Ritendra Datta, Jia Li, James Ze Wang. IMAGINATION: a robust image-based CAPTCHA generation system. In HongJiang Zhang, Tat-Seng Chua, Ralf Steinmetz, Mohan S. Kankanhalli, Lynn Wilcox, editors, Proceedings of the 13th ACM International Conference on Multimedia, November 6-11, 2005, Singapore. pages 331-334, ACM, 2005. [doi]
Abstract is missing.