Watermarking schemebased on Multiple Chaotic Maps

a watermarking scheme for Grayscale image is proposed based on a family of the chaotic maps and discrete cosine transform. Jacobian Elliptic mapis employed to encrypt of watermarked logo. Piecewise nonlinear chaotic map is also used to determine the location of DCT coefficients for the watermark embedding. The purpose of this algorithm is to improve the shortcoming of watermarking such as small key space and low security. Therefore the size of key space for initial conditions and control parameters is computed about and this key space is large enough to resist the attacks. Toevaluate the robustness and effectiveness of proposed method, several attacks are applied to the watermarked image and the best results have been reported. Keywords-Blind Digital Image Watermarking, Chaos, Discrete Cosine Transform, Multiple Chaotic Maps, JacobianEliptic Map, Piecewise nonlinear chaotic Map