Geoscience Reference
In-Depth Information
A Javascript Decoder for CitySAC in 3D
SDI Web Transaction
Siew Chengxi Bernad, Alias Abdul Rahman, Mohd Latif bin Zainal
and Fuziah binti Abu Hanifah
Abstract Sharing of spatial data using internet is getting common as seen in
various developments in Spatial Data Infrastructure (SDI). Spatial data sharing
requires standardized file format for interoperability which could be seen in dif-
ferent working groups in Geography Mark-up Language (GML) and CityGML
where different level of details (LOD) is described in CityGML for 3D city. In
order to solve the large dataset problem that arises due to XML describ-able
advantage used in CityGML, a schema-aware encoder (CitySAC) is invented and
achieved better compression ratio and required lesser time, compared to the novel
Lemper-Zipf-Markov (LZMA) algorithm. Since geometries and semantics data are
required in data transaction over the web services especially for analysis, the use
case of the proprietor schema-aware encoder is defined. The advantage of the
decoder is the availability for code-on-demand. This chapter discusses brief
introduction of the schema-aware development background as well as the related
works; the development of javascript decoder to solve the interoperability issue in
implementing CitySAC over the open web environment as well as the example
application.
Keywords 3D SDI
Javascript
Decoder
XML
CityGML
