遮罩颜色/透明度

var zooming = new Zooming({
    bgColor: 'rgb(0, 0, 0)',
    bgOpacity: '0.5'
});
zooming.listen('.img-zoomable');

<a href="images/1.jpg">
    <img class="img-zoomable" src="images/1s.jpg" alt="">
</a>