Follow the instructions in Readme.md to use this.

This code allows you to open up an image file and replace its pixels with stars as you move the mouse over the screen. Useful, right?

1. Download and unzip gist from https://gist.github.com/jsundram/5441782/download
2. Navigate to folder you unzipped this code to in Terminal
3. chmod +x install.sh
4. ./install.sh (this will take a while)
5. python starry.py "filename.jpg" from the command line. Press Ctrl-S to save.