def __init__(self, target_size, keep_ratio, interp=cv2.INTER_LINEAR):
        """
        Resize image to target size. if keep_ratio is True,
        resize the image's long side to the maximum of target_size
        if keep_ratio is False, resize the image to target size(h, w)
        Args:
            target_size (int|list): image target size
            keep_ratio (bool): whether keep_ratio or not, default true
            interp (int): the interpolation method
        """
        super(Resize, self).__init__()
        self.keep_ratio = keep_ratio
        self.interp = interp
        if not isinstance(target_size, (Integral, Sequence)):
            raise TypeError(
                "Type of target_size is invalid. Must be Integer or List or Tuple, now is {}".
                format(type(target_size)))
        if isinstance(target_size, Integral):
            target_size = [target_size, target_size]
        self.target_size = target_size

        Resize image to target size. if keep_ratio is True,
        resize the image's long side to the maximum of target_size
        if keep_ratio is False, resize the image to target size(h, w)
        Args:
            target_size (int|list): image target size
            keep_ratio (bool): whether keep_ratio or not, default true
            interp (int): the interpolation method
        
ppdet/data/transform/operators.py