Don't know exactly what it should look like, but I would try to give the images a height of 80% and let the browser/engine handle the width calculation of the Image.

If that's not what you want to achieve, I need more detailed information on that matter.

By the way: Using inset properties (top, right, bottom, left, ...) without a position attribute can lead to unexpected results in different browsers/engines and should not be rendered as per specification.