Filter feGaussianBlur

<svg width="300px" height="300px" viewBox="0 0 300 300">
	<defs>
		<filter id="filterGaussianBlur">
			<feGaussianBlur id="feGaussianBlur" stdDeviation="0" />
		</filter>
	</defs>
	<g id="svgElement4" filter="url(#filterGaussianBlur)">
		<image xlink:href="testbild.jpg" x="0" y="0" height="300px" width="300px"/>
	</g>
</svg>
			

Filter Combination

<svg width="300px" height="300px" viewBox="0 0 300 300">
	<defs>
		<filter id="heavycloud">
			<feTurbulence id="feTurbulence" baseFrequency=".01" numOctaves="3"/>
	 		<feComponentTransfer>
	 			<feFuncR type="linear" slope="2" intercept="-0.4"/>
	 			<feFuncG type="linear" slope="2" intercept="-0.4"/>
	 			<feFuncB type="linear" slope="2" intercept="-0.4"/>
	 			<feFuncA type="linear" slope="0" intercept="1"/>
	 		</feComponentTransfer>
			<feColorMatrix id="feColorMatrix" type="hueRotate" values="0" />
			<feGaussianBlur stdDeviation="2"/>
	  		<feColorMatrix type="matrix" result="A"
	    		values=
	    			"0.33 0.33 0.33 0 0 
	     			 0.33 0.33 0.33 0 0 
	     			 0.33 0.33 0.33 0 0 
	     			 0 0 0 0 1 
	    			"/>
	  		<feColorMatrix type="matrix" in="SourceGraphic" result="B"
	    		values=
	    			"1 0 0 0 0 
	     		 	 0 1 0 0 0 
	     		 	 0 0 1 0 0 
	     		 	 1 1 1 0 0
	    			"/>
		  	<feMerge>
		    	<feMergeNode in="A"/>
		    	<feMergeNode in="B"/>
		  	</feMerge>
		</filter>
	</defs>
	<g id="svgElement5">
		<image x="0" y="0" xlink:href="testbild.jpg" height="300" width="300"/>
	</g>
</svg>