75 lines
1.5 KiB
Python
75 lines
1.5 KiB
Python
#
|
|
# The Python Imaging Library
|
|
# $Id$
|
|
#
|
|
# GRIB stub adapter
|
|
#
|
|
# Copyright (c) 1996-2003 by Fredrik Lundh
|
|
#
|
|
# See the README file for information on usage and redistribution.
|
|
#
|
|
|
|
from . import Image, ImageFile
|
|
from ._binary import i8
|
|
|
|
_handler = None
|
|
|
|
|
|
def register_handler(handler):
|
|
"""
|
|
Install application-specific GRIB image handler.
|
|
|
|
:param handler: Handler object.
|
|
"""
|
|
global _handler
|
|
_handler = handler
|
|
|
|
|
|
# --------------------------------------------------------------------
|
|
# Image adapter
|
|
|
|
|
|
def _accept(prefix):
|
|
return prefix[0:4] == b"GRIB" and i8(prefix[7]) == 1
|
|
|
|
|
|
class GribStubImageFile(ImageFile.StubImageFile):
|
|
|
|
format = "GRIB"
|
|
format_description = "GRIB"
|
|
|
|
def _open(self):
|
|
|
|
offset = self.fp.tell()
|
|
|
|
if not _accept(self.fp.read(8)):
|
|
raise SyntaxError("Not a GRIB file")
|
|
|
|
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 OSError("GRIB save handler not installed")
|
|
_handler.save(im, fp, filename)
|
|
|
|
|
|
# --------------------------------------------------------------------
|
|
# Registry
|
|
|
|
Image.register_open(GribStubImageFile.format, GribStubImageFile, _accept)
|
|
Image.register_save(GribStubImageFile.format, _save)
|
|
|
|
Image.register_extension(GribStubImageFile.format, ".grib")
|