Quality Measures in Digital Halftones

Over about the last two decades the use of digitally generated halftone images has increased significantly. Halftone images which are created digitally from sampled and quantized images have some unique characteristics which affect the perceived image quality. Among these are the number of gray levels which can be reproduced at any spatial frequency, how the screen pattern chosen affects those gray levels, how tone reproduction is controlled and how the structured noise affects appearance. This paper provides an overview of some of the work on these effects.