Teak-Young Seung

Protecting GIS vector map using the k-means clustering algorithm and odd-even coding

For protecting the copyright of GIS vector map, this paper present a watermarking scheme based on polygon type of ESRI by using k-means clustering algorithm. This watermarking scheme use k-means clustering algorithm to make all polygons into some clusters. Then we embed a watermark bit to the mean distance length of each polygon in a cluster by using odd-even coding. Finally, we change the coordinates of vertices according to the new mean distance length of polygon which has been embedded watermark. From experimental results, we verify that the proposed scheme has outstanding invisibility and good robustness against various geometric attacks.

A Watermarking Scheme Using Polyline and Polygon Characteristic of Shapefile

This paper presented the watermarking scheme for copyright of GIS vector map based on ESRI shape file. The watermarking scheme mainly uses polyline length or polygon perimeter distribution. We embed a watermark bit to the local mean length/perimeter of a suitable group of polyline/polygon data by changing all coordinates of vertices according to the constraint of the robustness and the invisibility. Experimental results verified that the proposed scheme has the robustness against various geometric attacks.

Selective-encrypted GIS vector map with low complexity

Recently years, vector map has many advantages than raster map when it is used in many domains as research, education, military or digital map services. And in most cases vector map data contains confidential information which must be kept away from unauthorized users. Moreover, the producing process of a vector map is considerably complex, and the maintenance of a digital map requires substantial monetary, human resources. With the rapid development of vector map contents, a large volume of valuable vector map dataset has been illegal distributed by pirates, hackers or unauthorized users. Therefore the problem focuses on how to protect the vector map data for multimedia applications, storage and transmission. This paper presents the selective encryption algorithm for vector map protection for storage, transmission, distribution to authorized users. In proposed algorithm, we just select some values of polylines and polygons in DCT domain to encrypt by random algorithms and cryptography. Experimental results verified that proposed algorithm is effectively and security. Maps are changed whole after encryption process, and unauthorized users cannot access to copy or use them. Encrypted maps do not alter the size of file and it does not have loss accuracy. The error between original map and decrypted map is approximate zero.