在那个PaddleClas/ppcls/data/preprocess/ops/operators.py 里面可以找到这个算子的代码：

class ResizeImage(object):
    """ resize image """

    def __init__(self,
                 size=None,
                 resize_short=None,
                 interpolation=None,
                 backend="cv2"):
        if resize_short is not None and resize_short > 0:
            self.resize_short = resize_short
            self.w = None
            self.h = None
        elif size is not None:
            self.resize_short = None
            self.w = size if type(size) is int else size[0]
            self.h = size if type(size) is int else size[1]
        else:
            raise OperatorParamError("invalid params for ReisizeImage for '\
                'both 'size' and 'resize_short' are None")

        self._resize_func = UnifiedResize(
            interpolation=interpolation, backend=backend)

    def __call__(self, img):
        img_h, img_w = img.shape[:2]
        if self.resize_short is not None:
            percent = float(self.resize_short) / min(img_w, img_h)
            w = int(round(img_w * percent))
            h = int(round(img_h * percent))
        else:
            w = self.w
            h = self.h
        return self._resize_func(img, (w, h))