[scaturr]

You are correct. This would serve the purpose for many users who don't know how to go digging around for urls in JS, but more importantly its a tool for generating them on the client so a server doesn't have to - say for a CMS?

[nathankleyn]

That's all fine until Googlebot-Image comes along, collects up all your unwatermarked images, and displays them in search results for the world to use.

I can see this being useful for running as a batch process in Node/IO.js and uploading to, say, S3.

[scaturr]

Well what if you batch it in the browser? It is quite possible to use file inputs to generate watermarked images without ever storing the image you are watermarking, and then upload the result.

[nathankleyn]

Yep - that's totally possible. Actually, now you phrase it like that, I see what you mean about using it that way for a CMS, and it's an awesome idea.

[artursapek]

You could also use the canvas element to display the image & watermark as a flat layer.

[kuschku]

Still, the image would somehow have to be loaded in the browsers, at which point it’s easy to circumvent.