A zero-watermarking scheme based on spatial topological relations for vector dataset

Zero-watermarking technology uses the important features of the original data itself to construct watermark information. In the process of watermark construction, no modification is made to the original data, which can effectively solve the contradiction between the imperceptibility and robustness of the traditional embedded watermark. It is a hot spot in the field of high-precision geographic vector data protection. However, most of the existing zero-watermarking algorithms for vector geographic data are designed for one or several types of elements in vector geographic dataset and still cannot be applied to dataset with point, line, and polygon data types. To address this issue, this paper proposes a vector geographic data zero watermarking algorithm based on topology and metrics. Firstly, the topological relationship is used to describe the spatial relationship between different layer objects. Then, based on the rough classification of topological relations, metric parameters are introduced to enhance the distinguishability of spatial relations. Finally, the different spatial metric parameters obtained are combined to generate zero-watermark information about the data. The experimental results show that the proposed algorithm effectively solves the problem that the existing algorithm cannot be applied to the dataset and has good uniqueness and robustness. Under the applicable conditions of the existing algorithm, the efficiency of the proposed algorithm is 3-8 times that of the existing algorithm for the dataset with more graph layers and has excellent watermark extraction efficiency.