Abstract: In the traditional reversible watermarking for vector maps, the watermark is often at the risk of being over exposed as a result to the one-sided pursuit of watermark embedding capacity. To address this problem, a reversible watermarking algorithm with controlled perturbation degree is proposed in this paper. Firstly, the state interval axes of the coordinate points are designed based on the idea of quantized index modulation, while the state values of coordinate points are modulated by the watermark information, all to guarantee a successful embedding of watermarks. Secondly, to control the impact on the data quality by the embedding of watermarks, the maximum perturbation region method is introduced to confine the state interval of coordinate points. Finally, to upgrade the watermark capacity, the binary watermark information is decimalized to modulate the state value of coordinate points in the maximum perturbation region. The experimental results have been promising, according to which the proposed reversible watermarking for vector maps not only has an outstanding capacity and a controllable perturbation degree, but also demonstrates strong robustness against common geometric attacks and point attacks, thus strikes a great balance between watermark capacity, invisibility, and robustness.

Key words: vector maps, reversible watermarking, interval mapping, maximum perturbation region