Protecting geospatial data using digital watermarking

Geographical Information System (GIS) represents geographical information in raster as well as vector form. The compilation and management of this spatial data is expensive and time consuming task. With the fast development of Internet and communication technology, it becomes easy to copy or distribute the spatial data. Therefore copyright protection, authenticity, and spatial data source tracing have become important issues. One of the remarkable methods to solve these issues is digital watermarking. The objective of this paper is to propose a digital watermarking scheme which can be used for copyright protection of geospatial data. In the proposed algorithm, watermark is embedded in low frequency coefficients at third level of wavelet decomposition. Experimental results show that the proposed algorithm is robust against various attacks. It has been observed that increase in strength of embedding increases visual degradation. Normalized correlation is computed to calculate similarity measurement between original and detected watermark.