Polygon Mask Annotation Tool

Interactive tool for creating precise polygon masks with real-time visualization.

Use Cases

Domain	Description & Examples
Image Inpainting	✅ Precisely mark damaged areas 🖼️ Example: Old photo restoration
Medical Imaging	⚕️ Annotate organ boundaries in CT scans 🩺 Example: Lung nodule annotation
Satellite Analysis	🛰️ Extract building polygons 🌆 Example: Urban expansion studies

Features

• 🖱️ Left-click to add points | Right-click to undo
• 🔍 Adaptive window scaling with coordinate mapping
• 🎨 Generates 3-channel PNG masks
• 📏 Preserves original image dimensions
• 🔄 Real-time visual feedback

Installation

pip install opencv-python numpy

Usage

1. Place your image as test.png (or modify img_path in code)
2. Run:

python main.py

3. Annotate:
   • Left-click: Add vertex
   • Right-click: Remove last vertex
   • S: Save mask (auto-closed) and exit
   • ESC: Quit without saving

Output Example

Original Image	Generated Mask

Technical Notes

• Coordinate system conversion between screen and original image
• Automatic window centering with black borders
• BGR color space standard for OpenCV compatibility