Raster map   

A raster map consists of pixels (picture elements) of a certain size, e.g. 20m x 20m. Pixels are either codified by IDs, class names, values, or colors; this is determined by the domain of the map. A raster map should have coordinates, that is a georeference. In ILWIS, most spatial operations are performed on raster maps.

To obtain a raster map:

• rasterize an existing point, segment or polygon map, or
• create a new raster map and edit it with the pixel editor,
• use a satellite image which is already a raster map, or
• scan a map or photograph and import it into ILWIS.