Wavelet watermark

Wavelet Watermark

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DB Wavelet Watermark

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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';



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



Results



After subtracting to see that watermark cannot be seen



Detecting watermark



Trying the fruit image



Watermark Embedded



Detecting Watermark

• As you see Watermark

was not embedded in all the image



Using Haar

Wavelet



Using Haar Wavelet



Watermark embedded in certain locations



Detection of Watermark

• As you can see the watermark is

available in several locations



Scrambling image by Arnold





Histogram of imagesBaboon original image

Baboon Watermarked image



Images Output ResultBaboon Watermarked image


Wavelet watermark

Documents

function w

hfor j

w1for j

imge1w h

investintech pdf solutions

damga imgesi

damga uretme

watermark energy towatermark