This chapter serves as an introduction to the concepts of viewing raster images in the background.
The basic requirements for viewing raster references are listed below:
•Raster files must have a known geographical position. Some raster file formats contain the georeferencing information in the file header (for example, GeoTIFF and ECW). Alternatively, the georeferencing information can be stored in external files specific for raster file formats (for example, .TFW files for TIFF, .JGW files for JPG).
•The design file must provide the appropriate coordinate range for the position of the raster files.
•Raster references are displayed only in top views or rendered views.