Hierarchical watermarking scheme for image authentication and recovery

In this paper, we present an efficient and effective digital watermarking method for image tamper protection and recovery. Our method is efficient as it only uses simple operations such as parity check and the comparison between the average intensities. It is effective because the detection is hierarchically structured such that the accuracy of tamper localization can be ensured. That is, if a tampered block, as small as 2times2 pixels, is not detected in level-1 inspection, it will be detected in level-2 or level-3 inspection with probability nearly 1. Our method is also very storage effective, as it only requires a secret key K and a public chaotic mixing algorithm to recover a tampered image. Compared with the method in Celik et al (IEEE Trans. Image Proc., vol. 11, no. 4, pp. 585-594, 2002), our method not only is as simple and as effective in tamper detection and localization, it also provides the capability of tamper recovery