An image copyright protection system using chaotic maps

In this paper, a simple and efficient watermarking method is proposed by using visual cryptography, singular value decomposition and chaotic maps. The proposed scheme uses a gray-level image as watermark instead of binary logo or bit sequence. The proposed scheme is a zero-watermarking scheme, where the watermark is not embedded directly in the host image. The host image is encrypted with secret watermark image by constructing two shares- master share and ownership share. The two shares separately do not give any information about the watermark but when stacked together, the watermark is revealed. Singular value decomposition has been used to select the robust features of the host image and chaotic maps have been used to improve the security. Experimental study is conducted to evaluate the robustness of the algorithm against various signal processing and geometrical attacks.