如何获得LR图像
image = imread(path, is_grayscale=True)
label_ = modcrop(image, scale)
# Must be normalized
image = image / 255.
label_ = label_ / 255.
input_ = scipy.ndimage.interpolation.zoom(label_, (1./scale), prefilter=False)
input_ = scipy.ndimage.interpolation.zoom(input_, (scale/1.), prefilter=False)