concave-hull

I am looking for an OpenCV implementation of a function to find the concave hull of a set of points (as for the convexHull function). Does anyone know of it? Here is an explanation: http://ubicomp.algoritmi.uminho.pt/local/concavehull.html Thank you in advance. You can also use Growing Neural Gas algorithm. There are several implementations in web take a look at ( https://github.com/BelBES/libGNG ) for example. Video of the algorithm is here: http://www.youtube.com/watch?v=fVd4ly8wilY Very interesting java applet here: Also take a look at this site: http://www.demogng.de/ 来源： https:/

I have a set of points in an example ASCII file showing a 2D image. I would like to estimate the total area that these points are filling. There are some places inside this plane that are not filled by any point because these regions have been masked out. What I guess might be practical for estimating the area would be applying a concave hull or alpha shapes . I tried this approach to find an appropriate alpha value, and consequently estimate the area. from shapely.ops import cascaded_union, polygonize import shapely.geometry as geometry from scipy.spatial import Delaunay import numpy as np