function hide()
B=imread('E:\chan\mat\b.bmp','bmp');
imshow(B);pause;close;
[Bx,By,Bz]=size(B);
C=imread('E:\chan\mat\cc.bmp','bmp');
imshow(C);pause;close;
[Cx,Cy,Cz]=size(C);
for i=1:Cx    %%以下12行檢測
    for j=1:Cy
        for k=1:Cz
            b=bitand(C(i,j,k),240);
            E(i,j,k)=b;
            cc=bitor(bitshift(bitand(C(i,j,k),240),-4),240);
            F(i,j,k)=cc;
        end
    end
end
imshow(E);pause;close;
imshow(F);pause;close;
for i=1:Bx               %%隱藏開始
    for j=1:By
        for k=1:Bz
            if (i<=Cx)&(j<=Cy)&(k<=Cz)
               b=bitand(B(i,j,k),240);
               c=bitshift(bitand(C(i,j,k),240),-4);
               D(i,j,k)=bitor(b,c);
            else
               D(i,j,k)=B(i,j,k);
           end
        end
    end
end
imshow(D);pause;close;
imwrite(D,'E:\chan\mat\d.bmp')
for i=1:Bx               %%提取
    for j=1:By
        for k=1:Bz
            if (i<=Cx)&(j<=Cy)&(k<=Cz)
               U(i,j,k)=bitshift((bitand(D(i,j,k),15)),4);
           end
        end
    end
end
size(U)
imshow(U);pause;close;
imwrite(U,'E:\chan\mat\e.bmp')