基于DCT量化的数字图像水印

%------------------------NOTES--------------------------------------------- % Written by : zj - 01/05/07 % Contact : zxxyj0506@sina.com % CpoyRight@2007-2010 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % p --- the image which want to be embed watermark % w --- the binary watermark image % g --- the watermarked image % delta --- the coefficient (量化系数) p=imread('baboon512.jpg'); w=imread('shan.png'); delta=75; [wrow,wcol]=size(w); [pll,plh,phl,phh]=dwt2(p,'db1'); [row,col]=size(pll); numblk=row/8; pll_w=wembed(pll,w,delta,numblk); pw=idwt2(pll_w,plh,phl,phh,'db1'); g=uint8(pw); % g=imnoise(g,'gaussian',0,0.005); % g=imnoise(g,'salt & pepper',0.02); % g=imnoise(g,'speckle',0.02); psnr_im=psnr(p,g); [gll,glh,ghl,ghh]=dwt2(g,'db1'); abw=wabsract(gll,delta); nc=matrix_nc(w,abw); subplot(1,4,1);imshow(p);subplot(1,4,2);imshow(w); subplot(1,4,3);imshow(g);subplot(1,4,4);imshow(abw);