Abstract
A contour to grid conversion method is proposed. In the proposed method, Euclidean distance transformation is used to determine the nearest points on the contour with which given point is to be interpolated. By using this approach, complicated searching process of standard points for interpolation could be avoided, which results in simplified and stabilized algorithm. Also, the method can be applied to the contours which are not completely closed. Hence, the burden for restoration of contour can be reduced.
The conversion accuracy is evaluated by comparing the result with human-interpreted grid data. An average error for closed contours is 37cm when the elevation interval for contour is 10m, which is thought to be acceptable for many applications. Even in the case of not completely closed contours, the average error is 38cm, which is negligible degradation of accuracy compared to completely closed case.
