Hierarchical Methods of Line Simplification

Abstract

An important preprocessing operator in a digital mapping system is line simplification. A line-simplification operator generalizes digital, geographic base files to ensure that the amount of information to be displayed played matches the geographic scale at which it is displayed. Many different simplification algorithms have been proposed to accomplish this task. Each algorithm has an implicit objective regarding which points to retain when caricaturizing a line. Each caricature is dependent on a tolerance level specified at the outset. This paper proposes a hierarchical approach to line simplification. Hierarchical classification methods are frequently used to group objects by their thematic attributes. A similar method is now used for the parallel problem of line simplification. The advantage of this approach is that a set of line caricatures corresponding to alternate tolerance levels can be calculated and compactly stored in tree or list structures.