Glossary for Geospatial Science

24-bit raster object:  A raster in which each cell is represented by three bytes (24 bits) and can therefore assume 16,777,216 possible values.  When color images are stored in 24-bit rasters, 8 bits represent the intensity level for red, 8 bits green, and 8 bits blue.  With this scheme (256 possible levels for each color), each cell in a 24-bit color raster can take any one of 16,777,216 possible colors.