Suppose I have a set of 2d line segments that are all connected. I need an algorithm that finds the outermost segments in the set. That is, the minimal subset that bounds the same region.
Note: this is not the same as finding the convex hull of the points making up the segments.
Edit: On the top is the initial set of segments. Below that is the same outline with interior segments deleted. (Ignore the little grey crosses, they're just to mark intersection points.)
How would you do that with a pencil...?