Public watermarking for reversible image authentication

Nowadays, digital watermarking algorithms are widely applied to ownership protection and tampering detection of digital images. In this paper, a new reversible image ownership and tampering authentication scheme based on public key system is proposed In the scheme, the original image is split into many non-overlapping blocks. Feature information of image is extracted according the attribute of the block for some blocks, feature information is embedded into the differences of some pixels, and for the other blocks, the data is embedded in the lease significant bit of some pixels, the interesting point and usefulness of the algorithm lies in that watermarked image can be exactly restored into the same as the original image, and the secret key totally depend on the original image, this guaranteed the security of the algorithm. The experimental results show that the quality of the embedded image is very high, and the positions of the tampered parts are located correctly.