Abstract: When map data is to be processed for display in a mapping or navigation apparatus, the application processor (705) of the apparatus first checks to see whether any existing data in a local cache memory (706) represents a similar map part to the new data that is to be processed. This is done by means of a similarity analysis (601). If the map data already in the cache (706) is determined to be sufficiently similar to the map data that is to be displayed, new map data from a main map storage (230) is not loaded and processed, but instead the existing data in the cache (706) is processed for display of the map part in question. This has the benefit of a reduced system load, since already processed data does not need to be reloaded and reprocessed.

Abstract: When preparing a representation of map display information for use by a navigation device,a set of source map data (600) is subject to a similarity analysis step (601) to try to identify elements in the source map data (600) that are similar in terms of their shape and/or their appearance when displayed. A classification and transformation parameter generation step (602) then classifies elements in the map into groups of similar elements as determined by the similarity analysis (601) and also determines the parameters and conditions under which the identified map elements can be considered to be similar. This is then used to generate a map database that includes a library of predefined map display elements having parametrable aspects, which map display elements can then be used to construct a desired map for display.

Abstract: A technique is disclosed for calculating a sightseeing route from a start location to a destination location. The start location and the destination location may be the same as each other or different. The route is calculated to pass one or more attractors each representing a sightseeing attraction. A digital database resource (500) contains digital map information, the digital map information including a plurality of attractors. The technique comprises (a) determining (550) an initial route from the start location to the destination location, and setting the initial route as a current route; (b) determining (602) for each attractor in a candidate set of the attractors, a relative attraction value that is dependent on a distance between the attractor and the current route; (c) determining (604, 612) which attractor corresponds to a largest attraction value; (d) modifying (620) the current route to include a deviation to the attractor determined at step (c).