labelmev2 2.0.3

Image Polygonal Annotation with Python - V2 with 45x Faster Performance

LabelMe V2

Image Annotation Tool with Advanced Features & Performance Optimizations

Enhanced fork of wkentaro/labelme with 45x faster loading & productivity features

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🎯 What's New in This Fork

This enhanced version adds powerful polygon editing features, 45x faster image loading, and improved defaults to speed up your annotation workflow:

⚡ Breakthrough Performance: 45x Faster Loading

The biggest improvement in this fork - optimized TIFF/JPG/PNG loading for massive images:

Image Size	Before	After	Speedup
6050×12300 TIFF (71MB)	10 seconds	220ms	45x faster ⚡
Large JPG/PNG	2-3 seconds	200-400ms	10x faster
Cached images	N/A	<200ms	Instant navigation

How it works:

• ✅ Skip slow PIL conversion - load directly with Qt
• ✅ Skip JSON base64 decode - load from file when possible
• ✅ Smart image caching (3-image LRU cache)
• ✅ Automatic downsampling for huge images

Perfect for: Industrial inspection, PCB analysis, medical imaging, aerial photography

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✨ New Features

1. Performance Optimizations ⚡

Smooth annotation even with massive images and many polygons.

• Viewport Culling: 5-10x faster rendering with 100+ polygons
• Adaptive Downsampling: 4x less memory for large images (16000×8000)
• Optimized Loading: 45x faster for large TIFF files
• Configurable thresholds and quality settings
• Works automatically - no manual intervention

Example: Annotate 16000×8000 PCB images with 500 polygons smoothly on 4GB RAM.

2. Enhanced Zoom (Up to 5000%)

Maximum zoom increased from 1000% to 5000% (50x magnification) for tiny defect annotation.

• Configurable maximum zoom level
• Adjustable zoom increment for smooth control
• Perfect for PCB defects, microscopy, surface inspection
• Mouse wheel zooms centered on cursor position

Example: Annotate hairline cracks or solder bridges with pixel-level precision.

3. Multiple Point Addition (Ctrl+M)

Quickly refine polygon boundaries by adding multiple evenly-spaced points along edges.

• Hover over any polygon edge in edit mode
• Press Ctrl+M and enter number of points (1-100)
• Points are automatically distributed evenly
• Perfect for curved edges or complex boundaries

Example: Add 10 points to a curved car windshield edge in one action instead of clicking 10 times.

4. Polygon Merge (Ctrl+Shift+M)

Merge multiple polygons into one or batch-apply labels to disconnected objects.

• Select 2+ polygons (hold Ctrl while clicking)
• Press Ctrl+Shift+M to merge
• Smart handling:
  • Connected/overlapping → Single merged polygon
  • Disconnected objects → Multiple polygons with same label
  • Mixed → Intelligent separation based on connectivity

Example: Annotate 20 cars by drawing rough boxes, select all, merge once - all labeled "car" instantly.

5. Dark Mode (View → Dark Mode)

Eye-friendly dark theme inspired by VS Code.

• Toggle instantly via View menu
• Persistent setting saved in config
• Reduces eye strain during long sessions
• Professional color scheme

6. Improved Default Settings

Better defaults for faster annotation workflow:

Setting	Old Default	New Default	Why?
auto_save	false	true	Never lose work
store_data	true	false	Smaller JSON files
keep_prev_brightness_contrast	false	true	Consistent visuals
dark_mode	N/A	true	Eye comfort
canvas.fill_drawing	true	false	See through shapes
canvas.num_backups	10	20	More undo history
max_zoom	1000%	5000%	5x more zoom

7. Better Keyboard Shortcuts

More intuitive shortcuts that don't conflict:

Action	Old Shortcut	New Shortcut
Create Polygon	Ctrl+N	Ctrl+Shift+C
Create Rectangle	Ctrl+R	Ctrl+Shift+X
Edit Polygon	Ctrl+J	Ctrl+Shift+V

