hide1.asv

Contains Rsa and program for magnification of a small image.

clc;
clear all;
b=imread('vis.jpg');
b=rgb2gray(b);
[h,w]=size(b);
figure(1);
subplot(1,2,1);
imshow(b);
title('Original Image');
% b

t=input('Enter the text to be hidden:','s');
l=length(t);
disp(sprintf('Length of the given text:%d',l));
disp(sprintf('The ascii value of the givan text:\n'));
disp(sprintf('%d ',t));

% disp(sprintf('decimal to binary'));
k=1;
for i=1:l
    d=dec2bin(t(i),8);
    for j=1:8
        c(i,j)=d(j);
        e(k)=c(i,j);
        k=k+1;
    end;
end;
n=k;
% n
% c
% e

k=1;
for i=1:h
    for j=1:w
        if(k<n)
            f=dec2bin(b(i,j),8);
            f(8)=e(k);
%             f
            k=k+1;
            b(i,j)=bin2dec(f);
        end;
    end;
end;
figure(1);
subplot(1,2,2);
imshow(b);
title('Transmitted image with hidden text');
% b

k=1;
m=1;
for i=1:h
    for j=1:w
        if(k<n)
            f=dec2bin(b(i,j),8);
%             f
            s=bin2dec(f(8));
%             s
            r(m)=s;
            m=m+1;
            k=k+1;
        end;
    end;
end;
% r
m=1;
for i=1:l
    for j=1:8
        g(i,j)=r(m);
        m=m+1;
    end;
end;
% g
j=1;      
for i=1:l
    a(i)=128*g(i,1)+64*g(i,2)+32*g(i,3)+16*g(i,4)+8*g(i,5)+4*g(i,6)+2*g(i,7)+g(i,8);
end;
% a
disp(sprintf('Retrived message: %s',a));