Vector map watermark method based on object property characteristic

Abstract

The invention provides a vector map watermark method based on object property characteristics, comprising: using user input to generate watermark codes needed to be embedded; according to watermark capacity, defining the scale of the watermark formed by watermark objects that embedded into object set; for the vector map of the object watermark, using a modified grid density spatial cluster analysis method to generate a watermark embedded target set; in the property document of the vector map, searching the property characteristic information corresponding to the vector object in the embedded target set; according to the watermark information generated in the step (1), randomly selecting the vector element in the generated watermark embedded target set, embedding watermark code into the property coordinate information of the element; disordering the vector formed by all vector object sequences embedded by watermark marks, storing iteration number as a key; reading vector map property document, using a watermark detection program to extract watermark information, and judging the watermark existence state of map carrier according to watermark similarity.

Description

(1) Technical field [0001] The invention relates to an information processing method related to cartography and geographic information science, in particular to a vector map watermarking method. (2) Background technology [0002] Vector digital map is an important valuable information resource, and it is the core component of geographic information system, intelligent transportation system, Web map service and other technologies. In recent years, vector geospatial data has been widely used in the fields of resource management and configuration, ecological environment, business and military. Because vector digital maps are easy to copy and spread, there are data security problems such as infringement and tampering in the distribution and use of maps, especially in the military and national defense fields, which are becoming more and more harmful. [0003] Digital watermarking technology is a recognized information method that can realize the copyright protection and infringement i...

AI Technical Summary

Problems solved by technology

The space domain algorithm mainly adopts moving the coordinates of the vector object within a certain allowable range to embed the watermark. The algorithm is simple to implement, but its robustness is poor, which has a great impact on the map accuracy and cannot resist vector data compression attacks; the frequency domain algorithm uses discrete cosine The frequency domain coefficients are obtained by mathematical methods such as transform, Fourier transform or wavelet transform, and the watermark is embedded by adjusting the frequency domain coefficients. This type of algorithm is complex and has a certain impact on the accuracy of the map. It is still unable to resist vector data compression attacks.

From a practical point of view, the current digital watermarking of vector maps still cannot solve the loss of precision and resist vector data compression attacks, and lacks security and practicability

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