YouTuber Jose Argumedo took the 1941 Fleischer Studios Superman cartoon 'The Bulleteers' and upscaled it using Waifu2x, an image upscaler that uses deep convolutional neural networks. Waifu2x is trained on anime (as evidenced by the name) and it works remarkably well for any animation and even pixel art. Just look at the results. It looks better than any remastering I've ever seen and was done completely with machine learning. It's like looking at thosebotched art restorations but with the before and after images reversed.
Keep going for the full upscaled video, as well as what the original quality looks like.