Map forma vector conversion manner and device

摘要

PURPOSE:To obtain a enough result concerning accuracy as well while suppressing calculation cost low. CONSTITUTION:This device is provided with a main attention point detecting means 5 to sample a contour while moving forward on a contour information train obtained by trace, a sub attention point detecting means 6 to detect a point on the contour closest to the main attention point with a black picture element between as a sub attention point, a discriminating means 8 to discriminate whether a core line is extracted or the position of the main attention point is detected again by comparing a distance between the both attention points with a prescribed threshold value, a core line extracting means 10 to calculate a midpoint between the both attention points as a point expressing the core line based on the discriminated result and to store the point in a core line information storing means 11, and a main attention point estimating means 9 to predict the appearance of branched structure based on the discriminated result, to estimate a branch in a smoothly continuous direction from the extracted core line information and to newly set the main attention point.