| 摘要 |
PURPOSE: To attain accurate detection of a line segment independently of a position of discrimination by calculating an overlap area interposed between an extension line of a 1st line segment object and a 2nd line segment object and discriminating it that the 1st and 2nd line segment objects form a same line segment when a level corresponding to the area is a prescribed threshold level or below. CONSTITUTION: The device is made up of a pre-processing section 1, a line segment detection section 2, a line segment discrimination section 3 and a line segment synthesis section 4. Then an overlap area S interposed between an extension line of a line segment object 9MAX in a direction of an line segment object g1 and the line segment object g1 is calculated and whether or not the line segment object g1 forms a same line segment with the line segment object gMAX, is discriminated based on the magnitude of the overlap area S. Thus, it is avoided that a straight line is adopted for a curve in mistake or a substantially one-line-segment is thinned and a line segment is accurately detected independently of a position of discrimination. |
