Photon enlarging thumbnail images

My query here is my does it resize thumbnail images that they get distorted.
You could check this link http://cfci.org.in/category/cfci_difference/ and similarly all category links, the images are really coming bad! Can we have a solution like add noresize class or something in some places where I dont want to resize, and definitely how does small image resize into larger one’s?
Wanted to fix this issue soon,coz we going live by next week so!
Also according to your site, it says that you guys dont, but check the link I have shared.