A CLI I hacked together for use with FoundryVTT. Consumes JPEGs or PNGs and outputs icons in PNG format. Nothing wrong with https://rolladvantage.com/tokenstamp/, but I wanted something command-line based, completely offline, and more tailored to my workflow.
Usage:
tokenize path/to/image.jpg [images ...]
Input
example.jpg
tokenize example.jpg
Output
example_gold.png
example_silver.png