주파수 영역에서의 디지털 워터마킹 기법과 광학기기를 이용한 불법적인 영상획득 공격

In this paper, we present a digital watermarking method for digital contents which satisfies both the invisibility and the robustness to attacks to prohibit counterfeiting, modification, illegal usage and illegal re-production of image contents. This watermarking algorithm insert a watermark(digital hologram) by generated using Frenel transform which improve the robustness. The experiment results showed that the method satisfied enough the robustness against attack of an image capture using an optical instrument