Image with arched edges

Arched edges is to introduce the pseudo elements :before and :after, size them relative to the container, and transform: rotate(-10deg);. Setting a hardcoded left and right ensures that the pseudo elements lie on top of where the image’s shadow lies.

Source Code

<!Doctype>
<html>
<head>
  <style>
    .pic {
      width: 400px;
      height: 200px;
      background: url(img/tiger.png) no-repeat;
    }
    .shadow
    {
      position: relative;
    }
    .shadow:before, .shadow:after
    {
      position: absolute;
      z-index: -1;
      content: "";
      bottom: 25px;
      left: 10px;
      width: 50%;
      top: 80%;
      -webkit-box-shadow: 0 35px 20px #989898;
      -moz-box-shadow: 0 35px 20px #989898;
      box-shadow: 0 35px 20px #989898  ;
      -webkit-transform: rotate(-10deg);
      -moz-transform: rotate(-10deg);
      -o-transform: rotate(-10deg);
      -ms-transform: rotate(-10deg);
      transform: rotate(-10deg);
    }
    .shadow:after
    {
      -webkit-transform: rotate(10deg);
      -moz-transform: rotate(10deg);
      -o-transform: rotate(10deg);
      -ms-transform: rotate(10deg);
      transform: rotate(10deg);
      right: 10px;
      left: auto;
    }
  </style>
</head>
<body>
  <br><br>
  <div class="pic shadow">
  </div>
</body>
</html>

Rounded drop shadow

Here is another CSS technique for creating border shadows and dividers by utilizing curved CSS box shadows, the :before and :after pseudo-elements, and border radius.

Source Code

<!Doctype>
<html>
<head>
  <style>
    .pic {
      width: 400px;
      height: 200px;
      padding:30px;
      background:#ccc;
      margin:20px auto 60px;
      border-radius:2px;
    }
    .shadow{
      position:relative;
    }
    .shadow:after{
      z-index:-1;
      content:"";
      position:absolute;
      -webkit-box-shadow:0 0 40px rgba(0,0,0,0.8);
      -moz-box-shadow: 0 0 40px rgba(0,0,0,0.8);
      box-shadow:0 0 40px rgba(0,0,0,0.8);
      height:20%;left:10%;right:10%;width:80%;bottom:0px;
      -webkit-border-radius:100%;
      -moz-border-radius:100%;
      border-radius:100%;
    }
  </style>
</head>
<body>
  <br><br>
  <div class="pic shadow">
  <img src="img/tiger.png">
  </div>
</body>
</html>