Justin Hensley Thorsten Scheuermann Greg Coombe Montek Singh Anselmo Lastra Fast Summed-Area Table Generation and its Applications. 547-555 2005 24 Comput. Graph. Forum 3 http://www.eg.org/EG/CGF/volume24/issue3/v24i3pp547-555.pdf db/journals/cgf/cgf24.html#HensleySCSL05