Abstract:In order to protect the copyright of the image, this paper proposes one kind of zero-watermark algorithm in DWT domain
based on fractal theory. Firstly, the original image is transformed via DWT. Then, the vital features of the original image are
generated by fractal matching in the domain of low frequency. After that, the dual watermark is embedded in the original image by
establishing the relationship between the vital features and digital watermark image. The algorithm ideally solves the conflict between
the watermark robustness and invisibility without modifying the data of original image. Meantime, simulation results show
that it is also robust against common image processing and geometric distortion.