def _get_bbox_feature(image_size, feature_map, x_min, x_max, y_min, y_max):
    """Get bounding box features.

    The feature is the center pixel of a bounding box.

    Args:
        image_size (tuple): Size of an image in [x, y].
        feature_map (numpy.ndarray(numpy.float)): Feature map of size [x, y, n_features] of whole
            image where the bounding box lies in.
        x_min (int): Minimum X coordinate of bounding box.
        x_max (int): Maximum X coordinate of bounding box.
        y_min (int): Minimum Y coordinate of bounding box.
        y_max (int): Maximum Y coordinate of bounding box.

    Returns:
        numpy.ndarray(numpy.float): Feature of size [n_features.]

    """
    feature_map_size = feature_map.shape[:2]

    bbox_center_orig_images = ((x_min + x_max) / 2,
                               (y_min + y_max) / 2)
    bbox_center_relative = [center / size
                            for center, size in zip(bbox_center_orig_images, image_size)]

    bbox_center_feature_map = [int(relative_position * size)
                               for size, relative_position
                               in zip(feature_map_size, bbox_center_relative)]
    bbox_feature = feature_map[bbox_center_feature_map[0], bbox_center_feature_map[1], :]
    return bbox_feature