raster — raster spatial data type.
raster is a spatial data type used to represent raster data such as those imported from jpegs, tiffs, pngs, digital elevation models. Each raster has 1 or more bands each having a set of pixel values. Rasters can be georeferenced.
Requires PostGIS be compiled with GDAL support. Currently rasters can be implicitly converted to geometry type, but the conversion returns the ST_ConvexHull of the raster. This auto casting may be removed in the near future so don't rely on it.
This section lists the automatic as well as explicit casts allowed for this data type