It is often useful to display an image in the background when working with a model. To import an image, the user first selects File|Import|Image... The same dialog box can be displayed by selecting Edit|Edit Images... The user clicks the Select Image button to select the image to import. If a World (*.wld) file with the same file name as the selected image exists, it will be read and used to specify the location of the image. The user may also click the Import World File button to select a World file to read. There are at least two different world file formats. They are described at the following URLs:
Raster world file: https://webhelp.esri.com/arcgisdesktop/9.3/index.cfm?id=3046&pid=3034&topicname=World_files_for_raster_datasets
CAD world file: https://support.esri.com/index.cfm?fa=knowledgebase.techarticles.articleShow&d=16106
The user can also specify the location of the image without using a World file. To specify the location of the image, the user clicks on the image two or more times. For each point the user clicks, a dialog box will appear in which the user must specify the real world locations of the pixels that were clicked. The data will be entered in the table to the left of the image. To delete one of these points, delete one or more of the values for the point. If any of the values for a point is missing, the point will be ignored. The user must enter at least two points before the image can be imported. The user also must specify a name for the image and whether the image will be visible from the top, front, or side of the model. By default, the image will be visible; however, the user can hide it by unchecking the Visible checkbox.
Alternatively, the user can paste a set of coordinates along with (optionally) an ID for each point. Then the user selects a row for one of the points for which no pixel coordinates havebeen specified and clicks on the corresponding location on the image to specify the pixel coordinates.
Images can be in bmp, jpeg, png, emf, wmf and a variety of other formats.
In the United States, one convenient source of air photo and map images is the National Map https://www.usgs.gov/core-science-systems/national-geospatial-program/national-map
See also: Show or Hide Images dialog box.
