Performance Evaluation of Automatic Name Placement Functions for Geographical Database Systems

Geographical information systems have been studied and actively developed in various field. One of their characteristics that distinguishes them from paper-based maps is their ability to retrieve various kinds of geographical information, compose the information, and display it on maps. In addition, these operations must be done very quickly. The system is required to provide a visual and high-level user interface. When retrieved data are composed on maps, one of the major problems is to deal with character information, which is to place names appropriately so that each of them is easily associated with its feature. We must take into account the fact that the displayed map, since it is a form of visualized representation of data, may not be a complete map. For this reason, the output maps are desirable to be displayed in realtime, and also they must be legible. In this paper, we describe our automatic name placement functions and discuss their performances.