Top justifying portrait oriented pictures in slider

On the main page and category sliders is there a way to force portrait (vertical) orient pictures to show the top of the feature pictures instead of showing the center of the picture? Landscape oriented pictures (horizonal) look great, but I have a picture where the models head and legs are getting cut off in the sliders. I want to use the whole picture in the actual post, just have the picture on the slider shoves up so her head shows.