Computing simplified coverage polygons
11 days ago
- #simplification-algorithms
- #geo-processing
- #geographic-polygons
- Simplified geographic polygons are needed for various applications like public transport routing and emergency alerts.
- High-resolution geometry is unnecessary and costly for these use-cases, requiring simplification.
- Simplification must ensure the result covers the original geometry to avoid critical misses.
- Douglas-Peucker algorithm is commonly used but doesn't guarantee a hull and can produce self-intersecting polygons.
- Polygon offsetting with Clipper2 library can help create simplified hulls by merging small details.
- Combining offsetting with Douglas-Peucker and negative offsetting improves results for concave features.
- Truncating floating-point numbers in GeoJSON reduces storage and transfer size without affecting computational complexity.
- Questions remain about better algorithms for higher-quality simplification or further size reduction.