OCRmyPDF

http://ocrmypdf.readthedocs.io/

    

OCRmyPDF adds an OCR text layer to scanned PDF files, allowing them to be searched or copy-pasted.

ocrmypdf                      # it's a scriptable command line program
   -l eng+fra                 # it supports multiple languages
   --rotate-pages             # it can fix pages that are misrotated
   --deskew                   # it can deskew crooked PDFs!
   --title "My PDF"           # it can change output metadata
   --jobs 4                   # it uses multiple cores by default
   --output-type pdfa         # it produces PDF/A by default
   input_scanned.pdf          # takes PDF input (or images)
   output_searchable.pdf      # produces validated PDF output

See the release notes for details on the latest changes.

Main features

• Generates a searchable PDF/A file from a regular PDF
• Places OCR text accurately below the image to ease copy / paste
• Keeps the exact resolution of the original embedded images
• When possible, inserts OCR information as a "lossless" operation without disrupting any other content
• Optimizes PDF images, often producing files smaller than the input file
• If requested, deskews and/or cleans the image before performing OCR
• Validates input and output files
• Distributes work across all available CPU cores
• Uses Tesseract OCR engine to recognize more than 100 languages
• Scales properly to handle files with thousands of pages
• Battle-tested on millions of PDFs

For details: please consult the documentation.

Motivation

I searched the web for a free command line tool to OCR PDF files: I found many, but none of them were really satisfying:

• Either they produced PDF files with misplaced text under the image (making copy/paste impossible)
• Or they did not handle accents and multilingual characters
• Or they changed the resolution of the embedded images
• Or they generated ridiculously large PDF files
• Or they crashed when trying to OCR
• Or they did not produce valid PDF files
• On top of that none of them produced PDF/A files (format dedicated for long time storage)

...so I decided to develop my own tool.

Installation

Linux, Windows, macOS and FreeBSD are supported. Docker images are also available, for both x64 and ARM.

Operating system	Install command
Debian, Ubuntu	apt install ocrmypdf
Windows Subsystem for Linux	apt install ocrmypdf
Fedora	dnf install ocrmypdf
macOS	brew install ocrmypdf
LinuxBrew	brew install ocrmypdf
FreeBSD	pkg install py37-ocrmypdf
Conda	conda install ocrmypdf

For everyone else, see our documentation for installation steps.

Languages

OCRmyPDF uses Tesseract for OCR, and relies on its language packs. For Linux users, you can often find packages that provide language packs:

# Display a list of all Tesseract language packs
apt-cache search tesseract-ocr

# Debian/Ubuntu users
apt-get install tesseract-ocr-chi-sim  # Example: Install Chinese Simplified language pack

# Arch Linux users
pacman -S tesseract-data-eng tesseract-data-deu # Example: Install the English and German language packs

# brew macOS users
brew install tesseract-lang

You can then pass the -l LANG argument to OCRmyPDF to give a hint as to what languages it should search for. Multiple languages can be requested.

OCRmyPDF supports Tesseract 4.0 and the beta versions of Tesseract 5.0. It will automatically use whichever version it finds first on the PATH environment variable. On Windows, if PATH does not provide a Tesseract binary, we use the highest version number that is installed according to the Windows Registry.

Documentation and support

Once OCRmyPDF is installed, the built-in help which explains the command syntax and options can be accessed via:

ocrmypdf --help

Our documentation is served on Read the Docs.

Please report issues on our GitHub issues page, and follow the issue template for quick response.

Requirements

In addition to the required Python version (3.7+), OCRmyPDF requires external program installations of Ghostscript and Tesseract OCR. OCRmyPDF is pure Python, and runs on pretty much everything: Linux, macOS, Windows and FreeBSD.

Press & Media

• Going paperless with OCRmyPDF
• Converting a scanned document into a compressed searchable PDF with redactions
• c't 1-2014, page 59: Detailed presentation of OCRmyPDF v1.0 in the leading German IT magazine c't
• heise Open Source, 09/2014: Texterkennung mit OCRmyPDF
• heise Durchsuchbare PDF-Dokumente mit OCRmyPDF erstellen
• Excellent Utilities: OCRmyPDF
• LinuxUser Texterkennung mit OCRmyPDF und Scanbd automatisieren

Business enquiries

OCRmyPDF would not be the software that it is today without companies and users choosing to provide support for feature development and consulting enquiries. We are happy to discuss all enquiries, whether for extending the existing feature set, or integrating OCRmyPDF into a larger system.

from https://github.com/ocrmypdf/OCRmyPDF