Vue 3 DocumentScanner Component

A comprehensive Vue 3 component for document scanning with OpenCV.js integration, featuring mobile-optimized camera access, image processing, corner detection, and PDF generation.

Features

• 📱 Mobile-Optimized: Works seamlessly on mobile devices with camera access
• 🔍 Document Detection: Automatic corner detection using OpenCV.js
• 🖼️ Image Processing: Perspective correction, rotation, and enhancement
• 📄 PDF Generation: Multi-page PDF creation from scanned documents
• 🎛️ Flexible Configuration: Customizable OpenCV.js URL and component props
• 🧪 Comprehensive Testing: Unit and browser tests with Vitest

Installation

npm install document-scanner-vue

Peer Dependencies

You also need to install the required peer dependencies:

npm install vue@^3.4.0 jspdf@^3.0.0 @vueuse/core@^13.0.0

CSS Import

Important: You must import the CSS file in your main application:

// In your main.js or main.ts
import 'document-scanner-vue/dist/style.css'

Development

Development Server

Start the development server with the sample page:

npm run dev

This will:

1. Install dependencies in the dev/ directory
2. Start a Vite development server
3. Open a comprehensive testing interface at http://localhost:3000

Testing

Unit Tests

Run unit tests with mocked dependencies:

npm run test:unit          # Run once
npm run test:unit:watch    # Watch mode

Browser Tests

Run browser tests with real OpenCV.js:

npm run test:browser       # Run once
npm run test:browser:watch # Watch mode

All Tests

npm run test:all           # Run both unit and browser tests
npm run test:coverage      # Run with coverage report
npm run test:ui            # Open Vitest UI

Usage

Basic Usage

<template>
  <DocumentScanner 
    @pdf-created="handlePdfCreated"
  />
</template>

<script setup>
import DocumentScanner from './src/DocumentScanner.vue'

const handlePdfCreated = (pdfBlob) => {
  // Handle the generated PDF
  console.log('PDF created:', pdfBlob)
}
</script>

Advanced Configuration

<template>
  <DocumentScanner 
    :button-size="'lg'"
    :close-after-pdf-created="false"
    :label="'Scan Document'"
    :open-cv-url="'/path/to/opencv.js'"
    @pdf-created="handlePdfCreated"
  />
</template>

Props

Events

OpenCV.js Configuration

The component automatically loads the latest stable OpenCV.js version (4.10.0) by default. You can customize this:

<!-- Use default latest stable -->
<DocumentScanner />

<!-- Use custom URL -->
<DocumentScanner open-cv-url="https://custom-cdn.com/opencv.js" />

<!-- Use local file -->
<DocumentScanner open-cv-url="./assets/opencv.js" />

<!-- Use relative path -->
<DocumentScanner open-cv-url="/public/opencv.js" />

Testing Architecture

Unit Tests (tests/unit/)

• Environment: jsdom
• Mocks: OpenCV.js, DOM APIs, File APIs
• Focus: Component logic, composables, utilities
• Fast execution: No real OpenCV.js loading

Browser Tests (tests/browser/)

• Environment: Real browser (Playwright)
• Real OpenCV.js: Loads actual OpenCV.js library
• Focus: Integration testing, real image processing
• Slower execution: Full OpenCV.js initialization

Test Files Structure

tests/
├── setup.ts                 # Unit test setup with mocks
├── browser-setup.ts         # Browser test setup with real OpenCV.js
├── unit/
│   ├── useOpenCV.spec.ts    # OpenCV composable tests (using vue-opencv-composable package)
│   ├── DocumentScanner.spec.ts # Component tests
│   └── usePageManager.spec.ts  # Page management tests
└── browser/
    └── opencv-integration.browser.spec.ts # Real OpenCV.js tests

Development Environment

The dev/ directory contains a complete development environment:

• Real Component Integration: Uses the actual DocumentScanner component
• Live Configuration: Adjust props in real-time
• Debug Tools: Component state inspection, OpenCV status monitoring
• Mobile Testing: Network access for device testing
• Test Functions: File input, camera access, OpenCV functionality

Mobile Testing

Access the development server from mobile devices:

1. Start the dev server: npm run dev
2. Note the network URL (e.g., http://192.168.1.100:3000)
3. Open the URL on your mobile device
4. Test camera functionality and touch interactions

Project Structure

src/
├── DocumentScanner.vue      # Main component
├── composables/
│   ├── useOpenCV.ts        # OpenCV.js integration (now using vue-opencv-composable package)
│   ├── usePageManager.ts   # Page state management
│   └── useImageProcessing.ts # Image processing utilities
├── utils/
│   ├── opencvUtils.ts      # OpenCV.js utilities
│   └── imageProcessing.ts  # Image processing functions
└── types/
    └── index.ts            # TypeScript type definitions

dev/                        # Development environment
├── App.vue                 # Development interface
├── main.ts                 # Vue app initialization
├── index.html              # HTML entry point
├── package.json            # Dev dependencies
├── vite.config.ts          # Vite configuration
└── README.md               # Development guide

tests/                      # Test suite
├── setup.ts                # Unit test setup
├── browser-setup.ts        # Browser test setup
├── unit/                   # Unit tests
└── browser/                # Browser integration tests

Build

npm run build              # Build for production
npm run build:types        # Generate TypeScript declarations
npm run preview            # Preview production build

Bundle Analysis

Monitor and analyze bundle size:

npm run analyze            # Build and open bundle analyzer
npm run size               # Show file sizes in terminal

Current bundle sizes (after optimizations):

• ES Module: 124KB (32KB gzipped)
• CommonJS: 95KB (28KB gzipped)
• CSS: 34KB (6KB gzipped)

Bundle Size Strategy

This library uses several strategies to minimize bundle size:

1. External Dependencies: Large libraries like jsPDF and @vueuse/core are peer dependencies
2. Tree Shaking: Only import what you use
3. CSS Code Splitting: Disabled to create single CSS file
4. Source Maps: Available for debugging

Linting & Type Checking

npm run lint               # ESLint
npm run type-check         # TypeScript type checking

Contributing

1. Fork the repository
2. Create a feature branch
3. Add tests for new functionality
4. Ensure all tests pass: npm run test:all
5. Submit a pull request

License

MIT License - see LICENSE file for details.