FWIW, the blown-up "original" image doesn't match the small sized image posted by LoRd_MuldeR. The "original" image used by RAISR appears to be higher quality. So all the comparison images with "our" algorithms seem to be at a disadvantage here.
It's a pitty Google didn't find it necessary to make all the images from their PDF available as PNG (or even JPG). But maybe they had a good reason for that...
The biggest problem with all these neural network algorithms is that usually the guys publishing such "scientific" papers use *one* specific algorithm to downscale their images, and then their neural network just learns how to revert the downscaling. Obviously you can get pretty good results that way. But as soon as you feed those neural networks with images downscaled with a different algorithm (e.g. Lanczos instead of Catrom, or Bilinear or Box), the algos quickly fall apart. The only way to properly evaluate the quality of an upscaling algorithm is to test it with multiple different images, which were downscaled with different algorithms.