Rotate image by css, but crop it to be always same square

I would like to have rotate and zoom efect on pictures here http://cpband.itvp.eu/ , but i would like to keep them croped in the same box. like here http://cpband.itvp.eu/test.php

trick should be in overflow: hidden; , but I am not able to figureout how to make it work.

Thanks for the tips!