title: nivo slider image resize issue
body: <p>I have nivo slider in my web page. I need to display images of various width and height.The larger image displays behind the smaller image. Please refer the following screenshot.</p>
  
  <p><img src="https://i.stack.imgur.com/KcPWQ.jpg" alt="enter image description here"></p>
  
  <p>I have to remove displaying larger image behind the small image. Is there any possibility to do it with nivo slider? </p>