Abstract: A method of color halftoning using stochastic screening includes clustering, performing error diffusion and applying an adaptive criteria to change the cluster size according to the variation of the image color values. The method incorporates features from the traditional amplitude modulated (AM) digital halftoning methods, along with the advantages of frequency modulated (FM) techniques, recently introduced into the raster image processors of high resolution phototypesetters.

Abstract: A digital halftoning method for creating a gray-scale monochrome reproduction of a source image includes subdividing the source image into regions based on a trace of the space filing curve, further subdividing each of the regions into equally sized pixels, scanning the source image along the trace of the space filling curve to visit all pixels of the source image, calculating an average image intensity for each region, establishing a range of pixel cluster intensity levels based on a number of pixels in a cluster, and generating a dot pattern for each of the pixel clusters by activating individual ones of the pixels to an 0N state in accordance with a sequential order along the trace of the space filling curve.