OCR
Extract text from images using Optical Character Recognition with various algorithms.
OCR Block
This block is designed for performing OCR operations on images. Choose an algorithm from the Choose Algorithm dropdown to begin.
Overview
The OCR (Optical Character Recognition) block extracts text from images using advanced machine learning algorithms. It supports multiple OCR engines and can handle various image types, languages, and text formats.
Configuration Options
Algorithm Selection
Choose the OCR algorithm to use:
- Tesseract OCR: Open-source OCR engine with high accuracy
- Cloud OCR: Cloud-based OCR services (Google, Azure, AWS)
- Custom OCR: Use custom trained OCR models
- Hybrid OCR: Combine multiple OCR engines for better accuracy
Language Support
- Language Selection: Choose the language(s) of the text to recognize
- Multi-language: Support for multiple languages in a single image
- Language Detection: Automatic language detection
- Custom Languages: Support for custom language models
Processing Options
- Image Preprocessing: Apply preprocessing to improve OCR accuracy
- Text Layout: Handle different text layouts (single column, multi-column, etc.)
- Confidence Threshold: Set minimum confidence for text recognition
- Output Format: Choose output format (plain text, structured data, etc.)
How It Works
The OCR block:
- Receives Image: Gets image data from input message
- Preprocesses Image: Applies preprocessing to improve text recognition
- Runs OCR: Uses selected algorithm to extract text from image
- Returns Results: Sends extracted text with confidence scores
OCR Processing Flow
Image Input → Preprocessing → OCR Algorithm → Text Extraction → ResultsUse Cases
Document Digitization
Convert scanned documents to digital text:
scanned document → OCR → digital text → document managementReceipt Processing
Extract data from receipts and invoices:
receipt image → OCR → structured data → accounting systemHandwriting Recognition
Convert handwritten text to digital format:
handwritten document → OCR → digital text → processingLicense Plate Recognition
Extract text from license plates:
license plate image → OCR → plate number → database lookupCommon Patterns
Basic Text Extraction
// Configuration
Algorithm: Tesseract OCR
Language: English
Preprocessing: Basic
Output Format: Plain Text
Confidence Threshold: 0.8
// Input: Image with text
// Output: {
// text: "Extracted text content",
// confidence: 0.95,
// language: "en"
// }Structured Data Extraction
// Configuration
Algorithm: Cloud OCR
Language: English
Output Format: Structured
Layout Analysis: true
Confidence Threshold: 0.7
// Input: Form image
// Output: {
// fields: {
// "name": "John Doe",
// "address": "123 Main St",
// "phone": "555-1234"
// },
// confidence: 0.89
// }Multi-language OCR
// Configuration
Algorithm: Hybrid OCR
Languages: ["en", "es", "fr"]
Language Detection: true
Output Format: JSON
// Input: Multi-language document
// Output: {
// text: "Mixed language text",
// languages: ["en", "es"],
// confidence: 0.92
// }Advanced Features
Custom Model Training
Train custom OCR models for specific use cases:
- Domain Adaptation: Adapt models for specific industries or document types
- Training Data: Upload training data for custom text recognition
- Model Validation: Validate model performance and accuracy
- Model Deployment: Deploy trained models for production use
Advanced Preprocessing
Enhance OCR accuracy with advanced preprocessing:
- Image Enhancement: Improve image quality and contrast
- Noise Reduction: Remove noise and artifacts
- Skew Correction: Correct image rotation and skew
- Layout Analysis: Analyze and correct text layout
Real-time Processing
Handle real-time OCR processing:
- Streaming Support: Process image streams in real-time
- Low Latency: Optimize for minimal processing delay
- Scalability: Handle high-volume image processing
- Resource Management: Efficient resource utilization
Configuration Examples
Document Processing Pipeline
// Configuration
Algorithm: Tesseract OCR
Language: English
Preprocessing: Document Standard
Output Format: Structured
Confidence Threshold: 0.8
// Use case: Process business documentsReceipt Data Extraction
// Configuration
Algorithm: Cloud OCR
Language: English
Output Format: JSON
Field Extraction: true
Confidence Threshold: 0.7
// Use case: Extract data from receipts and invoicesHandwriting Recognition
// Configuration
Algorithm: Custom OCR
Model: Handwriting Recognition
Language: English
Preprocessing: Handwriting Optimized
Output Format: Plain Text
// Use case: Convert handwritten notes to digital textTips
- Choose Appropriate Algorithms: Select OCR algorithms that match your specific use case
- Optimize Image Quality: Ensure images are of good quality for optimal OCR results
- Use Preprocessing: Apply appropriate preprocessing to improve accuracy
- Set Confidence Thresholds: Adjust thresholds based on your accuracy requirements
- Handle Multiple Languages: Use appropriate language models for different languages
- Validate Results: Always validate OCR results for accuracy
Common Issues
Low OCR Accuracy
Issue: Poor text recognition results
Solution: Check image quality, preprocessing, and algorithm selectionSlow Processing
Issue: OCR processing takes too long
Solution: Optimize image preprocessing and use appropriate algorithmsMemory Issues
Issue: Out of memory errors with large images
Solution: Implement image resizing and optimize memory usageLanguage Detection Problems
Issue: Incorrect language detection
Solution: Specify languages explicitly or improve language detection modelsPerformance Considerations
Algorithm Selection
- Accuracy vs Speed: Balance between OCR accuracy and processing speed
- Resource Requirements: Consider CPU/memory requirements for different algorithms
- Model Size: Larger models may provide better accuracy but require more resources
Optimization Strategies
- Image Preprocessing: Optimize images for OCR processing
- Batch Processing: Process multiple images together for better efficiency
- Caching: Cache OCR results for repeated images
- Parallel Processing: Use multiple processing threads for better performance
Related Blocks
- Image Processor - For image preprocessing before OCR
- OCR Utils - For post-processing OCR results
- Text Processor - For processing extracted text
- debug - For monitoring OCR results