orientation_xldorientation_xldOrientationXldOrientationXldorientation_xld (算子)

名称

orientation_xldorientation_xldOrientationXldOrientationXldorientation_xld — 计算轮廓或多边形的方向。

签名

orientation_xld(XLD : : : Phi)

描述

算子 orientation_xldorientation_xldOrientationXldOrientationXldOrientationXldorientation_xld calculates the orientation of each input contour or polygon. The operator is based on elliptic_axis_xldelliptic_axis_xldEllipticAxisXldEllipticAxisXldEllipticAxisXldelliptic_axis_xld。In addition, the contour respectively polygon point with maximum distance to the center of gravity is calculated. If the column coordinate of this point is less than the column coordinate of the center of gravity the value of is added to the angle.假设轮廓或多边形是闭合的。 If this is not the case orientation_xldorientation_xldOrientationXldOrientationXldOrientationXldorientation_xld will artificially close the contours or polygons.

需要注意的是，orientation_xldorientation_xldOrientationXldOrientationXldOrientationXldorientation_xld 仅在轮廓或多边形在平面上包围区域时才会返回有效结果。特别需要注意的是，轮廓或多边形不得自相交。当传递开放轮廓或多边形时，这一点尤为重要，因为它们会被自动闭合，从而可能产生自相交的情况。可使用 test_self_intersection_xldtest_self_intersection_xldTestSelfIntersectionXldTestSelfIntersectionXldTestSelfIntersectionXldtest_self_intersection_xld 检测轮廓或多边形是否自相交。 If the contour or polygon intersects itself, useful values for the orientation can be calculated with orientation_points_xldorientation_points_xldOrientationPointsXldOrientationPointsXldOrientationPointsXldorientation_points_xld。

If more than one contour or polygon is passed, the values of the orientations are stored in a tuple in the same order as the respective contours or polygons in XLDXLDXLDXLDXLDxld。