Raster-vector conversion
Also called: Rasterisation, Vectorisation · Topic: Remote Sensing, GIS and GNSS · NCERT: Class 12, Ch 4 "Spatial Information Technology"
Meaning
Raster-vector conversion changes GIS data from one format to the other so all layers share one format. Raster data is a grid of equal cells. Vector data stores points, lines and polygons as coordinates. Vector-to-raster conversion (rasterisation) lays a grid of a chosen cell size over the vector data. It is more common, because most analysis is raster-based. Raster-to-vector conversion (vectorisation) is done to save storage space.
Example
A vector land-use map of Aligarh, Uttar Pradesh, is to be studied with a satellite image of the city. The land-use polygons are turned into a grid with the same cell size as the image, so the two layers can be overlaid.
Don't confuse with
- Georeferencing: conversion changes the data format. Georeferencing ties data to real-world coordinates without changing its format.
Related concepts
- Raster data model
- Vector data model
- Topology
- Digitisation
- Scanner
- Charge-coupled device
- Georeferencing
- Exact matching
- Hierarchical matching
- Fuzzy matching