U-Nets for segmentation

Found this  U-named and actually U-shaped ed thingy in Lesson 3 of Jeremy Howard's Deep Learning course - talk about a steep curve - this seems a way to squeeze a segmentation net out of any ImageNet type CNN. Reference is https://arxiv.org/abs/1505.04597  

U-Net: Convolutional Networks for Biomedical Image Segmentation

by Olaf Ronneberger, Philipp Fischer, Thomas Brox.

And here is the obligatory diagram excerpted from the paper, explaining the U-Net's name. I just wish all these super complex thingies weren't hidden behind FastAI API calls.

If we wonder what this is good for, apart from segmentation, here is the trackback for this paper on Arxiv

https://arxiv.org/tb/1505.04597

We can see superresolution is one application: https://towardsdatascience.com/deep-learning-based-super-resolution-without-using-a-gan-11c9bb5b6cd5