Cartographic Generalization (Selection) For 2D Map of Urban Area

In cartographic generalization process essential characteristics and behaviour of objects are to be preserved. When a map is represented graphically, if the represented scale is reduced, then some area features will become too insignificant to be represented, i.e. they will be too small to be viewed and cluttering the whole map making it illegible to view even according to the map's theme. These unimportant small area spatial objects are to be eliminated. This elimination procedure is part of generalization process called Selection. This paper presents a new approach to selection process of cartographic generalization. This technique includes three steps. These involve a process to calculate area of the spatial object i.e. polygon, drawing a virtual square, elimination of the spatial object after processing. Generally selection process doesn't consider the spatial density and eliminates all areas less than the threshold value. In virtual square method according to spatial density objects are eliminated. A virtual square is drawn around a spatial object and total number of spatial objects inside it is counted. If the count is greater than threshold then it is eliminated. This technique described in the paper has been tested using many examples and deployed in an application which is developed using Microsoft Visual C++, a robust platform for application development.