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Blocks ReferenceComputer vision

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:

  1. Receives Image: Gets image data from input message
  2. Preprocesses Image: Applies preprocessing to improve text recognition
  3. Runs OCR: Uses selected algorithm to extract text from image
  4. Returns Results: Sends extracted text with confidence scores

OCR Processing Flow

Image Input → Preprocessing → OCR Algorithm → Text Extraction → Results

Use Cases

Document Digitization

Convert scanned documents to digital text:

scanned document → OCR → digital text → document management

Receipt Processing

Extract data from receipts and invoices:

receipt image → OCR → structured data → accounting system

Handwriting Recognition

Convert handwritten text to digital format:

handwritten document → OCR → digital text → processing

License Plate Recognition

Extract text from license plates:

license plate image → OCR → plate number → database lookup

Common 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 documents

Receipt 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 invoices

Handwriting Recognition

// Configuration
Algorithm: Custom OCR
Model: Handwriting Recognition
Language: English
Preprocessing: Handwriting Optimized
Output Format: Plain Text

// Use case: Convert handwritten notes to digital text

Tips

  • 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 selection

Slow Processing

Issue: OCR processing takes too long
Solution: Optimize image preprocessing and use appropriate algorithms

Memory Issues

Issue: Out of memory errors with large images
Solution: Implement image resizing and optimize memory usage

Language Detection Problems

Issue: Incorrect language detection
Solution: Specify languages explicitly or improve language detection models

Performance 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