Random Sample Consensus (RANSAC) is a basic tool in computer vision and feature extraction. In the most prototypical case, it is used to find a line of best fit. It’s particularly good for noisy data.

The basic idea of RANSAC:

  • Randomly select two points from the data set and draw a line
  • Construct an “inlier set” by collecting all points close to this line by some specified threshold distance
  • Repeat the process until you get the inlier set with maximum data

Pros:

  • Robust to outliers and noise
  • Can trade off accuracy for speed
  • Very general concept that can be applied to a wide range of features

Cons:

  • No upper bound on the time it takes to get the solution
  • Does not guarantee the optimal solution (not even the existence of a solution)
  • Can estimate only one entity (e.g. only one line)