Research on a Digital Watermarking Algorithm Suitable to Vector Map

Vector map is an important and valuable information resource, which is a kind of basic data for many information systems related to spatial location, such as GIS, ITS, etc. To protect copyright of vector map, this article presents a digital watermarking algorithm based on double-grid, which hides watermark information into the least significant bit of node coordinates separately. Experiments prove that this algorithm with strong concealment and robustness could prevent from generic node editing and map cutting.