Thanks for your input ptrblck. I originally started this thread trying to find an issue on how I was reproducing the paper, because I have been getting result images with checkerboard artifacts. As an example, I provide you three images: the first is the original, the second is a super-resolution based on MSE Loss and the third is a super-resolution based on VGG Loss. This problem appears only when optimizing the network with the perceptual loss function based on VGG feature maps, as described in the paper. When optimized for MSE loss, as you can see in the shown picture, the expected results and metrics are achieved. Would you have some insight into this issue? I can share some of the code, if that helps, just let me know.

HR_1512×512 357 KB
 
SR_1512×512 278 KB
 
SR_1512×512 663 KB