Analysis of a DFT-based watermarking algorithm

Recently the watermarking technique is considered as an attractive solution to protect owner´s right of the digital materials, such as digital image, video and sound. Due to that, many watermarking techniques have been proposed in literatures during the last few years. However a few works consider the robustness of the watermark against geometrical transform, such as rotation, translation, scaling, etc. In this paper, we present an analysis of a DFT-based watermarking algorithm, which inherently provides invariant property of some geometrical transform. In this watermarking scheme, the original image is not required during the detection process. The developed method is resistant not only to geometrical transformation, but also to JPEG compression, filtering, corruption by noise. The experimental results show the watermark robustness and imperceptibility of this method.