A DWT-BASED DUAL-WATERMARK SCHEME FOR IMAGE AUTHENTICATION AND COPYRIGHT PROTECTION

This paper presents an improved dual-watermarking scheme for two purposes: one is to protect the copyright of an image with a robust watermark, and the other is to verify integrity of ROI (region of interest) with a fragile watermark. These two watermarks are embedded in different domains with different techniques. The advanced robust watermarking correlating the watermark information sequence with the watermark position sequence is embedded into coefficients of ROB (region of backgrounds) after DWT. Then the fragile-watermarking is embedded into the LSB (least significant bit) of ROI in spatial domain. Both theoretic analysis and experiment show that our proposed dual-watermarking scheme is effective to affirm copyright and verify content integrity simultaneity; furthermore, robustness and security of the robust watermark are greatly improved with associated-sequences technique.