Fridtjof Stein Efficient Computation of Optical Flow Using the Census Transform. 79-86 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3175&spage=79 2004 conf/dagm/2004 DAGM-Symposium db/conf/dagm/dagm2004.html#Stein04