Resize函数用于对PIL图像的预处理，它的包在：
from torchvision.transforms import Compose, CenterCrop, ToTensor, Resize
使用如：
def input_transform(crop_size, upscale_factor):
return Compose([
CenterCrop(crop_size),
Resize(crop_size // upscale_factor),
ToTensor(),
])
而Resize函数有两个参数，
CLASS torchvision.transforms.Resize(size, interpolation=2)
size (sequence or int) – Desired output size. If size is a sequence like (h, w), output size will be matched to this. If size is an int, smaller edge of the image will be matched to this number. i.e, if height > width, then image will be rescaled to (size * height / width, size)
interpolation (int, optional) – Desired interpolation. Default is PIL.Image.BILINEAR
size : 获取输出图像的大小
interpolation : 插值，默认的 PIL.Image.BILINEAR， 一共有4中的插值方法
Image.BICUBIC，PIL.Image.LANCZOS，PIL.Image.BILINEAR，PIL.Image.NEAREST
