METHOD AND DEVICE FOR DISPLAYING AND USING SHAPE INFORMATION IN GEOGRAPHICAL DATABASE

PROBLEM TO BE SOLVED: To provide a system and a method for storing data representing any map characteristics, excepting for straight lines, in a computer readable geographical database to be used for a navigation system. SOLUTION: A curved line generated by a computable function is matched with an image of any map characteristic except for a straight line. The computable function can be a polynomial having a shape limited by the coefficients. In an embodiment, the polynomial is a spline curve of a certain type, specifically, a Bezier curve with its shape limited by control points CP (m) (1) and CP (m) (2). The coefficients of the polynomial are related to the data representing the characteristics except for a straight line. When the polynomial is a Bezier curve, the control points CP (m) (1) and CP (m) (2) for generating the Bizier curve are related to the data representing the characteristic except for a straight line. Only these control points CP (m) (1) and CP (m) (2) are stored in the geographical database and used for displaying the characteristics except for a straight line so that a storage capacity can be remarkably decreased.