Blind city maps watermarking utilizing road width information

Geographic Information System (GIS) data is a valuable asset that should be protected using digital rights management (DRM) techniques. This paper introduces a new technique for watermarking city maps by altering a basic parameter of a road segment, namely its width to length ratio. A watermark is embedded in the map using an appropriate quantization of this ratio. The watermarked map retains its visual quality since the quadrilateral shape of the buildings and their alignment with road boundaries are maintained. The proposed approach performs blind detection through correlation of the detected watermark with the watermark under investigation and is robust against several attacks such as rotation, translation, uniform scaling and additive white Gaussian noise (AWGN).