Example of how to create watermark on NodeJS.
It's only test example, strongly not recommended to use in production.
For development, you will need Node.js installed on your environement. Also, you will need install this deps: Canvas and Sharp (instructions for installation you can find on this links).
git clone https://github.com/phyxolog/node-wm.git # or clone your own fork
cd node-wm
npm install # if error - look a "Requirements" section
# then copy in this folder some image with name "image.jpg"
node index.js