Improving accessibility of web-based GIS applications

Abstract

A major problem of Vector Active Map formats such as WebCGM and Scalable Vector Graphics (SVG) is that, in order to display them in most web browsers, either a plug-in has to be installed or an applet has to be downloaded. In this paper, a web service is presented whose functionality enables the transformation of vector active maps from SVG to a new DHTML (HTML + JavaScript) Active Map Representation, improving this way the accessibility of web-based GIS applications. This new representation, which is also part of the present work, includes a raster representation of the map and a vector representation of its geographic objects. The former is used as a background image of the map whereas the latter enables the response to user-triggered events. An R-tree spatial index structure is used to access the geographic objects affected by each event in order to execute the relevant action. © 2005 IEEE.