How does Douglas peucker algorithm work?

The Ramer-Douglas–Peucker algorithm is an algorithm for reducing the number of points in a curve that is approximated by a series of points. It does so by “thinking” of a line between the first and last point in a set of points that form the curve. It checks which point in between is farthest away from this line.

What is the role of the parameter epsilon in Ramer Douglas peucker algorithm?

The algorithm accepts typically one parameter, tolerance, sometimes called epsilon. To explain how is epsilon used, it is the best to start with the principle. Douglas-Peucker is an iterative algorithm – it removes the point, splits the line and starts again until there is no point which could be removed.

What is line simplification?

Line simplification is one of the generalization methods, used when converting large scale maps to smaller ones. This method is applied on linear features and boundaries of polygons. Most algorithms work on the vertices of the linear features.

Why line simplification is required?

Amazingly, simplification often allows the elimination of 95% or more points while retaining sufficient detail for visualization. For example, the GeoJSON file used to draw the continental United States above can be reduced from 531KB to 27KB with only minor visual changes.

What is the Ramer Douglas Peucker line simplification algorithm?

Ramer-Douglas-Peucker line simplification. The Ramer–Douglas–Peucker algorithm is a line simplification algorithm for reducing the number of points used to define its shape.

How is Douglas Peucker algorithm used in data science?

The first of which needed the algorithm to reduce the number of route points (latitude, longitudes) to be saved into the database while the latter uses the algorithm to fit a four point polygon around white pixels in a segmentation mask.

Which is the anchor point in the Douglas Peucker algorithm?

In their paper, Douglas & Peucker (1972) refers to these two points as the anchor point and the floating point, respectively. In our example, these points are A (start) and D (end).

What is the purpose of the polyline algorithm?

The purpose of the algorithm is, given a curve composed of line segments (which is also called a Polyline in some contexts), to find a similar curve with fewer points. The algorithm defines ‘dissimilar’ based on the maximum distance between the original curve and the simplified curve (i.e., the Hausdorff distance between the curves).