RANSAC
A robust model-fitting procedure that repeatedly samples minimal point sets and keeps whichever fit gets the most support.
RANSAC (RANdom SAmple Consensus) fits a model in the presence of outliers by repeatedly drawing a minimal random sample of points, fitting a candidate model to that sample, counting how many of the remaining points agree with it within a tolerance (its inlier count), and keeping the candidate with the largest inlier consensus across many iterations. See the RANSAC consensus guarantee for how many iterations that takes to trust with a given confidence.
Examples
Fitting a homography from 200 noisy matches, RANSAC repeatedly samples 4 points, fits a candidate homography, and counts inliers, keeping whichever sampled fit wins the most support across many iterations.
See also