function y=chaoswm(x)
%embeded watermarking proc.
%mask=[0 0 0 0 1 1 0 0
%      0 0 0 1 1 1 0 0
%      0 0 1 1 1 0 0 0
%      0 1 1 1 0 0 0 0
%      1 1 1 0 0 0 0 0
%      1 1 0 0 0 0 0 0
%      0 0 0 0 0 0 0 0
%      0 0 0 0 0 0 0 0]; 
%Bx=mask.*x;
%Lc=zigzag(size(mask));
y=zeros(8,8);
Cx=[5 4 3 2 1 1 2 3 4 5 6 6 5 4 3 2];
Cy=[1 2 3 4 5 6 5 4 3 2 1 2 3 4 5 6];
for i=1:4,
   for j=1:4,
      Cz(i,j)=x(Cx((i-1)*4+j),Cy((i-1)*4+j));
   end
end
y=Cz;