Solved by Nikronic in post #2 
              
              
                Hi, 
About ToTensor you are right, it standardizes input. Please see this post. 
About your questions: 


If you use mean=[0.5,...], std=[0.5,...] then a standardized input will be in [-1, 1] but this exactly true for ImanetNet mean and std. You can verify this by calculating (x - mean(x)) / std. 


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