image and text steganography

can any one correct this code please ?

this code hide the input message text in the cover image but the encoded message is not the input text (embedded text)

Simple Wavelet Steganography: Hide Message in Image using wavelet Transform Code MATLAB :

%%%%%%%%%%%%%%Encoding.m

clear 
close all
clc
im=imread('cameraman.tif');
wname='haar';

msg='Grasshopper Network';
data=[];
for(i=1:length(msg))
d=msg(i)+0;
data=[data d];
end

imshow(im);
[cA1,cH1,cV1,cD1] = dwt2(im,wname);
dec1 = [cA1 cH1; cV1 cD1 ];

figure;imshow(uint8(dec1));

M=max(data);
data_norm=data/M;
n=length(data);
[x y]=size(cH1);
cH1(1,1)=-1*n/10;
cH1(1,2)=-1*M/10;

for(i=1:1:ceil(n/2))
cV1(i,y)=data_norm(i);
end

for(i=ceil(n/2)+1:1:n)
cD1(i,y)=data_norm(i);
end

CODED1=idwt2(cA1,cH1,cV1,cD1,wname);

figure;imshow(uint8(CODED1))
[x y]=size(cA1);
imshow(uint8(CODED1))

ms=abs(CODED1-double(im));
ms=ms.*ms;
ms=mean(mean(ms))
ps= (255*255)/ms;
ps=10*log10(ps)
imwrite(uint8(CODED1),'Stego.bmp','bmp'); 
return

%%%END of encoding.m%%%%%%%%%%%%%%%%

%%%%%Decoding.m%%%%%%%%%%%%%%%%%
im=imread('Stego.bmp');
[cA11,cH11,cV11,cD11] = dwt2(CODED1,wname);
data=[]
data_norm=[];
n=ceil(abs(cH11(1,1)*10));
M=ceil(abs(cH11(1,2)*10));

for(i=1:1:ceil(n/2))
data_norm(i)=cV11(i,y);
end

for(i=ceil(n/2)+1:1:n)
data_norm(i)=cD11(i,y);
end
data=ceil(data_norm*M)-1;
msg='';
for(i=1:length(data))
msg=strcat(msg,data(i));
end

msg

[Geoff Hayes]

eng - when you say that the encoded message is not the input text do you mean that the decoded message is not Grasshopper Network, but something else? Is it Fq`rrgnoodqMdsvnqj instead?

[eng]

yes,i mean this sorry the decoded text is not the same the encoded text some letters is not correct

[Geoff Hayes]

What does the decoded text look like?

[eng]

when i have entred the encoded text 'Grasshopper Network' the decoded text is 'GqasshnooeqNesvnqj'

and any input text the decoded also is not the same

[Image Analyst]

Attach your m-file with the paperclip icon, or read this.

[Geoff Hayes]

So some of the characters in the decoded message are off by one. This could be due to the fact that the encoded image, CODED1, is cast as uint8 before being written to file, and then the decoded message is obtained as

 data=ceil(data_norm*M)-1;

The subtraction of one works for some of the characters in the message (mapping them back to their original value) while it fails for others. You could contact the author of the code (copied from here), as there seems to be some known problems with the decoding.