1. A method for generating an array of output binary signals suitable for application to a display device to generate a halftone image in response to an array of input signals characterizing a gray-scale image, said method comprising the steps of: (a) filtering said input signals using a first eye-model filter reflecting characteristics of human vision to derive first signals representative of an estimate of the gray scale image as perceived by a human eye; (b) filtering sequences of binary signals using a filter reflecting characteristics representative of said display device to produce second signals representing an estimate of an output of said display device; (c) filtering said second signals using a second eye-model filter to produce third signals; (d) forming an error signal representative of a difference between said first and third signals; and (e) selecting as the output binary signals to be applied to said display device one of said sequences of binary signals which sequence realizes a preselected error criterion.