Douglas–Peucker algorithm
A common simplification algorithm that removes vertices while keeping the shape within a tolerance.
Category: Operations · Also known as: Douglas Peucker, DP algorithm, line simplification algorithm
Definition (expanded)
Douglas–Peucker (often written Douglas Peucker) is widely used for line and polygon simplification. Given a tolerance, it keeps points needed to preserve the overall shape and removes others. Aggressive tolerance can introduce artifacts or even invalid polygons.
Common mistakes
- Using a tolerance that removes small-but-important features.
- Assuming simplification preserves validity (it can create self-intersections).
Related terms
SimplifyReduces vertex count while approximating the shape to improve performance and reduce file size.ToleranceA threshold distance used by simplify, snapping, and some repair operations.VertexA single coordinate point in a ring or line; polygons are made of many vertices.Valid geometryA geometry that follows topological rules (closed rings, no self-intersections, properly nested holes, etc.).Self-intersectionWhen a polygon boundary crosses itself (a bow-tie shape), often making it invalid.