I have a radiograph .img file without the header file. However, the researchers who have published the file have given this information about it
High resolut
Just in case anybody else is looking at these images and wants to convert them in batches, or outside of Python and without needing any programming knowledge... you can convert them pretty readily at the command line in Terminal with ImageMagick (which is installed on most Linux distros anyway, and available for OS X and Windows) like this:
convert -size 2048x2048 -depth 16 -endian MSB -normalize gray:JPCLN130.IMG -compress lzw result.tif
which makes them into compressed 16-bit TIF files that can be viewed in any application. They also then take up half the space on disk without loss of quality since I specified LZW compression.
Likewise, if you want 16-bit PNG files, you can use:
convert -size 2048x2048 -depth 16 -endian MSB -normalize gray:JPCLN130.IMG result.png