Reversible watermarking algorithm of vector maps based on ECC

Abstract

Robustness of current watermarking schemes of vector maps is mainly dependent on algorithms of watermark embedding and extraction, while few works have been done focusing on error correction algorithms after watermark extraction. In this paper, a reversible watermarking scheme is proposed for vector maps based on error correction codes (ECC). Original copyright information is firstly expressed by a binary array (copyright watermark data), for which ECC are then generated exploiting XOR operation. Then, the copyright watermark data and its corresponding ECC are merged to compose the final watermark data. To enhance the robustness of this scheme under geometric transformation, watermarks are embedded into polar coordinates of map vertices. After watermark extraction, this scheme can not only obtain the original copyright information, but also recover the original map content accurately. Both theoretical analysis and comprehensive experimental results validate the reversibility, invisibility, capacity and robustness of the proposed watermarking scheme.