How to capture image from Tab using node.js

I am developing application using Node.js. I want to capture image and store it in DataBase. If i use OPERA mobile 12.10 ,how can I use this with Node.js?

node.js
websocket
opera
image-capture

I would consider using PhantomJS. It is trivial to take screenshots of webpages with phantom (see this example: technews.js)

As a basic approach:

Call server function for making a screenshot from your browser (for instance jQuery.post)
Create server code in node.js that handles the request
Launch phantomjs as a child process when handler is called and store the result in the database