Kazumasa Iwata Koichi Kise Tomohiro Nakai Masakazu Iwamura Seiichi Uchida Shinichiro Omachi Capturing Digital Ink as Retrieving Fragments of Document Images. 1236-1240 2009 ICDAR http://dx.doi.org/10.1109/ICDAR.2009.192 conf/icdar/2009 db/conf/icdar/icdar2009.html#IwataKNIUO09