OCRmyPDF/docs/installation.rst

Installation
============

OCRmyPDF requires Python 3.5 (or newer) and Tesseract 3.04 (or newer).

Installing on Debian and Ubuntu 16.10 or newer
----------------------------------------------

Users of Debian 9 ("stretch") or later or Ubuntu 16.10 or later may simply

.. code-block:: bash

    apt-get install ocrmypdf

Installing on macOS
-------------------

A `Homebrew <https://brew.sh>`_ tap is available for macOS:

.. code-block:: bash

    brew tap jbarlow83/ocrmypdf
    brew install ocrmypdf


.. warning::

    Users who previously installed OCRmyPDF on macOS using ``pip install ocrmypdf`` should remove the pip version (``pip3 uninstall ocrmypdf``) before switching to the Homebrew version.

.. _Docker-install:

Installing the Docker image
---------------------------

For many users, installing the Docker image will be easier than installing all of OCRmyPDF's dependencies. For Windows, it is the only option.

If you have `Docker <https://docs.docker.com/>`_ installed on your system, you can install
a Docker image of the latest release.

Follow the Docker installation instructions for your platform.  If you can run this command
successfully, your system is ready to download and execute the image:

.. code-block:: bash

    docker run hello-world
   
OCRmyPDF will use all available CPU cores.  By default, the VirtualBox machine instance on Windows and macOS has only a single CPU core enabled. Use the VirtualBox Manager to determine the name of your Docker engine host, and then follow these optional steps to enable multiple CPUs:

.. code-block:: bash

    # Optional step for Mac OS X users
    docker-machine stop "yourVM"
    VBoxManage modifyvm "yourVM" --cpus 2  # or whatever number of core is desired
    docker-machine start "yourVM"
    eval $(docker-machine env "yourVM")

Assuming you have a Docker engine running, you can download one of the three available images:

+-----------------------------+---------------------------------------------+---------------------------------------------------------------------------------+
| Image name                  | Download command                            | Notes                                                                           |
+-----------------------------+---------------------------------------------+---------------------------------------------------------------------------------+
| ocrmypdf                    | ``docker pull jbarlow83/ocrmypdf``          | Latest ocrmypdf with Tesseract 3.04. Includes English, French, German, Spanish. |
+-----------------------------+---------------------------------------------+---------------------------------------------------------------------------------+
| ocrmypdf-polyglot           | ``docker pull jbarlow83/ocrmypdf-polyglot`` | As above, with all available language packs.                                    |
+-----------------------------+---------------------------------------------+---------------------------------------------------------------------------------+
| ocrmypdf-tess4              | ``docker pull jbarlow83/ocrmypdf-tess4``    | Latest ocrmypdf with Tesseract 4.00.00alpha and English, French, German,        |
|                             |                                             | Spanish, Portuguese, Chinese Simplified, Arabic and Russian (the top 8).        |
+-----------------------------+---------------------------------------------+---------------------------------------------------------------------------------+

For example:

.. code-block:: bash

    docker pull jbarlow83/ocrmypdf-tess4

Then tag it to give a more convenient name, just ocrmypdf:

.. code-block:: bash

    docker tag jbarlow83/ocrmypdf-tess4 ocrmypdf

.. _docker-polyglot:

The alternative "polyglot" image provides `all available language packs <https://github.com/tesseract-ocr/tesseract/blob/master/doc/tesseract.1.asc#languages>`_.

You can then run ocrmypdf using the command:

.. code-block:: bash

    docker run --rm ocrmypdf --help
  
To execute the OCRmyPDF on a local file, you must `provide a writable volume to the Docker image <https://docs.docker.com/userguide/dockervolumes/>`_, and both the input and output file must be inside the writable volume.  This example command uses the current working directory as the writable volume:

.. code-block:: bash

    docker run --rm -v "$(pwd):/home/docker" <other docker arguments>   ocrmypdf <your arguments to ocrmypdf>

In this worked example, the current working directory contains an input file called ``test.pdf`` and the output will go to ``output.pdf``: 

.. code-block:: bash

    docker run --rm -v "$(pwd):/home/docker"   ocrmypdf --skip-text test.pdf output.pdf

.. note:: The working directory should be a writable local volume or Docker may not have permission to access it.

