Cropping slide images from the middle

A little help, guys.

I was wondering if it is possible to crop the images in the slider from the middle, instead of from the top. I’ve defined the slide-height in the style.css:

.slides {
height: 400px;
}

The size of the slide is perfect and the cropping occurs, but from the top of the image. Can I crop it from the middle and out, instead of from the top down?