A new optical system is proposed for digital watermarking. The proposed system uses binary phase hologram and Mach-Zehnder interferometer. The mark image to be hidden is randomly phase-modulated image, and its Fourier-transformed hologram image is sup...
A new optical system is proposed for digital watermarking. The proposed system uses binary phase hologram and Mach-Zehnder interferometer. The mark image to be hidden is randomly phase-modulated image, and its Fourier-transformed hologram image is superposed on the original image. The mark image, the information for authentication, is extracted by using Mach-Zehnder interferometer. The availability of the proposed watermarking system is confirmed by computer simulation and optical experiment.