universal-annotator 0.1.9

Universal Annotation Tool for images

📦 Universal Annotator

A modern, high-performance image annotation tool for computer vision datasets.

Universal Annotator is a powerful, desktop-grade, and user-friendly tool engineered for creating high-quality bounding box annotations with exceptional speed. It's built for computer vision practitioners who demand a fast, flexible, and reliable annotation workflow.

🔥 Key Features

🧰 Core Annotation & Data

• Format Flexibility: Supports TXT (YOLO), JSON, and COCO formats with auto-detection.
• Bounding Boxes: Create, edit, move, and resize annotations efficiently.
• Nested Annotations: The ability to draw boxes inside existing boxes.
• Smart Data Handling:
  • Intelligent natural sorting (e.g., image_2.jpg before image_10.jpg).
  • Smart JSON class discovery.
  • Automatic label file creation prompt for new datasets.
• Reliable Workflow: Auto-save when navigating, selection memory (restores selection per image).
• Image Support: Supports common formats: JPG, PNG, BMP, TIFF, WebP.

🎨 User Experience (UI/UX)

• Professional Dark Theme: Advanced, high-contrast dark UI for reduced eye strain.
• Optimized Navigation: Mouse-wheel image zoom, full menu bar, and rich status bar.
• Speed-Focused Shortcuts: Descriptive tooltips and a comprehensive help dialog (F1) with optimized keyboard shortcuts.
• Modes: Dedicated Edit Mode (E) and View Mode (V) for focused work.

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🚀 Installation

Universal Annotator is available directly on PyPI.

Install from PyPI

pip install universal-annotator

Run the Application

universal-annotator

Optional: Use a Virtual Environment

It is highly recommended to use a virtual environment to manage dependencies:

python3 -m venv venv
source venv/bin/activate       # On Linux/macOS
# venv\Scripts\activate        # On Windows
pip install universal-annotator
universal-annotator

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🧭 Basic Usage Guide

1. Load Dataset

• Select your Image Folder and your Label Folder.
• The annotation format is auto-detected.
• If the label folder is empty, the app will offer to create label files in your chosen format (TXT, JSON, or COCO).

2. Draw Bounding Boxes

• Press E to switch to Edit Mode.
• Press M to switch to Draw Mode.
• Click & drag to draw a new box.
• Select a class from the popup dialog.
• Navigate between images with A (Previous) / D (Next) keys or the navigation buttons.

3. Edit Annotations

• Select an existing box to move or resize it.
• Drag the box handles to resize.
• Press Delete to remove the selected box.
• Draw nested boxes inside existing annotations.

4. Save

• Press S to save manually.
• Alternatively, enable Auto Save in the UI settings.
• The status bar will confirm all save actions.

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📁 Supported Annotation Formats

Format	Structure	Notes
TXT	<class_id> <x_center> <y_center> <width> <height>	Standard YOLO format.
JSON	{"annotations": [{"bbox": [x, y, w, h], "category_id": 0}]}	Custom simple JSON structure.
COCO	Fully supported	Reads and writes _annotations.coco.json.

🗂 Exporters & Converters

The tool includes powerful conversion utilities. All conversion tools are non-destructive and avoid overwriting your root labels.

Outputs are placed into dedicated folders, such as converted_txt/, converted_json/, etc.

Supported Conversions:

• TXT → JSON
• JSON → TXT
• TXT → COCO JSON
• COCO → JSON
• COCO → TXT
• JSON Folder → COCO merge

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🎮 Keyboard Shortcuts

Key	Action
A	Previous Image
D	Next Image
S	Save
E	Edit Mode
V	View Mode
M	Draw Bounding Box
X	Exit Draw Mode
Delete	Remove selected box
F1	Help dialog / View shortcuts

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⚙ Configuration

You can easily customize the tool's behavior and class definitions:

• Classes: Edit sample_classes/classes.txt to define your class names:

  person
  car
  bicycle
  dog
  cat
  

• App Settings: Edit utils/config.py to change default settings like colors, line widths, app name, and version.

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🛠 Troubleshooting

Issue	Solution
Images not loading	Ensure file formats are supported (JPG, PNG, etc.) and check folder permissions.
Labels not found	Verify that label filenames match image filenames and the correct label folder is selected.
Shortcuts not working	Make sure the application window is focused.

🚧 Known Limitations & Future Enhancements

Known Limitations (v0.1.4)

• No in-place label editing (must delete and recreate a box to change its class).
• Only rectangular bounding boxes are supported.

🛠️ Future Enhancements

• Polygon and segmentation support (High Priority)
• Change class label of existing box
• Customizable keyboard shortcuts
• Analytics dashboard
• Undo/Redo functionality
• Plugin system

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🤝 Contributing

Pull requests are welcome! If you have a feature idea or a bug fix, please check out the contribution guide:

📄 See the CONTRIBUTING_UI.md file for details.

📄 License

                              LICENSE
                         Version  18 Nov 2025

THIS SOFTWARE LICENSE IS PROVIDED "ALL CAPS" SO THAT YOU KNOW IT IS SUPER SERIOUS AND YOU DON'T MESS AROUND WITH COPYRIGHT LAW BECAUSE YOU WILL GET IN TROUBLE HERE ARE SOME OTHER BUZZWORDS COMMONLY IN THESE THINGS WARRANTIES LIABILITY CONTRACT TORT LIABLE CLAIMS RESTRICTION MERCHANTABILITY. NOW HERE'S THE REAL LICENSE:

0. It's a public domain.
1. Do whatever you want with it.

👨‍💻 Author & Version

• Author: Madan Mohan Jha
• Current Version: v0.1.8
• Updated: November 2025