Error in getting output

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

Risposte (1)

Image Analyst
Image Analyst il 21 Dic 2012

0 voti

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 Commenti

kash
kash il 21 Dic 2012
The secret signal and host signal have same waveform ,plz chk it at
but the embedded signal is not same as host.secret and host have more or less same shape but embeddded signal is totally different
Image Analyst
Image Analyst il 21 Dic 2012
Modificato: Image Analyst il 21 Dic 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 il 21 Dic 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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il 21 Dic 2012

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