Featured Image Set Size on All Posts

I’m looking for a plugin that will set a specific size on all featured images for posts (even if that means some parts of the image aren’t visible.)

My clients do not have the software nor the time to crop every photo they have for a featured image, so I’d like to integrate a plugin that will automatically crop/resize the image for them. Basically, the client will upload the image and when it appears on a carousel on the front page, it will be cropped down automatically.

Is there anything on the market like this?