Blind Dual Image Watermarking for Copyright Protection, Tamper Proofing and Self-Recovery

In this paper, a blind dual image watermarking scheme for copyright protection, tamper proofing and self-recovery is proposed. For purpose of copyright protection, we use binary handwritten signature, a high correlative biometric to owner as robust watermark, and embed it into hybrid domain constructed by dual tree complex wavelet transform (DT-CWT) and discrete cosine transform (DCT). For purpose of tamper proofing and self-recovery, source encoding output bits generated by set partitioning in hierarchical trees (SPIHT) encoding are embedded into image based on least significant bits (LSB) replacement, moreover, in order to enhance the robustness of self-recovery, repeated encoding technique is adopted, and hash-based check bits are used for tamper proofing. Experimental results indicate the proposed watermarking mechanism can withstand various image processing attacks, accurately locate and recover the tampered area of an image, especially it has the ability of tamper discrimination that other existing schemes do not have. It can find application for joint ownership and content authentication synchronously.