Line segment, type of end of the segment
For constraints to be established in the future, corners to be detected, it is important to know if each one of the ends of the segment is because of an occlusion or it is a "detected" end of the segment. In other words, if the end of the segment is because a smaller range or a larger range, respectively.
We could add 2 attributes, a boolean for each end, detected_end_1 or something like that.