var filtersFactory = (function(){
	var ob = {};
	ob.createFilter = createFilter;
	ob.createAlphaToLuminanceFilter = createAlphaToLuminanceFilter;

	function createFilter(filId){
        	var fil = document.createElementNS(svgNS,'filter');
        	fil.setAttribute('id',filId);
                fil.setAttribute('filterUnits','objectBoundingBox');
                fil.setAttribute('x','0%');
                fil.setAttribute('y','0%');
                fil.setAttribute('width','100%');
                fil.setAttribute('height','100%');
                return fil;
	}

	function createAlphaToLuminanceFilter(){
                var feColorMatrix = document.createElementNS(svgNS,'feColorMatrix');
                feColorMatrix.setAttribute('type','matrix');
                feColorMatrix.setAttribute('color-interpolation-filters','sRGB');
                feColorMatrix.setAttribute('values','0 0 0 1 0  0 0 0 1 0  0 0 0 1 0  0 0 0 1 1');
                return feColorMatrix;
	}

	return ob;
}())