/awesome-ocr

Links to awesome OCR projects

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Awesome OCR

Awesome

This list contains links to great software tools and libraries and literature related to Optical Character Recognition (OCR).

Contributions are welcome, as is feedback.

Software

OCR engines

  • tesseract - The definitive Open Source OCR engine Apache 2.0
  • EasyOCR - OCR engine built on PyTorch by JaidedAI, Apache 2.0
  • ocropus - OCR engine based on LSTM, Apache 2.0
  • ocropus 0.4 - Older v0.4 state of Ocropus, with tesseract 2.04 and iulib, C++
  • kraken - Ocropus fork with sane defaults
  • gocr - OCR engine under the GNU Public License led by Joerg Schulenburg.
  • Ocrad - The GNU OCR. GPL
  • ocular - Machine-learning OCR for historic documents
  • SwiftOCR - fast and simple OCR library written in Swift
  • attention-ocr - OCR engine using visual attention mechanisms
  • RWTH-OCR - The RWTH Aachen University Optical Character Recognition System
  • simple-ocr-opencv and its fork - A simple pythonic OCR engine using opencv and numpy
  • Calamari - OCR Engine based on OCRopy and Kraken
  • doctr - A seamless & high-performing OCR library powered by Deep Learning

Older and possibly abandoned OCR engines

  • Clara OCR - Open source OCR in C GPL
  • Cuneiform - CuneiForm OCR was developed by Cognitive Technologies
  • Eye - an experimental Java OCR (image-to-text) application
  • kognition - An omnifont OCR software for KDE
  • OCRchie - Modular Optical Character Recognition Software
  • ocre - o.c.r. easy
  • xplab - A GTK 2 tool for pattern matching
  • hebOCR - Hebrew character recognition library (previously named hocr, see Wikipedia article) GPL

OCR file formats

hOCR

  • hocr-tools - Tools for doing various useful things with hOCR files, Apache 2.0
  • hocr-spec - hOCR 1.2 specification
  • ocr-transform - CLI tool to convert between hOCR and ALTO, MIT
  • hocr-parser - hOCR Specification Python Parser
  • hOCRTools - hOCR to ALTO conversion XSLT

ALTO XML

TEI

  • TEI-OCR - TEI customization for OCR generated layout and content information
  • TEI SIG on Libraries - Best Practices for TEI in Libraries
  • GDZ - METS/TEI-based GDZ document format

PAGE XML

  • PAGE-XML Schema - XML schema of the PAGE XML format along with documentation and examples
  • omni:us Pages Format (OPF) - XML schema very similar to PAGE XML that has some additional features.
  • py-pagexml - Python library for handling PAGE XML and OPF files.

OCR CLI

  • OCRmyPDF - OCRmyPDF adds an OCR text layer to scanned PDF files, allowing them to be searched
  • Pdf2PdfOCR - A tool to OCR a PDF (or supported images) and add a text "layer" (a "pdf sandwich") in the original file making it a searchable PDF. GUI included. Tesseract and cuneiform supported.
  • Ocrocis - Project manager interface for Ocropy, see also external project homepage
  • tesseract-recognize - Tesseract-based tool that outputs result in Page XML format (docker image).

OCR GUI

  • moz-hocr-editor - Firefox Addon for editing hOCR files Discontinued
  • qt-box-editor - QT4 editor of tesseract-ocr box files.
  • ocr-gt-tools - Client-Server application for editing OCR ground truth.
  • Paperwork - Using scanners and OCR to grep paper documents the easy way.
  • Paperless - Scan, index, and archive all of your paper documents.
  • gImageReader - gImageReader is a simple Gtk/Qt front-end to tesseract-ocr.
  • VietOCR - A Java/.NET GUI frontend for Tesseract OCR engine, including jTessBoxEditor a graphical Tesseract box data editor
  • PoCoTo - Fast interactive batch corrections of complete OCR error series in OCR'ed historical documents.
  • OCRFeeder - GTK graphical user interface that allows the users to correct characters or bounding boxes, ODT export and more.
  • PRImA PAGE Viewer - Java based viewer for PAGE XML files (layout + text content). Also supports ALTO XML, FineReader XML, and HOCR.
  • LAREX - A semi-automatic open-source tool for Layout Analysis and Region EXtraction on early printed books.
  • archiscribe - Web application for transcribing OCR ground truth from Archive.org. Deployed instance available at https://archiscribe.jbaiter.de/, results are available in @jbaiter/archiscribe-corpus.
  • nw-page-editor - Simple app for visual editing of Page XML files. Provides desktop and server docker-based versions.

OCR Preprocessing

OCR as a Service

OCR evaluation

OCR libraries by programming language

Crystal

Elixir

  • tesseract_ocr - Elixir library wrapping the tesseract executable.

Go

  • gosseract - Golang OCR library, wrapping Tesseract-ocr.

Java

  • Tess4J - Java Native Access bindings to Tesseract.
  • tess-two - Tools for compiling Tesseract on Android and Java API.

.Net

Object Pascal

PHP

Python

  • pytesseract - A Python wrapper for Google Tesseract.
  • pyocr - A Python wrapper for Tesseract and Cuneiform.
  • ocrodjvu - A library and standalone tool for doing OCR on DjVu documents, wrapping Cuneiform, gocr, ocrad, ocropus and tesseract
  • tesserocr - A Python wrapper for the tesseract-ocr API

Javascript

  • ocracy - pure javascript lstm rnn implementation based on ocropus
  • gocr.js - Javascript port (emscripten) of gocr
  • ocrad.js - Javascript port (emscripten) of ocrad
  • tesseract.js - Javascript port (emscripten) of Tesseract
  • node-tesseract-ocr - A simple wrapper for the Tesseract OCR package.
  • node-tesseract-native - C++ module for node providing OCR with tesseract and leptonica.

Ruby

  • rtesseract - Ruby library wrapping the tesseract and imagemagick executables.
  • ruby-tesseract - Native Tesseract bindings for Ruby MRI and JRuby
  • ocr_space - API wrapper for free ocr service ocr.space. Includes CLI

Rust

  • tesseract.rs - Rust bindings for tesseract OCR.
  • leptess - Productive and safe Rust bindings/wrappers for tesseract and leptonica.

R

Swift

  • Tesseract OCR iOS - Swift and Objective-C wrapper for Tesseract OCR.
  • SwiftOCR - Fast and simple OCR library written in Swift. Optimized for recognizing short, one line long alphanumeric codes.

OCR training tools

  • glyph-miner - A system for extracting glyphs from early typeset prints
  • ocrodeg - Document image degradation for OCR data augmentation

Datasets

Ground Truth

  • Rescribe - Transcriptions of Caroline Minuscule Manuscripts PDM 1.0

Literature

OCR-related publication and link lists

Blog Posts and Tutorials

OCR Showcases

  • abbyy-finereader-ocr-senate - Using OCR to parse scanned Senate Financial Disclosure forms.
  • cvOCR - An OCR system for recognizing resume or cv text, implemented in Python and C and based on tesseract
  • MathOCR - A printed scientific document recognition system, pre-alpha

Academic articles

2011 and before

2012

2013

2014

2015

2016

2017

2018