Author here. As far as I know there is no way to do blur with CSS in IE10+ https://github.com/Schepp/CSS-Filters-Polyfill#a-word-regard... so we must use canvas to be cross-browser.
http://blogs.msdn.com/b/ie/archive/2011/10/14/svg-filter-eff...
Edit: to clarify, the image would need to be moved into the SVG (which could be a simple DOM manipulation of the original <img> tag).
Of course, you could always just force IE9 mode... ;)