Map display device and map display method

Abstract

The invention provides a map display device and map display method that enhance the information density of displayed road names while maintaining legibility of a map image. First, the map drawing unit draws, to an image storage unit, a map image of roads and so forth in a desired scale, by using the background layer of a first hierarchy corresponding to the desired scale. Second, the map drawing unit draws place names and facility names by using the character layer of the first hierarchy to superimpose them on the map image. Third, the map drawing unit extracts the road names that do not overlap with the map characters of the place names and facility names on the map image by using the character layer of the first hierarchy, and superimposes them on the map image at the normal character size. Fourth, the map drawing unit extracts, by using the character layer of a second hierarchy corresponding to a scale level smaller by one step than the desired scale level, road names that do not overlap with the map characters of the other road names, place names, facility names and so forth on the map image, and superimposes them on the map image at a smaller character size. Finally, the map drawing unit superimposes the vehicle position mark on the map image.