Plot sky region defined by header and data
    header : FITS header
    data   : Data array

def plot_skyreg(header, data, **kwargs):
    """ Plot sky region defined by header and data
    header : FITS header
    data   : Data array
    """
    kwargs.setdefault('cmap','binary')
    fig = plt.figure()
    ax = pywcsgrid2.subplot(111, header=header)
    ax.set_ticklabel_type("dms")
    im = ax.imshow(data, origin="center", **kwargs)
    ax.grid()
    ax.add_compass(loc=1,coord='fk5')
    ax.add_compass(loc=4,coord='gal')
    return ax, im