Digital Watermarking using Phase hologram and Optical Interferometer

위상 홀로그램과 광학적 간섭계를 이용한 디지털 워터마킹

A digital watermark is an invisible mark embedded in a digital image which used for copyright protection. In this paper, we propose a new optical watermarking system. A optical watermarking system is applied for digital watermarking by phase hologram and Mach-Zehnder interferometer. A optical watermarking technique to be hidden is phase modulated in a random patten, and its Fourier-transformed hologram image is superposed on a content image. The autentication information extract by using Mach-zehnder interferometer.