I don’t think any of IFF file formats can compresses (lousy) a picture similar JPEG levels.
PNG levels of compression can archive by using an auto LHA compression device handlers for IFF files
(Recalling from memory on my A3000's HD setup, which is currently being rebuilt for WinUAE/Amithlon).
I think powerpacker has a similar trick.
I also recall, IFF is copyrighted to good old Electronic Arts (together with CBM's Amiga 1000 project) back in 1985, in the interest of standardising file formats for Amiga platform.
Did EA ever charge the use of their format?
I don't recall EA ever did this...(Correct me if I'm wrong).
"You can't create a standard that doesn't infringe patents - PNG or Ogg Vorbis could equally be challenged. So it's no good saying something is patent free."
IFF standard is even older than the claimed ~1986 patent. So I think IFF is safe at the moment, unless EA modify its conditions.