I thought this was a huge waste of resources and rewrote the tool to pure js, I just didn't see any reason for Dart here.
To use this in console, run
node shaky-node.js textfile imagefile.png
Please note that while this pull request is not merged, there's no way to make node-canvas use custom font, so please install the ttf font locally.
And please use the
shaky.html file as a sample of in-browser use.