#!/usr/bin/env python3

import astropy.io.fits as pyfits
import numpy

import os
import sys


if __name__ == "__main__":

    proto_fn = sys.argv[1]

    hdulist = pyfits.open(proto_fn)
    img = hdulist[0].data

    psf = img[:img.shape[0], :img.shape[0]]

    phdu = pyfits.PrimaryHDU(data=psf)
    phdu.writeto(sys.argv[2], overwrite=True)