🎓 Lecture2PDF AI

Convert Lecture Videos into Clean, Study-Ready PDFs Automatically

Stop wasting hours taking screenshots during lectures. Let Lecture2PDF AI detect slides, extract key frames, and generate organized PDFs in minutes.

🚀 Fast • 🔒 Private • 📚 Student Friendly

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📖 Overview

Lecture2PDF AI is a Chrome Extension that automatically extracts presentation slides from lecture videos and converts them into a downloadable PDF.

Whether you're studying from YouTube, Udemy, Coursera, or recorded college lectures, Lecture2PDF AI helps you focus on learning instead of manually capturing screenshots.

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❌ The Problem

Imagine watching a 2-hour lecture.

Every time the slide changes, you:

• Pause the video
• Take a screenshot
• Save it
• Resume watching

After the lecture, you end up with:

• Hundreds of screenshots
• Duplicate images
• Disorganized notes
• Hours wasted

Most students spend more time collecting notes than actually studying.

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✅ The Solution

Lecture2PDF AI automates the entire process.

Simply:

1. Open a lecture video
2. Click Scan Video
3. Review detected slides
4. Generate PDF

That's it.

The extension handles everything automatically.

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✨ Features

🔍 Smart Slide Detection

Automatically identifies meaningful slide transitions throughout the lecture.

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🧠 Adaptive Thresholding

Uses Otsu's Thresholding Algorithm to dynamically determine the best detection threshold for each video.

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📸 Duplicate Reduction

Filters unnecessary captures and focuses on important slide changes.

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🖼 Slide Review Dashboard

Preview all detected slides before generating the final PDF.

You can:

• Review captures
• Remove unwanted slides
• Fine-tune results

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📄 PDF Generation

Convert selected slides into a professional PDF instantly.

Perfect for:

• Exam preparation
• Revision notes
• Quick review sessions

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🔒 Privacy First

Everything runs locally in your browser.

No:

• Cloud uploads
• External servers
• Data collection
• Tracking

Your lecture data never leaves your device.

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🚀 How It Works

Open Lecture Video
        ↓
Scan Video
        ↓
Detect Slide Changes
        ↓
Review Captured Slides
        ↓
Generate PDF
        ↓
Download Notes

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⚙️ Technology Stack

Technology	Purpose
JavaScript	Core Application Logic
Chrome Manifest V3	Extension Framework
HTML/CSS	User Interface
Canvas API	Frame Processing
PDF-Lib	PDF Generation
Otsu's Method	Threshold Optimization
Service Workers	Background Processing

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🧠 Detection Algorithm

Frame Analysis

Lecture2PDF samples frames across the lecture timeline and converts them into lightweight brightness grids.

This significantly reduces processing cost while maintaining accuracy.

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Change Detection

Consecutive frames are compared to calculate visual differences.

The algorithm ignores:

• Mouse movements
• Cursor activity
• Minor animations

while detecting actual slide transitions.

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Adaptive Threshold Selection

Instead of relying on a fixed threshold, Otsu's Method automatically calculates the optimal threshold for every lecture.

Benefits:

• Higher accuracy
• Fewer duplicates
• Better results across different video styles

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📦 Installation

Method 1: Install from Source

1. Clone the Repository

git clone https://github.com/RajGahoi/lecture2pdf.git

cd lecture2pdf

Or download the ZIP file and extract it.

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2. Open Chrome Extensions

Open Chrome and visit:

chrome://extensions/

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3. Enable Developer Mode

Turn ON Developer Mode from the top-right corner.

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4. Load the Extension

Click:

Load Unpacked

Select the project folder containing:

manifest.json

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5. Pin the Extension

Click the Extensions icon and pin:

Lecture2PDF AI

The extension is now ready to use.

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📚 Usage

Step 1

Open any lecture video.

Supported platforms include:

• YouTube
• Coursera
• Udemy
• Khan Academy
• PhysicsWallah
• Unacademy
• Most HTML5 video players

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Step 2

Click the Lecture2PDF AI extension icon.

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Step 3

Press:

🔍 Scan Video

The extension will automatically analyze the lecture.

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Step 4

Review the detected slides.

Remove any unwanted captures if necessary.

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Step 5

Click:

⚡ Generate PDF

The PDF will be generated and downloaded automatically.

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🎯 Use Cases

👨‍🎓 Students

Create revision notes instantly.

👩‍🏫 Teachers

Generate lecture handouts from recorded sessions.

📚 Online Learners

Capture key slides from online courses.

🎓 Exam Preparation

Build concise study material quickly.

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🔮 Future Roadmap

• AI-powered lecture summarization
• OCR text extraction
• Export to Markdown
• Export to Notion
• Multi-language support
• Smart chapter detection
• Lecture transcript integration
• Cloud synchronization

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🤝 Contributing

Contributions are welcome.

If you'd like to improve the project:

1. Fork the repository
2. Create a feature branch
3. Commit your changes
4. Open a Pull Request

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⭐ Support

If Lecture2PDF AI saved you time, please consider giving this repository a star.

It helps more students discover the project and motivates future development.

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Built for Students ❤️

Transform lectures into organized study material — automatically.

⭐ Star the project if you found it useful.