Patent ID: 6351319
Filing Date: 2002-02-26
Classification: H04N

Abstract:
A method for processing image data, comprising the steps of;(a) thresholding a plurality of pixels having a first number of grey levels to generate a group of pixels having a second number of grey levels, the first number being greter than the second level, and threshold error values, one for each pixel; (b) determining if the group of pixel values from the thresholding process produce an undesirable pattern; (c) modifying the group of pixel values to eliminate the undesirable patter when said step (b) makes a positive determination; (d) generating a plurality of modification pixel error values based on the modification performed in said step (c); (e) compensating the threshold error values for pixels in adjacent pixels based on the modification pixel error values generated in said step (d) in conjunction with a set of weighting coefficients; and (f) diffusing the threshold error values to adjacent pixels based on a set of weighting coefficients, the modification pixel error values being related to the weighting coefficients used to diffuse the threshold error values.