Issue with Slideshow manager plugin

I am using slide show manager for changing background image of home page of my website. I need to position a bigger banner in a smaller div. I want to align the image centrally on this div.ie by cropping equal width from both sides. I could use background-position:center in css if i use background-image in css. But Slideshow manager plugin uses <img> tag for images. So what can I use instead.

Thanks in advance.
Isac Joseph