def corner_extent(ul, ll, ur, lr):
    """Get min/max extent based on corner coord
    """
    xmin = min(ul[0], ll[0], ur[0], lr[0])
    xmax = max(ul[0], ll[0], ur[0], lr[0])
    ymin = min(ul[1], ll[1], ur[1], lr[1])
    ymax = max(ul[1], ll[1], ur[1], lr[1])
    extent = [xmin, ymin, xmax, ymax]
    return extent
