A semi-fragile pinned sine transform watermarking system for content authentication of satellite images

A novel semi-fragile watermarking scheme for the content authentication of satellite images using the pinned sine transform (PST) is presented in this paper. In the PST domain, the image field is first decomposed into two mutually orthogonal sub-fields, namely, the boundary field and the pinned field. The watermark is embedded into the pinned field of PST, which contains the texture information of the original image. This important property of the pinned field provides the scheme with special sensitivity to any texture alteration to the watermarked image. It is desirable to the authentication of satellite images, to which the texture characters are crucial for semantic understanding. The watermarking system can localize the portions of a watermarked image that have been tampered maliciously with high accuracy as well as approximately recover it, while maintaining a high degree of image integrity. The interblock relationship introduced in the process of PST renders the watermarking scheme resistant to content cutting-and-pasting attacks. The watermark can still survive slight non-malicious manipulations, which is desirable in many practical applications in satellite remote sensing. Simulation results demonstrated that the probability of tamper detection of this authentication scheme is higher than 98%.