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DESCRIPTION
Image Watermark using Wavelet
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Wavelet Watermark
Copyright©2010 CompanynameFree template by Investintech PDF Solutions
DB Wavelet Watermark
Copyright©2010 CompanynameFree template by Investintech PDF Solutions
What does dmg do?
% Damga uretme% % imgew: Damga imgesi% imge1: Orjinal imge% function W=dmg(imgew,imge1); [w h]=size(imgew');[w1 h1]=size(imge1');a=1;b=1;W=zeros(size(imge1')); for i=1:w:w1 for j=1:h:h1 W(i:a*w,j:b*h)=imgew'; b=b+1; end a=a+1; b=1;end W=W';
Copyright©2010 CompanynameFree template by Investintech PDF Solutions
Adding Watermark
function [D]=blockdwt2(A,W); [row,col]=size(A); Tr=250;k=0.02; [ca,ch,cv,cd] = dwt2(A,'db1');c1 = [ch cv cd]; [h, w] = size(ca');[m, n] = size(c1'); W=dmg(W,A); [caa chh cvv cdd]=dwt2(W,'db1');W=caa;size(W);
% Adding watermark image. for i=1:h for j=1:w if ca(i,j)>Tr Ca(i,j)=ca(i,j)+k*W(i,j); % <--------k*abs(double(c1(i,j)))*W(i,j); de olabilir else Ca(i,j)=ca(i,j); end endend
Wavelet transform of image and watermark
Adding the watermark energy to the original image
Copyright©2010 CompanynameFree template by Investintech PDF Solutions
Results
Copyright©2010 CompanynameFree template by Investintech PDF Solutions
After subtracting to see that watermark cannot be seen
Copyright©2010 CompanynameFree template by Investintech PDF Solutions
Detecting watermark
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Trying the fruit image
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Watermark Embedded
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Detecting Watermark
• As you see Watermark
was not embedded in all the image
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Using Haar
Wavelet
Copyright©2010 CompanynameFree template by Investintech PDF Solutions
Using Haar Wavelet
Copyright©2010 CompanynameFree template by Investintech PDF Solutions
Watermark embedded in certain locations
Copyright©2010 CompanynameFree template by Investintech PDF Solutions
Detection of Watermark
• As you can see the watermark is
available in several locations
Copyright©2010 CompanynameFree template by Investintech PDF Solutions
Scrambling image by Arnold
Copyright©2010 CompanynameFree template by Investintech PDF Solutions
Copyright©2010 CompanynameFree template by Investintech PDF Solutions
Histogram of imagesBaboon original image
Baboon Watermarked image
Copyright©2010 CompanynameFree template by Investintech PDF Solutions
Images Output ResultBaboon Watermarked image