OpenFront Map Generator

Convert any image into a playable map for openfront.io.

What it does

Takes a grayscale (or any) image and maps brightness values to terrain types:

Terrain	Color
Water	Dark navy
Plain	Green
Highland	Tan
Mountain	Light gray

Usage

Web (recommended)

Just open index.html in a browser — no install needed.

1. Upload a PNG/JPG/WebP image
2. Adjust the Water / Plain / Highland thresholds with the sliders
3. Pick an algorithm (Legacy, Smooth, or Advanced)
4. Download the result as openfront_map.png

Python (desktop GUI)

Requires Python 3 with Pillow, numpy, and tkinter.

pip install pillow numpy

Put your source image at input.png, then run:

python image_to_map.py

Adjust sliders in the GUI and hit SAVE to export map_output.png.

Docker

docker compose up

Algorithms (web version)

• Legacy — pixel-perfect, no post-processing
• Smooth — removes small noise islands and smooths jagged coastlines (configurable min island size and passes)
• Advanced — edge margin control for cleaner borders

Tips

• Use a heightmap or topographic image for best results
• Toggle Invert Brightness if land and water are swapped
• Higher "smooth passes" = softer coastlines but slower render