Thanks for your advice ! I have tried those experiments:

[vkl-git]

Thanks for your advice ! I have tried those experiments:

1. I have decoded the z-LR pair with z of standard deviation [0, 0.1, 0.2, ... 1.0, 1.1]. When deviation is less than 0.5, The black reigions disappear. However, the image is blurry and lacks details.

2.I also have added a small number to the division to protect against divide by zero . But tn the training stage, "RuntimeError: 'DivBackWard0' return nan values in its 1th output." still exists.

For Adding Nosie :
I have added noise to the HR image that you mentioned . And The pixel value in the input HR ranges [0, 255] , [-0.5, 0.5] or [0, 1] ?

Originally posted by @Alan-xw in #2 (comment)

[vkl-git]

Hello, in my own training set, I encountered the same problem as you, when the number of iterations reached 1000, NaN situation appeared.Could you please tell me how you solved this problem?