Merge pull request #24 from takis/issue19

Add inline PNG support

docs/common_use_cases.rst

@@ -213,3 +213,53 @@ Add metadata
     # 550 bytes PDF
     with open('metadata.pdf', 'wb') as f:
         document.write(f)
+
+
+Display inline QR-code image
+----------------------------
+
+.. code-block:: python
+
+    import pydyf
+    import qrcode
+
+    # Create a QR code image
+    image = qrcode.make('Some data here')
+    raw_data = image.tobytes()
+    width = image.size[0]
+    height = image.size[1]
+
+    document = pydyf.PDF()
+    stream = pydyf.Stream(compress=True)
+    stream.push_state()
+    x = 0
+    y = 0
+    stream.transform(width, 0, 0, height, x, y)
+    # Add the 1-bit grayscale image inline in the PDF
+    stream.inline_image(width, height, 'Gray', 1, raw_data)
+    stream.pop_state()
+    document.add_object(stream)
+
+    # Put the image in the resources of the PDF
+    document.add_page(
+        pydyf.Dictionary(
+            {
+                "Type": "/Page",
+                "Parent": document.pages.reference,
+                "MediaBox": pydyf.Array([0, 0, 400, 400]),
+                "Resources": pydyf.Dictionary(
+                    {
+                        "ProcSet": pydyf.Array(
+                            ["/PDF", "/ImageB", "/ImageC", "/ImageI"]
+                        ),
+                    }
+                ),
+                "Contents": stream.reference,
+            }
+        )
+    )
+
+    # 909 bytes PDF
+    with open("qrcode.pdf", "wb") as f:
+        document.write(f, compress=True)
+

pydyf/__init__.py

@@ -3,6 +3,7 @@
 
 """
 
+import base64
 import re
 import zlib
 from codecs import BOM_UTF16_BE
@@ -364,6 +365,44 @@ def transform(self, a, b, c, d, e, f):
             _to_bytes(a), _to_bytes(b), _to_bytes(c),
             _to_bytes(d), _to_bytes(e), _to_bytes(f), b'cm')))
 
+    def inline_image(self, width, height, color_space, bpc, raw_data):
+        """Add an inline image.
+
+        :param width: The width of the image.
+        :type width: :obj:`int`
+        :param height: The height of the image.
+        :type height: :obj:`int`
+        :param colorspace: The color space of the image, f.e. RGB, Gray.
+        :type colorspace: :obj:`str`
+        :param bpc: The bits per component. 1 for BW, 8 for grayscale.
+        :type bpc: :obj:`int`
+        :param raw_data: The raw pixel data.
+
+        """
+        if self.compress:
+            data = zlib.compress(raw_data)
+        else:
+            data = raw_data
+        enc_data = base64.a85encode(data)
+        self.stream.append(
+            b' '.join(
+                (
+                    b'BI',
+                    b'/W', _to_bytes(width),
+                    b'/H', _to_bytes(height),
+                    b'/BPC', _to_bytes(bpc),
+                    b'/CS',
+                    b'/Device' + color_space.encode(),
+                    b'/F',
+                    b'[/A85 /Fl]' if self.compress else b'/A85',
+                    b'/L', _to_bytes(len(enc_data) + 2),
+                    b'ID',
+                    enc_data + b'~>',
+                    b'EI',
+                )
+            )
+        )
+
     @property
     def data(self):
         stream = b'\n'.join(_to_bytes(item) for item in self.stream)