How do I get a Chinese Visa Photo?

My wife and I are going to see our son graduate at Xiamen University in mid July. We have completed all the necessary documentation for the L but we are worried about how we will get photos in the measurements required by the application centre. Does anybody know the easiest way to get this done. We intend to post the application. The booths just print passport sized photos and some now print sized photos; but only for USA and India. I am worried as it's getting a bit close now and the specifications for these photos seem to be very tight.