Large Image Viewer

A simple, high-performance viewer for very large images using OpenSeadragon's Deep Zoom technology. Initially conceived to inspect full wafer images in semiconductor fabrication processes but should fit many other applications.

Features

• Gigapixel Support: Smoothly view images up to 2GB
• Simple to Use: Double-click to start, drag & drop images
• Fast Processing: Uses libvips for efficient tile generation
• Persistent Cache: Processed images are cached for instant reload
• Modern UI: Clean, dark interface with image management

Quick Start

Option 1: Docker (Recommended)

# Start the viewer
docker-compose up

# Open browser to http://localhost:5000

Option 2: Windows

Double-click start-viewer.bat

Option 3: Command Line

python run.py

The browser opens automatically. Drag & drop images to view them.

Usage

1. Drop an image into the upload area (or click to browse)
2. Wait for processing - large images may take a minute
3. Navigate - scroll to zoom, drag to pan, use controls to rotate
4. Switch images - click any image in the sidebar
5. Delete - hover over an image and click the trash icon

Keyboard Shortcuts

Key	Action
+ / -	Zoom in / out
R	Rotate 90°
F	Toggle fullscreen
0	Reset view
Arrow keys	Pan
?	Show help

Supported Formats

• JPEG (.jpg, .jpeg)
• PNG (.png)
• TIFF (.tiff, .tif)
• BMP (.bmp)
• WebP (.webp)

Maximum file size: 2GB

How It Works

1. When you upload an image, it's converted to Deep Zoom Image (DZI) format
2. DZI creates a pyramid of tiles at multiple zoom levels
3. OpenSeadragon loads only the tiles visible on screen
4. Result: smooth panning and zooming even for gigapixel images

Processed tiles are stored in the ./tiles/ directory and reused on subsequent loads.

Requirements

For Docker

• Docker and Docker Compose

For Native Python

• Python 3.9+
• libvips library (installation guide)

Command Line Options

python run.py --help

Options:
  --port PORT      Port to run on (default: 5000)
  --no-browser     Don't auto-open browser

Project Structure

LargeImageViewer/
├── src/
│   ├── __init__.py
│   ├── __main__.py
│   ├── app.py             # Main application
│   └── static/
│       └── vendor/
│           └── openseadragon/
├── run.py                 # Entry point
├── start-viewer.bat       # Windows launcher
├── docker-compose.yml
├── Dockerfile
├── pyproject.toml
├── requirements.txt
├── README.md
├── LICENSE
└── tiles/                 # Generated (gitignored)

Troubleshooting

"libvips not found" - Install libvips or use Docker instead

Slow processing - Normal for very large images. A 1GB TIFF may take 1-2 minutes.

Out of memory - Increase Docker memory limit or system RAM

License

MIT License - see LICENSE for details.

Credits

• OpenSeadragon - Deep zoom viewer
• libvips - Fast image processing
• Flask - Web framework