def from_lt(rsize, ltm, ltv):
dbinx = rsize / ltm[<NUM_LIT:0>]<EOL>dbiny = rsize / ltm[<NUM_LIT:1>]<EOL>dxcorner = (dbinx - rsize) - dbinx * ltv[<NUM_LIT:0>]<EOL>dycorner = (dbiny - rsize) - dbiny * ltv[<NUM_LIT:1>]<EOL>bin = (_nint(dbinx), _nint(dbiny))<EOL>corner = (_nint(dxcorner), _nint(dycorner))<EOL>return bin, corner<EOL>
Compute the corner location and pixel size in units
    of unbinned pixels.

    .. note:: Translated from ``calacs/lib/fromlt.c``.

    Parameters
    ----------
    rsize : int
        Reference pixel size. Usually 1.

    ltm, ltv : tuple of float
        See :func:`get_lt`.

    Returns
    -------
    bin : tuple of int
        Pixel size in X and Y.

    corner : tuple of int
        Corner of subarray in X and Y.