#
# 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.
#
from PIL import Image, ImageFile, _binary
__version__ = "0.2"
_handler = None
if str != bytes:
long = int
##
# Install application-specific WMF image handler.
#
# @param handler Handler object.
[文档]def register_handler(handler):
global _handler
_handler = handler
if hasattr(Image.core, "drawwmf"):
# install default handler (windows only)
class WmfHandler(object):
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())
# --------------------------------------------------------------------
word = _binary.i16le
[文档]def short(c, o=0):
v = word(c, o)
if v >= 32768:
v -= 65536
return v
dword = _binary.i32le
#
# --------------------------------------------------------------------
# Read WMF file
def _accept(prefix):
return (
prefix[:6] == b"\xd7\xcd\xc6\x9a\x00\x00" or
prefix[:4] == b"\x01\x00\x00\x00"
)
##
# Image plugin for Windows metafiles.
[文档]class WmfStubImageFile(ImageFile.StubImageFile):
format = "WMF"
format_description = "Windows Metafile"
def _open(self):
# 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
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
size = (x1 - x0) * 72 // inch, (y1 - y0) * 72 // inch
self.info["wmf_bbox"] = x0, y0, x1, y1
self.info["dpi"] = 72
# print self.mode, self.size, self.info
# sanity check (standard metafile header)
if s[22:26] != b"\x01\x00\t\x00":
raise SyntaxError("Unsupported WMF file format")
elif dword(s) == 1 and s[40:44] == b" EMF":
# enhanced metafile
# get bounding box
x0 = dword(s, 8)
y0 = dword(s, 12)
x1 = dword(s, 16)
y1 = dword(s, 20)
# get frame (in 0.01 millimeter units)
frame = dword(s, 24), dword(s, 28), dword(s, 32), dword(s, 36)
# normalize size to 72 dots per inch
size = x1 - x0, y1 - y0
# calculate dots per inch from bbox and frame
xdpi = 2540 * (x1 - y0) // (frame[2] - frame[0])
ydpi = 2540 * (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:
raise SyntaxError("Unsupported file format")
self.mode = "RGB"
self.size = size
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 IOError("WMF save handler not installed")
_handler.save(im, fp, filename)
#
# --------------------------------------------------------------------
# Registry stuff
Image.register_open(WmfStubImageFile.format, WmfStubImageFile, _accept)
Image.register_save(WmfStubImageFile.format, _save)
Image.register_extension(WmfStubImageFile.format, ".wmf")
Image.register_extension(WmfStubImageFile.format, ".emf")