Held for the ?rst time outside Europe, the 15th International Conference on DiscreteGeometryforComputer ImagerytookplaceinMontr eal(Canada)from September30toOctober2,2009.Thisconferenceaddressedalargeinternational audience: 61 papers were submitted originating from 14 di?erent countries. Following a thorough reviewing process, remodeled for the previous conf- ence held in Lyon, 42 papers were accepted and scheduled for either oral (21) or poster presentation (21). All these papers appear in these proceedings, and whether a paper was presented orally or not was based on our appreciation of...