%由位平面重構出多分辨水印
  function G=bit_rec(G0) %M為多分辨水印的尺寸,G0為三維矩陣
           M=size(G0,1);
            G=zeros(M,M);
             for i=1:M   
                 for j=1:M
                   for l=1:8
                        G(i,j)= G(i,j)+2^(l-1)*G0(i,j,l);
                   end
                 end
              end