RESEARCHING THE GRAPHICS FORMAT OF SVG AND ITS APPLICATION IN WEBGIS
Y. Liu, S. Li, Y. Zheng, G. Li
Department of hydrography and cartography,
With the development of Internet and its popularization in the world, WebGIS that combined Web and GIS has become a hotpoint in the field of GIS. But the data transmission format in the network is a bottleneck in WebGIS. Many vector graphics are used in GIS, yet HTML can’t support vector graphics showing which is the main file format when browses and changes data in Internet/Intranet. If we use raster graphics to transmit data, the burden of network must be heavy. SVG(Scalable Vector Graphics) can break the complexion and bring the new development to graphics and image technology in network.
1.The age gestates SVG
In 1998, W3C(World Wide Web Consortium) received two projects for the new graphic format, that are PGML(Precision Graphics Markup Language) and VML(Vector Markup Language). VML adapts to the general vector images, but PGML can make more images which are more rich and colorful and fit the specialty design and the public publish. In order to accelerate the development of image standard, W3C decides to amalgamate their strongpoint and put forward the new vector format——SVG.
2. The traits of SVG
The fascination of SVG is apt at using. It’s traits are the following: it is a kind of vector format, zooms in and zooms out freely, it has the independent text, the file size is small and it possesses the strong display and interaction.
4. The valuation of putting SVG in WebGIS
In WebGIS, if we use SVG, we can finish the graphic design and the text edition simultaneity. It will help to realize the geo-spatial data standardization and structure, and easy to search in network. The serving operation of WebGIS will be improved, reducing the multi-interaction between server and client, and increasing the speed of operation among GIS users.