Gallery view : Is there a way to determine the cropped image?

I like the gallery view, but there is one thing that can be enhanced I think.
If you have some “portrait” images - i.e. the height of the picture is bigger than the width - there is an option to crop the images, so there is only a portion visible.
I have the impression that this portion is “centered”, so that the upper part and the lower part is not shown.
Wouldn’t it be great to have an option on the crop parameter, giving the options : top, center, bottom ?
So you can choose which part of the image you want to show…That would be great !!!