Study of Digital Image Watermarking in Curvelet Domain

The rapid development of Internet caused a set of challenging problems regarding security. Everyone can duplicate the digital data without permission. Therefore, it raised the awareness of the copyright problems in the e-commerce age. Digital watermarking is a technique of embedding a hidden signal into digital contents to identify the legitimate owner, track unauthorized use or detect intentional tampering. To increase the robustness of watermark, many research papers have been proposed to embed the watermark in different frequency domains rather than in spatial domain. For the same reason, this thesis focuses on embedding the watermark into the Curvelet Transform developed by Candµes and Donoho. In tradition, Curvelet watermarks are embedded into all frequency bands. However, the study of individual band or mixed bands behavior and their usage on watermarking have not been reported. Thus, this thesis provides a detailed study of the watermarking using individual band or mixed-bands based on the Curvelet Transform.... Mehr