An elastic map system with cognitive map-based operations

Abstract

An elastic map system is presented that enables users to stretch a digital map as if it were an elastic sheet or a tangible device. The system enhances focus+context maps, which displays both local detailed data and global context data in the same view. The system enables users to treat elements of cognitive maps (or mental images of maps), such as paths, landmarks, districts, and others, which were classified by Lynch, as elements of a city’s image. Users are able to collect map objects into a context area and enlarge them in a focus area based on previous geographical knowledge. The system provides uniform scaling of focus and context areas by introducing a glue area between the two areas. This scaling is controlled by using a displacement function and ensures angles, proportionality in distances, and parallelism between lines in focus and context areas are preserved. Furthermore, the system enables users to treat any shaped focus area with an arrangement function to arrange the displacement function so as to be suitable for a focus area of any shape, e.g. a user-specified district or both sides of a user-specified road.