METHOD AND EQUIPMENT FOR CONVERTING HALF-TONE VALUE INTO BINARY VALUE

摘要

PURPOSE: To improve a method and a device for converting a halftone value into a binary value so that a pattern being an obstacle to the capture of satisfactory reproduction quality can be completely avoided, and a high speed at the time of screened recording can be obtained. CONSTITUTION: A recording face is divided into partial areas without any clearance. One area constituted of plural threshold values is assigned to each part area by random selection from a stock constituted of plural stored threshold areas having different threshold distribution. Those threshold values are compared with a belonging halftone value D(x, y) for each point and line, a binary value B(x, y) is formed, and whether or not one possible exposure point in a recording face should be exposed as a dot is judged based on this binary value. Also, the D(x, y) is address designated from a picture memory 7 by a first address generator 9 and a first address converter 10, and a binary value memory 16 is address designated by a second address generator 11, second address converter 12, and index memory 13.