Towards Efficient Putrajaya 3D SDI Using Schema-Aware Compressor for CityGML

Abstract

Describing 3D city model over distributed service architecture using Open Geospatial Consortium (OGC) standard, CityGML, is getting popular e.g., Berlin-3D Spatial Data Infrastructure (SDI), Heidelberg-3D SDI, etc. Currently, visualizing 3D city model over the web using X3D is getting common where Web 3D Service (W3DS) publish 3D models in compliance with W3C X3D standard. However, involvement of 3D analysis in 3D SDI environment for Web Processing Service (WPS) requires CityGML whilst this human readable schema often raises issues such as large data that consumes high bandwidth and storage etc. Transmitting CityGML over web services without compression is unpractical due to the typical problem for CityGML. Utilizing conventional compression techniques like WinZIP, GZip, and etc., could reduce large bandwidth consumption for transmitting CityGML over the internet. However, specific schema-aware compression technique shown in this chapter could achieve even higher compression ratio and require lesser time due to utilizing the advantage of parallel programming. Moreover, compressed data is filtered and can be used for smart devices. This distinguishes the advantage using this compressor instead of conventional compression as the filtered data is relatively smaller in file size whilst maintaining essential geometries and attributes information without requiring to decompress back to original file. This chapter discusses how the technique is developed and integrated into simulated Putrajaya 3D SDI, and the results are also illustrated. We also highlight the future directions of the research in the final section.