Method and system for achieving enhanced gray levels in a screen cell array

摘要

A method and system for digitally reproducing an image on a printing plate that includes enhancing gray levels so that plate may be imaged at lower resolutions and therefore higher speed. An image is scanned and a two dimensional array of optical density values. A comparison is made with a screen cell array having a repetitive pattern of a plurality of different screen cells. Each screen cells includes screen comparison values which when arranged in a sequence of increasing values are interleaved with values in a similarly arranged sequence of values from one of the different screen cells of the screen cell array. Pixel comparisons generate a binary value which is used to selectively operate a laser beam to expose microdots on a printing plate.