Hybrid Polyline Simplification for GIS Vector Map Data Compression

Data Compression for Network GIS

Data compression algorithms can be categorized into lossless and lossy. Bit streams generated by lossless compression algorithm can be faithfully recovered to the original data. If loss of one single bit may cause serious and unpredictable consequences in original data (for example, text and medical image compression) lossless compression algorithm should be applied. If data consumers can toler...

Dictionary Design Algorithms for Vector Map Compression

Selective Encryption Algorithm for GIS Vector Map Using Geometric Objects

This paper presents the novel 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 aft...

Planar and non-planar topologically consistent vector map simplification

This article contains a mathematical analysis of strategies for determining topological consistency of vector map simplifications. Such techniques exploit assumptions that can be made regarding the similarity of corresponding objects in successive simplifications. We propose that all topological relationships may be classified as planar or non-planar. A formal analysis of techniques for determi...

Preserving Coincidence and Incidence Topologies in Saalfeld's Polyline Simplification Algorithm

In this paper, we firstly describe two topological configurations that are not considered by Saalfeld’s polyline simplification algorithm: the coincidence topology, concerning the overlapping of two polylines or the overlapping of a feature point and a polyline, and the incidence topology, concerning the incidence of two polylines without having the incidence point represented as a common verte...