Note that ``ocrmypdf`` has its own separate ``-v VERBOSITYLEVEL`` argument to control debug verbosity. All Docker arguments should before the ``ocrmypdf`` image name and all arguments to ``ocrmypdf`` should be listed after.

In some environments the permissions associated with Docker can be complex to configure. The process that executes Docker may end up not having the permissions to write the specified file system. In that case one can stream the file into and out of the Docker process and avoid all permission hassles, using ``-`` as the input and output filename:

.. code-block:: bash

    docker run --rm -i   ocrmypdf <other arguments to ocrmypdf> - - <input.pdf >output.pdf

For convenience, a shell alias can hide the docker command:

.. code-block:: bash

    alias ocrmypdf='docker run --rm -v "$(pwd):/home/docker" ocrmypdf'
    ocrmypdf --version  # runs docker version

Or in the wonderful `fish shell <https://fishshell.com/>`_:

.. code-block:: fish

    alias ocrmypdf 'docker run --rm -v (pwd):/home/docker ocrmypdf'
    funcsave ocrmypdf

.. note::

    The ocrmypdf Docker containers are designed to be used for a single OCR job. The ``docker run --rm`` argument tells Docker to delete temporary storage associated with container when it is done executing.

Manual installation on macOS
----------------------------

These instructions probably work on all macOS supported by Homebrew.

If it's not already present, `install Homebrew <http://brew.sh/>`_.

Update Homebrew:

.. code-block:: bash

    brew update

Install or upgrade the required Homebrew packages, if any are missing:

.. code-block:: bash

    brew install libpng openjpeg jbig2dec libtiff     # image libraries
    brew install qpdf
    brew install ghostscript
    brew install python3
    brew install libxml2 libffi leptonica
    brew install unpaper   # optional
   
Python 3.5 and 3.6 are supported.

Install the required Tesseract OCR engine with the language packs you plan to use:
   
.. code-block:: bash

    brew install tesseract                       # Option 1: for English, French, German, Spanish

.. _macos-all-languages:

.. code-block:: bash

    brew install tesseract --with-all-languages  # Option 2: for all language packs

Update the homebrew pip and install Pillow:

.. code-block:: bash

    pip3 install --upgrade pip
    pip3 install --upgrade pillow

You can then install OCRmyPDF from PyPI, for the current user:

.. code-block:: bash

    pip3 install --user ocrmypdf

or system-wide:

.. code-block:: bash

    pip3 install ocrmypdf

The command line program should now be available:

.. code-block:: bash

    ocrmypdf --help


Installing on Ubuntu 16.04 LTS
------------------------------

No package is currently available for Ubuntu 16.04, but you can install the dependencies manually:

.. code-block:: bash

    sudo apt-get update
    sudo apt-get install \
        unpaper \
        ghostscript \
        tesseract-ocr \
        qpdf \
        python3-pip \
        python3-cffi

If you wish install OCRmyPDF for the current user:

.. code-block:: bash

    pip3 install --user ocrmypdf

Alternately, system-wide. Note that this may modify the system Python environment:

.. code-block:: bash

    sudo pip3 install ocrmypdf

If you wish to install OCRmyPDF to a virtual environment to isolate the system Python, you can
follow these steps.

.. code-block:: bash

    python3 -m venv venv-ocrmypdf
    source venv-ocrmypdf/bin/activate
    pip3 install ocrmypdf


Installing on Ubuntu 14.04 LTS
------------------------------

Installing on Ubuntu 14.04 LTS (trusty) is more difficult than some other options,
because it is older and does not provide ``pip``.

Update apt-get:

.. code-block:: bash

    sudo apt-get update

Install system dependencies:

.. code-block:: bash

    sudo apt-get install \
        software-properties-common python-software-properties \
        zlib1g-dev \
        libjpeg-dev \
        libffi-dev \
        qpdf

We will need backports of Ghostscript 9.16, libav-11 (for unpaper 6.1),
Tesseract 4.00 (alpha), and Python 3.6. This will replace Ghostscript and
Tesseract 3.x on your system. Python 3.6 will be installed alongside the system
Python 3.

