Question

我正在尝试使用astropy将WCS转换为像素，但是当我尝试读取图像时：

from astropy import wcs

w = wcs.WCS('image_file.fits')

我得到以下例外：

*WARNING: Unexpected extra padding at the end of the file.  This padding may not be preserved when saving changes. [astropy.io.fits.header]
Traceback (most recent call last):
  File "make_stamps.py", line 29, in <module>
    w = wcs.WCS(image_file)
  File "/Users/anaconda/lib/python2.7/site-packages/astropy/wcs/wcs.py", line 385, in __init__
    fobj = fits.open(header)
  Fhttp://stackoverflow.com/posts/41513868/editile "/Users/anaconda/lib/python2.7/site-packages/astropy/io/fits/hdu/hdulist.py", line 139, in fitsopen
    return HDUList.fromfile(name, mode, memmap, save_backup, cache, **kwargs)
  File "/Users/anaconda/lib/python2.7/site-packages/astropy/io/fits/hdu/hdulist.py", line 281, in fromfile
    save_backup=save_backup, cache=cache, **kwargs)
  File "/Users/anaconda/lib/python2.7/site-packages/astropy/io/fits/hdu/hdulist.py", line 839, in _readfrom
    hdu = _BaseHDU.readfrom(ffo, **kwargs)
  File "/Users/anaconda/lib/python2.7/site-packages/astropy/io/fits/hdu/base.py", line 423, in readfrom
    **kwargs)
  File "/Users/anaconda/lib/python2.7/site-packages/astropy/io/fits/hdu/base.py", line 483, in _readfrom_internal
    header = Header.fromfile(data, endcard=not ignore_missing_end)
  File "/Users/anaconda/lib/python2.7/site-packages/astropy/io/fits/header.py", line 451, in fromfile
    padding)[2]
  File "/Users/anaconda/lib/python2.7/site-packages/astropy/io/fits/header.py", line 520, in _from_blocks
    raise IOError('Header missing END card.')
IOError: Header missing END card.*

我在使用fits.open()之前遇到此错误，但能够通过添加"ignore_missing_end=True"来解决问题。但是，"ignore_missing_end"似乎不是wcs类的参数。如何使用astropy.wcs.wcs？

读取图像

Answer 1

astropy.wcs.WCS可以使用文件名只是一个方便的选项，所以你不能将astropy.io.fits.open接受的（所有）参数传递给这个函数也就不足为奇了。

但是，使用astropy.io.fits.Header创建WCS非常容易。因此，您可以打开文件，提取相关标题并自己创建WCS：

from astropy.io import fits
from astropy.wcs import WCS

with fits.open('your_file.fits', mode='readonly', ignore_missing_end=True) as fitsfile:
    # if you want the first extension, otherwise change the [0].
    wcs = WCS(fitsfile[0].header)  
# Now you can use your WCS, for example:
print(wcs)

Astropy WCS：“IOError：Header缺少END卡。”

1 个答案: