Awesome OCR

Overview

Awesome OCR curates the best optical character recognition projects, tools, and resources for extracting text from images, PDFs, and scanned documents.

OCR Engines

Tesseract OCR

• Tesseract: Google's powerful open-source OCR engine supporting 100+ languages
• Originally developed by HP, now maintained by Google
• Supports multiple image formats
• Trainable for custom fonts and languages
• Command-line and API interfaces

Deep Learning-Based OCR

• EasyOCR: Deep learning-based OCR supporting 80+ languages
• PaddleOCR: Practical ultra-lightweight OCR system by Baidu
• MMOCR: Comprehensive text detection and recognition toolbox
• TrOCR: Transformer-based OCR from Microsoft
• Doctr: Document Text Recognition from Mindee

Commercial OCR Services

• Google Cloud Vision API: Cloud-based OCR with high accuracy
• AWS Textract: Extract text and data from documents
• Azure Computer Vision: Microsoft's OCR service
• ABBYY FineReader: Enterprise OCR solution

Language Wrappers and Libraries

Python

• pytesseract: Python wrapper for Tesseract
• pyocr: Python wrapper for Tesseract and Cuneiform
• EasyOCR: Ready-to-use OCR with 80+ languages
• OCRmyPDF: Add OCR text layer to scanned PDFs
• DocTR: End-to-end OCR for documents

JavaScript/Node.js

• tesseract.js: Pure JavaScript OCR
• node-tesseract-ocr: Node.js wrapper for Tesseract
• OCR.space API: Simple REST API for OCR

Go

• gosseract: Go wrapper for Tesseract OCR
• Native Go implementations

Ruby

• rtesseract: Ruby wrapper for Tesseract
• Ruby Tesseract bindings

Java

• Tess4J: Java JNA wrapper for Tesseract
• OCR4J: Java OCR library

.NET/C#

• Tesseract.NET: .NET wrapper for Tesseract
• IronOCR: Commercial .NET OCR library
• Syncfusion OCR: .NET OCR processor

PHP

• tesseract-ocr-for-php: PHP wrapper
• Laravel OCR packages

Other Languages

• Crystal: tesseract-ocr wrapper
• Elixir: tesseract_ocr library
• R: tesseract package

Text Detection

Scene Text Detection

• EAST (Efficient and Accurate Scene Text): Fast text detection
• CRAFT (Character Region Awareness): Character-level text detection
• DB (Differentiable Binarization): Real-time text detection
• TextSnake: Flexible text detector

Document Layout Analysis

• LayoutParser: Toolkit for document layout analysis
• Detectron2: Facebook's detection platform
• DocUNet: Document unwarping

Preprocessing and Enhancement

Image Processing

• OpenCV: Computer vision library for preprocessing
• Pillow: Python Imaging Library
• Image binarization techniques
• Deskewing and denoising
• Contrast enhancement

Document Preprocessing

• Perspective correction
• Shadow removal
• Background elimination
• Resolution enhancement

Specialized OCR Applications

Handwriting Recognition

• HTR (Handwritten Text Recognition) systems
• Transkribus: Historical document transcription
• Monk: Handwriting OCR
• Cursive text recognition

Mathematical Formula Recognition

• LaTeX-OCR: Convert images to LaTeX
• Mathpix: Mathematical OCR service
• InftyReader: Math document recognition

Receipt and Invoice OCR

• Receipt scanning applications
• Invoice data extraction
• Structured data parsing
• Key-value pair extraction

License Plate Recognition

• OpenALPR: Automatic license plate recognition
• EasyALPR: License plate detection and recognition
• Country-specific ALPR systems

Document Understanding

• LayoutLM: Document understanding models
• DocFormer: End-to-end transformer for document understanding
• Form understanding and extraction
• Table detection and recognition

Training and Datasets

Datasets

• ICDAR: Competition datasets for text detection
• COCO-Text: Large-scale text detection dataset
• SynthText: Synthetic text dataset
• IIIT 5K-Word: Scene text dataset
• Street View Text: Google's street view dataset

Training Tools

• Tesseract training tools
• Data augmentation for OCR
• Synthetic data generation
• Fine-tuning pretrained models

Evaluation and Benchmarking

• Character Error Rate (CER)
• Word Error Rate (WER)
• Edit distance metrics
• Benchmark datasets
• Performance comparisons

PDF and Document Processing

PDF OCR Tools

• OCRmyPDF: Add searchable text to PDFs
• PDFMiner: Extract text from PDFs
• Tabula: Extract tables from PDFs
• pdfplumber: Detailed PDF analysis

Document Conversion

• PDF to text conversion
• Image to searchable PDF
• Batch processing tools
• Cloud document APIs

Mobile OCR

• ML Kit: Google's mobile OCR
• iOS Vision Framework: Apple's text recognition
• Mobile Document Scanner: Apps with OCR
• Real-time camera OCR

Integration and Deployment

Docker Containers

• Dockerized Tesseract
• OCR microservices
• Scalable OCR solutions

Cloud Deployment

• AWS Lambda OCR functions
• Google Cloud Run deployments
• Azure Functions for OCR

API Services

• REST API wrappers
• GraphQL OCR services
• Webhook integrations

Best Practices

• Image quality optimization
• Language and script detection
• Post-processing and correction
• Confidence scoring
• Error handling strategies

Use Cases

• Digitizing historical documents
• Automated data entry
• Accessibility (text-to-speech)
• Business card scanning
• Bank check processing
• Passport and ID verification
• Medical record digitization