Stefano Ermon's group proposed training neural networks to denoise images, reasoning that the ability to denoise an image would indicate sufficient understanding of its structure to build a generative procedure.

“diffusion models back in 2019 with my PhD student Yang Song and so we kind of like came up with this idea of let's train a neural network to denoise images and if you can denoise an image then you really are understanding enough about the structure of the image that it should be possible to build like a generative procedure based on these denoisers and that basically became the kind of like underlying technology of”