Tomohiro Nakai Koichi Kise Masakazu Iwamura Camera-Based Document Image Retrieval as Voting for Partial Signatures of Projective Invariants. 379-383 2005 conf/icdar/2005 ICDAR http://doi.ieeecomputersociety.org/10.1109/ICDAR.2005.64 db/conf/icdar/icdar2005.html#NakaiKI05