If you prefer to not modify your system in this matter, consider using a Docker container.

.. code-block:: bash

    sudo add-apt-repository ppa:vshn/ghostscript -y
    sudo add-apt-repository ppa:heyarje/libav-11 -y
    sudo add-apt-repository ppa:alex-p/tesseract-ocr -y
    sudo add-apt-repository ppa:jonathonf/python-3.6 -y

    sudo apt-get update

    sudo apt-get install \
        python3.6 \
        ghostscript \
        tesseract-ocr \
        tesseract-ocr-eng \
        libavformat56 libavcodec56 libavutil54 \
        wget

Now we need to install ``pip`` and let it install ocrmypdf:

.. code-block:: bash

    wget -O - -o /dev/null https://bootstrap.pypa.io/get-pip.py | python3.6
    pip3.6 install ocrmypdf

These installation instructions omit the optional dependency ``unpaper``, which is only available at version 0.4.2 in Ubuntu 14.04. The author could not find a backport of ``unpaper``, and created a .deb package to do the job of installing unpaper 6.1 (for x86 64-bit only):

.. code-block:: bash

    wget -q 'https://www.dropbox.com/s/vaq0kbwi6e6au80/unpaper_6.1-1.deb?raw=1' -O unpaper_6.1-1.deb
    sudo dpkg -i unpaper_6.1-1.deb


Installing on ArchLinux
-----------------------

The author is aware of an `ArchLinux package for ocrmypdf <https://aur.archlinux.org/packages/ocrmypdf/>`_. It seems like the following command might work.

.. code-block:: bash

    pacman -S ocrmypdf


Installing on Windows
---------------------

Direct installation on Windows is not possible.  Install the _`Docker` container as described above.  Ensure that your command prompt can run the docker "hello world" container.

Running on Windows
~~~~~~~~~~~~~~~~~~

The command line syntax to run ocrmypdf from a command prompt will resemble:

.. code-block:: bat

    docker run -v /c/Users/sampleuser:/home/docker ocrmypdf --skip-text test.pdf output.pdf

where /c/Users/sampleuser is a Unix representation of the Windows path C:\\Users\\sampleuser, assuming a user named "sampleuser" is running ocrmypdf on a file in their home directory, and the files "test.pdf" and "output.pdf" are in the sampleuser folder. The Windows user must have read and write permissions.

`Bash on Ubuntu on Windows <https://github.com/Microsoft/BashOnWindows>`_ should also be a viable route for running the OCRmyPDF Docker container.

Installing HEAD revision from sources
-------------------------------------

If you have ``git`` and Python 3.5 or newer installed, you can install from source. When the ``pip`` installer runs,
it will alert you if dependencies are missing.

To install the HEAD revision from sources in the current Python 3 environment:

.. code-block:: bash

    pip3 install git+https://github.com/jbarlow83/OCRmyPDF.git

Or, to install in `development mode <https://pythonhosted.org/setuptools/setuptools.html#development-mode>`_,  allowing customization of OCRmyPDF, use the ``-e`` flag:

.. code-block:: bash

    pip3 install -e git+https://github.com/jbarlow83/OCRmyPDF.git

On certain Linux distributions such as Ubuntu, you may need to use 
run the install command as superuser:

.. code-block:: bash

    sudo pip3 install [-e] git+https://github.com/jbarlow83/OCRmyPDF.git

Note that this will alter your system's Python distribution. If you prefer 
to not install as superuser, you can install the package in a Python virtual environment:

.. code-block:: bash

    git clone -b master https://github.com/jbarlow83/OCRmyPDF.git
    python3 -m venv
    source venv/bin/activate
    cd OCRmyPDF
    pip3 install .

However, ``ocrmypdf`` will only be accessible on the system PATH after
you activate the virtual environment.

To run the program:

.. code-block:: bash

    ocrmypdf --help

If not yet installed, the script will notify you about dependencies that
need to be installed. The script requires specific versions of the
dependencies. Older version than the ones mentioned in the release notes
are likely not to be compatible to OCRmyPDF.