Multiplexing and encryption of images using phase grating and random phase mask

Abstract. Recent developments in the areas of image processing have guided a new paradigm for research work in communication of images over the internet. Hence, secure storage and retrieval of digital images is a demanding task for future communication services. A scheme to securely store and encrypt multiple images using sinusoidal phase grating is highlighted. In the proposed scheme, images are modulated using different spatial frequencies and orientation angles. In addition, images have been encrypted using random phase mask after filtering. In order to avoid any human intervention in the system, an intensity graph is plotted to retrieve the images by applying inverse Fourier transform. Using this method, it is possible to independently store, encrypt, and retrieve multiple images due to absence of aliasing problem.