Was it cut and dried? I've seen plenty of comparisons and I'll admit that was my first thought too. But then again, what's the relationship between plagiarism and following a paradigm that another artist has established? After all, you only need to stick "Chinese landscape" into Google and it starts to look as though Roger Dean may just have 'followed a paradigm' or two himself. And as for floating islands - they date back through Swift to Homer and probably earlier. Should Braque have paid Picasso royalties? For that matter you can see the pre-echoes of cubism in the painting of Cezanne. I'm not saying Roger Dean wasn't plagiarised, I just think he may have beel ill-advised to sue.

Shifting the paradigm is the nub of it. If an artist is so influential that they move the aesthetic goalposts - Uccello, Harunobu, Picasso etc., then, perversely, they somehow lose the moral copyright; and with it, the legal one, too.

Dean is hardly amongst those luminaries, but his influence on psychedelic and speculative art was profound. He's probably shot himself in the foot.

It's always going to be tricky, which is why lawyers prefer word for word plagiarism when they look at writing. It doesn't help that the industry in popular music litigation, for instance, has descended into absolute bollocks with vague similarities touted as copying, and lawyers counting notes up and notes down to see if there are 4 or 5 matches.

Listened to Danny Boyle interviewed on the subject recently. he mentioned the try-on period leading up to release of a film, when there's so much invested that it can seem cheaper to settle a claim, genuine or not than delay putting it into cinemas. He freely admitted to borrowing from various places when he directed Trainspotting, including A Clockwork Orange and Gravity's Rainbow. In fact he admitted going to some effort to imitate Clockwork Orange look, feel and even camera shots in places. 

Dean does what he does rather well. That said, I agree he's not up there with Picasso et al in that his paradigm is a 'niche' paradigm: he didn't change the course of art, or even the course of fantasy art. As a good dialetical materialist I say that what he does finds its origins in what went before, which is rather obvious really. Was he plagiarised? Probably - a bit Should he have sued or simply basked in the glory of being imitated? Probably basked. It obviously got him pretty angry - enough to instruct a firm of lawyers and risk taking on the big-money. A few bottles of Laphroaig and a few days reflection might have been wiser. It may not be right or just, but it always looks different when somebody who already has the glittering prizes gets litigious to when a newcomer screams that their work has been stolen. Look at the way J K Rowling gets all legal on the heads of her fan-fic followers. Not a good look, particularly in light of the debt she owes to people like Frank Richards, or more to the point, Jill Murphy.

FWIW I consider Dean a talented illustrator, perhaps less talented than e.g Howard Pyle and Alan Aldridge, and more talented than Norman Rockwell.

I've had 15 hours in Elite Dangerous now  :-O It's pretty awesome. So far I've been doing courier missions and trading commodities between systems to make enough money to get a new ship. I have a lovely Cobra Mk III now with a fair bit more cargo space. Why I got 30k credits for shipping 3 tons of water for my last mission I don't know.