copy base64 image to clipboard

[artem....@logicify.com]

i need copy to clipboard some image, and then paste into powerpoint. For external images i can do it, fro example:
<img src="http://www.mysite.com/image1.png"/>
document.execCommand('copy') works fine
but if i try copy image like this
<img src="data:image/png;base64,image data here..."/>
or
i try set src by jquery
$('#myimage').attr('src',chrome.extension.getURL('/images/image1.png'));
in background.html i can see these images, it loads.
But when i try to copy and paste image into powerpoint, word or somewhere i getting nothing. Something tells me, the url is incompatible for this programs.
So is there another way to copy image to clipboard (like in firefox)?