Scale and Crop an image in Internet Explorer

Hi

For my subsites I have a theme where I allow admins to upload their own banner images. As the site admin might upload images of any height and width, I have the below css code to control the image size. In principle i want to scale the image and then crop it automatically to fit my theme.

.myslider img {
max-height: 625px !important;
width: 100% !important;
width: auto\9;
max-width: 100%;
object-fit: cover;
}

This css works perfectly for all browsers except Internet Explorer. How do I get this working for IE.

ps: I am not a css expert.

Thanks