Fadoua Drira Frank Lebourgeois Hubert Emptoz OCR Accuracy Improvement through a PDE-Based Approach. 1068-1072 2007 conf/icdar/2007 ICDAR http://doi.ieeecomputersociety.org/10.1109/ICDAR.2007.188 db/conf/icdar/icdar2007.html#DriraLE07a