Abstract: A method for generating a halftone image includes the steps of, for each input pixel, adding a previously determined error term to the input pixel value to obtain a modified input pixel value; determining an error diffusion threshold level based on the input pixel value; applying a quantization operation to the modified input pixel value using the determined error diffusion threshold level for obtaining an output pixel value; and determining an error contribution. The error diffusion threshold level depends on a result of a comparison operation performed between the input pixel value and a threshold value selected from a set of threshold values, the selection of the threshold value being based on the position of the input pixel in the input image.
Type:
Grant
Filed:
December 13, 2006
Date of Patent:
June 14, 2011
Assignee:
Oce-Techonologies B.V.
Inventors:
Ferruccio Cittadini, Jacques C. E. Pervillé