You are actually posting in the Photoshop forum, but you can find the Premiere Elements forum at:
Just one thing, are you referring to files with a .img file extension, or files that have a file name starting with img ? As a file extension, .img usually refers to disk image files used for copying and burning CDs and DVDs. I also wonder if these are still image files, or video files, seeing as you are talking about Premiere Elements?
The file extension is .img. The files will not play in Premier Elements!
The answers will be in the details.
What version of Premiere Elements are you using and on what computer operating system is it running?
What program created these .img files?
Are these disc images that you want to copy to a disc CD, DVD, or Blu-ray? Depending on the answer, you may need a program other
than Premiere Elements to achieve your goal, and conversion may be inappropriate for the end product that you seek.
Premiere Elements (any version) will not support for import or export a file with a .img file extension.