Secure and robust watermarking scheme based on the hybrid optical bi-stable model in the multi-transform domain

A good watermarking scheme should guarantee its robustness to various attacks. Most watermarking algorithms can resist some general image attacks, while some algorithms display the weak robustness to the rotation attack. To improve the robustness of the digital watermarking scheme against the rotation attack, a new secure watermarking scheme based on the hybrid optical bi-stable model in the multi-transform domain is proposed. In the proposed scheme, the original image is decomposed by the three-level dual tree complex wavelet transform. The dual tree complex wavelet transform possesses approximate translation invariance, good directional selectivity and moderate redundancy. Then the watermark image is scrambled by the Arnold transform and the chaos sequence based on the hybrid optical bi-stable model. Afterwards, the real low frequency is divided into some small matrices of size 8 × 8 and a coefficient matrix is generated after performing the discrete cosine transform on each matrix. To enhance the robustness of the watermarking algorithm, singular value decomposition is employed and the singular values of the watermark image are embedded into the real low frequency regions of the host image with a suitable embedding rule. Experimental results demonstrate that the proposed watermarking scheme is much better in terms of the robustness of the image.