| 摘要 |
PURPOSE:To easily calculate the center lines of a pair of opposite line data by calculating the coordinates of opposite points of the opposite line data, calculating the coordinates of the middle points between the opposite points, and storing the calculated coordinates of the middle points in a data base. CONSTITUTION:A computer 3 extracts line data indicating road boarders from the data base 1 and generates the pair of opposite line data 13 and 17. Then the points 1-5 on the line data 17 corresponding to the points 1-5 on the line data 13 are calculated. At this time, perpendiculars are drawn from the points on the line data 13 to the line data 17 and the coordinates of their intersections are regarded as the coordinates of the corresponding points. Further, when the point on the line data 13 is an inflection point, the coordinates of the inflection point on the line data 17 are regarded as the coordinates of the corresponding point. Then the middle points 1-5 between the corresponding points are found and connected to obtain center line data. The data on the calculated center line are stored in the data base 1. |
