Towards unambiguous map labeling - Integer programming approach and heuristic algorithm

Abstract

The development of computer systems that emulate human expertise in decision making is a common task in the automation of processes like planning, design, prediction or control. When it comes to map design, one of the problems of the cartographer is to orchestrate the elements of the map so that it clearly conveys its information to the readers. Several disciplines, such as Computational Geometry, Cartography and Operations Research have devoted diverse efforts to automate this task, commonly identified in the research domain as the Point-Feature Label Placement (PFLP). These approaches aim to avoid or minimize overlapping elements on the map, but almost no attempt to model possible ambiguities of feature and label pairs has been conducted so far. This article presents four Integer Programming formulations for the PFLP problem that incorporate ambiguity as an indicator of the solution quality. A very basic heuristic procedure is also introduced as an alternative to the exact formulations for large instances. All the proposed methods are tested on several maps of Spanish municipalities. Finally, some conclusions and recommendations are given.