<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_corner(hdr, rsize=1):
 """Obtain bin and corner information for a subarray. ``LTV1``, ``LTV2``, ``LTM1_1``, and ``LTM2_2`` keywords are extracted from the given extension header and converted to bin and corner values (0-indexed). ``LTV1`` for the CCD uses the beginning of the illuminated portion as the origin, not the beginning of the overscan region. Thus, the computed X-corner has the same origin as ``LTV1``, which is what we want, but it differs from the ``CENTERA1`` header keyword, which has the beginning of the overscan region as origin. .. note:: Translated from ``calacs/lib/getcorner.c``. Parameters hdr : obj Extension header. rsize : int, optional Size of reference pixel in units of high-res pixels. Returns ------- bin : tuple of int Pixel size in X and Y. corner : tuple of int Corner of subarray in X and Y. """

    ltm, ltv = get_lt(hdr)
    return from_lt(rsize, ltm, ltv)