Image hiding using lsb steganography

Good day sir, i saw your code on steganography using LSb steganography in Math work, a very good code but if i run it, it gives this errors please how do i resolve them.

??? Array dimensions must match for binary array op.

Error in ==> imagehiding2 at 17
S = double(bitor(bitand(x,bitcmp(2^n-1,8)),bitshift(y,n-8))); %StegoSecond error
??? Error using ==> bitcmp
Values in A should not have "on" bits in positions greater than N.

Error in ==> imagehiding2 at 17
S = double(bitor(bitand(x,bitcmp(2^n-1,8)),bitshift(y,n-8))); %Stego

second error

??? Array dimensions must match for binary array op.

Error in ==> imagehiding2 at 17
S = double(bitor(bitand(x,bitcmp(2^n-1,8)),bitshift(y,n-8))); %Stego