Is there an easy way to save a section from a rendered web page as an image?

I want开发者_StackOverflow to provide the ability to save some rendered data/charts (with the titles and other information not included in the image) by specifying the coordinates and size in the browser window that contains the data I want to save. Is there any way to do this?

You can use firefox and X11 virtual desktop on your server and make screenshots.
Like is described here