WaifuLabs uses GANs (generative adversarial networks) to create millions of anime portraits, which can be used as avatars or game characters. They made this video and blog post that explains how GANs work.
You can think of it as a pair of AIs that spar against each other in order to learn:
- The first AI is called the Generator. It's task is to learn how to draw.
- The second AI is called the Discriminator. It's task is to learn how to tell fake drawings (produced by an AI) from real drawings (produced by a human artist).
Both AIs are exposed to anime data from human artists and offered feedback on how they performed on their respective tasks. At the very end, we separate out the Generator and run it as the artist behind the scenes.
It is interesting to note that like human rivals, it is imperative that they grow at the same rate. When one AI dominates the other, both stop learning.