orientation_region — Orientation of a region.
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, in the rotated coordinate system, 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.
In the documentation of this chapter (Regions / Features), you can find an image illustrating regions which vary in their orientation.
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.
In case of empty region all parameters have the value 0.0 if no other behavior was set (see set_system('no_object_result',<Result>)).
Region(s) to be examined.
Orientation of region (arc measure).
Assertion: - pi <= Phi && Phi < pi
If F is the area of a region the mean runtime complexity is O(sqrt(F)).
The operator orientation_region returns the value 2 (H_MSG_TRUE) if the input is not empty. The behavior in case of empty input (no input regions available) is set via the operator set_system('no_object_result',<Result>). The behavior in case of empty region (the region is the empty set) is set via set_system('empty_region_result',<Result>). If necessary an exception is raised.
threshold, regiongrowing, connection