WordPress Thumbnail Generator Behavior

Hi,

I’m running a template website where each post is a template that i would like to display in the best way possible. The current wordpress thumbnail script makes an image out of the middle/center of any given post’s featured image. I’d like to modify the script to generate an image using the Top/middle instead or find a new plugin that would do this.

I’m not sure if this is possible but if it’s a simple parameter change, that would be great. Any help is appreciated.

Thanks!