Hello, I made some code based on tizenketto pen. It's cross-browser and filters can be overlapped. This is the main code trigger:
var tl = new TimelineLite();
tl.fromTo( progressEase, .5, { progress:0 }, { progress:1, ease:Strong.easeOut, onUpdate:cssFilterTween, onUpdateParams:[ "{self}", { target:image, filter:"blur", start:0, end:4 } ] } );
Check the full code here: http://codepen.io/jeanpaze/pen/gaPqeK
I hope this help someone and will be nice to see this as a GSAP plugin. Feel free to improve!