Approaches to Creating Screen Capture Functionality on a Web Page

I have read the various posts here on SO regarding screen capturing, but none seem to be answering my situat开发者_如何学运维ion.

On our website (inside a web page), essentially here is what I would like to be able to do.

1. User clicks on a 'capture region of screen' button
2. They get some sort of draggable/sizable box they can use to define the area to capture
3. the captured area gets converted into a (preferrably) .png
4. image is uploaded (or at least made available to upload - maybe saved somewhere)

I realize this is not doable with javascript alone. So, I am open to a Java or Flash solution, and/or even a commercial solution (a drop-in java applet that I can add to our site).

So, is something like this available, or any other ideas on how I might approach this?

Thanks.

Check out PhantomJS. http://www.phantomjs.org/

Actually it will re-render page on your server stack and you can save it as a png. Not same as your desired workflow, but definitely worth checking out.