Viewing file:  McIdasImagePlugin.py (1.86 KB) -rw-r--r--
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#
# The Python Imaging Library.
# $Id$
#
# Basic McIdas support for PIL
#
# History:
# 1997-05-05 fl Created (8-bit images only)
# 2009-03-08 fl Added 16/32-bit support.
#
# Thanks to Richard Jones and Craig Swank for specs and samples.
#
# Copyright (c) Secret Labs AB 1997.
# Copyright (c) Fredrik Lundh 1997.
#
# See the README file for information on usage and redistribution.
#
from __future__ import annotations
import struct
from . import Image, ImageFile
def _accept(prefix: bytes) -> bool:
return prefix[:8] == b"\x00\x00\x00\x00\x00\x00\x00\x04"
##
# Image plugin for McIdas area images.
class McIdasImageFile(ImageFile.ImageFile):
format = "MCIDAS"
format_description = "McIdas area file"
def _open(self) -> None:
# parse area file directory
assert self.fp is not None
s = self.fp.read(256)
if not _accept(s) or len(s) != 256:
msg = "not an McIdas area file"
raise SyntaxError(msg)
self.area_descriptor_raw = s
self.area_descriptor = w = [0] + list(struct.unpack("!64i", s))
# get mode
if w[11] == 1:
mode = rawmode = "L"
elif w[11] == 2:
# FIXME: add memory map support
mode = "I"
rawmode = "I;16B"
elif w[11] == 4:
# FIXME: add memory map support
mode = "I"
rawmode = "I;32B"
else:
msg = "unsupported McIdas format"
raise SyntaxError(msg)
self._mode = mode
self._size = w[10], w[9]
offset = w[34] + w[15]
stride = w[15] + w[10] * w[11] * w[14]
self.tile = [("raw", (0, 0) + self.size, offset, (rawmode, stride, 1))]
# --------------------------------------------------------------------
# registry
Image.register_open(McIdasImageFile.format, McIdasImageFile, _accept)
# no default extension
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