问题
I'd like to find the largest convex hull which fits in the interior of a set of points. I have a set of points which are roughly circular, with a large number of outlier points outside of the circle I'd like to fit. Imagine a circle with "solar flares"... I want to fit the circle and completely ignore the flares. I've tried various fit and culling strategies, but they aren't working well.
I've searched quite a bit and not found a solution. Thanks in advance.
回答1:
The notion you need may be alpha shapes. The convex hull is a sub-set of the alpha-shape for an extreme value for alpha. The alpha shape is fitting a set of point closer than the convex hull with some values for alpha.
Theory has been developed by Edelbrunner. This is a good start: http://www.mpi-inf.mpg.de/~jgiesen/tch/sem06/Celikik.pdf
For computation, you must: compute delaunay triangulation and/or voronoi diagram, then select points that observe one condition.
Example alpha shape:
This is in fact a concave hull, and it may disregard outliers.
来源：https://stackoverflow.com/questions/16324139/fit-maximum-convex-hull-to-interior-of-a-set-of-points