Halftoning is a method by which an arrangement of black and white pixels is used to simulate a gray scale on a b/level output device. In the ideal case, the tone produced is directly proportional to the number of black dots per unit area—the response is linear. However, the response of real printing devices is typically nonlinear because real printers do not generate nonoverlapping perfect dots, and where these dots overlap, they interact in a nonlinear way. In many printers, the tone observed is darker than that expected of an ideal device. The tone production capabilities of the electrophotographic
write-black printer are examined. Recent work in the literature has attempted to model this phenomenon with large round dots that saturate (are not additive) when overlapped. Measured reflectance data from specific write-black electrophotographic printers are presented as a means of assessing the ability of this model to accurately predict the tone response of various halftoning algorithms
on these devices.