#
# The Python Imaging Library
# $Id$
#
# WMF stub codec
#
# history:
# 1996-12-14 fl Created
# 2004-02-22 fl Turned into a stub driver
# 2004-02-23 fl Added EMF support
#
# Copyright (c) Secret Labs AB 1997-2004. All rights reserved.
# Copyright (c) Fredrik Lundh 1996.
#
# See the README file for information on usage and redistribution.
#
# WMF/EMF reference documentation:
# https://winprotocoldoc.blob.core.windows.net/productionwindowsarchives/MS-WMF/[MS-WMF].pdf
# http://wvware.sourceforge.net/caolan/index.html
# http://wvware.sourceforge.net/caolan/ora-wmf.html
from __future__ import annotations
from . import Image, ImageFile
from ._binary import i16le as word
from ._binary import si16le as short
from ._binary import si32le as _long
_handler = None
[docs]
def register_handler(handler):
"""
Install application-specific WMF image handler.
:param handler: Handler object.
"""
global _handler
_handler = handler
if hasattr(Image.core, "drawwmf"):
# install default handler (windows only)
class WmfHandler:
def open(self, im):
im._mode = "RGB"
self.bbox = im.info["wmf_bbox"]
def load(self, im):
im.fp.seek(0) # rewind
return Image.frombytes(
"RGB",
im.size,
Image.core.drawwmf(im.fp.read(), im.size, self.bbox),
"raw",
"BGR",
(im.size[0] * 3 + 3) & -4,
-1,
)
register_handler(WmfHandler())
#
# --------------------------------------------------------------------
# Read WMF file
def _accept(prefix: bytes) -> bool:
return (
prefix[:6] == b"\xd7\xcd\xc6\x9a\x00\x00" or prefix[:4] == b"\x01\x00\x00\x00"
)
##
# Image plugin for Windows metafiles.
[docs]
class WmfStubImageFile(ImageFile.StubImageFile):
format = "WMF"
format_description = "Windows Metafile"
def _open(self):
self._inch = None
# check placable header
s = self.fp.read(80)
if s[:6] == b"\xd7\xcd\xc6\x9a\x00\x00":
# placeable windows metafile
# get units per inch
self._inch = word(s, 14)
# get bounding box
x0 = short(s, 6)
y0 = short(s, 8)
x1 = short(s, 10)
y1 = short(s, 12)
# normalize size to 72 dots per inch
self.info["dpi"] = 72
size = (
(x1 - x0) * self.info["dpi"] // self._inch,
(y1 - y0) * self.info["dpi"] // self._inch,
)
self.info["wmf_bbox"] = x0, y0, x1, y1
# sanity check (standard metafile header)
if s[22:26] != b"\x01\x00\t\x00":
msg = "Unsupported WMF file format"
raise SyntaxError(msg)
elif s[:4] == b"\x01\x00\x00\x00" and s[40:44] == b" EMF":
# enhanced metafile
# get bounding box
x0 = _long(s, 8)
y0 = _long(s, 12)
x1 = _long(s, 16)
y1 = _long(s, 20)
# get frame (in 0.01 millimeter units)
frame = _long(s, 24), _long(s, 28), _long(s, 32), _long(s, 36)
size = x1 - x0, y1 - y0
# calculate dots per inch from bbox and frame
xdpi = 2540.0 * (x1 - y0) / (frame[2] - frame[0])
ydpi = 2540.0 * (y1 - y0) / (frame[3] - frame[1])
self.info["wmf_bbox"] = x0, y0, x1, y1
if xdpi == ydpi:
self.info["dpi"] = xdpi
else:
self.info["dpi"] = xdpi, ydpi
else:
msg = "Unsupported file format"
raise SyntaxError(msg)
self._mode = "RGB"
self._size = size
loader = self._load()
if loader:
loader.open(self)
def _load(self):
return _handler
[docs]
def load(self, dpi=None):
if dpi is not None and self._inch is not None:
self.info["dpi"] = dpi
x0, y0, x1, y1 = self.info["wmf_bbox"]
self._size = (
(x1 - x0) * self.info["dpi"] // self._inch,
(y1 - y0) * self.info["dpi"] // self._inch,
)
return super().load()
def _save(im, fp, filename):
if _handler is None or not hasattr(_handler, "save"):
msg = "WMF save handler not installed"
raise OSError(msg)
_handler.save(im, fp, filename)
#
# --------------------------------------------------------------------
# Registry stuff
Image.register_open(WmfStubImageFile.format, WmfStubImageFile, _accept)
Image.register_save(WmfStubImageFile.format, _save)
Image.register_extensions(WmfStubImageFile.format, [".wmf", ".emf"])