Some raster formats can be represented by one or more extensions. Not all are recognized by ArcGIS by default.
If you have a valid raster format that does not have a standard file extension, such as an ARC Digitized Raster Graphic (ADRG) legend file, you can modify the file extension that will be searched for by clicking it in the format list and typing the new file extension.
- You can access the Raster File Formats Properties dialog box from the Customize menu in the ArcGIS Desktop applications.
- In ArcMap (ArcGlobe or ArcScene), click the Customize menu, click ArcMap Options, click the Raster tab, click the Raster Dataset tab, then click File Formats.
- In ArcCatalog, click the Customize menu, click ArcCatalog Options, click the General tab, click Raster Files in the data types list, then click Properties.
- Scroll down to the appropriate raster format in the list.
- Click in the File Extensions column to the right of the raster format's name.
- Move the pointer to the end of the file extensions list.
- Type a semicolon (;), then type the letters that compose the file extension.
- Press ENTER.
- Click OK to close each dialog box.
For example, if you add the file extension *.jpeg to the File Extensions column to the right of JFIF (JPEG), both .jpg and .jpeg files will be recognized as JFIF images.