Get pixcels of div element and create image object

I have a map div that has google or bing map. And I added polygons and lines on it. Now I want to select rectangle area on map div and get it as an image object. I mean that I want to get a capture of map.

So I want to read div object pixcels from start point to end point and save it. But I can not do this.

Is this possible on javascript. Or is there a short way?