Gaussian blur cutoff at edges

I am working on an svg export utility for a drawing program on android. I am having a problem that the behind blur is cutoff past the shape boundaries - looks like i need to resize the viewBox or increase the margin or something. Does anyone know the best way?

The test file url is here - it d开发者_如何转开发ownloads as the mime type isn't setup correctly on the server and I cant restart it at the moment :(. There are embedded images and fonts in the file, Which is why it's big. But if you save it to disk you can open in chrome, ff, etc...

An enlarged example of this problem is given. Notice the square edges on the orange glow.

The filter canvas has default values : x=y=-10% and width=height=120%. You can change them with the x, y, width and height attributes on the filter element.

Try to set a bigger canvas :

<filter x="-50%" y="-50%" width="200%" height="200%"/>

Yet, since the canvas is bigger, there will be performance loss.