Thank you for the answer.
But, There is still an error.
/usr/local/lib/python3.6/dist-packages/torchvision/transforms/transforms.py in __call__(self, pic)
    125 
    126         """
--> 127         return F.to_pil_image(pic, self.mode)
    128 
    129     def __repr__(self):

--> 100         raise TypeError('pic should be Tensor or ndarray. Got {}.'.format(type(pic)))
TypeError: pic should be Tensor or ndarray. Got <class 'PIL.Image.Image'>.

Original image is PNG file. That’s matter?
I think ImageFolder is the problem.