http://www.tmcnet.com/usubmit/2006/02/27/1410727.htm
"To help cut the number of unsuitable pictures, the UKPS has asked people not to use home printers to make their photographs because the photographic quality and the paper may not be acceptable. Also, applicants have been told not to digitally enhance pictures as this can reduce quality and make an image that is unsuitable for biometric technology leading to problems when crossing borders. Officials added: 'If people wear glasses, we strongly advise removing them when having the photo taken to eliminate the risk of them causing reflection or otherwise reducing the quality of the photo.'"
