Evaluation of spatial relations in watermarked geospatial data

Abstract

Due to rapid growth of distributed network and Internet, it becomes easy for data providers and users to access, manage, and share voluminous geospatial data in digital form through geostreaming methods. The increased availability of tools and techniques to access and disseminate geospatial data has made more urgent to protect it. In recent years, there is significant research on copyright protection of geospatial vector data using digital watermarking. As geospatial data is different from digital images, image watermarking evaluation methods cannot be directly applied to watermarked geospatial data. At present, watermarking algorithms are mainly focusing on robustness evaluation and error analysis. One of the important aspects related to vector data quality i.e. topological relationship inspection is neglected. In this paper, an attempt has been made to incorporate invisible watermark in geospatial vector data using wavelet based watermarking algorithm and the resulted watermarked data has been evaluated in terms of polygon closure, topological relationship consistency and impact on visualization. The study helps to choose suitable watermark embedding strength such that the topological relationship can be preserved in addition to robustness.