Object Selection Algorithm for Magnifier Glass Map Considering Balance and Readability

A magnifier glass map is one of the basic and important tools in GIS software for map browsing. In order to trade off information unbalance between the window and data visualized in magnifier glass map, a piecewise scale change function is taken as a method for projection to construct the relationship among observing object and its neighbors under the Voronoi k order adjacency relation. Taking objective equilibrium distribution and deformation readability into account, two parameters are proposed and calculated quantitatively using Voronoi k order adjacency relation and constrained area of a Voronoi region, with one being the parameter controlling the target distribution balance and the other being target deformation readability. We also presentthe target selection algorithm. Through comparative experiments, we determined the stability of targets accounting for the large deformation in the magnifier glass map representation, providing some certain practical value.