calculate turning points / pivot points in trajectory (path)

Question

I\'m trying to come up with an algorithm that will determine turning points in a trajectory of x/y coordinates. The following figures illustrates what I mean: green indicate

Answer 1

Another idea is to examine the left and the right surroundings at every point. This may be done by creating a linear regression of N points before and after each point. If the intersecting angle between the points is below some threshold, then you have an corner.

This may be done efficiently by keeping a queue of the points currently in the linear regression and replacing old points with new points, similar to a running average.

You finally have to merge adjacent corners to a single corner. E.g. choosing the point with the strongest corner property.