TEXTify (OCR) #

TEXTify is a Dart package that provides utilities for working with text representations in a specific character set. It is designed to handle text processing tasks for the English language and a limited set of characters.

It is 100% cross-platform, utilizing native Dart and Flutter code, and works offline without any package dependencies.

Why TEXTify? #

TEXTify addresses common limitations of existing OCR (Optical Character Recognition) solutions:

1. Small & Fast: Most OCR libraries are heavy and often rely on external system dependencies or remote cloud services, complicating deployment and increasing costs.

2. Supports All Platforms: Many OCR solutions only supports some platforms, TEXTify works on Android, iOS, macOS, Windows, Linux, and Web.

3. Offline: Works 100% offline without requiring internet connectivity or cloud services for text extraction.

4. Privacy: No dependency on external services means your data stays on device, ensuring complete privacy and security.

5. Simplified Setup: Popular solutions like Tesseract require complex build configurations, including C/C++ compilation, which can be difficult to manage across platforms.

TEXTify overcomes these issues with a lightweight, pure Dart implementation that works seamlessly across all Flutter platforms, including web, without external dependencies.

Installation #

Add this to your package's pubspec.yaml file:

dependencies:
  textify:

Then run:

flutter pub get

How to use #

Here is an example of how to use TEXTify:

import 'package:textify/textify.dart';

// load your image
ui.Image inputImage = await loadImage('scan.png');

// instentiate TEXTify once
Textify textify = await Textify().init();

// Optionally apply English dictionary word correction
textify.applyDictionary = true;

// extract text from the image
String extractedText = await textify.getTextFromImage(image: inputImage);

print(extractedText);

Configuration #

TEXTify provides extensive configuration options to customize OCR behavior for different use cases:

Basic Configuration #

import 'package:textify/textify.dart';

// Create Textify instance with custom configuration
final textify = Textify(
  config: TextifyConfig(
    dilationSize: 25,           // Controls pixel merging (higher = more merging)
    excludeLongLines: true,     // Ignore long horizontal/vertical lines
    attemptCharacterSplitting: true,  // Try to separate touching characters
    applyDictionaryCorrection: false, // Use dictionary for better accuracy
    matchingThreshold: 0.4,     // Minimum match confidence (0.0-1.0)
    maxProcessingTimeMs: 30000, // Maximum processing time
  ),
);

// Initialize and use
await textify.init();
final text = await textify.getTextFromImage(image: inputImage);

Preset Configurations #

TEXTify includes optimized presets for common scenarios:

// Fast processing (lower accuracy, quicker results)
final fastTextify = Textify(config: TextifyConfig.fast);

// High accuracy (slower, better results)
final accurateTextify = Textify(config: TextifyConfig.accurate);

// Robust for challenging images (handles noise, low quality)
final robustTextify = Textify(config: TextifyConfig.robust);

// Default balanced configuration
final defaultTextify = Textify(); // Uses TextifyConfig()

Configuration Options #

Performance Tuning #

• Speed Priority: Use TextifyConfig.fast for quick processing when accuracy is less critical
• Accuracy Priority: Use TextifyConfig.accurate for maximum accuracy on clean documents
• Robust Processing: Use TextifyConfig.robust for challenging images with noise or low quality

Features #

• Extracts text from clean digital images
• Supports standard fonts like "Arial", "Courier", "Helvetica", "Times New Roman"
• Fully cross-platform
• Pure Dart and Flutter implementation
• Works 100% Offline
• No external package dependencies

Limitations #

• Supported for clean digital images (no handwriting)
• Limited character set support
• No support for special formatting (italic, variable size etc.)
• Text must be free of images and framing (aka no borders)

Supported Characters #

This package currently supports the following characters, with plans to expand support in the future:

• Uppercase letters: ABCDEFGHIJKLMNOPQRSTUVWXYZ
• Lowercase letters: abcdefghijklmnopqrstuvwxyz
• Digits: 0123456789
• Punctuation marks: /\(){}[]<>,;:.!@#$&*-+=?

While the current character set is limited, future updates will aim to include broader language support, starting with common accented characters and symbols.

Input image - Clean Digital Image Guidelines #

What Makes a Clean Digital Image? #

Font Selection

• Use Helvetica (sans-serif) or Courier (monospace)
• Keep font size consistent and large (12pt+ size)
• Maintain uniform character width, especially with Courier

Text Spacing Requirements

• Letters must not touch or overlap
• Maintain consistent gaps between words
• Use standard line spacing (1.5 recommended)
• Keep clear margins around text

Best Practices

• Clean, computer-generated documents
• Scanned image of high resolution: Minimum 300+ DPI
• Format: TIFF or PNG preferred
• Use OCR-friendly fonts
• High contrast between text and background
• Clean, white background
• Black text for optimal readability
• Remove any background noise or artifacts
• Keep text alignment consistent
• Avoid decorative or script fonts
• Minimal background noise (e.g., no watermarks)
• High contrast between text and background
• No handwritten or italic text
• Isolated characters (not touching other artifacts)

Quick Validation Checklist

• ✅ Text is clearly separated
• ✅ Fonts are similar to Helvetica, Courier, Times New Roman
• ✅ Size is consistent throughout
• ✅ No touching characters
• ✅ Clean background
• ✅ High contrast
• ✅ Proper resolution

Language Support #

TEXTify is currently designed to work with the English language only. While it may handle some text in other languages that use the supported character set, its functionality is optimized and intended for English text processing.

Components #

How to generate the above graph. Run these commands on macOS .

dart pub global activate lakos
brew install graphviz
./tools/graph.sh

Please contribute and report issues on the GitHub repository. https://github.com/vteam-com/textify