Patent ID: 6226104
Filing Date: 2001-05-01
Classification: H04N

Abstract:
A method of recording a halftone dot image with a plurality of halftone dots each constituted of one or more record pixels utilizing tone reproduction of each pixel, the method comprising the steps of:providing a unit block including a plurality of record pixels, each record pixel being divided into M pieces of divisions where M is an integer having a value of at least 2;(a) providing a threshold pattern having threshold values that are assigned respectively to the divisions in the unit block;(b) comparing a given multi-tone image signal with the threshold values in the threshold pattern to thereby generate an image recording signal for each record pixel, the image recording signal representing one of at least three pixel-density levels for each record pixel, the multi-tone image signal having a common value for the M divisions of the same record pixel; and(c) recording each record pixel with a pixel-density represented by the image recording signal, thereby producing halftone dots constituted of one or more of the recorded pixels to reproduce a halftone dot image,wherein the step (b) comprises the step of:(i) comparing the threshold values assigned to the M divisions of each pixel with the multi-tone image signal to obtain M pieces of binary comparison results, and generating the image recording signal as a function of a sum of the M pieces of binary comparison results.