Multipurpose Image Watermarking Method Based on Mean-removed Vector Quantization

Digital watermarking technique has been presented and widely researched to solve some important issues in the digital world, such as copyright protection, copy protection, and content authentication. Conventional watermarking algorithms are mostly based on discrete cosine transform (DCT), discrete Fourier transform (DFT), and discrete wavelet transform (DWT). Most of these algorithms are designed for only one purpose. In recent years, some multipurpose digital watermarking methods based on DWT and DFT have been presented to achieve the goal of both content authentication and copyright protection. Lately, several robust watermarking schemes based on vector quantization (VQ) have been presented, but they can be used only for copyright protection. In this paper, we present a novel multipurpose digital image watermarking method based on a mean-removed vector quantizer (MRVQ) structure. In the proposed method, the fragile watermark and the robust watermark are embedded in mean indices and residual indices using different techniques, and both of them can be blindly extracted. Simulation results demonstrate the effectiveness of our algorithm in terms of robustness and fragility.