Convert a div block to an image

Hello,

I would love to use CMS to generate web banners that match the content from our LPs (neat idea right?).

So I’d like to create divs with custom text on top of images, then be able to save them (right click>save) from the published page.

html2canvas seems like it should get the job done but I don’t even know where to start with the custom code for it inside webflow.
http://html2canvas.hertzen.com/

Any tips or examples would be appreciated.