根据图片主要颜色生成背景渐变JS插件

<script type="text/javascript" src="dist/grade.js"></script>

<!-- 渐变将被应用在div元素上 -->

<div class="gradient-wrap">

    <img src="./samples/finding-dory.jpg" alt="" />

</div>

<div class="gradient-wrap">

    <img src="./samples/good-dinosaur.jpg" alt="" />

</div>

<script type="text/javascript">

    window.addEventListener('load', function(){

        /*

            A NodeList of all your image containers (Or a single Node).

            The library will locate an <img /> within each

            container to create the gradient from.

         */

        Grade(document.querySelectorAll('.gradient-wrap'))

    })

</script>