quadw = reshape(...
         kron ([repmat([2, -1, 2, 0], 1, (m(3) - 3) / 4), 2, -1, 2],...
          kron ([repmat([2, -1, 2, 0], 1, (m(1) - 3) / 4), 2, -1, 2]',...
                [repmat([2, -1, 2, 0], 1, (m(2) - 3) / 4), 2, -1, 2])),m)*...
		64 / 27;