为了解决空间信息网络传输和空间信息共享的版权保护问题,提出了一种具有鲁棒性的2D矢量图形的水印算法。在GIS中,矢量图形是其最基本的表达方式,常需针对2D矢量图形的大数据集进行水印嵌入处理,本方法先将空间矢量图层按照自身所含的多边形特征进行分解;对分解后的矢量多边形进行分析,选择合适的多边形的线段,在其顶点处嵌入水印;而提取水印的过程,则是对原矢量图形和水印图形进行分析,根据嵌入水印顶点的位置或坐标值得到水印信息的序列。实验结果证明,该方法对于空间信息的常规图形操作,如矢量图层的坐标变换、平移、旋转、缩放,以及图形的剪切,点的添加删除等,均具有较强的鲁棒性。

In order to protect the copyright of the transmission and sharing of the geospatial information,this paper presents a robust watermarking algorithm for 2D vector graphics.In GIS system,vector graphics is a basic type of imformation and a large dataset of 2D vector graphics are often needed to perform watermark embedding for the security purpose.The processing method,Includes: Firstly,decompose the vector graphics into the polygons that layer has;Then analyze these polygons and embedded the watermark in the start and end points of the selected line.In the procedure of extracting watermark,the original graphics and the watermarked graphics were analyzed and extracted the sequence of the watermark information according to the position or the coordinate of the vector.The experimental results show that the method is rubust against the general operations of the spatial graphics such as transformation,translation,rotation,scaling,cropping and vertex insertion/removal etc.