<!DOCTYPE html>
<html>
<head>
    <style>
        .box {
            width: 200px;
            height: 200px;
            background-color: green;
            filter: url(#sharpen);
        }
    </style>
</head>
<body>
	<svg style="display:none;" xmlns="http://www.w3.org/2000/svg" version="1.1">
		<defs>
			<filter id="sharpen">
    			<feConvolveMatrix order="3 3" preserveAlpha="true" kernelMatrix="0 0 0 0 1 0 0 0 0" />
  			</filter>
		</defs>
	</svg>
    <div class="box"></div>
</body>
</html>