<script src="resources/ensure-hidpi.js"></script>
<style>
    #box {
        width: 100px;
        height: 100px;
        background-color: green;
        filter: url("#a");
    }
</style>
<body>
    <div id="box"></div>
    <svg>
        <filter id="a">
            <feComponentTransfer/>
            <feGaussianBlur stdDeviation="0"/>
        </filter>
    </svg>
</body>