Implementing steganography in wavelet transform

Hi

here's my code for implementing steganography in wavelet transform, trying to hide text in cover image, but the problem is that when the text message is longer that 'hello' it wont work, I dont know how to fix it :)

by the way, If you can help me with other source codes for implementing steganography in wavelet transform especially image steganography in wavelet transform, I would really appreciate it :)

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

msg='Hello world';
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
%%End of Decoding.m

[Veena Nayak]

This code works properly of we use cover image in bitmap(.bmp) format. Hence try to use cameraman.bmp instead of cameraman.tif

[Mia Gonzalez]

Do you know how we can do the decoding phase using the saved image from the encoding, rather than the variable CODED1? When I do, I am not able to recover the message.

[Erwin Langi]

Mia Gonzalez, I think i found the solution for your decoding phase and the variable CODED1 can be used in decode session.

I simply take the decoding phase to a new script and i change the msg variable to msg1 (or you can change to other name). After i run the encoding phase, then i run the decoding phase. done

the other way is to make function script that return stego, msg, ect..