Innovative Software Development in GIS

Chapter 9

WEBGEN: Web Services to Share Cartographic Generalization Tools

9.1. Introduction

This chapter describes WEBGEN, a framework offering cartographic generalization operations as Web processing services. Originally, WEBGEN was designed with the purpose of being a common research platform allowing people to share generalization algorithms, and contribute to more and more advanced experiments. Very soon, however, it became apparent that the architecture might also have benefits for other types of users, such as national mapping agencies (NMAs) and GIS providers. While the original version of WEBGEN used the SOAP protocol for service descriptions and communication mode, the following release was compatible with the Open Geospatial Consortium (OGC)'s Web Processing Services (WPS), which are widely supported by GIS. The latest version is available as open source.

9.2. Historical background

Cartographic generalization is the process that enables us to create a map readable at a given scale from often highly detailed geographical data (such as the data acquired by national mapping agencies). These data can only be represented as such at a very large scale. As soon as the scale is reduced, the objects on the map become too small to be read by the reader. Figure 9.1 shows this phenomenon in more detail. A map at a scale of 1:10 k quickly becomes unreadable if it is reduced. However, the map at a 1:50 k scale has a simplified content: the objects represented on it have been exaggerated ...