A refining localization watermarking for image tamper detection and recovery
In this paper, we propose an efficient watermarking algorithm for image tamper localization and recovery. To enhance the accuracy of tamper localization, the algorithm contains basic authentication and refining authentication. Basic authentication can locate all blocks that contain the tampered pixels by the basic authentication watermark. Refining authentication can exclude some genuine pixels from the tampered block by the refining authentication watermark that is generated based on image disordering. Finally, we fuse the two authentication results and take some post-processing measures to obtain the accuracy authentication result. The recovery watermark is the feature of every block, which is generated using the important DCT coefficients. Theoretical analysis and simulation results show that the proposed algorithm can improve the accuracy of tamper localization. At the same time, the algorithm can also approximately recover the tampered pixels.