% The masks are created by
% comparing the normalized images
% with the average image.
% Differences are detected then
% filtered to grow their areas.
% Finally a limit is added to require
% greater than 2 pixels exceeding
% the difference threshold within the
% 7x7 filter area.

% Build the 2-d Averaging Filter
bf = [ones(7,7)]/49;

m1 = abs(bt - double(b1n)) > 25;
m1(:,:,1) = filter2(bf,m1(:,:,1))<0.05;
m1(:,:,2) = filter2(bf,m1(:,:,2))<0.05;
m1(:,:,3) = filter2(bf,m1(:,:,3))<0.05;
disp('Mask');
m1 = uint8(m1);

m2 = abs(bt - double(b2n)) > 25;
m2(:,:,1) = filter2(bf,m2(:,:,1))<0.05;
m2(:,:,2) = filter2(bf,m2(:,:,2))<0.05;
m2(:,:,3) = filter2(bf,m2(:,:,3))<0.05;
disp('Mask');
m2 = uint8(m2);

m3 = abs(bt - double(b3n)) > 25;
m3(:,:,1) = filter2(bf,m3(:,:,1))<0.05;
m3(:,:,2) = filter2(bf,m3(:,:,2))<0.05;
m3(:,:,3) = filter2(bf,m3(:,:,3))<0.05;
disp('Mask');
m3 = uint8(m3);

m4 = abs(bt - double(b4n)) > 25;
m4(:,:,1) = filter2(bf,m4(:,:,1))<0.05;
m4(:,:,2) = filter2(bf,m4(:,:,2))<0.05;
m4(:,:,3) = filter2(bf,m4(:,:,3))<0.05;
disp('Mask');
m4 = uint8(m4);

m5 = abs(bt - double(b5n)) > 25;
m5(:,:,1) = filter2(bf,m5(:,:,1))<0.05;
m5(:,:,2) = filter2(bf,m5(:,:,2))<0.05;
m5(:,:,3) = filter2(bf,m5(:,:,3))<0.05;
disp('Mask');
m5 = uint8(m5);

m6 = abs(bt - double(b6n)) > 25;
m6(:,:,1) = filter2(bf,m6(:,:,1))<0.05;
m6(:,:,2) = filter2(bf,m6(:,:,2))<0.05;
m6(:,:,3) = filter2(bf,m6(:,:,3))<0.05;
disp('Mask');
m6 = uint8(m6);

m7 = abs(bt - double(b7n)) > 25;
m7(:,:,1) = filter2(bf,m7(:,:,1))<0.05;
m7(:,:,2) = filter2(bf,m7(:,:,2))<0.05;
m7(:,:,3) = filter2(bf,m7(:,:,3))<0.05;
disp('Mask');
m7 = uint8(m7);

m8 = abs(bt - double(b8n)) > 25;
m8(:,:,1) = filter2(bf,m8(:,:,1))<0.05;
m8(:,:,2) = filter2(bf,m8(:,:,2))<0.05;
m8(:,:,3) = filter2(bf,m8(:,:,3))<0.05;
disp('Mask');
m8 = uint8(m8);

m9 = abs(bt - double(b9n)) > 25;
m9(:,:,1) = filter2(bf,m9(:,:,1))<0.05;
m9(:,:,2) = filter2(bf,m9(:,:,2))<0.05;
m9(:,:,3) = filter2(bf,m9(:,:,3))<0.05;
disp('Mask');
m9 = uint8(m9);

ma = abs(bt - double(ban)) > 25;
ma(:,:,1) = filter2(bf,ma(:,:,1))<0.05;
ma(:,:,2) = filter2(bf,ma(:,:,2))<0.05;
ma(:,:,3) = filter2(bf,ma(:,:,3))<0.05;
disp('Mask');
ma = uint8(ma);