2D Vector Map Fragile Watermarking with Region Location

Locating the original region of tampered features is a challenging task for existing 2D vector map fragile watermarking methods. This article presents a 2D vector map fragile watermarking framework that locates not only the current but also the original region of tampered feature groups. In particular, we propose dividing the features of the host vector map into groups, and embedding a watermark consisting of location-bits and check-bits into each group at the sender side. At the receiver side, by comparing the extracted and calculated check-bits, one can identify tampered groups and locate their current regions. Then the location-bits extracted from the mapping groups are used to indicate the original regions of the tampered groups. To demonstrate and analyze the applicability of this framework, we instantiate it by proposing a simulated annealing (SA)-based group division method, a group mapping method, a minimum encasing rectangle (MER) based location-bits generation method and a check-bits generation method, and use an existing reversible data hiding method for watermark embedding. The experimental results show that the proposed framework can locate all the regions influenced by tampering, and the SA-based group division method can get a better region location ability.