My implementation of a U-Net similar to the FBPConvNet after:

K. H. Jin, M. T. McCann, E. Froustey and M. Unser, "Deep Convolutional Neural Network for Inverse Problems in Imaging," in IEEE Transactions on Image Processing, vol. 26, no. 9, pp. 4509-4522, Sept. 2017, https://doi.org/10.1109/TIP.2017.2713099 https://github.com/panakino/FBPConvNet