一种支持多版权的地理数据增量水印方法

目前地理数据水印方法有很多,但大都缺少对地理数据同步保护的考虑,同时没有在同步保护的基础上进行多版权水印嵌入的方法。分析了地理数据增量水印和多版权水印的问题,基于量化调制技术,提出了一种能兼顾增量水印和多版权水印的地理数据水印方法。该方法采用基于距离划分的策略,将特征点集划分成两个可重现的不相交子集,通过分别缩放两个子集嵌入双重水印,保证了所有顶点都只在精度范围内修改一次,使保真性得到控制。此外,缩放调制策略使地理数据形状尽可能得到保证。实验表明,该方法能满足增量水印和多版权水印的要求,同时具有很好的鲁棒性。

Geographical Watermarking Method Supporting Incremental and Multiple Watermark Embedding

There are a lot of geographical data watermarking methods,but most of them lack consideration for the protection of fractional geographical data.This paper analyzed incremental and multiple watermarking problems on geographical data.Based on variable step quantization modulation technique,this paper proposed a watermarking method which can be used for both incremental and multiple watermark embedding.By dividing the feature set points into two disjoint subsets and zooming up/out all points in the subsets respectively,the method ensures the watermark embedding without disturbing the multiple watermarks,and guarantees that all the vertices are modified within the scope of fidelity for one time.So fidelity is controlled.In addition,by using the zoom modulation strategy,the shape of geographical data is preserved as well as possible.Experiments show that the method can meet the requirements of the incremental and multiple watermarks,and has good robustness as well.