  Holographic information hiding is a technique for embedding holograms or
images into another hologram, used for copyright protection and steganography
of holograms. Using deep neural networks, we offer a way to improve the visual
quality of embedded holograms. The brightness of an embedded hologram is set to
a fraction of that of the host hologram, resulting in a barely damaged
reconstructed image of the host hologram. However, it is difficult to perceive
because the embedded hologram's reconstructed image is darker than the
reconstructed host image. In this study, we use deep neural networks to restore
the darkened image.