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📦 Installation

From PyPI (Recommended)

pip install labelmev2

From Source

# Clone this enhanced version
git clone https://github.com/jakhon37/LabelMeV2.git
cd LabelMeV2

# Install with pip
pip install -e .

# Or use uv (faster)
uv pip install -e .

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🚀 Quick Start

# Launch labelme
labelme

# Enable dark mode (if not already on)
View → Dark Mode

# Try the new features:
# 1. Draw a polygon
# 2. Press Ctrl+Shift+V to enter edit mode
# 3. Hover over an edge and press Ctrl+M
# 4. Enter "5" to add 5 points
# 5. Adjust the points as needed

New Feature Quick Reference

Feature	Shortcut	Usage
High Zoom (5000%)	Mouse wheel	Scroll on image to zoom up to 50x magnification
Add Multiple Points	Ctrl+M	Edit mode → Hover edge → Ctrl+M → Enter count
Merge Polygons	Ctrl+Shift+M	Select multiple → Ctrl+Shift+M
Dark Mode	View menu	View → Dark Mode (toggles instantly)
Edit Mode	Ctrl+Shift+V	Enter polygon editing mode

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📚 Documentation

• New Features Guide: docs/NEW_FEATURES.md
• Contributing: CONTRIBUTING.md
• Original Documentation: See wkentaro/labelme for:
  • Basic usage and examples
  • Export formats (VOC, COCO)
  • AI-assisted annotation
  • Command-line tools
  • Video annotation
  • Classification/segmentation workflows

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🎬 Examples

Polygon Refinement Workflow

1. Draw rough polygon around object
2. Ctrl+Shift+V (edit mode)
3. Hover over curved edge
4. Ctrl+M → Enter "8" → OK
5. Adjust 8 new points to match boundary perfectly

Batch Labeling Workflow

1. Draw boxes around 15 cars (quick rough boxes)
2. Ctrl+Click each box to select all
3. Ctrl+Shift+M (merge)
4. Result: 15 separate polygons all labeled "car"

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🔧 Configuration

Enhanced defaults in ~/.labelmerc:

# New/modified defaults
auto_save: true
dark_mode: true
store_data: false
keep_prev_brightness_contrast: true

# Zoom settings
zoom_increment: 1.45  # 45% per step (ultra fast for quick navigation)
max_zoom: 5000        # 5000% = 50x magnification

# New features config
default_num_points_to_add: 1

shortcuts:
  add_multiple_points: Ctrl+M
  merge_polygons: Ctrl+Shift+M
  create_polygon: Ctrl+Shift+C
  create_rectangle: Ctrl+Shift+X
  edit_polygon: Ctrl+Shift+V

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🤝 Contributing

Contributions welcome! See CONTRIBUTING.md for:

• Development setup
• Code style guidelines
• Testing procedures
• Feature implementation details

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📄 License

GPL-3.0-only - Same as original wkentaro/labelme

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🙏 Acknowledgments & Credits

This project is based on wkentaro/labelme

• Original Author: Kentaro Wada
• Original Repository: https://github.com/wkentaro/labelme
• License: GPL-3.0 (maintained in this fork)

This enhanced version builds upon the excellent foundation of the original labelme, adding:

Performance Enhancements by Jakhongir Nodirov:

• ⚡ 45x faster image loading for large TIFF/JPG/PNG files
• 🖼️ Smart image caching with LRU eviction
• 🎨 Viewport culling for smooth rendering with hundreds of polygons
• 📊 Optimized memory usage for massive images

New Features:

• 🔍 Enhanced zoom up to 5000% for tiny defect inspection
• ➕ Multiple point addition (Ctrl+M) for quick polygon refinement
• 🔗 Polygon merge (Ctrl+Shift+M) for batch labeling
• 🌙 Dark mode for comfortable annotation sessions
• ⚙️ Improved default settings for faster workflows

Maintained by: Jakhongir Nodirov ([e-mail])

For the complete original labelme documentation and features, please visit the official repository.

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⭐ Support

If you find these enhancements useful:

• ⭐ Star this repository
• 🐛 Report issues on GitHub Issues
• 💬 Share feedback and suggestions
• ⭐ Also star the original labelme project!