get_corner

acstools.utils_calib.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.