| 摘要 |
PURPOSE:To make operation easy by calculating an angle between a final selecting element and a next selection candidate element, preferentially selecting one element with the smaller angle out of the plural selection candidate elements when contour tracking is executed along an inner track and selecting one element with the larger angle when the contour tracking is executed along an outer track. CONSTITUTION:The contour tracking is executed like an arrow from a start element BA and arrives at a first end point (a). At such a time, the angle between a final selecting element Ca in this side of the end point (a) and next selection candidate elements aD and aE in a counter-clockwise direction is calculated with the final selecting element Ca as a reference. Based on this angle and either an inner or outer tracking direction, the selection of the next selection candidate element is determined according to a prescribed condition. Namely, when the contour tracking is executed along the inner track, one element with the smaller angle is selected and when the contour tracking is executed along the outer track, one element with the larger angle is selected preferentially out of the plural selection candidate elements. Thus, the operation is made easy. |
