Crop Images that are Uploaded with the Customizer

I’m working on a theme and have incorporated the image upload feature in a custom section of the customizer using WP_Customize_Image_Control. Everything is working fine. I can upload the image and display it in the template files.

The problem is that I need to force a crop on the image (much like what happens when you upload a featured image) so that the image the template outputs is a specific size.

I’ve seen some topics on here regarding adjusting the size of the custom header image, etc, but I’m not looking to use the custom header image. I’d like to use custom controls so that they all appear in the correct sections.

Any suggestions?

Thanks!