Idea like idea is great but you will still have to have some central entity from my understanding or some "nonprofit" that is going to control if images are truly yours and that you haven't used any form of plagiarism. Thing what's happening latley with popular social platform on blockchain - steemit is that they have a lot of people who steal other people works and post it as their own. I see the same problem here.
Although I am not sure how these 2 projects combat with this issue, but this is one of the biggest ones that I personally know of.
Why do you need a noon profit organization on top of that?? I don't get it.....
Why can't those stock photographs companies settle for a hefty 15% of the sale revenues like Wemark does?