Quick Hull

Quick Hull is a well-known algorithm to envelope a set of points.

From wikipedia: It uses a divide and conquer approach similar to that of QuickSort, which its name derives from. Its average case complexity is considered to be O(n * log(n)), whereas in the worst case it takes O(n2) (quadratic).

Usage:

    QuickHullModifier quickHullModifier = new QuickHullModifier();
    List<Point2D> convexHull = quickHullModifier.quickHull(listOfPoints);

Example:

For an interactive example you can run the Quick Hull Example in the package examples.basic.

You can find more details in QuickHullApplication

Illustration:

Before/After Quick Hull Modifier

Application:

The Quick Hull method can be used in hand tracking algorithms. It could be the first step to find the hand gesture:

Image from: http://anikettatipamula.blogspot.ro/2012/02/hand-gesture-using-opencv.html