Robust Shape Fitting via Peeling and Grating Coresets

http://www.cs.duke.edu/~pankaj/publications/papers/core-outlier.pdf

Let P be a set of n points in R^d. A subset S of P is called a (k,epsilon)-kernel if for every direction, the

direction width of S epsilon-approximates that of P, when k outliers can be ignored in that direction.