Abstract
To protect the security of vector maps, we propose a novel reversible watermarking scheme for vector maps based on a multilevel histogram modification. First, a difference histogram is constructed using the correlations of adjacent coordinates, and the histogram is divided into continuous regions and discontinuous regions by combining the characteristics of vector map data. Second, the histogram bins that require modification are determined in the continuous regions through the optimal peak value, and the peak values are chosen from the flanking discontinuous regions in both directions; the watermarks are embedded by adopting the multilevel histogram modification strategy. The watermark extraction process is the reverse of the embedding process, and after completing the watermark extraction, the carrier data can be recovered losslessly. The experimental results show that the proposed algorithm has good invisibility and is completely reversible. Compared with similar algorithms reported previously, it achieves higher watermark embedding capacity under the same embedding distortion with lower complexity, thereby having a higher application value.
Highlights
With the rapid development of geographic information technology, vector map data are being widely used in many fields, such as digital Earth, geographic information systems (GIS), navigation and positioning, and urban planning [1,2]
Ni et al [19] first proposed the reversible watermarking method based on histogram shifting, in which the histogram bins between the peak point and the nearest zero point are shifted to the right by one digit, and watermarks are embedded by modifying the peak value
We performed simulation experiments using the data from 50 vector maps with different scales and different element types, and the performance of the algorithm was comprehensively evaluated in terms of the invisibility, reversibility, watermark capacity, and time complexity
Summary
With the rapid development of geographic information technology, vector map data are being widely used in many fields, such as digital Earth, geographic information systems (GIS), navigation and positioning, and urban planning [1,2]. Digital watermarking technology [6,7,8,9], as an effective means of security to protect data, has been gradually applied to vector maps in recent years, and it has achieved good results. To vector maps, which was not very effective on data with poor coordinate correlations To solve this problem, watermarks were embedded by extending the Manhattan distance, which achieved better invisibility and embedding capacity; the location map must be saved to label the coordinate points of the difference expansion, which results in the cost of a certain embedding capacity. From the perspective of the research method, methods such as differential expansion, iteration, and quantization are currently used to embed reversible watermarks in vector maps, and they pose significant disturbances to the maps; as a result, some algorithms must save the location map and other ancillary information, which to a certain extent costs embedding capacity.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
