[1] King Saud Univ, Dept Software Engn, Coll Comp & Informat Sci, Riyadh 11451, Saudi Arabia
[2] Chinese Acad Sci, Inst Automat, Natl Lab Pattern Recognit, Beijing 100190, Peoples R China
[3] Tech Univ Darmstadt, Multimedia Commun Lab KOM, D-64289 Darmstadt, Germany
[4] Univ Ottawa, Sch Elect Engn & Comp Sci, Ottawa, ON K1N 6N5, Canada