Xia Zhuge Koji Nakano Clipping-Free Halftoning and Multitoning Using the Direct Binary Search. 1192-1201 2009 92-A IEICE Transactions 4 http://search.ieice.org/bin/summary.php?id=e92-a_4_1192&category=A&year=2009&lang=E&abst= db/journals/ieicet/ieicet92a.html#ZhugeN09