Digital halftoning is to quantize a continuous-tone image to a binary image or a color image with limited colors that the output halftoned image looks like the original multitone image when viewed from a distance.
Half-tone screen: A screen placed in front of the film in a process camera to break up a continuous-tone image into dots of varying sizes to produce a half-tone.There are two types:ruled glass screens and contact screens which are in common use .