Often there is also a browse image product in JPG or PNG format. There's an archival data product that usually has a IMG extension. Spacecraft image data exists in NASA's Planetary Data System (PDS) in several different formats. But when I just need to open one or a few images to do quick-and-dirty image processing, it's overkill, and there are some data sets it doesn't know how to handle. I am a big fan of the IMG2PNG tool created by Björn Jónsson, which can batch-convert large numbers of files at once. It explains how you can open archival NASA science data directly in Photoshop without needing to use any other tools. This post will be a little arcane for most readers of this site, but I hope it will be a useful trick for those of you who are into spacecraft image processing.
