Metadata-Version: 1.1
Name: img2pdf
Version: 0.2.4
Summary: Convert images to PDF via direct JPEG inclusion.
Home-page: https://gitlab.mister-muffin.de/josch/img2pdf
Author: Johannes 'josch' Schauer
Author-email: josch@mister-muffin.de
License: LGPL
Download-URL: https://gitlab.mister-muffin.de/josch/img2pdf/repository/archive.tar.gz?ref=0.2.4
Description-Content-Type: UNKNOWN
Description: img2pdf
        =======
        
        Losslessly convert raster images to PDF. The file size will not unnecessarily
        increase. It can for example be used to create a PDF document from a number of
        scans that are only available in JPEG format. Existing solutions would either
        re-encode the input JPEG files (leading to quality loss) or store them in the
        zip/flate format which results into the PDF becoming unnecessarily large in
        terms of its file size.
        
        Background
        ----------
        
        Quality loss can be avoided when converting JPEG and JPEG2000 images to PDF by
        embedding them into the PDF without re-encoding them. This is what img2pdf
        does. It thus treats the PDF format merely as a container format for storing
        one or more JPEGs without re-encoding the JPEG images themselves.
        
        If you know an existing tool which allows one to embed JPEG and JPEG2000 images
        into a PDF container without recompression, please contact me so that I can put
        this code into the garbage bin.
        
        Functionality
        -------------
        
        This program will take a list of raster images and produce a PDF file with the
        images embedded in it.  JPEG and JPEG2000 images will be included without
        recompression and the resulting PDF will only be slightly larger than the input
        images due to the overhead of the PDF container.  Raster images in other
        formats (like png, gif or tif) will be included using the lossless zip/flate
        encoding which usually leads to a significant increase in the PDF size if the
        input was for example a png image. This is unfortunately unavoidable because
        there is no other way to store arbitrary RGB bitmaps in PDF in a lossless way
        other than zip/flate encoding. And zip/flate compresses bitmaps worse than png
        is able to compress them.
        
        As a result, this tool is able to losslessly wrap raster images into a PDF
        container with a quality to filesize ratio that is typically better (in case of
        JPEG and JPEG2000 images) or equal (in case of other formats) than that of
        existing tools.
        
        For example, imagemagick will re-encode the input JPEG image (thus changing
        its content):
        
        	$ convert img.jpg img.pdf
        	$ pdfimages img.pdf img.extr # not using -j to be extra sure there is no recompression
        	$ compare -metric AE img.jpg img.extr-000.ppm null:
        	1.6301e+06
        
        If one wants to losslessly convert from any format to PDF with
        imagemagick, one has to use zip compression:
        
        	$ convert input.jpg -compress Zip output.pdf
        	$ pdfimages img.pdf img.extr # not using -j to be extra sure there is no recompression
        	$ compare -metric AE img.jpg img.extr-000.ppm null:
        	0
        
        However, this approach will result in PDF files that are a few times larger
        than the input JPEG or JPEG2000 file.
        
        img2pdf is able to losslessly embed JPEG and JPEG2000 files into a PDF
        container without additional overhead (aside from the PDF structure itself),
        save other graphics formats using lossless zip compression, and produce
        multi-page PDF files when more than one input image is given.
        
        Also, since JPEG and JPEG2000 images are not reencoded, conversion with img2pdf
        is several times faster than with other tools.
        
        Usage
        -----
        
        The images must be provided as files because img2pdf needs to seek in the file
        descriptor.
        
        If no output file is specified with the `-o`/`--output` option, output will be
        done to stdout. A typical invocation is:
        
        	img2pdf img1.png img2.jpg -o out.pdf
        
        The detailed documentation can be accessed by running:
        
        	img2pdf --help
        
        
        Bugs
        ----
        
        If you find a JPEG or JPEG2000 file that, when embedded cannot be read
        by the Adobe Acrobat Reader, please contact me.
        
        For lossless conversion of formats other than JPEG or JPEG2000, zip/flate
        encoding is used.  This choice is based on tests I did with a number of images.
        I converted them into PDF using the lossless variants of the compression
        formats offered by imagemagick.  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 method, contact me.
        
        I have not yet figured out how to determine the colorspace of JPEG2000 files.
        Therefore JPEG2000 files use DeviceRGB by default. For JPEG2000 files with
        other colorspaces, you must explicitly specify it using the `--colorspace`
        option.
        
        It might be possible to store transparency using masks but it is not clear
        what the utility of such a functionality would be.
        
        Most vector graphic formats can be losslessly turned into PDF (minus some of
        the features unsupported by PDF) but img2pdf will currently turn vector
        graphics into their lossy raster representations. For converting raster
        graphics to PDF, use another tool like inkscape and then join the resulting
        pages with a tool like pdftk.
        
        A configuration file could be used for default options.
        
        Installation
        ------------
        
        On a Debian- and Ubuntu-based systems, dependencies may be installed
        with the following command:
        
        	apt-get install python3 python3-pil python3-setuptools
        
        You can then install the package using:
        
        	$ pip3 install img2pdf
        
        If you prefer to install from source code use:
        
        	$ cd img2pdf/
        	$ pip3 install .
        
        To test the console script without installing the package on your system,
        use virtualenv:
        
        	$ cd img2pdf/
        	$ virtualenv ve
        	$ ve/bin/pip3 install .
        
        You can then test the converter using:
        
        	$ ve/bin/img2pdf -o test.pdf src/tests/test.jpg
        
        The package can also be used as a library:
        
        	import img2pdf
        
        	# opening from filename
        	with open("name.pdf","wb") as f:
        		f.write(img2pdf.convert('test.jpg'))
        
        	# opening from file handle
        	with open("name.pdf","wb") as f1, open("test.jpg") as f2:
        		f1.write(img2pdf.convert(f2))
        
        	# using in-memory image data
        	with open("name.pdf","wb") as f:
        		f.write(img2pdf.convert("\x89PNG...")
        
        	# multiple inputs (variant 1)
        	with open("name.pdf","wb") as f:
        		f.write(img2pdf.convert("test1.jpg", "test2.png"))
        
        	# multiple inputs (variant 2)
        	with open("name.pdf","wb") as f:
        		f.write(img2pdf.convert(["test1.jpg", "test2.png"]))
        
        	# writing to file descriptor
        	with open("name.pdf","wb") as f1, open("test.jpg") as f2:
        		img2pdf.convert(f2, outputstream=f1)
        
        	# specify paper size (A4)
        	a4inpt = (img2pdf.mm_to_pt(210),img2pdf.mm_to_pt(297))
        	layout_fun = img2pdf.get_layout_fun(a4inpt)
        	with open("name.pdf","wb") as f:
        		f.write(img2pdf.convert('test.jpg', layout_fun=layout_fun))
        
Keywords: jpeg pdf converter
Platform: UNKNOWN
Classifier: Development Status :: 5 - Production/Stable
Classifier: Intended Audience :: Developers
Classifier: Intended Audience :: Other Audience
Classifier: Environment :: Console
Classifier: Programming Language :: Python
Classifier: Programming Language :: Python :: 2
Classifier: Programming Language :: Python :: 2.7
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3.5
Classifier: Programming Language :: Python :: Implementation :: CPython
Classifier: Programming Language :: Python :: Implementation :: PyPy
Classifier: License :: OSI Approved :: GNU Lesser General Public License v3 (LGPLv3)
Classifier: Natural Language :: English
Classifier: Operating System :: OS Independent
