HALFTONING METHOD AND APPARATUS, AND COMPUTER-READABLE RECORDING MEDIUM IN WHICH HALFTONING PROGRAM IS RECORDED

A halftoning apparatus free of the occurrence of moiré and other artifacts under a simple technique. In the apparatus, a binarizing section converts the multilevel value of a given noteworthy pixel of the multilevel input image into a binary value while pixels of the input image are scanned successively, an error diffusing section diffuses an occurred error in binary value with respect to the noteworthy pixel to unscanned pixels adjacent to the noteworthy pixel by one diffusion technique, and an error diffusion technique changing section changes the diffusion technique to another in accordance with a predetermined manner as the scanning of the successive pixels of the multilevel input image progresses.