| Summary: | 碩士 === 大同大學 === 資訊工程學系(所) === 94 === In many watermarking systems, the main principle to retrieve the watermark is based on the knowledge of the positions for embedding the watermark. However, the geometric distortions rearrange the watermark embedding positions, and this often results in the failure of the watermark retrieval. In this thesis, the proposed scheme aims at resisting the rotation, scaling, and translation of the geometric distortions.
The scheme contains a private share generation phase and a secret image retrieval phase. In the private share generation phase, the scheme employs the RST-invariant domain to obtain the feature share of the host image, and then generate the corresponding private share based on the secret sharing scheme for authentication. In the secret image retrieval phase, the feature share of the suspect image is retrieved from the RST-invariant domain, and then combined with the private share to regain the secret image for copyright authentication.
The experimental results show that the scheme can withstand several attacks such as averaging, contrast adjustment, Gaussian blurring, JPEG compression, median filtering, Brightness-adjustment, sharpening, uniform noise adding, variance noise adding, slight affine transformation, slight pinching, slight punching, rescaling, lines removing, rotating, rotating with cropping, rotating with scaling, equalization, and print-and-scan.
|
|---|
