  We study the strong gravitational lensing due to the Kerr black holes with
angular momentum $a$ and the Kerr-Newman black holes with additional charge
$Q$. We first derive the analytical expressions of the deflection angles of
light rays that particularly diverge as they travel near the photon sphere. In
this strong deflection limit, the light rays can circle around the black hole
multiple times before reaching the observer, giving relativistic images. The
obtained analytical expressions are then applied to compute the angular
positions and the magnifications of relativistic images due to the supermassive
galactic black holes. In this work, we focus on the outermost image with
reference to the optical axis. We find that its angular separation from the one
closest to the optical axis and the magnification increase in angular momentum
$a$ of the black holes for light rays with direct orbits. Additionally, the
effects of the charge $Q$ of black holes also increase the angular separation
of the outermost image from the others and the magnification for both direct
and retrograde orbits. The potentially increasing observability of the
relativistic images from the effects of angular momentum and charge of the
black holes will be discussed.
