In 2005, the twelfth edition of the conference Discrete Geometry for Computer Imagery was held in Poitiers, France, April 13-15, 2005. The conference was organized by the laboratory SIC (Signal, Image, Communications) of the University of Poitiers, Centre National de la Recherche Scienti?que and the Technical Committee 18 of the International Association for Pattern Recog- tion. DGCI 2005 was sponsored by the Faculty of Science, the University of Poitiers, the Conseil G' en' eral de la Vienne and the Region of Poitou-Charentes. The aim of the conference was to present recent advances in both...