A robust watermarking scheme for city image

Abstract

In this paper, we propose an effective watermarking scheme based on Radon transform for city image. The robustness against rotation attack is achieved using the translation property of the Radon transform. The Radon transform emphasizes and detects the linear characteristic to calculate the angle of image rotation. The watermark is a hologram generated by quantization based on the cover image. We used hologram quantization to spread the watermark information and analyze the cover image detail. The hologram is transformed by a discrete fractional random transform (DFRNT) with a random seed β. It makes the watermark security. The proposed method uses discrete wavelet transform (DWT) domain. DWT domain watermarking is robust to signal processing attacks. For improving the accuracy of detecting, we fix the center of image and swivel that the pixels of image boundary move 1 notch at a time. The proposed algorithm also robust to the spatial Effect attack. We have performed an intensive simulation to show the robustness in rotation of the proposed method.