Imagine (.img) Reader

Intergraph Corporation has contracted with me to write an Erdas Imagine (.img) to GeoTIFF raster translator. They have gratiously agreed to release the source to the translator under an OpenSource license.

Please note that I am not an employee of Intergraph, and represent them in no way.

The reader consists of a C++ API for reading any information from the Erdas Imagine heirarchical file architecture files, and a high level program for translating raster and georeferencing data to GeoTIFF. At this time the API is not really adequately documented ... if you have an interest in using the API please contact me and I will bundle it up more cleanly.

The API also supports writing a minimal Imagine file. In addition to it's utilization in img2tif, the API is also incorporated into GDAL which provides translation tools to and from Imagine format.


The img2tif program converts an Imagine .img file into one or more GeoTIFF files.

Usage: img2tif [-i img_filename] [-o tif_basename] [-c] [-v n...]
       [-rgb [red_band green_band blue_band]] [-?] [-quiet]

    -i    input .img file
    -o    output base file name
          Output files will be named base_name1.tif ... base_nameN.tif,
          where N = no. of bands.
    -rgb  produce an RGB image file from the indicated band numbers
          within an existing imagine file.
    -s    output file is in strips (tiles is default)
    -c    packbits compress flag (def=uncompressed)
    -v    overview sampling increment(s) (0=single, 98=full set minus 2x,
          99=full set)  Examples: -v 2 4 8   -v 0   -v 99
    -quiet Don't produce a translation report.
    -?    Print this explanation of command line arguments


Things to note:

Other Imagine Format Resources


The img2tif translator was written by Frank Warmerdam ( Suggestions for improvement are welcome.

The development of this utility was funded by Intergraph Corporation who agreed for it to released freely.

The development of Erdas Imagine write support was funded by PCI Geomatics, for whom I am incorporating it into GeoGateway.

The img2tif utility uses the libtiff library written by Sam Leffler, and the libgeotiff library written by Niles Ritter.

Thanks to Dave Mayes of BAE Systems, for providing sample files demonstrating the compressed format.