lsb_embed.m

lsb embedding for invisible image watermarking

[u pathname] = uigetfile('*.*', 'To select the Cover Image');
buffer = pwd;
t = [pathname u];
Image = imread(t);
[row col dim] = size(Image);
stego2 = Image;
maxnumber = round((row*col)/8);
[y, pathname] = uigetfile('*.*', 'To select the Text File');
buffer = pwd;
text = [pathname y];
text = textread(text, '%s', 'whitespace', '/b/t')
str1 = char(text(1))
str2 = char(text(2))
str3 = char(text(3))
str4 = char(text(4))
for i = 1:max(size(str1))
    t = dec2bin(char(str1),8);
end
for i = 1:max(size(str2))
    t1 = dec2bin(char(str2),8);
end
for i = 1:max(size(str3))
    t2 = dec2bin(char(str3),8);
end
for i = 1:max(size(str4))
    t3 = dec2bin(char(str4),8);
end
text = cat(1,t,t1,t2,t3)
[row1 col1] = size(text)
key = inputdlg('Enter the Password :', 'Password');
key = dec2bin(char(key),8);
K = encrypt(text,key);
w = prod(size(K))
f = dec2bin(w,20)
if(w <= maxnumber)
    for e = 1:20
        t = dec2bin(double(Image(1,e,1)),8);
        t(8) = f(e);
        t = bin2dec(t);
        stego2(1,e,1) = t;
    end
    index = 1;
    j = 21;
    i = 1;
    while (index <= w)
        if(j <= size (stego2(:,:,1),2))
            t = dec2bin(double(Image(i,j,1)),8);
            t(8) = K(index);
            t = bin2dec(t);
            stego2(i,j,1) = t;
            j = j+1;
            index = index+1;
        else
            j = 1;
            i = i+1;
        end
    end
    code = 2;
    code = dec2bin(code,3);
    index = 1;
    i = row;
    j = round(col/3);
    while (index <= 3)
        t = dec2bin(double(Image(i,j,3)),8);
        t(8) = code(index);
        t = bin2dec(t);
        stego2(i,j,3) = t;
        j = j-1;
        index = index+1;
    end
imwrite (stego2, 'r.bmp');
[filename, pathname] = uiputfile({'*.bmp'; 'All Files (*.*)'}, 'Save as');
formatFile = strcat(filename, '.bmp');
    if(filename == 0)
        msgbox('Your Cover Image Will Not Saved');
    else
    imwrite(stego2,formatFile);
    p = 'Finish Hidding Encrypted Text Into Cover Image';
    msgbox(p, 'End Hiding Text');
    figure('name', 'After Hidding', 'NumberTitle', 'off'), imshow(Image);
    figure('name', 'Before Hiding', 'NumberTitle', 'off'), imshow(stego2);
    end
else
    errordlg('You Cant Hide This Long Text Into This Image, Please Choose Other Big Image Or Small Text','Failed To Hide');
end