This will generate an object from a predefined image stored as base64 (should be easy to add an option to feed an image in).
This is very specific, and generates a map from left -> right, bottom -> top.
npm i paletteread --save
or
bower i paletteread --save
requires https://github.com/Automattic/node-canvas which has some pretty serious req's. FYI.
var p = require('paletteread');
var palette = new p();
<script src="paletteread/src/index.js"></script>
...
<script>
let foo = new paletteread();
</script>