Reversible Data Embedding for Tamper-Proof Watermarks

In this paper, a novel reversible data embedding for tamper-proof watermarks is proposed. A reversible watermark is embedded into robust watermark in the discrete wavelet transform (DWT) domain using a feature map and a location map. Generally, the robust watermark is used for the purpose of ownership protection. But if the robust watermark is tampered or faked by malicious attacker, even though the robust watermark is exactly extracted from watermarked image, it cannot verify the ownership. In our algorithm, we embed the reversible watermark into the robust watermark. Through the watermark extracted from the robust watermark, we can verify its authenticity. Generally, the purpose of reversible data embedding is authentication and reversibility of image. But in our approach, reversible watermark is embedded into the robust watermark. We focus on authentication and reversibility of the robust watermark. If the watermark extracted from the robust watermark is authenticated, the watermark is used to restore the embedding distortion. The proposed algorithm is capable of not only the authentication of robust watermark but also the restoration of the robust watermark from the embedding distortion