Patent ID: 6049395
Filing Date: 2000-04-11
Classification: H04N

Abstract:
A method of digitally reproducing an image on a printing plate comprising:providing a digitization of the image;determining a two dimensional array of optical density values from the digitization of the image;comparing each pixel of the two dimensional array with a correspondingly located pixel in a screen cell array comprised of a repetitive pattern of a plurality of different screen cells, each screen cell having a two dimensional array of screen comparison values for producing a printed dot which expands in size when compared with increased optical density values, each screen cell including 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 in the screen cell array;generating a binary value for each comparison in response to whether or not the value of the pixel from the two dimensional array exceeds the screen comparison value of the screen cell array pixel; andselectively exposing microdots on the printing plate to a laser beam in accordance with the generated binary values.