A Reversible Watermarking for 2D Vector Map Based on Triple Differences Expansion and Reversible Contrast Mapping

Aiming at the insufficient of the existed reversible watermarking for 2D vector map in capacity, imperceptibility and the requirement of high correlation in vector data, a reversible watermarking based on triple differences expansion and reversible contrast mapping is proposed in this paper. By establishing a new coordinates system, relative coordinates are constructed as cover data. The differences of every two adjacent relative coordinates are classified into 4 categories according to their values, and the watermark is embedded into the relative coordinates by using triple differences expansion and reversible contrast mapping. Experimental results and analysis indicate that the proposed watermarking significantly improves the capacity, imperceptibility, and it is robust against translation, rotation and scaling.