topojson/topojson
Topojson
TopoJSON is a topological geographic data format and a set of tools that convert standard GeoJSON into a more compact representation. It reduces file size by encoding shared boundaries between adjacent features as reusable arcs, eliminating duplicate boundary coordinates and preserving the spatial relationships between map regions.
The format achieves compression through several encoding techniques. Arc-sharing compression lets neighboring polygons reference a single arc, while coordinate quantization maps geographic coordinates to a fixed integer grid, reducing floating-point precision overhead. Delta-encoded arc storage further shrinks data by recording cumulative coordinate differences, and an indexed arc reference system defines each polygon as a sequence of integer arc indices for compact cross-referencing.
TopoJSON is used for web map optimization, enabling faster loading and rendering of interactive map visualizations in browser-based mapping applications. It provides a command-line utility for shrinking geographic data files and a JavaScript library for topology-aware coordinate encoding, making it a practical tool for cartographic data management and geographic data compression.
Features
- Topological JSON Formats - Represents geographic features as connected arcs and shared boundaries to reduce file size and preserve spatial topology.
- Cartographic Data Management - Manages cartographic data with topological encoding to maintain spatial relationships while minimizing file size.
- Geographic - Compresses geographic data files by encoding shared boundaries as reusable arcs.
- GeoJSON to TopoJSON Converters - Encodes GeoJSON data into a topological format to reduce file size and preserve adjacency information.
- Topological Edge Encoding - Uses topological relationships to remove redundant edges between neighboring regions before encoding.
- Topology Encoders - Stores geographic shapes as a graph of shared arcs instead of independent coordinate lists.
- Coordinate Quantization - Maps geographic coordinates to a fixed integer grid, reducing floating-point precision overhead.
- Web Map Optimizations - Optimizes map data for faster loading and rendering in browser-based mapping applications.
- Arc-Based Geometry Representations - Encodes shared boundaries between polygons as reusable arcs to eliminate coordinate redundancy.
- Map Data Optimizers - Ships a JavaScript library that accelerates map data loading and rendering through topology-aware coordinate encoding.
- Geographic Data Compressors - Provides a command-line utility for shrinking geographic data files by removing duplicate edges while preserving topology.
- Interactive Map Visualizations - Creates lightweight data files for interactive map visualization by removing redundant shared boundaries.
- Delta-Encoded Arcs - Records arc points as cumulative deltas to reduce numerical magnitude and improve compression.
- Indexed Arc References - Defines polygons as sequences of integer arc indices for compact cross-referencing.
- Data Processing Tools - Converts GeoJSON to TopoJSON for efficient map storage.
- Format Conversion - Convert between spatial and TopoJSON formats.
