def METHOD_NAME(
    self,
    image_paths: Dict[str, List[str]],
    is_training: bool,
) -> Dict:
    """
    Read images, process them, and stack them. One sample can have multiple images,
    resulting in a tensor of (n, 3, size, size), where n <= max_img_num_per_col is the available image number.
    Parameters
    ----------
    image_paths
        One sample may have multiple image columns in a pd.DataFrame and multiple images
        inside each image column.
    is_training
        Whether to process images in the training mode.
    Returns
    -------
    A dictionary containing one sample's images and their number.
    """
    mm_data = self.prepare_one_sample(image_paths=image_paths, is_training=is_training)
    ret = {self.image_key: self.train_processor(mm_data) if is_training else self.val_processor(mm_data)}
    return ret