We perform a numerical analysis of the double random phase encryption-decryption technique to determine how, in the case of both amplitude and phase encoding, the two decryption keys (the image- and Fourier-plane keys) affect the output gray-scale image when they are in error. We perform perfect encryption and imperfect decryption. We introduce errors into the decrypting keys that correspond to...

Some image encryption systems based on modified double random phase encoding and joint transform correlator architecture produce low quality decrypted images and are vulnerable to a variety of attacks. In this work, we analyse the algorithm of some reported methods that optically implement the double random phase encryption in a joint transform correlator. We show that it is possible to signifi...

In this paper, we propose an optical image watermarking scheme using the fractional Fourier transform. A two-dimensional watermark is encrypted using a double random fractional order Fourier domain encoding technique. The encrypted image is watermarked into a three-dimensional intensity image reconstructed from a real in-line digital hologram. The watermark is recovered by applying the correspo...

A random local phase encoding method is presented for encrypting a secret image. Some random polygons are introduced to control the local regions of random phase encoding. The data located in the random polygon is encoded by random phase encoding. The random phase data is the main key in this encryption method. The different random phases calculated by using a monotonous function are employed. ...

Random phase encoding is a unique technique for volume hologram which can be applied to various applications such as holographic multiplexing storage, image encryption, and optical sensing. In this review article, we first review and discuss diffraction selectivity of random phase encoding in volume holograms, which is the most important parameter related to multiplexing capacity of volume holo...

AIMS/BACKGROUND This study was undertaken to confirm the association between diffuse retinal pigment epitheliopathy (DRPE) and systemic corticosteroid therapy. This finding can be of help in determining an aetiological factor in DRPE and associated diseases. Corticosteroids may contribute to the development of leakage in the presence of a retinal pigment epitheliopathy or central serous chorior...