clc clear close function [N] = nume1(X) [m,n]=size(X); N=m*n; endfunction function [psnr, mse, maxerr]=psnr_mse_maxerr(X, Xapp) X=double(X); Xapp=double(Xapp); absD=abs(X-Xapp); A=absD.^2; mse=sum(A(c)/nume1(X); psnr=10*log10(255*255/mse); maxerr=round(max(absD(:))); endfunction function [A]=gray2bin(B) [m,n]=size(B) for i=1:m for j=1:n if (B(I,j)>200) A(I,j)=1; else A(i,j)=0; end end end endfunction function [c]=bit_set(c,b) [m,n]=size(c); for i=1:m for j=1:n c(i,j)=bitset(c(i,j),1,b(i,j)); end end endfunction function [d]=bit_get(c) [m,]=size(c); for i=1:m for j=1:n d(i,j)=bitget(c(I,j),1); end end endfunction a=imread('//original image(.jpeg)'); b=imread('//watermark image(.jpeg)'); b=gray2bin(b); [m,n]=size(a); a=double(a); c=a; c=bit_set(c,b); d=bit_get(c); figure ShowImage(a,'Origial image'); title('Original image'); figure ShowImage(b,'Watermark image'); title('Watermark image'); figure ShowImage(d,'extracted watermark'); title('extracted watermark'); psnr=psnr_mse_maxerr(a,c); correlation=corr2(b,d); disp(correlation,'correlation between watermark image and extracted watermark=')