I converted viceversa as
pil_img = Image.open(img)
print(pil_img.size)
pil_to_tensor = transforms.ToTensor()(img).unsqueeze_(0)
print(pil_to_tensor.shape)
tensor_to_pil = transforms.ToPILImage()(pil_to_tensor.squeeze_(0))
print(tensor_to_pil.size)
(1200, 1200)
torch.Size([1, 3, 1200, 1200])
(1200, 1200)
thanks to ptrblk. 