Solved by RaLo4 in post #2 
              
              
                This is normal. 

This is exactly what torchvision.transforms.Normalize does. 
for example one popular thing to do would be, using torchvision.transforms.ToTensor to make your image of range [0,255] to a tensor of range [0,1] and then use torchvision.transforms.Normalize with mean and std of 0.5 ov…