Patent ID: 6697169
Filing Date: 2004-02-24
Classification: H04N

Abstract:
A method for reproducing a gray level image in a bi-tonal medium, comprising:a comparison step comprising (a) comparing a summed value with a threshold value to make a print or no print decision characterized by a corresponding one of two print values, and (b) subtracting said corresponding one print value from said summed value to generate a difference; a diffusing step comprising (a) storing at least one of a succession of differences generated by said comparison step and (b) combining at least a corresponding one of said differences with an incoming gray level pixel to form a sum and providing said sum as said summed value of said comparison step, wherein said produced diffused image is characterized by a set of elongate artifacts having a prevailing artifact direction; determining said threshold value of said comparison step from a matrix of threshold values, the matrix having a spatial-chromatic correlated noise pattern.