Polygons to raster
Algorithm
The Polygons to raster operation rasterizes a polygon map. The output raster map always uses the same domain as the input segment map. The user has to specify the georeference for the output raster map.
Process:
For each polygon, the corresponding pixels in the raster map are found; these pixels are assigned the class name, ID or value of the polygon.
Other pixels obtain the undefined value.
- The pixel size indicated in the georeference for the output map, has a large influence on the size (in bytes) of the output raster map. Mind that rasterizing on a pixel size of 10 m instead of 50 m increases the size of the raster map by a factor 25.
- If you want to rasterize only a portion of your polygon map, you can select or create a georeference that does not cover the total area of your polygon map during rasterization.
For ILWIS 1.4 users:
- During rasterization, an .INF table is not produced anymore. To know the area of polygons, length of segments, nr. of points etc., you can calculate the histogram of a polygon, segment or point map with the Histogram operation.
See also:
Polygons to raster : functionality