"World files" have been implemented now. These are similar to the .trf files in TransDEM and serve the same purpose, storing georeferencing information for an associated image file.
They contain scale (in meters per pixel), rotation (which must be 0 for TransDEM) and origin (geographic WGS84 by default, but can also be a projected system, unknown in the file). Here is an example in VicGrid94:
Code:
3.883166
0
0
-3.883166
2473541.8
2418110.5
For a .jpg image file the world file will be named .jpgw or, more often, .jgw
When opening a plain image file for georeferencing, TransDEM will try to locate a World File with the same name in the same directory. If successful this will save the user from entering the coordinates manually.
The same technique will also be used to save one step in georeferencing Google Earth images. TransDEM will not only look for world files but also for placemark files (.kml,/.kmz).