base colorof the surface, before applying the effects of varying light and camera angles (called incidence angle i and emission angle e in the technical description). Pixels in the displacement map contain the height of the surface at the corresponding locations.
.IMGfilename extensions). Although not typically supported by general-purpose computer graphics software, these formats are directly readable by some GIS programs. The data formats are documented in PDS labels, which are either separate text files with a
.LBLfilename extension or embedded as fixed-length headers. Other than the possible header, most .IMG files are uncompressed 2D binary arrays of numbers. Some data is also available in TIFF or JPEG2000 formats.