The user may define subclasses of this class.
NormalRaster is similar to ImageRaster, with the exception that the origin is assumed to be in the southwest as opposed to the northwest.
Instances of this class are typical two dimensional rasters, with the origin of the grid and the reference point for each cell assumed to be the lower left hand (southwest) corner, of the grid and cell respectively. Note though that the coordinate for the lower left hand cell is not necessarily (1,1); if the raster is part of a larger raster structure - as with a tiling system for example - the coordinate value for the lower left hand cell could take on any value. Band interleaved, band sequential, run length encoded, and quadtree structures for the actual values are accommodated through appropriate use of the inherited attribute contents from the domain StructuredData. With normal raster data that does not meet the restrictions of this class, the class Raster may be used directly.