test/index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style>
        img, div{
            width: 500px;
            height: 500px;
            display: block;
            margin-bottom: 100px;
            opacity: 0;
            transition: all 1s;
        }
    </style>
</head>
<body>
    <img src="" class="img-load" data-src="http://gw.alicdn.com/bao/uploaded/TB1niChLpXXXXX2XXXXXXXXXXXX-300-74.png" alt="">
    <img class="img-load" data-src="http://gw.alicdn.com/bao/uploaded/TB1_FlkLpXXXXbTXVXXXXXXXXXX-725-288.png" alt="">
    <img src="" class="img-load" data-src="http://gw.alicdn.com/bao/uploaded/TB1WDRuLpXXXXXiXFXXXXXXXXXX-172-208.png" alt="">
    <img data-cache=1 class="img-load" data-src="http://gw.alicdn.com/bao/uploaded/TB1QgdaLXXXXXXcXXXXXXXXXXXX-140-50.png" alt="">
    <div data-cache=1 class="img-load" data-src="http://gw.alicdn.com/bao/uploaded/TB1a373KVXXXXc6XXXXXXXXXXXX-140-50.png" alt=""></div>
    <script src="../src/img.js"></script>
    <script>
        SI.img({
            fadeIn: function() {
                this.style.opacity = 1;
            }
        })
    </script>
</body>
</html>