HTML5 Gaussian blur effect

How is apple able to achieve the (apparent) Gaussian blu开发者_如何学Gor effect for the photos in the background in this demo:

http://www.apple.com/html5/showcase/gallery/

Now we are in 2012, look a this:

http://css-plus.com/2012/03/gaussian-blur/

and this:

http://blurjs.com/

In case you want to do something similar with Canvas, check out StackBlur. Works great! I know it's not Gaussian blur but it should be close enough. :)

Looking at the source, those are prerendered. No HTML5 trickery for that part, unfortunately.

Example: http://images.apple.com/html5/showcase/gallery/images/polo9b-small.png