code: def get_corner(hdr, rsize=1):
      
      ltm, ltv = get_lt(hdr)
      return from_lt(rsize, ltm, ltv)
docs: 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.