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#
# The Python Imaging Library.
# $Id: McIdasImagePlugin.py 2134 2004-10-06 08:55:20Z fredrik $
#
# Basic McIdas support for PIL
#
# History:
# 97-05-05 fl Created (8-bit images only)
#
# Thanks to Richard Jones <richard.jones@bom.gov.au> 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.
#
__version__ = "0.1"
import string
import Image, ImageFile
def i16(c,i=0):
return ord(c[1+i])+(ord(c[i])<<8)
def i32(c,i=0):
return ord(c[3+i])+(ord(c[2+i])<<8)+(ord(c[1+i])<<16)+(ord(c[i])<<24)
def _accept(s):
return i32(s) == 0 and i32(s, 4) == 4
##
# Image plugin for McIdas area images.
class McIdasImageFile(ImageFile.ImageFile):
format = "MCIDAS"
format_description = "McIdas area file"
def _open(self):
# parse area file directory
s = self.fp.read(256)
if not _accept(s):
raise SyntaxError, "not an McIdas area file"
# get mode
if i32(s, 40) != 1 or i32(s, 52) != 1:
raise SyntaxError, "unsupported McIdas format"
self.mode = "L"
# get size
self.size = i32(s, 36), i32(s, 32)
# setup image descriptor
prefix = i32(s, 56)
offset = i32(s, 132)
self.tile = [("raw", (0, 0) + self.size, offset,
("L", prefix + self.size[0], 1))]
# FIXME: should store the navigation and calibration blocks
# somewhere (or perhaps extract some basic information from
# them...)
# --------------------------------------------------------------------
# registry
Image.register_open("MCIDAS", McIdasImageFile, _accept)
# no default extension
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