Towards Visual Summaries of Geographic Databases Based on Chorems

Abstract

For many applications, it is very important to get an overview of database contents; and in the case of geographic database, a visual summary can be very helpful for a decision-maker or for any person in charge of a territory. To get such a visual summary, a two-step process is built, first a phase of spatial data mining process extracts geographic knowledge, and a second phase visualizes it by means of chorems -which can be defined as schematized representations of territory. In other words, semantic generalization must be followed by geographic generalization. The scope of this paper is to present the last results of an international project.

API, Cloud computing, WebGIS et cartographie

“…cit.). From the cartographic database we can finally obtain the map (cfr., for instance, Laurini, 1992 and, in order to deepen the so called "Chorem" visualisation of the Database extracted information: Brunet, 1986;Laurini et alii, 2006;Laurini, 2009). Using cartographic generalisation procedures we can later derive minor scale maps (for further study with particular regard to the changeover from manual to automatic generalisation, see Bianchin et al, 2003).…”

“…Bianchin (2009) observes "the object topology on the ground is complete, but there are no objects at all, only a photographic continuum" (2009). As many Authors already wrote (cfr., for instance, Robinson, 1976 and1995;Bertin, 2010;Brunet, 1987;Mac Eachren, 1995;Harley, 2002), a map is essentially a territorial representation, not the territory itself (captured by an aerial photograph or at a hypothetical, absurd 1:1 scale). Not all the geographic objects can be positioned on the map and this in any eventuality would certainly not be desirable.…”