Abstract: Map displays have been an important element in the feature set of in-car navigation systems. Actually, with modem equipment extending such system functionality to personal digital assistants (PDAs) and cellular telephones, virtually all travelers may use and benefit from the present invention. Early digital displays were monochrome, single-line-vector, planar representations. Color, area fill, scale-dependent attribute selection, labeling, heading-up rotation, line thickness, signs and icons have all been added to make the display more informative and intuitive. Still today, the designer is challenged to provide a more informative, less distracting display to serve the multitasking driver. More recently, perspective view and 3D objects have gained popularity because of their added utility as well as aesthetic appeal. Just as the planar map is a special case of the perspective map, perspective is a special case of the variable-scale map.

Abstract: A system and method for manipulating digital map information, that allows the operator to view or modify map object or item attributes from either a graphical window or a text window. In one embodiment, when the user selects a map item within the graphical window (202), the text window (210) displays a text record that includes attributes (242) associated with the currently selected item. Attributes may include, for example, a street name, or a relationship of the current item to another item. The system can display these relationships within the text window. In one embodiment, the attributes that include links to related map items or to related items of information are highlighted or are visibly identified (249) in some manner. The operator can then select a highlighted attribute to traverse to, and display the new map item. The graphical window display can be updated in parallel with the text window.

Abstract: An electronic map is stored as a collection of nodes and links. Roads in the map are assigned priorities for pathfinding purposes. A node's priority originally corresponds to the priority of the road associated with the node. Electronic maps can be made more useful by adding short cuts to the map. A short cut generator is disclosed that creates short cuts by building compound links and/or raising the priority of certain nodes. A compound link is a link that represents travel along multiple links of the electronic map.

Abstract: A navigation device displays major routes and direction indications without a specific destination requirement. Where several possible destinations are presented, the device displays information for a destination at or when nearing decision points for traveling to the destination. Direction indicators can be presented on top of an appropriately scaled map having routes displayed which are integral to the indicators and directions. A destination displayed may be selected to retrieve detailed driving instructions to that specific destination. In one embodiment, the navigation device displays direction indications to major destinations, entrances, exits, and other important facilities in a “highway sign” fashion at major decision points.

Abstract: A system is disclosed for using speech recognition with map data. For example, a user could state a location. The system will recognize the words spoken and find the location on a map using an electronic map database. The map can be displayed such that the location is depicted. Alternatively, the user could state two locations. The system will recognize the words spoken, find both locations on the map using an electronic map database, determine a path between the locations and report that path to the user.

Abstract: A method and apparatus for computing sign text for exit ramps from limited access highways of an electronic map network. First and second name lists containing names of road elements ahead of and behind respective simple and compound exit ramps are generated. Sign text for simple exit ramps is computed using a first process having the first and second name lists as inputs. Sign text for compound exit ramps is computed using a second process having the first and second name lists as inputs.

Abstract: A system is disclosed for identifying matching arcs in sets of geometric objects, such as a pair of electronic maps, without relying on attributes being assigned to the arcs. An arc in a first set of geometric objects is identified as matching an arc in a second set of geometric objects, when the arc in the first set is co-bounded on both sides by polygons which match the corresponding co-bounding polygons of the arc in the second set. A determination is made of which polygons in the first set of geometric objects match polygons in the second set of geometric objects, by computing and comparing a set of similarity metrics. Examples of characteristics for which similarity metrics are determined include, proximity, area, shape and rotation. Each similarity metric is determined in an isolated fashion, so that no other metric is reflected in the metric being measured.

Abstract: A system is disclosed for warping models made from geometric objects, such as electronic maps, to correct local distortions in the models without compromising model topology. A set of transformation functions are derived from relationships between points in a first model that match points in a second model. The transformation functions are then applied to the points in the first model to generate a new model with reduced distortion. In order to provide for reducing local distortions, warping is applied to selected corresponding regions of the first model and the second model by triangulating these regions and generating transformation functions for each corresponding pair of triangles. Topology preservation is achieved by identifying matching points in the first model and the second model that have a potential for causing topology deviations. Such matching points are then excluded from the process of developing transformation equations to be used in the warping process.