HalfToner: A Tool for Comparing Halftoning Algorithms. - Clovis M. Nogueira Neto; Julio Cesar dos S. Lins; Mayra Gomes de C. Cerqueira; Paula Renata C. Carvalho; Suzana M. de Borba Maranhao; Alejandro César Frery (SIBGRAPI, 2001)