Digital image synthesis and multiple-image encryption based on parameter multiplexing and phase-shifting interferometry

A novel digital image synthesis and multiple-image encryption technique based on parameter multiplexing and phase-shifting interferometry by discrete Fresnel transform is proposed. Both the image synthesis and the multiple-image encryption can be realized with the same system arrangement and similar principles, while the former is achieved by using different sets of parameters (wavelength and distance) and the same set of random phase masks, and the latter with different sets of random phase masks. The feasibility of this method and its robustness against occlusion and additional noise attacks are verified by computer simulations. The encryption capacity of the system is analyzed in term of the correlation coefficient. This technique is simple with a lensless setup, highly secure, and particularly suitable for the image transmission via Internet.