Georeference file formats

Whenever you specify an image file, the application will attempt to georeference that image by searching for known georeferencing data. Depending on the image file format, this spatial data may be present as a separate header file or may be embedded within the image itself.

The application searches for georeferencing data in the following sequence, and will stop searching at the first valid header that it finds:

• Georeference (.GRF) file (3D images only)
• MapInfo TAB file (.TAB) file
• ArcView World File
• ER Mapper Header (ERS) file (associated with ECW files and occasionally with BIL files)
• GeoTIFF internal tag (only found in a GeoTIFF image file)
• ECW internal header (only found in a compressed ECW file)
• Esri HDR file (associated with BIL, BSQ, and BIP files)

With the exception of the GeoTIFF and ECW headers, which are embedded within the image files, header files must always be in the same folder and have the same name as the associated image file, with the appropriate file extension. For example, the myfilename.HDR header file will georeference the myfilename.BIL image file.