EMF image support

docx/image/__init__.py

@@ -14,6 +14,7 @@
 from docx.image.jpeg import Exif, Jfif
 from docx.image.png import Png
 from docx.image.tiff import Tiff
+from docx.image.emf import Emf
 
 
 SIGNATURES = (
@@ -26,4 +27,5 @@
     (Tiff, 0, b'MM\x00*'),  # big-endian (Motorola) TIFF
     (Tiff, 0, b'II*\x00'),  # little-endian (Intel) TIFF
     (Bmp,  0, b'BM'),
+    (Emf,  40, b' EMF')
 )

docx/image/constants.py

@@ -102,6 +102,7 @@ class MIME_TYPE(object):
     JPEG = 'image/jpeg'
     PNG = 'image/png'
     TIFF = 'image/tiff'
+    EMF = 'image/emf'
 
 
 class PNG_CHUNK_TYPE(object):

docx/image/emf.py

@@ -0,0 +1,70 @@
+# encoding: utf-8
+
+from __future__ import absolute_import, division, print_function
+
+from .constants import MIME_TYPE
+from .exceptions import InvalidImageStreamError
+from .helpers import BIG_ENDIAN, StreamReader
+from .image import BaseImageHeader
+import struct
+
+class Emf(BaseImageHeader):
+    """
+    Image header parser for PNG images
+    """
+    @property
+    def content_type(self):
+        """
+        MIME content type for this image, unconditionally `image/png` for
+        PNG images.
+        """
+        return MIME_TYPE.EMF
+
+    @property
+    def default_ext(self):
+        """
+        Default filename extension, always 'png' for PNG images.
+        """
+        return 'emf'
+
+    @classmethod
+    def from_stream(cls, stream,filename=None):
+        """
+        Return a |Emf| instance having header properties parsed from image in
+        *stream*.
+        """
+
+        """
+        @0 DWORD iType; // fixed
+        @4 DWORD nSize; // var 
+        @8 RECTL rclBounds;
+        @24 RECTL rclFrame; // .01 millimeter units L T R B
+        @40 DWORD dSignature; // ENHMETA_SIGNATURE = 0x464D4520
+        DWORD nVersion;
+        DWORD nBytes;
+        DWORD nRecords;
+        WORD  nHandles;
+        WORD  sReserved;
+        DWORD nDescription;
+        DWORD offDescription;
+        DWORD nPalEntries;
+        SIZEL szlDevice;
+        SIZEL szlMillimeters;
+        """
+        stream.seek(0)
+        x = stream.read(40)
+        stream.seek(0)
+        iType,nSize = struct.unpack("ii",x[0:8])
+        rclBounds = struct.unpack("iiii",x[8:24])
+        rclFrame = struct.unpack("iiii",x[24:40])
+
+        dpi = 300
+        horz_dpi = dpi
+        vert_dpi = dpi
+        mmwidth = (rclFrame[2]-rclFrame[0])/100.0
+        mmheight = (rclFrame[3]-rclFrame[1])/100.0
+        px_width = int(mmwidth*dpi*0.03937008)
+        px_height = int(mmheight*dpi*0.03937008)
+
+        #1 dot/inch  =  0.03937008 pixel/millimeter
+        return cls(px_width,px_height,horz_dpi,vert_dpi)

docx/image/image.py

@@ -188,7 +188,7 @@ def _ImageHeaderFactory(stream):
 
     def read_32(stream):
         stream.seek(0)
-        return stream.read(32)
+        return stream.read(64)
 
     header = read_32(stream)
     for cls, offset, signature_bytes in SIGNATURES:

samples/testaddemf.py

@@ -0,0 +1,32 @@
+import docx
+from docx import Document
+from docx.oxml.ns import nsdecls
+from docx.oxml import parse_xml
+from docx.enum.text import WD_ALIGN_PARAGRAPH
+from docx.shared import Mm
+
+
+def docx_addpicture(document, path, width_mm, caption):
+    paragraph = document.add_paragraph()
+    paragraph.alignment = WD_ALIGN_PARAGRAPH.CENTER
+    run = paragraph.add_run()
+    run.add_picture(path, width=Mm(width_mm))
+    # DOCX missing bookmarks
+    # DOCX numbering goes next paragraph (WHY?)
+    # See Issue: https://github.com/python-openxml/python-docx/issues/138
+    if caption != "":
+        paragraph = document.add_paragraph(style="Caption")
+        p = paragraph._p  # this is the actual lxml element for a paragraph
+        run = paragraph.add_run("Figure ")
+        fld_xml = ('<w:fldSimple %s w:instr=" SEQ Figure \* ARABIC "/>' %
+                   nsdecls('w'))
+        fldSimple = parse_xml(fld_xml)  # this goes AFTER the field (!)
+        #p.addnext(fldSimple)
+        paragraph.add_run(" " + caption)
+
+
+document = Document()
+
+docx_addpicture(document,"testaddemf.emf", width_mm=100,caption="Groups Implementation")
+
+document.save("testaddemf.docx")