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Editing: WmfImagePlugin.py
# # 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 . import Image, ImageFile from ._binary import i16le as word from ._binary import si16le as short from ._binary import si32le as _long _handler = None 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): return ( prefix[:6] == b"\xd7\xcd\xc6\x9a\x00\x00" or prefix[:4] == b"\x01\x00\x00\x00" ) ## # Image plugin for Windows metafiles. 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 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"])
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