| 摘要 |
PROBLEM TO BE SOLVED: To obtain a road map display device capable of performing a transformation processing for displaying a road map in a bird-eye view at a high speed. SOLUTION: This display device is provided with a bird-eye view display range determining means 101 determining a trapezoid range on road map data corresponding to a bird-eye view to be displayed, a map data storage means 102 storing road map data on a two-dimensional plane, a rotating transformation means 104 rotatingly transforming coordinate values of elemental points of the road map data to be included in the trapezoid range on the two-dimensional plane, a parameter determining means 105 determining a trapezoid transformation parameter at the time of trapezoidally transforming the trapezoid range, a trapezoid transforming means 106 trapezoidally transforming the rotatingly transformed coordinate values of the elemental points on the two-dimensional plane by using the trapezoid transformation parameter and a plotting means 107 plotting a bird-eye view on a display device 108 based on the coordinate values of the elemental points which are transformed by the trapezoid transforming means. Thus, a transformation processing from the road map data on an ordinary two-dimensional plane to data for displaying the bird-eye view can be performed at a high speed.
|
