Implementing Watermarking DWT bad result?

Question

0 votos

I tried to implement this journal on matlab, i finally finish the code but sometimes it still give wrong output. I wanted to ask if i missed something in my code from the journal?

http://in3.uoc.edu/opencms_in3/export/sites/in3/webs/grups_de_recerca/Kison/_resources/documents/J1.pdf

Embedding method :

 f=wavread('classic1.wav','double');
if mod(length(f),2)~=0
    f=[f 0];
end
rawsignal=f;
leftchanel=f(1:size(f),1);
rightchanel=f(1:size(f),2);
[cA1,cD1] = dwt(leftchanel,'haar');
[cA2,cD2] = dwt(cA1,'haar');
[cA3,cD3] = dwt(cA2,'haar');
l_crop=mod(length(cD3),10);
crop=cD3(end-(l_crop-1):end);
segmentT=cD3(1:end-(l_crop));
segment=buffer(segmentT,10);
m=1:10;
sumS=sum(abs(segment(m,:)));
c=sumS/10;
k=6;
l=1;
alpha=2;
Watermark='Test watermarking';
word = char(Watermark);
binary = dec2bin(word,8);
binary_t=transpose(binary);
bin=binary_t(:)-'0';
[X,Y]=size(segment);
for i=1:Y
    if(l==length(bin)+1), break, end
    for j=1:X
        if(l==length(bin)+1), break, end
        if(c(i)==0), break,end 
        if (abs(segment(j,i)/c(i))<(k)) && (abs(segment(j,i)/c(i))>-(k) )
            if(bin(l)==1)
                segment(j,i)=c(i).*alpha;
                l=l+1;
            elseif (bin(l)==0)
                segment(j,i)=-(c(i)).*alpha;
                l=l+1; 
            end     
        else
            if(l==length(bin)+1), break, end
            segment(j,i)=segment(j,i);
        end
      end
  end
segmentd3=segment(:);
segmentd3(end+1:end+l_crop)=crop;
cA2=idwt(cA3,segmentd3,'haar');
cA1=idwt(cA2,cD2,'haar');
leftchanel_recon=idwt(cA1,cD1,'haar');
watermarked2=[leftchanel_recon,rightchanel];
hasil=(rawsignal-watermarked2);
wavwrite(watermarked2,44100,'watermarked.wav');

Extracting method :

f=wavread('watermarked.wav','double');
if mod(length(f),2)~=0
    f=[f 0];
end
rawsignal=f;
leftchanel=f(1:size(f),1);
rightchanel=f(1:size(f),2);
[cA1,cD1] = dwt(leftchanel,'haar');
[cA2,cD2] = dwt(cA1,'haar');
[cA3,cD3] = dwt(cA2,'haar');
l_crop=mod(length(cD3),10);
crop=cD3(end-(l_crop-1):end);
segmentT=cD3(1:end-(l_crop));
segment=buffer(segmentT,10);
m=1:10;
sumS=sum(abs(segment(m,:)));
c=sumS/10;
k=6;
l=1;
alpha=2;
con=(k+alpha)/2;
[X,Y]=size(segment);
for i=1:Y
    if(l==209), break, end
    for j=1:X
        if(l==209), break, end
        if(c(i)==0), break,end
        if (segment(j,i)/c(i)<(k)) && (segment(j,i)/c(i)>-(k) )
            if (segment(j,i)/c(i)<=con) && (segment(j,i)/c(i)>=0)
                 watermark(l,1)=1;
                 l=l+1;
            elseif (segment(j,i)/c(i)>=-con) && (segment(j,i)/c(i)<0)
                watermark(l,1)=0;
                l=l+1;
            end
        end
    end
end
hasil=char(bin2dec(reshape(num2str(watermark),8,[]).')).';