JPEG2000 support

README.md

@@ -1,17 +1,17 @@
 img2pdf
 =======
 
-Lossless conversion of images to PDF without unnecessarily re-encoding JPEG
-files. Thus, no loss of quality and no unnecessary large output file.
+Lossless conversion of images to PDF without unnecessarily re-encoding JPEG and
+JPEG2000 files. Thus, no loss of quality and no unnecessary large output file.
 
 background
 ----------
 
-PDF is able to embed JPEG images as they are without re-encoding them (and
-hence loosing quality) but I was missing a tool to do this automatically, thus
-I wrote this piece of python code.
+PDF is able to embed JPEG and JPEG2000 images as they are without re-encoding
+them (and hence loosing quality) but I was missing a tool to do this
+automatically, thus I wrote this piece of python code.
 
-If you know how to embed JPEG images into a PDF container without
+If you know how to embed JPEG and JPEG2000 images into a PDF container without
 recompression, using existing tools, please contact me so that I can put this
 code into the garbage bin :D
 
@@ -19,12 +19,12 @@ functionality
 -------------
 
 The program will take image filenames from commandline arguments and output a
-PDF file with them embedded into it. If the input image is a JPEG file, it will
-be included as-is without any processing. If it is in any other format, the
-image will be included as zip-encoded RGB. As a result, this tool will be able
-to lossless wrap any image into a PDF container while performing better (in
-terms of quality/filesize ratio) than existing tools in case the input image is
-a JPEG.
+PDF file with them embedded into it. If the input image is a JPEG or JPEG2000
+file, it will be included as-is without any processing. If it is in any other
+format, the image will be included as zip-encoded RGB. As a result, this tool
+will be able to lossless wrap any image into a PDF container while performing
+better (in terms of quality/filesize ratio) than existing tools in case the
+input image is a JPEG or JPEG2000 file.
 
 For the record, the imagemagick command to lossless convert any image to
 PDF using zip-encoding, is:
@@ -32,24 +32,25 @@ PDF using zip-encoding, is:
 	convert input.jpg -compress Zip output.pdf
 
 The downside is, that using imagemagick like this will make the resulting PDF
-files a few times bigger than the input JPEG and can also not output a
-multipage PDF.
+files a few times bigger than the input JPEG or JPEG2000 file and can also not
+output a multipage PDF.
 
 img2pdf is able to output a PDF with multiple pages if more than one input
-image is given, losslessly embed JPEGs into a PDF container without adding more
-overhead than the PDF structure itself and will save all other graphics formats
-using lossless zip-compression.
+image is given, losslessly embed JPEG and JPEG2000 files into a PDF container
+without adding more overhead than the PDF structure itself and will save all
+other graphics formats using lossless zip-compression.
 
 bugs
 ----
 
-If you find a JPEG that, when embedded can not be read by the Adobe Acrobat
-Reader, please contact me.
-
-For lossless conversion of other formats than JPEG, zip/flate encoding is used.
-This choice is based on a number of tests I did on images.  I converted them
-into PDF using imagemagick and all compressions it has to offer and then
-compared the output size of the lossless variants. In all my tests, zip/flate
-encoding performed best. You can verify my findings using the test_comp.sh
-script with any input image given as a commandline argument. If you find an
-input file that is outperformed by another lossless compression, contact me.
+If you find a JPEG or JPEG2000 file that, when embedded can not be read by the
+Adobe Acrobat Reader, please contact me.
+
+For lossless conversion of other formats than JPEG or JPEG2000 files, zip/flate
+encoding is used.  This choice is based on a number of tests I did on images.
+I converted them into PDF using imagemagick and all compressions it has to
+offer and then compared the output size of the lossless variants. In all my
+tests, zip/flate encoding performed best. You can verify my findings using the
+test_comp.sh script with any input image given as a commandline argument. If
+you find an input file that is outperformed by another lossless compression,
+contact me.

img2pdf.py

@@ -4,6 +4,7 @@ import Image
 import sys
 import zlib
 import argparse
+import struct
 from datetime import datetime
 
 def parse(cont, indent=1):
@@ -38,6 +39,8 @@ class obj():
 def main(images, dpi, title=None, author=None, creator=None, producer=None,
     creationdate=None, moddate=None, subject=None, keywords=None):
 
+    version = 3 # default pdf version 1.3
+
     now = datetime.now()
 
     info = dict()
@@ -67,15 +70,32 @@ def main(images, dpi, title=None, author=None, creator=None, producer=None,
     pagestuples = list()
 
     for im in images:
-        imgdata = Image.open(im)
-        width, height = imgdata.size
-        if dpi:
-            dpi_x, dpi_y = dpi, dpi
+        try:
+            imgdata = Image.open(im)
+        except IOError:
+            # test if it is a jpeg2000 image
+            im.seek(0)
+            if im.read(12) != "\x00\x00\x00\x0C\x6A\x50\x20\x20\x0D\x0A\x87\x0A":
+                print "cannot read input image"
+                exit(1)
+            # image is jpeg2000
+            imgformat = "JP2"
+            im.seek(48)
+            height, width = struct.unpack(">II", im.read(8))
+            color = "RGB" # TODO: read real colorspace
+            if dpi:
+                dpi_x, dpi_y = dpi, dpi
+            else:
+                dpi_x, dpi_y = (96, 96) # TODO: read real dpi
         else:
-            dpi_x, dpi_y = imgdata.info.get("dpi", (96, 96))
-        pdf_x, pdf_y = 72.0*width/dpi_x, 72.0*height/dpi_y # pdf units = 1/72 inch
-        imgformat = imgdata.format
-        color = imgdata.mode
+            width, height = imgdata.size
+            if dpi:
+                dpi_x, dpi_y = dpi, dpi
+            else:
+                dpi_x, dpi_y = imgdata.info.get("dpi", (96, 96))
+            imgformat = imgdata.format
+            color = imgdata.mode
+
         if color == 'L':
             color = "/DeviceGray"
         elif color == 'RGB':
@@ -84,11 +104,18 @@ def main(images, dpi, title=None, author=None, creator=None, producer=None,
             print "unsupported color space:", color
             exit(1)
 
+        pdf_x, pdf_y = 72.0*width/dpi_x, 72.0*height/dpi_y # pdf units = 1/72 inch
+
         # either embed the whole jpeg or deflate the bitmap representation
         if imgformat is "JPEG":
             ofilter = [ "/DCTDecode" ]
             im.seek(0)
             imgdata = im.read()
+        elif imgformat is "JP2":
+            ofilter = [ "/JPXDecode" ]
+            im.seek(0)
+            imgdata = im.read()
+            version = 5 # jpeg2000 needs pdf 1.5
         else:
             ofilter = [ "/FlateDecode" ]
             imgdata = zlib.compress(imgdata.tostring())
@@ -147,7 +174,7 @@ def main(images, dpi, title=None, author=None, creator=None, producer=None,
 
     xreftable = list()
 
-    result  = "%PDF-1.3\n"
+    result  = "%%PDF-1.%d\n"%version
 
     xreftable.append("0000000000 65535 f \n")
     for o in objects: