Digital halftoning by iterative isotropic error feedback

An error diffusion scheme for digital halftoning is proposed. The scheme is an iterative and isotropic error feedback process. Also, to compensate for the nonlinear tone reproduction by laser printers due to ink drop overlaps, we incorporate Pappas-Neuhoff's simplified printer model into the new error diffusion scheme. It appears that the proposed halftoning technique enhances the perceived tone continuity of halftone hard copies, and it alleviates the objectionable structured halftone textures of some existing methods. In addition, a mechanism is suggested to preview a halftone print on a gray-level CRT monitor. The user can interactively set the desired brightness of the halftone print and balance image contrast and tone continuity, which are two mutually exclusive subjective criteria for halftone reproduction.