Two-Layer Binary Image Authentication With Tampering Localization

In this paper, a novel two-layer blind binary image authentication scheme is proposed, in which the first layer is targeted at the overall authentication and the second layer is targeted at identifying the tampering locations. The "flippability" of a pixel is determined by the three "connectivity-preserving" transition criterions described in H. Yang and A.C. Kot, (2005). The image is partitioned into multiple micro-blocks and the micro-blocks are classified into eight categories. The block identifier is defined adaptively for each class and embedded in those "qualified" and "self-detecting" micro-blocks in order to identify the tampered locations. The block identifier is defined in such a way that any changes occurred either to the "qualified" or its neighboring "un-qualified" micro-blocks render the retrieved block identifier different from the one embedded. Experimental results validate the arguments made. Discussions on the accuracy of localization of tamperings are provided