How to save the contents of Data URI to image

In Google Chrome the method chrome.tabs.captureVisibleTab(inte开发者_C百科ger windowId, object options, function callback) (captureVisibleTab) will return a data URL of the JPEG encoding of the visible area of the captured tab.

We want to save that content as image to hard disk without opening/passing the contents into new HTML page.

Does anybody know how it can be done by JavaScript. Please provide help.

Thanks.