;
CC(:,n:n+size(DD,2)-1)=DD ;
CC=bin2dec(CC);
X = idwt2(CC,cH,cL,cD,'haar');
%%%%%%rescaling%%%%%%%%%
mi=min(min(y));
mx=max(max(y));
B=nma_rescale(X,mi,mx)
mat=X;
matmin = mi;
matmax = mx;
newmat = 2 * (mat - matmin) ./ (matmax - matmin) - 1;
subplot(3,1,1),plot(y);
subplot(3,1,2),plot(B);
In the above code after embeddeding the secret signal with the host signal,the embeeded image is not a signal wave
The process aove is speech stegnography,
please tell why the embedded signal is not a signal wave

Answers (1)

Image Analyst
Image Analyst on 21 Dec 2012
Well I suppose since the secret signal did not replace the target signal, but was combined with it in a special way, that neither signal is a sine wave nor has its original form anymore. Why did you think that it would remain a sine wave after combining with the host signal?
  3 Comments
Image Analyst
Image Analyst on 21 Dec 2012
Edited: Image Analyst on 21 Dec 2012
I know that - none of the three signals ("secret," "host," and "embedded" which I guess is the output signal) are the same. But once the secret signal that is " to be embedded" actually GETS embedded into the host, the result will not look like either one. Explain this: ",the embeeded image is not a signal wave". What is "a signal wave"???? All three waveforms are signals so I don't know what you're talking about. And what image? I thought these were 1D sounds. BTW, I am not an expert in steganography. I'm not sure anyone here is, at least not that I recall. Please try to carefully rephrase your question using the most accurate terminology you can.
kash
kash on 21 Dec 2012
if i take two signals host and secret as same signal and embedded it ,i should get the same signal,but i am not getting same signal

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