I am looking for an algorithm, that is able to detect the contour of the attached scatter plot (only for the area y<4, y>4 is not relevant for me). I need that contour to filter out the points that are on it to make some measurements. Background: The points represent nodes from a meshed part and I want to do some measurements afterwards (see second picture). If someone has any ideas on how I can do this other than using the contour let me know.
I tried different approaches with alpha shapes, concave/convex hull and delaunay but none of them was able to detect the contour correctly.
