def multiple_bbox(bbox, img_height, img_width):
        """normalize bbox to be betwween 0, 1

        Args:
            bbox (list): original labeled bounding box;
            img_width(int): image width;
            img_height(int): image height;
        Returns:
            norm_bbox: normolized bbox
        """
        xmin, ymin, xmax, ymax= bbox[0], bbox[1], bbox[2], bbox[3]
        b0 = ymin * img_height
        b1 = xmin * img_width
        b2 = ymax * img_height
        b3 = xmax * img_width
        return [b0, b1, b2, b3]