There were several attempts to bring John Carter to film going all the way back to Bob Clampett's attempts in 1936 with an animated version. I think prior to the advent of CGI it would have been impossible to satisfactorily portray the fantastic imagination of Edgar Rice Burroughs and his wondrous and weird Barsoom, so animation would have been the best option. Disney made a fun little Mars & Beyond show back in the 50's that had a snippet of Barsoom. Then there is this terrific fan made animation that shows more imagination and faithfulness to the book than the recent live action film.
The John Carter live action movie was enjoyable, certainly better than the unfair reviews claimed, but it missed many opportunities. They did have great artists working on the concepts and I love the Art Of book. But in an earlier iteration there was a concept artist who I felt really nailed the energy and exotic flavor of the books. Rafael Kayanan. Here are a sample of some of the concepts he did.
Now some of you might be saying "but he drew John and Dejah with clothes on! The books say they are butt naked!!". Ok, ok, but you know we are never going to get butt naked John and Dejah on film except maybe on PornHub. Still, these are some kick-ass concepts.
You can see more of Rafael Kayanan's Barsoom concepts here.