Is there a way to adjust the display of the featured image at the top of the post?

I’m not exactly sure how the featured image at the top of post has it’s display calculated. It appear that it is stretched to full width, and then some part, possibly the middle, of the image is then shown. This works many times, but not always. For example, I have an image of a person grabbed from a youtube video, and all I see if his nose and teeth. It would be really cool if there was a way to tweak the display of the featured image at the top of the post on a post-by-post basis. For example, have a box in the post editor that allowed one to tweak a few metrics, like:
– Percentage Width (default 100%, but could lower it)
– Show Top/Middle/Bottom (default Middle)
There could be finer controls here as well, such as setting a number where the middle of the image should be (i.e. 50 is the middle)
Thanks.