Rich-information reversible watermarking scheme of vector maps

With the increasing rampant infringements of vector maps, rich-information watermarking technology is being more and more essential for forceful copyright declaration. Most of the existing watermarking algorithms of vector maps, however, cannot embed abundant copyright information. In this paper, a rich-information and reversible watermarking scheme is proposed for vector maps based on the ideas of compression coding of watermarking image and decimal-hex conversion of vertex coordinates. It recodes the original watermarking image to shorten the length of the final watermark data and groups map vertices to choose cover data for watermark embedding. And the reversible embedding is then carried out by modifying the polar coordinates of map vertices. While the proposed compression coding method of watermarking image and the decimal-hex conversion of map vertices guarantee the embedding of rich-information watermark data, the reversible watermarking method provides recovery of the original map content. Comprehensive experimental results show that the proposed scheme is suitable for vector map applications where abundant copyright information is required while the number of map vertices is limited.