An intelligent and blind dual color image watermarking for authentication and copyright protection

In this paper, a blind dual watermarking scheme for color images is proposed by embedding an invisible robust watermark to protect copyright, as well as a fragile watermark is embedded for image authentication. For the purpose of copyright protection, the robust watermark is embedded into the blue channel of RGB color space based on DWT, HVS and SVD domains using a specialized PSO optimization to balance the trade-off between robustness and imperceptibility. In addition, the robust watermarking capacity in SVD is doubled by inserting two robust watermark bits into each selected blocks and the robust watermark can be extracted blindly. For the purpose of authentication, a fragile watermark is embedded into all channels of RGB color space using a new way to manipulate the diagonal singular values. The authenticity of a suspected image can be verified in the absence of original watermark and host images. The combination of robust and fragile watermarking in the proposed scheme provides a suitable mechanism to protect valuable and original color images. According to the experimental and comparative results, the proposed scheme provides superior outcomes with high robustness, imperceptibility, and capacity along with a good accuracy rate in locating the tampered area of an image.