FitsStubImagePlugin.py
1.59 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
#
# The Python Imaging Library
# $Id$
#
# FITS stub adapter
#
# Copyright (c) 1998-2003 by Fredrik Lundh
#
# See the README file for information on usage and redistribution.
#
from . import Image, ImageFile
_handler = None
def register_handler(handler):
"""
Install application-specific FITS image handler.
:param handler: Handler object.
"""
global _handler
_handler = handler
# --------------------------------------------------------------------
# Image adapter
def _accept(prefix):
return prefix[:6] == b"SIMPLE"
class FITSStubImageFile(ImageFile.StubImageFile):
format = "FITS"
format_description = "FITS"
def _open(self):
offset = self.fp.tell()
if not _accept(self.fp.read(6)):
raise SyntaxError("Not a FITS file")
# FIXME: add more sanity checks here; mandatory header items
# include SIMPLE, BITPIX, NAXIS, etc.
self.fp.seek(offset)
# make something up
self.mode = "F"
self._size = 1, 1
loader = self._load()
if loader:
loader.open(self)
def _load(self):
return _handler
def _save(im, fp, filename):
if _handler is None or not hasattr("_handler", "save"):
raise IOError("FITS save handler not installed")
_handler.save(im, fp, filename)
# --------------------------------------------------------------------
# Registry
Image.register_open(FITSStubImageFile.format, FITSStubImageFile, _accept)
Image.register_save(FITSStubImageFile.format, _save)
Image.register_extensions(FITSStubImageFile.format, [".fit", ".fits"])