What Is a Raster Image?
A raster image is a type of computerized image that consists of row after row of tiny dots (pixels). If you have a scanner and scanner software, you can create a raster image by scanning a paper map. After you scan a map image and store the image in a file, you can display the file using MapInfo Pro.
There are many different raster image file formats. For a list of the raster image files that MapInfo Pro can read, see MapInfo Pro Data File Support in the MapInfo Pro Install Guide.
What Does It Mean To Register a Raster Image?
When you register a raster map image, you enter map coordinates (e.g. longitude/latitude degrees), and you indicate which locations on the raster image correspond to those coordinates. You must register each raster image before displaying the image in MapInfo Pro, so that MapInfo Pro can perform geographic calculations, such as distance and area calculations, when displaying the raster map.
The first time you open a raster image file in MapInfo Pro, MapInfo Pro will ask you if you want to register it or use it simply for display. Click the Register button to open the Image Registration dialog box. By completing this dialog box, you tell MapInfo Pro how to register the raster image and determine the coordinate system for the image. MapInfo Pro stores the raster image's registration information in a table file for future re-use. The next time you run MapInfo Pro, you can re-open the raster table without repeating the registration process. Thus, you only need to register each raster image once.
Raster image files provided by MapInfo Pro are already registered. You do not need to perform the registration process when you display the sample raster data included with MapInfo Pro.