def empty(region):
    """
    Check if a region is empty or inconsistent

    :param region: region as an array [xmin, ymin, xmax, ymax]
    :type region: list of four float
    :returns: True if the region is considered empty (no pixels inside),
        False otherwise
    :rtype: bool"""
    return region[0] >= region[2] or region[1] >= region[3]