A spatial proximity based compression method for GML documents

  • Authors:

  • Qingting Wei;Jihong Guan

  • Affiliations:

  • Dept. of Computer Science and Technology, Tongji University, Shanghai, China,School of Software, Nanchang University, Nanchang, Jiangxi, China;Dept. of Computer Science and Technology, Tongji University, Shanghai, China

  • Venue:
  • WAIM'13 Proceedings of the 14th international conference on Web-Age Information Management
  • Year:
  • 2013

Quantified Score

Hi-index 0.00

Visualization

Abstract

Geography Markup Language (GML) has become a standard for encoding and exchanging geographic data in various geographic information systems (GIS) applications. Whereas, high-precision spatial data in GML documents often causes high cost in GML storage and transmission as well as parsing. In this paper, we propose a spatial proximity based GML compression method for GML document compression, which transforms spatial data (coordinates in GML documents) into blocks of coordinates and compress coordinates effectively. Concretely, ordered coordinate dictionaries are constructed firstly, and coordinates are encoded as their ordinal numbers in the coordinate dictionaries. Then, delta encoding and LZW encoding are employed to compress the coordinate dictionaries and coordinate ordinal numbers respectively. Finally, the output of the delta encoder and LZW encoder is streamed to a spatial data container. Extensive experiments over real GML documents show that the proposed method outperforms the existing major XML and GML compression methods in compression ratio, while maintaining an acceptable compression efficiency.