Pillow/PIL/DcxImagePlugin.py
Brian Crowell a7e3b2e47b py3k: The big push
There are two main issues fixed with this commit:

* bytes vs. str: All file, image, and palette data are now handled as
  bytes. A new _binary module consolidates the hacks needed to do this
  across Python versions. tostring/fromstring methods have been renamed to
  tobytes/frombytes, but the Python 2.6/2.7 versions alias them to the old
  names for compatibility. Users should move to tobytes/frombytes.

  One other potentially-breaking change is that text data in image files
  (such as tags, comments) are now explicitly handled with a specific
  character encoding in mind. This works well with the Unicode str in
  Python 3, but may trip up old code expecting a straight byte-for-byte
  translation to a Python string. This also required a change to Gohlke's
  tags tests (in Tests/test_file_png.py) to expect Unicode strings from
  the code.

* True div vs. floor div: Many division operations used the "/" operator
  to do floor division, which is now the "//" operator in Python 3. These
  were fixed.

As of this commit, on the first pass, I have one failing test (improper
handling of a slice object in a C module, test_imagepath.py) in Python 3,
and three that that I haven't tried running yet (test_imagegl,
test_imagegrab, and test_imageqt). I also haven't tested anything on
Windows. All but the three skipped tests run flawlessly against Pythons
2.6 and 2.7.
2013-01-10 08:46:56 -06:00

78 lines
1.8 KiB
Python

#
# The Python Imaging Library.
# $Id$
#
# DCX file handling
#
# DCX is a container file format defined by Intel, commonly used
# for fax applications. Each DCX file consists of a directory
# (a list of file offsets) followed by a set of (usually 1-bit)
# PCX files.
#
# History:
# 1995-09-09 fl Created
# 1996-03-20 fl Properly derived from PcxImageFile.
# 1998-07-15 fl Renamed offset attribute to avoid name clash
# 2002-07-30 fl Fixed file handling
#
# Copyright (c) 1997-98 by Secret Labs AB.
# Copyright (c) 1995-96 by Fredrik Lundh.
#
# See the README file for information on usage and redistribution.
#
__version__ = "0.2"
from . import Image, _binary
from .PcxImagePlugin import PcxImageFile
MAGIC = 0x3ADE68B1 # QUIZ: what's this value, then?
i32 = _binary.i32le
def _accept(prefix):
return i32(prefix) == MAGIC
##
# Image plugin for the Intel DCX format.
class DcxImageFile(PcxImageFile):
format = "DCX"
format_description = "Intel DCX"
def _open(self):
# Header
s = self.fp.read(4)
if i32(s) != MAGIC:
raise SyntaxError("not a DCX file")
# Component directory
self._offset = []
for i in range(1024):
offset = i32(self.fp.read(4))
if not offset:
break
self._offset.append(offset)
self.__fp = self.fp
self.seek(0)
def seek(self, frame):
if frame >= len(self._offset):
raise EOFError("attempt to seek outside DCX directory")
self.frame = frame
self.fp = self.__fp
self.fp.seek(self._offset[frame])
PcxImageFile._open(self)
def tell(self):
return self.frame
Image.register_open("DCX", DcxImageFile, _accept)
Image.register_extension("DCX", ".dcx")