wname = 'db2'
% load image
load detfingr
[m,n] =  size(X);
m = m-rem(m,8);
n = n-rem(n,8);
X = X(1:m,1:n);

% compute DWT
[CA1,CH1,CV1,CD1] =dwtper2(X,wname);
[CA2,CH2,CV2,CD2] =dwtper2(CA1,wname);
[CA3,CH3,CV3,CD3] =dwtper2(CA2,wname);


figure(1)
imshow(X,[]);
title('original');
pause
figure(2)
imshow([CA1 ,CV1 ; CH1 ,CD1 ],[]);
title('stage 1');
pause
figure(3)
imshow([[CA2 ,CV2 ; CH2 ,CD2 ],CV1 ; CH1 ,CD1 ],[]);
title('stage 2');
pause
figure(4)
imshow([[[CA3 ,CV3 ; CH3 ,CD3 ],CV2 ; CH2 ,CD2 ],CV1 ; CH1 ,CD1 ],[]);
title('stage 3');