REPORT Negoescu_Idiap-RR-18-2010/IDIAP Flickr Groups: Multimedia Communities for Multimedia Analysis Negoescu, Radu-Andrei Gatica-Perez, Daniel Hua, Xian-Sheng Ed. Worring, Marcel Ed. Chua, Tat-Seng Ed. EXTERNAL https://publications.idiap.ch/attachments/reports/2010/Negoescu_Idiap-RR-18-2010.pdf PUBLIC Idiap-RR-18-2010 2010 Idiap July 2010