Thumbnail size for a specific categories

Is there a way to change the thumbnail size for a specific category?

My images are set to 200 x ?

The current ones that I have work fine as they are per portioned

Like this

I have added some other products which are taller than the current ones that I am using

So they are looking like this. Which I think is too large. Is there a way to scale just these down?

What would be the best way to fix this.

Thanks in advance.

What I ended up doing was create an image of 200 x 197 and scaling the image down to fit in this area and uploading the thumbnail separately. This is a temporary fix but it works for now.