关于 orientation_region 区域定向的问题

orientation_region 区域定向，指定方向的规则是什么呢？

基于算子 elliptic_axis等效区域为椭圆的参数来进行区域角度的认定！
怎么计算呢？官方的文档解释如下：

1. The operator orientation_region calculates the orientation of the region. The operator is based on elliptic_axis. In addition the point on the contour with maximal 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 Pi is added to the angle.
   
2. If more than one region is passed the results are stored in tuples, the index of a value in the tuple corresponding to the index of a region in the input.
   

复制代码

大概意思就是计算椭圆轮廓到重心的最大距离的点，如果该点的列坐标小于重心列坐标，那么就将这个点的PI值加到角度当中！